The owners of the patent RU 2588229:

SUBSTANCE: invention relates to the field of construction, namely to reinforced concrete multi-storey frames without crossbars for the construction of residential, industrial and civil buildings, both for normal construction conditions and for construction in seismic areas.

From the prior art, a contact joint of precast concrete columns is known with a break in the rods of longitudinal working reinforcement in the joint, with the butts of the columns supported by a layer of high-strength mortar, while steel plates are installed on the supporting ends of the columns, installation of short reinforcing bars through the joint in channels filled with high-strength with a solution, it is provided for edging the end in the form of a steel ledge, as well as the installation of steel liners in the center and along the contour of the joint in the gap between the steel end plates equal to the size of the gap. (1) (see RF patent N 2233368, MCP E04B 1/38, 2004).

The disadvantage of this technical solution is the high complexity of making this joint, in addition, the use of differently deformable materials in the contact zone of columns will lead to stress concentration in areas of less deformable materials and, as a result, local (local) cracking, as well as through passage of short rods in additional channels violates the integrity of the reinforced concrete section of the columns and, as a result, a decrease in the bearing capacity of the butt joint.

It is also known a technical solution for the arrangement of contact joints of prefabricated reinforced concrete columns with a break in the working reinforcement, with the ends of the columns resting on a thin layer of mortar without connecting the reinforcement (2) (see A.P. Vasiliev, N.G. Matkov, M.F. Zhanseitov ., Contact joints of columns with a break in the longitudinal reinforcement., Concrete and reinforced concrete N 8, 1982)

This well-known technical solution and its experimental study allows us to conclude that it is advisable to use it for multi-storey building frames. The disadvantage of this butt joint is that it is unsuitable for tensile forces.

Known arrangement of joints of reinforced concrete columns with reinforcement of the end joined sections of reinforced concrete columns with metal elements. (3) (V.S. Plevkov, M.E. Goncharov, Study of the work of joints of reinforced concrete columns reinforced with metal elements under static and short-term dynamic loading, Vestnik TSSU N 2, 2013)

This study of the zone of joints of reinforced concrete columns shows that the bearing capacity of the joint using metal clips in the zone of joined columns increases by 30-40%.

A technical solution is known for the connection of a prefabricated reinforced concrete column and a prefabricated over-the-column floor slab of a transom-free, capital-free frame of a building, in which the connection is carried out using trapezoidal connecting plates welded on one side to the power reinforcement of the columns exposed in the overlap zone, on the other hand, to the monolithic in the over-column floor slab steel shell. (4) (see RF patent N 2203369, MCP E04B 1/38, 2003)

The disadvantage of this technical solution is the laboriousness and material consumption for the installation of the shell in the above-column slab, in addition, this connection, until the joint is monolithic, has insufficient rigidity due to the high flexibility of the exposed power reinforcement of the columns. It should be attributed to the disadvantages of this technical solution the fact that trapezoidal connecting elements are welded to the exposed power reinforcement of the columns for fastening the above-column plates and at the same level the connecting elements of the longitudinal power reinforcement of the columns are welded. This circumstance leads to a decrease in the quality of welded joints. The negative qualities of this technical solution also include the floor-by-floor adjustment of the position of the outlets of the power reinforcement of the columns when changing its floor-by-floor diameter.

It is known to connect a slab of a beamless prefabricated monolithic floor with a prefabricated column, where the column in the support zone of the slab has a recess along the perimeter of the column (5) (USSR patent N 872674, MKI E04B 1/20, 1981)

The disadvantage of this technical solution is the insufficient bearing capacity of this joint for punching in a flat overlap.

A technical solution is known for the butt joint of a monolithic beamless reinforced concrete floor with a monolithic column in which steel plates are rigidly fixed to the vertical reinforcement cages of the floor in the joint area, the plates are made with a length of at least 2h + 2a, where h is the thickness of the slab, a is the thickness of the concrete protective layer. (6) (see RF patent N 2194825, MCP E04 B 5/43.2002).

This technical solution increases the bearing capacity of the butt joint by shear force.

The closest technical solution adopted for the prototype is the design of a transomless reinforced concrete frame, which includes one or more storey non-cantilever prefabricated columns with exposed power reinforcement at the intersection with the floor, prefabricated over-column floor slabs with through holes framed by a steel shell for the passage of multi-storey columns and butt connection with them, prefabricated span slabs, monolithic sections combined with each other into a single floor disk, while the installation of span slabs is carried out by protruding consoles on the corresponding support tables, over-column and span slabs have loop outlets on the end ribs through the overlap of which reinforcing bars are passed with subsequent concreting of the joint cavity. (7) (see RF patent N 2247812, MCP E04B 5/43, 2005)

The technical solution of inter-slab joints in this design of a frameless frame is hinged, which limits the span of a prefabricated monolithic floor. In addition, this design of the prefabricated-monolithic floor is rigid for the options for solving space-planning tasks, and also for this technical solution, the shortcomings set forth in the analogue (4) are valid.

The objective of the invention of a prefabricated-monolithic frameless frame is to increase the range of solving space-planning problems, increase the bearing capacity of frame structures and its nodal connections, and increase the manufacturability of work on the construction of frame structures.

This invention of a prefabricated monolithic reinforced concrete frame without crossbars is a series of technical solutions with options for the execution of prefabricated frame elements and their possible layout in combination with monolithic sections, depending on planning, technological factors, as well as the industrial base for the production of prefabricated reinforced concrete products.

Variants of technical solutions for a prefabricated monolithic reinforced concrete frame without crossbars with hinged monolithic inter-slab joints, with rigid (continuous) monolithic inter-slab joints, as well as options for a free combination of prefabricated reinforced concrete elements with span monolithic sections of the floor, interconnected in a continuous disk of floor, are presented.

The drawings show:

in fig. 1 - a schematic fragment of the plan of a prefabricated monolithic frameless frame with configuration options for prefabricated frame elements and their possible layout in combination with monolithic sections;

in fig. 2 - an enlarged fragment of the 1st floor plan of a reinforced concrete frame without crossbars with hinged monolithic inter-slab seams between prefabricated above-column and span slabs;

in fig. 3 - an enlarged fragment of the second floor plan of a reinforced concrete frame without crossbars with rigid (continuous) monolithic inter-slab seams between prefabricated floor slabs;

in fig. 4 - an enlarged fragment of the III floor plan of a reinforced concrete frame without crossbars with rigid (continuous) monolithic inter-slab seams between prefabricated floor slabs and a rigid (continuous) connection of prefabricated slabs with monolithic span sections of the floor;

in fig. 5 - transverse section I-I(with diagonal connections);

in fig. 6 - cross section I-I (with monolithic diaphragms);

in fig. 7 - Node 1 (section A1-A1) - butt joint of a multi-storey continuous prefabricated cantilevered column with a prefabricated over-column floor slab;

in fig. 8 - view B1-B1 of node 1 - butt connection of a multi-storey continuous prefabricated cantilevered column with a prefabricated above-column floor slab;

in fig. 9 - Node 2 (section A2-A2) - node of butt connection of prefabricated cantilevered columns between themselves and butt joint of columns with above-column floor slab;

in fig. 10 - view B2-B2 of node 2 - butt connection of prefabricated non-cantilever columns to each other and butt connection of columns with an above-column floor slab;

in fig. 11 - section A4-A4 - section along the butt joint of prefabricated non-cantilever columns between themselves and with a monolithic section of the floor;

Fig 12 - view B3-B3-butt connection of prefabricated cantilevered columns between themselves and with a monolithic section of the floor;

in fig. 13 - Node 2 (section A3-A3) - the node of the butt connection of prefabricated non-cantilever columns to each other and the butt joint of the columns with the above-column floor slab;

in fig. 14 - section A5-A5 - section along the butt joint of prefabricated cantilevered columns between themselves and with a monolithic section of the floor;

in fig. 15 - section A6-A6 at the junction of the mounting support ledge and the mounting support platform for mounting above-column and span slabs for overlapping with hinged inter-slab joints;

in fig. 16 - section A7-A7 on the device of a monolithic slab joint for overlapping with hinged slab joints;

in fig. 17 - section A8-A8 along the assembly fixation of prefabricated floor slabs between themselves for overlapping with rigid (continuous) interslab seams;

in fig. 18 - section A9-A9 on the device of a monolithic inter-slab seam with a rigid (continuous) connection of prefabricated floor slabs;

in fig. 19 - section A10-A10 along a rigid (continuous) junction of prefabricated floor slabs with a monolithic span section of the floor for non-welding connection using U-shaped anchors and U-shaped anchor outlets;

in fig. 20 - section A11-A11 along a rigid (continuous) connection of prefabricated floor slabs with a monolithic span of the floor by welding U-shaped anchors to embedded parts of prefabricated floor slabs;

in fig. 21 - section A12-A12 along a rigid (continuous) joint of prefabricated floor slabs with a monolithic span of the floor by welding U-shaped anchors reinforced with rigid inserts to embedded parts of prefabricated floor slabs;

in fig. 22 - enlarged fragment IV, detailing of a fragment of the ceiling with a balcony section of the slab, as well as the installation of a curtain wall with a facing layer of brick;

in fig. 23 - view B4-B4 - detail of the fastening of the contour support corner for supporting the facing layer of the outer wall of brick;

in fig. 24 - section A13-A13 on the reinforcement of the rib between the holes for placing insulation packs on the balcony sections of prefabricated floor slabs;

in fig. 25 - section A14-A14 for the placement of insulation packages on balcony areas in the body of prefabricated floor slabs;

in fig. 26 - Node 5 (section A15-A15) node for the installation of a floor curtain wall with a facing layer of brick;

in fig. 27 - section A16-A16 - for the installation of a floor-by-story curtain wall of prefabricated three-layer wall panels;

in fig. 28 - Node 6 (section A17-A17) node for the installation of an external fence with a hinged ventilated facade;

in fig. 29 - Knot 3 - the attachment point of the diagonal ties in the upper level between themselves and with the bonded floor slab;

in fig. 30 - view B5-B5 of node 3 - fastening of diagonal braces with a braced floor slab;

in fig. 31 - section A18-A18 along node 4 - fastenings of diagonal braces in the upper level to each other;

in fig. 32 - Knot 4 - the attachment point of the diagonal braces to the column in the lower level;

in fig. 33-section A19-A19 along the attachment point of the diagonal braces to the column in the lower level;

in fig. 34 - Node 7 - node for connecting a monolithic diaphragm with a column;

in fig. 35 - section A20-A20 along the junction of the monolithic diaphragms with the column;

in fig. 36 - section A21-A21 along the interfloor connection of monolithic diaphragms.

Reinforced concrete prefabricated-monolithic frameless frame with hinged monolithic interplate joints includes reinforced concrete one or more storey non-consolidated columns 1, prefabricated over-column floor slabs 2 with holes 3 for passing columns 1 and butt connection with them, prefabricated span slabs 4, monolithic sections in the form of hinged inter-slab seams combined into a single floor disk, while the prefabricated above-column floor slabs 2 and span slabs 4, for mounting assembly, are equipped with mounting support projections 5 and support platforms 6, and embedded parts are installed on the support surfaces of the support projections 5 and support platforms 6, for example, from steel corners 7, to which are welded - shaped stiffeners 8 from vertical steel plates, embedded in the body of prefabricated slabs 2 and 4 and welded to the longitudinal upper and lower rods of the anchoring frames 9. In hinged monolithic interplate seams between prefabricated slabs 2, 4 in the areas between the mounting supports 5, 6, along the inter-slab joints, the installation of the upper and lower horizontal rods 10 is provided at the inner corners of the overlap of the U-shaped loop anchor outlets 11, installed at the ends of the prefabricated slabs 2, 4, followed by concreting with monolithic concrete 12.

Reinforced concrete prefabricated-monolithic frame without crossbars with rigid monolithic inter-slab seams includes prefabricated reinforced concrete one or more storey cantilevered columns 1, prefabricated over-column floor slabs 13 with holes 3 for passing columns 1 and butt connection with them, prefabricated span slabs 14, broadened monolithic inter-slab seams , or monolithic span sections 15 combined into a single continuous floor disk, while mounting fixation of prefabricated floor slabs 13, 14 is carried out using steel plates 16 welded to embedded parts from channel profiles 17 and to vertical loop anchor outlets of trapezoidal shape 18 located on adjacent end surfaces of joined slabs, while the connection of prefabricated slabs 13 and 14, in the areas between the areas of mounting fixation, is carried out along widened monolithic interplate seams by installing, along the joint contour, upper and lower horizontal reinforcing bars 10, located on the inside the lower overlap angles of the U-shaped loop anchor outlets 19 from the end faces of adjacent prefabricated floor slabs 13 and 14, while the length of the overlap of the U-shaped loop anchor outlets 19 from the end faces of adjacent floor slabs 13 and 14 must be at least 15d, where d - diameter of anchor releases.

For the version of the prefabricated monolithic reinforced concrete frameless frame with the replacement of one or more span slabs 14 with a monolithic span 15, the connection of prefabricated slabs 13 and 14 with a monolithic span 15 is carried out by installing horizontal upper and lower reinforcing bars 10 along the joint contour at the inner corners of the overlap p-shaped vertical loop anchor outlets 19 from the end surfaces of prefabricated floor slabs 13 and 14 and vertical p-shaped loop anchors 20 installed along the contour of the junction of monolithic span sections 15 with prefabricated floor slabs 13, 14, while the length of the overlap of the vertical p-shaped loop anchor outlets 19 from the end faces of adjacent floor slabs 13 and 14 and vertical U-shaped loop anchors 20 must be at least 15d, where d is the maximum diameter of anchor outlets 19 or anchors 20.

The connection of prefabricated floor slabs 13 and 14 with a monolithic span 15 can also be performed using vertical U-shaped loop anchors 20 or 21 welded to vertical embedded parts from channel profiles 17 located on the end surfaces of prefabricated floor slabs 13, 14, while -shaped loop anchors 21, at the end sections have stiffeners 22 made of steel plates welded along the vertical axis, between the upper and lower rods of the U-shaped loop anchors 21.

The device of balcony sections of the floor is proposed to be performed in two versions:

either the balcony part of the ceiling rests on columns 1 placed outside the outer fence of the building with external above-column balcony slabs 23 and span balcony slabs 24, or the balcony part of the ceiling is integral (continuous) with above-column 2, 13 and span 4, 14 floor slabs, while in plates 2, 4, 13, 14 are provided with holes 25, in the plane of the outer fence, to accommodate insulation packages, while the reinforcement of the ribs between the holes 25 is carried out by vertical reinforcing cages 26, which have stiffeners 27 from steel plates welded in the upper and lower reinforcing bars frames 26.

For a prefabricated monolithic reinforced concrete frame without girder with monolithic hinged or rigid monolithic interplate joints, longitudinal interplate joints are made staggered with an offset in each transverse row of joined prefabricated floor slabs 2, 4, 13, 14 by an amount not less than the anchoring length of the maximum diameter of the working reinforcement of plates 2 , 4, 13, 14.

The device for supporting connection of above-column slabs 2, 13 with prefabricated cantilever columns 1 is carried out as follows: columns 1 are made with vertical embedded parts 28, 29, 30 installed in recess 31 from the outer faces of column 1 along its perimeter within and not less than the thickness of the ceiling, above-column plates 2, 13 are made with vertically arranged trapezoidal outlets 32 of steel plates rigidly connected to the upper and lower rods of the anchor reinforcement cages 33 installed along the perimeter of the through holes 3.

The connection of prefabricated columns 1 and above-column slabs 2, 13 is carried out using steel connecting elements 34, for example, from unequal corners welded to vertical embedded parts 28, 29 of columns 1 and to vertical trapezoidal outlets 32 from above-column floor slabs 2, 13, followed by concreting of the joint cavity between the recessed part 31 of the column 1 and the end surfaces 35 of the through holes 3 of the above-column floor slabs 2, 13, while the end surfaces 35 of the above-column slabs 2, 13 are inclined from the vertical forming a wedge-shaped cavity of a monolithic joint.

When connecting reinforced concrete non-cantilever columns 1 with a monolithic span section of the floor 15, vertical U-shaped loop anchors 21 are installed, welded to the vertical embedded parts 28, 29 of the columns 1, installed in the recess 31 from the outer edges, along the contour of the column 1, while p- shaped loop anchors 21 at the end sections have stiffeners 22 made of steel plates welded along the vertical axis between the upper and lower rods of the loop anchors 21, followed by concreting with a monolithic floor section 15.

Butt joints of non-cantilever reinforced concrete columns 1 of the frame are carried out by resting on each other with flat ends through the mortar joint 36 within the thickness of the interfloor overlap, while the ends of the joined columns 1 are made with indirect reinforcement with reinforcing meshes 37 and internal reinforcing clips 38, in addition, along the perimeter of the ends of the joined columns 1 are provided with vertical embedded parts 29, 30 in the recess 31 from the outer faces of the column 1.

The connection of the joined columns 1 is carried out by welding the V-shaped reinforcing connecting elements 39 along the planes of the vertical embedded parts 29, 30, followed by concreting with monolithic concrete of the floor.

In addition to technical solutions that have significant differences from the technical solutions of analogues and prototypes, in the illustrative example of a precast-monolithic reinforced concrete frame without crossbars, technical solutions which are not the subject of this invention, but their use in this example of a precast-monolithic reinforced concrete frame without crossbars is appropriate.

In the exemplary embodiment, the device of diagonal ties 40 is presented, which are recommended to be arranged during the construction of a prefabricated monolithic frame without crossbars under normal construction conditions, also with a seismicity of no more than 7 points.

The connection of the diagonal ties 40 is carried out at the lower level by means of connecting plates 41 welded to the embedded parts of the columns 1 and the diagonal ties 40, at the upper level by welding the intermediate element 42 of the box section to the embedded parts of the braces 40 and to the anchor outlets 18 of trapezoidal shape from the end faces openings of the bonded floor slab 43 with the help of steel plates 44, while the end sections of the anchor outlets 18 are provided with rigid inserts 22 of steel plates between the upper and lower rods of the anchor outlet 18. The cavity of the butt joint of the diagonal ties 40 with the bonded floor slab 43 is concreted with concrete 12.

For construction conditions with a seismicity of 8 or more points, it is recommended to perform monolithic diaphragms of stiffness 45 in a prefabricated monolithic frame without crossbars.

Monolithic stiffness diaphragms contain, in addition to double-sided reinforcement along the field of a monolithic diaphragm, vertical reinforcement 46 and elements of connection with the foundation, columns, floor slabs from rigid inserts 46 and reinforcing anchor cages 48.

The device of a floor mounted external fence is carried out using, for example, a brick facing layer 49, which is laid along the contour corner 50 welded to the embedded parts of the channel section 51 located at the outer end of the intermediate floor, and the contour corner has vertical slots 52 to make a vertical welding flank seam in at the point of joining with embedded parts 51, in addition, along the supporting surface of the contour corner 50, along the outer edge, a horizontal thrust rod 53 is welded to prevent slipping of the facing brickwork 51 from the supporting surface of the contour bearing corner 50. A sealing elastic gasket is laid floor by floor under the contour bearing corner 50 54. On the outside of the brickwork 49, the floor horizontal seam for supporting and sealing the brick facing masonry is closed with a decorative flashing 55.

A variant of the floor mounted external fencing are, for example, prefabricated external wall panels 56 supported floor by floor over a layer of cement-sand mortar on interfloor floors. To fix the outer wall panels 56 in the plane of the facade of the building 57, on the joined ends of the outer wall panels 56, a ledge 58 and a protrusion 59 are provided, which, when docked dry, ensure that the facade surfaces of the joined outer wall panels 56 coincide with the plane of the facade of the building 57. Lower and upper the end surfaces of the joined outer wall panels 56 are separated by sealing elastic gaskets 54. From the outside, the seams between the outer wall panels 56 are closed with a decorative strip 60.

For an external fence using a ventilated facade 61, floor by floor, along the contour of the floor slabs, a building envelope is made of brickwork 62, or from precast concrete partitions, to which the system of structures of the ventilated facade 61 is attached. The external fence of the basement of the building is made using prefabricated vertical wall slabs 63 installed along the outer contour of the ceiling. Wall slabs 63 are supported by a cross-cast reinforced concrete belt 64, which has a perimeter ledge 65 for absorbing horizontal forces from soil pressure.

1. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, interconnected into a single floor disk , characterized in that the joined columns rest on each other with flat ends through the mortar joint within the thickness of the ceiling, while the ends of the joined columns are made with indirect reinforcement with reinforcing meshes and internal reinforcing clips, in addition, along the perimeter of the ends of the joined columns, vertical embedded parts are provided in deepening from the outer faces of the column, while the connection of the joined columns is carried out by welding V-shaped reinforcing connecting elements along the planes of vertical embedded parts, followed by concreting the joint with monolithic concrete of the floor.

2. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-storey cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the columns are made with vertical embedded parts installed in the recess from the outer faces of the column along its perimeter within the thickness of the floor, and the above-column floor slabs are made with vertically located trapezoidal outlets made of steel plates rigidly connected to the upper and lower rods of the anchor reinforcement cages, through holes installed along the perimeter, while the connection of prefabricated columns and above-column floor slabs is carried out using supporting steel connecting elements in the form of plates or unequal angles welded to the vertical embedded parts m of columns and to vertical trapezoidal outlets from above-column floor slabs with subsequent concreting of the joint cavity between the recessed part of the columns and the end surfaces of the through holes of the above-column floor slabs, while the end surfaces of the through holes of the above-column floor slabs are inclined from the vertical, forming a wedge-shaped cavity of a monolithic joint.

3. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated above-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, interconnected into a single floor disk , characterized in that the longitudinal monolithic sections in the form of interslab seams are made staggered with an offset in each transverse row of joined prefabricated floor slabs by an amount not less than the anchoring length of the maximum diameter of the working reinforcement of prefabricated floor slabs.

4. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the prefabricated above-column and prefabricated span slabs are equipped with mounting support projections and support platforms, and on the support surfaces of the support projections and support platforms, embedded parts made of steel plates or corners are installed, to which are welded - shaped stiffeners from vertical plates embedded in the body of prefabricated floor slabs and vertical anchoring frames welded to the longitudinal upper and lower rods.

5. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the mounting fixation of prefabricated floor slabs between themselves is carried out using steel plates welded to embedded parts from channel profiles and to vertical loop anchor outlets of a trapezoidal shape located on adjacent end surfaces of the joined slabs, while the connection of prefabricated slabs in the areas between sections of mounting fixation is carried out by installing along the contour of the joint of the upper and lower horizontal reinforcing bars located at the inner corners of the overlap of the U-shaped loop anchor outlets from the end faces of adjacent prefabricated floor slabs, while the length is not the overlap of U-shaped loop anchor outlets from the end faces of adjacent floor slabs should be at least 15d, where d is the diameter of the anchor outlets, followed by concreting of the cavity between the slabs.

6. A prefabricated monolithic reinforced concrete frame without crossbars according to claim 5, characterized in that the vertical loop anchor outlets of a trapezoidal shape, located on the end surfaces of the joined plates at the end sections, have stiffeners made of steel plates welded along the vertical axis of the anchor outlets to their upper and bottom rods.

7. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the connection of prefabricated over-column and prefabricated span slabs with monolithic span sections of the floor is carried out by installing horizontal upper and lower reinforcing bars along the joint contour, located at the inner corners of the overlap of U-shaped loop anchor outlets from the end faces of prefabricated floor slabs and vertical u-shaped loop anchors installed along the contour of the junction of monolithic span sections of the floor with prefabricated floor slabs, while the length of the overlap of the u-shaped loop anchor outlets from the ends of the prefabricated floor slabs and p-shaped loop anchors The cores installed along the contour of the junction of monolithic span sections with prefabricated floor slabs should be at least 15d, where d is the diameter of the anchors and anchor outlets.

8. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined together into a single floor disk , characterized in that the connection of prefabricated floor slabs with monolithic span sections of the floor is carried out using vertical U-shaped loop anchors welded to vertical embedded parts from channel profiles located on the end surfaces of prefabricated floor slabs, while U-shaped loop anchors on the end sections have stiffening ribs made of steel plates welded along the vertical axis of loop anchors between their upper and lower rods, followed by concreting of the connection with a monolithic span section of the floor.

9. Prefabricated monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story cantilevered columns, prefabricated over-column floor slabs with through holes for the passage of columns and butt connection with them, prefabricated span slabs, monolithic sections, combined with each other into a single floor disk , characterized in that on the balcony sections of over-column or span slabs that have holes in the plane of the outer walls for the placement of insulation packages, the reinforcement of the ribs between the holes for the placement of insulation packages is carried out by vertical reinforcing cages that have stiffeners made of steel plates welded to top and bottom reinforcing bars of vertical frames.

10. Prefabricated-monolithic reinforced concrete frame without girder, formed by prefabricated one- and more-story consoleless columns, monolithic ceiling, characterized in that the columns are made with vertical embedded parts installed in the recess from the outer faces of the column along its perimeter within the thickness of the ceiling, while the connection of prefabricated columns with a monolithic ceiling is carried out using vertical u-shaped loop anchors welded to the vertical embedded parts of the columns, and the u-shaped loop anchors at the end sections have stiffeners made of steel plates welded along the vertical axis of the loop anchors between their upper and lower rods, followed by concreting of the joint with concrete of a monolithic floor.

The invention relates to the field of construction, in particular to a prefabricated monolithic reinforced concrete frame without crossbars. The frame is formed by prefabricated cantilevered columns, prefabricated over-column floor slabs with through holes for passing columns, span slabs and monolithic sections. Options for connecting columns and floor slabs are proposed. The technical result of the invention is to increase the bearing capacity of the frame structures and its nodal connections. 9 n. and 1 z.p. f-ly, 36 ill

Architectural structures of multi-storey buildings General requirements required for multi-storey buildings Multi-storey residential buildings residential buildings from 6 to 9 floors; high-rise buildings from 10 to 25 floors. According to the requirement for the required minimum number of elevators depending on the number of floors: Buildings 6 9 floors require 1 elevator; building 10 19 floors. 2 elevators; buildings 20 25 floors. In accordance with federal law Russian Federation dated 2009 No. 384FZ Technical regulation on the safety of buildings and ...

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Topic 1. Structural systems of multi-storey buildings. Lecture 1, 2, 3

Literature:

1. Manual for the design of residential buildings. Issue 3. Structures of residential buildings (to SNiP 2.08.01-85).

2. Magai A.A. Architectural design high-rise buildings and complexes. M., ASV, 2015.

Architectural structures of multi-storey buildings

General requirements for multi-storey buildings

Multi-storey residential buildings residential buildings from 6 to 9 floors; high-rise buildings from 10 to 25 floors.

According to the requirement for the required minimum number of elevators, depending on the number of storeys:

Buildings 6 9 floors require 1 elevator;

buildings 10 19 floors ………………. 2 elevators;

building 20 25 floors………………... 3 elevators.

In accordance with the Federal Law of the Russian Federation of 2009 No. 384-FZ "Technical Regulations on the Safety of Buildings and Structures", buildings and structures are divided into three levels of responsibility:

1) an increased level of responsibility - buildings and structures classified as especially dangerous, technically complex or unique objects;

2) normal level of responsibility - all buildings and structures, with the exception of buildings and structures of increased and reduced levels of responsibility;

3) a reduced level of responsibility - buildings and structures for temporary (seasonal) purposes, as well as buildings and structures for auxiliary use associated with the construction or reconstruction of a building or structure or located on land plots provided for individual housing construction.

Design values ​​of forces in elements building structures and the foundation of a building or structure must be determined taking into account the reliability factor for liability, the accepted value of which should not be lower than:

1) 1.1 - in relation to the building and structure of an increased level of responsibility;

2) 1.0 - in relation to the building and structure of the normal level of responsibility;

3) 0.8 - in relation to the building and structure of a reduced level of responsibility.

For buildings and structures with an increased level of responsibility, it is recommended to determine wind and snow loads based on the results of blowing the model in a wind tunnel or numerical simulation. Strength calculations of the load-bearing structures of buildings and structures of an increased level of responsibility should be performed using at least two different software systems to increase the degree of reliability of calculations.

Types of constructive systems of multi-storey buildings.

Main:

I wireframe,

II wall,

III receiver (core),

IV shell (pipe).

Combinations :

I + II frame-wall,

I + III frame-stem,

II + III barrel-wall,

II + IV shell-wall,

III + IV stem-shell (pipe in a pipe).

Basic structural systems

1. Frame CS

In frame structural systems, the main vertical load-bearing structures are the frame columns, to which the load from the ceilings is transferred directly (beamless frame) or through crossbars (crossbar frame). The strength, stability and spatial rigidity of frame buildings is ensured by the joint work of floors and vertical structures. Depending on the type of vertical structures used to ensure strength, stability and rigidity, there are bonded, frame and frame-bonded frame systems.

With a bonded frame systema crossbar frame or a crossbar frame with non-rigid nodes of crossbars with columns is used. With non-rigid nodes, the frame practically does not participate in the perception of horizontal loads (except for the columns adjacent to the vertical stiffening diaphragms), which makes it possible to simplify the structural solutions of the frame nodes, use the same type of crossbars over the entire height of the building, and design the columns as elements that work mainly in compression. Horizontal loads from floors are perceived and transferred to the base by vertical stiffening diaphragms in the form of walls or through diagonal elements, the belts of which are columns (see Fig. 4). To reduce the required number of vertical stiffening diaphragms, it is recommended to design them with a non-rectangular shape in plan (angle, channel, etc.). For the same purpose, columns located in the plane of vertical stiffening diaphragms can be combined with distribution grillages located at the top of the building, as well as at intermediate levels along the height of the building.

In frame frame systemvertical and horizontal loads are perceived and transferred to the base by a frame with rigid nodes of crossbars with columns. Frame frame systems are recommended for low-rise buildings.

In a frame-bonded frame systemvertical and horizontal loads are perceived and transmitted to the base jointly by vertical stiffening diaphragms and a frame frame with rigid crossbar assemblies with columns. Instead of through vertical stiffening diaphragms, rigid inserts can be used to fill individual cells between crossbars and columns. Frame-braced frame systems are recommended if it is necessary to reduce the number of stiffening diaphragms required to absorb horizontal loads.

In frame buildings of bonded and frame-bonded structural systemsalong with stiffening diaphragms, spatial elements of a closed shape in plan, called trunks, can be used. Frame buildings with stiffening trunks are called frame-stem buildings.

Frame buildings, the vertical supporting structures of which are the frame and load-bearing walls (for example, external, intersectional, stairwell walls), are called frame-wall. Buildings of a frame-wall structural system are recommended to be designed with a frameless frame or with a frame with non-rigid joints between the crossbars and columns.

In shaft structural systems, vertical bearing structures are shafts, formed mainly by the walls of stair-lift shafts, on which floors are supported directly or through distribution grillages. According to the method of supporting the interfloor ceilings, stem systems are distinguished with cantilever, shelf and suspendedfloor support.

1.1. Frame-ste new system(with incomplete frame).

External or internal walls in this system are replaced by individual frame posts, which gives flexibility to the planning solution, the possibility of creating relatively large rooms, inside which only columns are placed. It is relatively easy to rearrange or remove partitions when changing the purpose of the premises. The disadvantage of this system is the significant material consumption of the outer walls.

1.2. Frame-stem system.

Flat diaphragms of frame rigidity are combined into a spatial support of the trunk, which has a significantly higher rigidity than individual diaphragms, and therefore is able to perceive higher horizontal loads. The trunk perceives all horizontal loads on the building and part of the vertical ones. The walls of the shaft are either made of monolithic reinforced concrete or steel. With this system, hinged connection of frame elements is possible. The trunk, as a rule, is located in the central part of the building and its volume is used to accommodate elevators, stairs and utilities. The space between the central shaft and the outer walls is free from supports. The frame in this system is steel or reinforced concrete.

2. Bearing CS with wall bearing elements

In these systems, the vertical load-bearing structures are solved in the form of walls that take all vertical and horizontal loads. The walls are combined into a spatial system with the help of vertical stiffening diaphragms and horizontal floor disks.

There are three main schemes of the system with load-bearing walls: longitudinal-wall; cross-wall; cross-wall.

It is a series of parallel walls oriented along the building, the distance between which is called the span. Accordingly, one-, two- and three-span buildings are distinguished. All spans can be the same or different sizes. The stability of the longitudinal walls in their plane is ensured by setting stiffness diaphragms in the perpendicular direction (individual walls, walls of staircases). The distance between the transverse stiffening diaphragms depends on the thickness of the wall, its material and the vertical distance between the horizontal supports (ceilings) and is regulated by SNiP "Masonry and Reinforced Masonry Structures".

Scheme with longitudinal load-bearing wallsused in buildings up to 17 floors. The advantage of this scheme is the possibility of changing the floor plan during the reconstruction of buildings, as well as the use of local wall materials. The main disadvantage is that the thickness of the walls is determined not only by the strength calculation, but also by the requirements of the thermal protection of the premises, which can lead to a significant consumption of materials.

Cross-wall schemeused in buildings up to 70 floors high. The distance between the transverse walls is called a step. There are narrow (up to 3.6 m) and wide (over 3.6 m) pitch of transverse walls. The thickness of the walls is determined only by the calculation of strength and may be insignificant. External walls perform only enclosing functions and can be made of lightweight efficient materials. Their thickness is determined primarily by the need for thermal protection of the premises. The longitudinal stability of the building is provided by stiffening diaphragms (as a rule, these are the walls of staircases oriented along the longitudinal axis of the building) and floor disks.

The advantage of this scheme is the use of light enclosing structures, the possibility of arranging large openings in them. The main disadvantage is the difficulty in upgrading buildings due to the relatively often located transverse capital walls.

Cross-wall scheme. It is used in buildings with a cellular planning structure, especially in seismic areas.

3. CS in the form of cross flat walls,

Perceiving all vertical and horizontal loads

Example for points 2 and 3:Structural system with transverse load-bearing walls of the Izmailovo Hotel, Moscow, Russia:

Structural solution: a pile field with a monolithic grillage, a prefabricated reinforced concrete frame according to the nomenclature of typical products with prefabricated stiffening walls. Enclosing structures on an individual basis. It was planned to make prefabricated enclosing panels and pylons on white cement in stainless steel formwork.

4. Stem structural system.

Vertical load-bearing structures are spatial elements of a closed shape in plan - trunks that perceive all vertical and horizontal loads acting on the building. Overlappings are based directly on the trunks and can be single or multi-stem.

Depending on the method of supporting the floors on the trunk, two main schemes are distinguished:

with console and

Hanging ceilings.

In accordance with this, the buildings of the stem CS are classified as buildings with cantilevered and suspended floors.

In buildings with cantilevered floorsthe outer walls do not reach the level of the foundation, but are supported either by cantilever structures supported on the trunk of the floors, or by cantilever belts. Cantilever floors are larger in plan than the ground floor, which is usually left open.

In buildings with suspended floorsfloor structures are supported on the one hand on the central stair-lift shaft, and on the other hand on vertical suspensions (steel or reinforced concrete). The pendants are fixed either to the top of the trunk or to the cantilever head.

By the type of main supports, perceiving all vertical and horizontal loads,constructive schemes of buildings with suspended floors are conditionally divided into the following main groups:

With barrel supports;

With rack supports;

With arched supports;

With combined supports, for example in the form of a trunk and racks.

The considered constructive scheme opens up a wide scope for finding interesting compositional solutions for buildings. Suspensions in buildings of these types can be made of steel strips, rolled profiles, ropes, rods, monolithic reinforced concrete prestressed, prefabricated prestressed, steel-reinforced concrete.

4.1. Structural scheme with a monolithic shaft supporting panel structures on consoles.

4.2. Shell-stem structural system.

In contrast to the shell system, it is characterized by the fact that in the perception of horizontal and vertical loads, together with the inner shaft, a closed outer shell-box is involved, formed by the structures of the outer walls of the building and capable of operating under the action of horizontal loads as a whole due to appropriate connections.

5. Shell (box) and suspension systems.

Examples: "Sire Tower":

John Hancock buildings in Boston

The John Hancock Center is a 100-story skyscraper in Chicago. main feature skyscraper lies in its hollow structure, resembling a large quadrangular column.

4. Stem structural systems

Since the 1960s, newly invented structural systems - barrel and shell - have been actively introduced into high-rise construction. Their invention was patented by the American engineer F. Kahn in 1961.

Stem structural system as the main load-bearing structure of the building, perceiving loads and impacts, contains a vertical spatial rod stiffening shaft (closed or open section) for the entire height of the building. Since the trunk is most often located in the geometric center of the plan, the common term "stiffening core" has also arisen. Stiffeners are the most specific internal vertical supporting structure for high-rise construction. The ceilings rest directly on the shafts, the buildings can be single or multi-stem. The most common design option is a centrally located monolithic reinforced concrete shaft. Depending on the load (number of floors), the thickness of the shaft walls in the lower tier can reach 60-80 cm, and in the upper tier it can be reduced to 2030 cm.

In terms of design and planning, the relatively rarely accepted design of an open profile shaft, for example, a cruciform section, is successful. It eliminates the labor-intensive and metal-intensive installation of numerous overhead jumpers required in shafts of a closed section, and simplifies the installation of elevators. The restriction in their use is justified only in especially high structures, when the rigidity of the open-section shaft may be insufficient.

Steel structures shafts are in most cases a lattice system, concreted after installation. Exceptions to this rule are extremely rare when the trunk has not only bearing, but also architectural and compositional functions.

Stiffeners are the most specific internal vertical supporting structure for high-rise construction. It is inherent in most high-rise buildings of various structural systems: stem, stem-wall, frame-stem and shell-stem.

The shaft structural system is characterized by the fact that all horizontal and vertical loads are perceived by the structures of the shaft, consisting of monolithic walls or separate diaphragms, combined into a spatial element. It is used in cases where it is necessary to increase the depreciation ability of the structure to seismic shocks. In shaft structural systems, vertical bearing structures are shafts, formed mainly by the walls of stair-lift shafts, on which floors are supported directly or through distribution grillages.

Stem systems have their own varieties: cantilever support of ceilings on the trunk, suspension of the outer part of the ceiling to the upper bearing console "hanging house" or its support by means of walls on the underlying carrier console, intermediate arrangement of floor-high bearing consoles with transfer of load from part of the floors to them.

The trunk or core in high-rise buildings is a rigid (monolithically made) stair-lift assembly. In the first case, the ceilings are rigidly fixed in the walls of the shaft, in the second case they rest freely on the shaft and, in addition, are held by hangers fixed in the upper or intermediate part of the shaft. In buildings with cantilever floors (floors), the outer walls do not reach the level of the foundation, but are supported either by cantilever structures of the floors supported on the shaft, or by cantilever belts. The ceilings are supported on the one hand by the central stair-lift shaft, and on the other - by vertical suspensions (steel or reinforced concrete). Suspensions in buildings of these types can be made of steel strips, rolled profiles, ropes, rods, monolithic reinforced concrete prestressed, prefabricated prestressed, steel-reinforced concrete. The pendants are fixed either to the top of the trunk or to the cantilever head. The dimensions of the cantilever floors in plan exceed the dimensions of the lower floor, which, as a rule, remains open.

According to the type of main supports, which perceive all vertical and horizontal loads, the structural schemes of buildings with suspended floors are conditionally divided into three main groups: with shaft supports; with rack supports; with arched supports. A special group is represented by buildings with combined supports, for example, in the form of a trunk and racks.

This constructive scheme opens up wide opportunities for finding interesting architectural, planning and compositional solutions for buildings.

Another system used in the construction of high-rise buildings is the suspension system, which is usually built from the bottom up, when the floors can be suspended from the stiffening core and trusses (coverings). Since each floor is first installed on the ground and then lifted up, interior work can continue on the upper floors while the new level is being installed at ground level. The process can also go in the opposite direction in suspended structures, i.e. after the completion of the installation of the stiffeners and trusses, the floors are mounted from top to bottom and the internal work proceeds in the same sequence. There are several possible advantages to this reverse arrangement: the protective scaffolding over the entire height of the building is no longer needed, but only used for one floor, while the individual working levels are protected by the floor above. The deployment of a winter construction site requires less effort, the ground floor remains open and can be used for building fixtures, which is especially convenient in the city center. Suspended structures are not subject to the risk of buckling this allows the use of flexible ties. This advantage can be quickly lost with mandatory fire retardant cladding (for example, in the case of the Bank of Hong Kong and Shanghai, (architects Foster and partners). The length of the connecting ties is subject to changes as a result of the difference in winter and summer temperatures, and these changes are exacerbated with each additional floor. The requirements of the suspension systems for the façade are very flexible.The screeds can be moved inward to prevent their expansion due to temperature differences, or installed outside with appropriate protection.In both cases, changes in length must be absorbed by the expansion joint.

One of the tallest buildings with suspended floors is the 31-storey building of the Standard Bank Center in South Africa with four underground tiers. The dimensions of the building in the plan are 33.1x33.1 m, the height is -130 m. The main bearing structure is a 4-section trunk measuring 14.2x14.2 m with monolithic reinforced concrete walls. At the levels of the 11th, 21st and 31st floors, reinforced concrete prestressed cantilever belts with an overhang of 10.45 m rest on the shaft. Two prestressed reinforced concrete hangers are attached to the ends of the cantilevers on each side of the building, which support the structure of the nine floors below. The floor structures are designed as ribbed reinforced concrete slabs, resting on one side on the walls of the central shaft, and on the other side on contour reinforced concrete beams attached to hangers. The span of the contour beams is 14.2 m, the outreach is 5 m.

An example of the use of a suspension system is the building of the BMW Tower (Munich, Germany), in which the three-dimensional solution is a four-leaf plan, which made it possible to maximize the use of the light front of the entire building and give it a plastic expressive shape, and the technical recessed on the facade the floor divides the volume into two unequal parts, interrupting the monotony of the facade (Fig. 3.4.6). Since the tower is a building with suspended floors, its construction was carried out in a special way. All 22 floors were made on the ground and then raised. Four powerful trunks with additional columns support suspended floors. The height of the building is 101 meters and the diameter is 52 meters.

The scheme with cantilever floors was used in the construction of the 37-storey administrative building Tour du Midi, 149.2 m high, in Brussels (Fig. 3.4.7). The dimensions of the building are 38.6 x 38.6 m. The building is supported by a central stair-lift shaft measuring 19.7 x 19.7 m with a concreted steel frame. The load-bearing elements of the floors are cantilevered prefabricated monolithic reinforced concrete beams the length of the entire building, embedded in the walls of the trunk. Departure of consoles 9.65 m.

The considered stem systems are not a common design solution. The most common systems with combined solutions: shaft in combination with either a frame frame, or with a load-bearing box of external walls, or with load-bearing walls diaphragms.

In terms of design and planning, the relatively rarely accepted design of an open profile shaft, for example, a cruciform section, is successful. It eliminates the labor-intensive and metal-intensive installation of numerous overhead jumpers required in shafts of a closed section, and simplifies the installation of elevators. The restriction in their use is justified only in especially high structures, when the rigidity of the open-section shaft may be insufficient. The steel structures of the shafts are in most cases a lattice system, concreted after installation. Exceptions to this rule are extremely rare when the trunk has not only load-bearing, but also architectural and compositional functions.

An example of a high-rise building of a frame-stem structural system is the 57-storey administrative building "Maine Montparnasse" in Paris (France), 200 m high. The building has a biconvex shape in plan with a steel frame and a monolithic shaft with dimensions in plan of 37x16 m and a stepped shape in height. The outer columns are steel I-profile, located with a step of 5.7 m; walls from hinged panels. Another example is the 39-story building of the Stadt Berlin Hotel in Berlin, Germany. The building is rectangular in plan, 50x24 m in size; made with reinforced concrete outer columns spaced at 3.0 m intervals and inner walls of a multi-cell shaft of stair-lift shafts with a total size of 48x9.3 m. Thickness from 70 cm to 30 cm. One of additional ways increasing the rigidity of buildings of the frame-stem structural system is the installation of horizontal belts - trusses that connect the frame with the stiffening shaft at several levels along the height of the building, which makes it possible to design buildings with a height of 250 meters or more. Horizontal chords are rigidly connected to the shaft structures and pivotally connected to the outer columns. When the shaft bends, the belts act as spacers, transferring axial stresses directly to the columns around the perimeter of the building. These columns, in turn, work as rods that prevent the trunk from deflecting. Thus, the shaft completely perceives the horizontal shear forces, and the horizontal chords transfer the vertical shear load from the shaft to the frame structures of the outer walls. At the same time, the building works as a whole according to a scheme similar to that of a box-section cantilever rod. An example of a suspension system is the 114-metre Hypo-House in Munich, the third tallest skyscraper in the city. According to the constructive solution, this building is similar to the BMW building, the same four cylinders, but already along the outer contour they support the floors. The building was renovated in 2006. Further reconstruction of the building will include its transfer to the "Green Building" green building, which will require further reconstruction of significant changes in terms of engineering systems and equipment, since the building currently has central air conditioning.

5. Structural scheme with a monolithic shaft supporting panel structures on consoles.

6. Shell (box) and suspension systems.

Shell (box) systems

Since the 1960s, newly invented structural systems - box-shaped (shell) and stem - have been actively introduced into high-rise construction. Their invention was patented by the American engineer F. Kahn in 1961.

The box structural system is the most rigid structural system, since its supporting structures are located along the outer contour. Therefore, it is most often used in the design of the tallest buildings 200 m and above.

The main box system is accompanied by two combined optionsshell-stem ("pipe in pipe") and sheath-diaphragmatic ("bundle of pipes").

In a box systemin the center of the plan, a shaft is located with elevator shafts and common halls located in its space. The trunk perceives the main share of all loads, and bearing elements located along the perimeter of the building in the form of separate racks (columns), lattice systems (trusses, composite rods, etc.), pylons, which can also be combined into a single structure. The rigidity of the stem system, its stability and ability to damp forced vibrations are ensured by embedding the central stem into the foundation.

An individual specific task in the design of shell buildings was the solution of the design of the bearing outer shell, which combines load-bearing and enclosing functions.

A means of increasing the rigidity of the shell can also be the transition from shell toshell-diaphragm construction ("bundle of pipes").The shell structure is made of both steel elements and reinforced concrete. Reinforced concrete shells are performed as monolithic or prefabricated, but most often from structural lightweight concrete, combining the load-bearing and heat-insulating functions of the wall. AT last years shells in Europe are mainly made of heavy concrete (perforated wall) with subsequent insulation and external cladding.

For elements of steel shells, rolled or welded elements of a closed rectangular section are most often used, also with subsequent insulation and cladding.

To increase the resistance to external influences of the bearing system of buildings with a height of more than 250 m, mainly trunk structural systems are used: “pipe in pipe” and “pipe in a truss”. Most of the high-rise shell-type buildings are built on a shell-and-shell system, although some prominent buildings, such as the 100-story John Hancock Building in Chicago and the Taipei International Financial Center, have a shell-and-truss structural system (Figure 3.3. one). According to this scheme, the outer perimeter of the walls is rigidly connected to the shaft and additionally reinforced with powerful diagonal ties. In this case, the entire building works as a rigid console embedded in the body of the foundation.

The shell (box-shaped) CS is based on the principle of the perception of all horizontal loads only by the outer wall box, which is usually solved in the form of a rigid spatial lattice (diagonal or diagonal).

In fact, the lattice is the elements of the frame, placed on the perimeter of the building. The racks of the frame serve as piers, the crossbars of the frame as overhead lintels. Internal supports (most often a centrally located shaft) work only for vertical loads. Within the central shaft there are elevators, stairwells, all the main engineering communications. With such a system, it is possible to design buildings that are wide in plan and deep working rooms with artificial lighting and a microclimate.

Since the bulk of the load-bearing structures are located along the contour of the building, this increases the resistance of the building to horizontal loads and gives the shell system an advantage over other systems, primarily in the construction of high-rise buildings. In addition, it is possible to facilitate the design of the ceilings, since they are freed from the transmission of horizontal loads to the shaft.

The shell (box-shaped) structural system is based on the principle of taking all horizontal loads only by the outer wall box, which is usually solved in the form of a rigid spatial lattice (straight or diagonal).

Examples: "Sire Tower":

Chicago is called the "Windy City" the average wind speed here is 16 miles per hour. To ensure the stability of the skyscraper, the architect Bruce Graham used a structure of steel connected square-section pipes, forming a rigid frame of the building.

The lower part of the Sire Tower up to the 50th floor consists of nine pipes combined into a single structure and forming a square at the base of the building, spread over the territory of two city blocks.

Above the 50th floor, the frame begins to narrow. Seven pipes go to the 66th floor, five more to the 90th floor, and two pipes form the remaining 20 floors. The amount of steel spent on the construction of this tubular frame would be enough to create 52,000 cars. It is very cruel: the top of the building sways with a maximum amplitude of only 1 foot (0.3 m).

The total mass of the building is 222,500 tons. It stands on 114 stone-filled concrete piles driven deep into a solid rock base. The lowest level of the tower lies 13 m below street level. More than 600,000 cubic meters of concrete went into pouring the foundation - enough to build an 8-lane five-mile freeway. 3220 km of electric cable was laid in the building. And telephone cables (their length is 69,200 km) can wrap our entire planet around the equator 1.75 times.

Frame-stem system "Petronas Tower", Kuala Lumpur, Malaysia:

The twin towers of the shopping and business center "Petronas Tower" are 452 meters high each. The foundation supports of the towers are underground at a depth of more than 100 m, the total area of ​​the complex is about 1 million m2.

This glass, concrete and steel building was designed by Ranhill Bersecutu and Thornton Tomasetti. During the study of the area, it turned out that different soil is located under the towers, which would cause a drawdown of one of the towers. Therefore, it was decided to move them 60 meters and drive piles 100 meters, making it the largest foundation in the world. In plan, the building has an octagonal star symbol of Islam. This was facilitated by the participation of the Prime Minister of Malaysia, who wants to build a building in the style of Islam. Both buildings are connected by an air bridge at the 42nd floor level. The bridge provides not only fire safety, but also affects the overall reliability of the building, already designed at a high level. A huge amount of steel went into the construction of the Petronas Tower 36,910 tons. Due to the use of materials only from Malaysia, it was necessary to try to replace the steel with new elastic concrete, which was successfully produced here for the new high-rise. The building has underground parking for 4500 cars. The building is equipped with high-speed elevators, so it takes only 90 seconds to get to the top floor. For the elevator, due to the limited space, an interesting scheme was used - the elevators themselves are two-story, respectively, one of them stops only on even floors, and the other on odd ones.

6.1. Box-barrel (shell-barrel) structural system (or "pipe in pipe")

Box-barrel (shell-barrel) structural system (or “pipe in pipe”) is characterized by the fact that horizontal and vertical loads in the building are perceived jointly by the inner shaft and a closed outer box (shell) formed by the load-bearing structures of the outer walls. The outer box is usually made in the form of a rigid spatial grid, the elements of which are steel or reinforced concrete columns, installed, as a rule, with a small step, and floor strapping beams. The elements of the lattice, along with the carriers, also perform enclosing functions. With a large column pitch, the lattice is reinforced with braces or diagonal belts, located in two or more tiers along the height of the building. Sometimes the outer box is formed by monolithic reinforced concrete walls with openings.

The joint work of the outer shell and the inner shaft is provided by vertical connections (grillages) within the technical floors, as well as hard disks of floors. Due to the joint work of the outer shell and the shaft, when using the shell-stem system, the rigidity of the entire structure increases by 3050% compared to the frame-stem structural system and, accordingly, deflections from horizontal loads are reduced.

This system was called "Tube-A-Tube" ("pipe in a pipe"). The outer shell is usually made in the form of a rigid spatial non-braced lattice, the elements of which are steel or reinforced concrete columns and floor strapping beams. Columns are installed, as a rule, with a small step. With a large column pitch, the lattice is reinforced with braces or diagonal belts placed in two or more tiers along the height of the building. Sometimes the outer shell is formed by monolithic reinforced concrete walls with openings.

Examples:

Stem-frame system of the BMW building, Munich, Germany

The construction of the building took place from 1968 to 1972 and was built just in time for the start of the Olympic Games held in the city. The architect was the Austrian Karl Schwanzer. The 22-story skyscraper, 101 meters high, was opened on May 18, 1973. Externally, the building is designed like a four-cylinder engine, and the nearby museum depicts a cylinder head. All four "cylinders" are not on the ground, but on an inconspicuous central base. The diameter of the building is 52.3 meters. Construction cost 109 million marks. As of 2013, the building has about 1,500 employees.

Data

It was originally planned to place a huge corporate logo on the supporting cross at the top of the tower, but the architectural department of Munich considered it too catchy. The company began a lawsuit, and during it, at the beginning of the Olympics, they hung out their logos, printed on canvas, so that they could be seen from the Olympic stadium. For this, BMW was fined 110,000 marks. Only in the fall of 1973, the concern received permission to hang out its logos on all four sides.

7. Large-panel buildings

For low-span floors, it is recommended to use a cross-wall structural system. The dimensions of the structural cells are recommended to be assigned from the condition that the floor slabs rest on the walls along the contour or on three sides (two long and one short).

For medium-span floors, cross-wall, cross-wall or longitudinal-wall structural systems can be used.

With a cross-wall structural system, it is recommended that the outer walls be designed as load-bearing, and the dimensions of the structural cells should be assigned so that each of them is covered by one or two floor slabs.

With a cross-wall structural system, the outer longitudinal walls are designed as non-bearing. In buildings of such a system, it is recommended to design load-bearing transverse walls through the entire width of the building, and arrange internal longitudinal walls so that they unite the transverse walls at least in pairs.

With a longitudinal-wall structural system, all external walls are designed as load-bearing. The step of transverse walls, which are transverse stiffening diaphragms, must be substantiated by calculation and taken no more than 24 m.

In large-panel buildings, in order to absorb the forces acting in the plane of the horizontal stiffening diaphragms, prefabricated reinforced concrete floor slabs and coatings are recommended to be interconnected by at least two ties along each side. The distance between the bonds is recommended to take no more than 3.6 m. The required section of the bonds is assigned by calculation. It is recommended to take the cross section of the bonds in such a way (Fig. 6) that they ensure the perception of tensile forces of at least the following values:

for connections located in ceilings along the length of a building extended in plan, - 15 kN (1.5 tf) per 1 m of the width of the building;

for ties located in floors perpendicular to the length of a building extended in terms of plan, as well as ties of compact buildings, - 10 kN (1 tf) per 1 m of building length.

Monolithic construction

How it all began. History of monolithic construction

Ancient Rome. The history of the development of monolithic construction is interesting. The first and most famous example of a building using this method dates back to 118-120. AD In Rome, a remarkable monument of the era of Emperor Hadrian has been preserved - the temple of all the gods - the Pantheon (architect Apollodorus).

Russia. At the beginning of the 20th century, in connection with the search for new forms, new possibilities of concrete were discovered, and the traditional aesthetics of architectural composition was replaced by a different aesthetics of constructivism.

New technologies also appeared in Russia, and they appeared in the 19th century, thanks to the construction of temples and palaces. In 1802, reinforced monolithic concrete was used in the construction of the floors of the palace in Tsarskoye Selo (now - the city of Pushkin). In the 80s of the 19th century, a number of buildings were built in St. Petersburg, including the building of the State Bank (70-72 Fontanka River Embankment), the walls and ceilings of which were made of monolithic reinforced concrete.

Since the end of the 1920s, various monolithic structures have been introduced into construction practice: shells, domes, tents, etc. So, in Moscow, the Central Telegraph was built (Tverskaya St., 7 (1927-1929)), the Izvestia house on Pushkin Square (1927-1929), the buildings of the ministries of light industry and agriculture (Sadovo-Spasskaya St. , d.11/1); in Leningrad - the House of Soviets (Moskovsky Prospekt, 212). The versatility of monolithic construction made it possible to change the usual forms, creating a new architectural image of the country.

In 1947, it was decided to build skyscrapers that were in no way inferior to American models, and ideally surpassed them (a task almost similar to that set by Emperor Hadrian during the construction of the Pantheon).

Prior to the construction of high-rise buildings in Moscow, there was no practice of erecting structures higher than 10 floors. We had to build and design in parallel. It was also necessary to take into account the complex geology of Moscow soils. Therefore, despite the similarity of our skyscrapers with American skyscrapers, they are much lower than their prototypes.

All the "Seven Sisters" were founded on the same day, September 7, 1947 - on the day of the eight hundredth anniversary of Moscow: the building of Moscow State University on Sparrow Hills (310 m), resembles the facade of a government building in Manhattan (Manhattan Municipal Building); hotel "Ukraine" (200 m); a residential building on Kudrinskaya Square (156 m, reminiscent of the Cleveland skyscraper Terminal Tower); residential building on Kotelnicheskaya embankment (176 m); administrative and residential building on Red Gate Square (138 m); the building of the Ministry of Foreign Affairs (172 m, there is a resemblance to the Woolworth Building in Manhattan (Woolworth Building)) and the Leningradskaya Hotel (136 m, analog of the courthouse in Manhattan (Manhattan United States Courthouse)).

Perspectives. In monolithic housing construction, two directions of development can be traced. One of them is associated with the mass construction of ordinary buildings (mainly residential), the other is aimed at the construction of unique structures. The first direction covers a huge housing market of all categories. The demand for quality housing is growing, at the same time the need for a variety of architectural solutions that create a modern look for "sleeping" areas is growing. There can be no doubt: there will be enough work in this area for 100 years.

The second direction is the construction of entire complexes according to individual projects, which serve as town-planning accents (an example is the office center "Moscow-City"). (Marina Alazneli, SVEZA press service)

Prefabricated reinforced concrete buildings

A panel is a planar prefabricated element used for the construction of walls and partitions. A panel with a height of one floor and a length in plan not less than the size of the room it encloses or divides is called a large panel, panels of other sizes are called small panels.

A prefabricated slab is a prefabricated planar element used in the construction of floors, roofs and foundations.

A block is a self-sustaining during installation prefabricated element of a predominantly prismatic shape, used for the construction of external and internal walls, foundations, ventilation and garbage chutes, placement of electrical or sanitary equipment. Small blocks are installed, as a rule, manually; large blocks - using mounting mechanisms. Blocks can be solid or hollow.

Large blocks of concrete buildings are made of heavy, lightweight or cellular concrete. For buildings with a height of one or two floors with an expected service life of not more than 25 years, gypsum concrete blocks can be used.

A volumetric block is a prefabricated part of the volume of a building, fenced from all or some sides.

Volumetric blocks can be designed bearing, self-supporting and non-bearing.

A load-bearing block is called a volumetric block, on which volumetric blocks located above it, floor slabs or other supporting structures of the building are supported.

A self-supporting block is called a three-dimensional block, in which the floor slab is floor-by-floor supported by load-bearing walls or other vertical load-bearing structures of the building (framework, stair-lift shaft) and participates with them in ensuring the strength, rigidity and stability of the building.

A non-bearing block is a volumetric block that is installed on the floor, transfers loads to it and does not participate in ensuring the strength, rigidity and stability of the building (for example, a sanitary cabin installed on the floor).

Prefabricated buildings with walls made of large panels and ceilings made of prefabricated slabs are called large-panel buildings. Along with planar prefabricated elements in a large-panel building, non-bearing and self-supporting three-dimensional blocks can be used.

A prefabricated building with walls made of large blocks is called a large-block building.

A prefabricated building made of load-bearing three-dimensional blocks and planar prefabricated elements is called a panel-block building.

A prefabricated building made entirely of three-dimensional blocks is called a three-dimensional block building.

Unification and industrialization of solutions in multi-storey civil engineering

To date, the All-Union Construction Catalog of standard structures and products from various materials for buildings and structures of all types of construction has been created.

On the basis of and in development of the All-Union catalogue, sectoral and territorial catalogs for housing and civil construction have been created, oriented towards the existing local production and raw material bases. In total, more than 130 catalogs are currently used in housing and civil construction. A powerful construction industry has been created in the country. Such a grand industrial base required the development of a new system an open typing system. Its meaning is that the object of typification is not buildings or their parts, but a strictly verified limited assortment of industrial products, from a set of which in various combinations buildings, diverse in space-planning solutions and facade architecture, should be completed.

This fundamentally new typification system is largely implemented in the method of the Unified catalog of unified products for construction in Moscow (territorial catalog TK1-2). It consists of: panel structures for the construction of residential buildings; frame-panel structures (with a prefabricated reinforced concrete unified frame) for the construction of civil and industrial buildings.

The main provisions of the Unified catalog: all sizes are subject to the rules of modular coordination (MKRS); regulated the rules for binding all prefabricated products to the coordinate axes of buildings; combinatorics of characteristic architectural and constructive situations are revealed; the most progressive and economical types of structures were selected; unified junctions of structural elements have been developed; unified normative loads and a number of other parameters (thermophysical, etc.); series of geometric dimensions of spans, steps, heights were unified.

The geometric parameters accepted as the base of the Unified Catalog are subject to certain regularities based on mathematical modular series; the main module is 0.6 m and, if necessary, an additional module 0.3 m. The catalog is based on this modular range. It contains the necessary nomenclature for the construction of residential buildings with a floor height of 2.8 m and with a single modular range of dimensions in terms of 1.2; 1.8; 2.4; ...; 6.6m (M = 0.6m), public buildings with a floor height of 3; 3.3; 3.6; 4.2; 4.8; 6.0 m, based on a single modular range of plan sizes 1.8; 2.4; 3; 3.6; 4.8; 6; 7.2; 9; 12; fifteen; eighteen; 24 m

When compiling the catalog, the implementation of various structural systems of buildings is provided: panel with a narrow, wide and mixed pitch of transverse load-bearing walls for residential buildings; frame crossbars with transverse and longitudinal directions for residential and public buildings, etc. The number of storeys of residential buildings is provided for 9, 12, 16, 25 floors, public - up to 30 floors.

The catalog includes a wide range of products that ensure the creation of a variety of architectural, planning and volumetric structures of buildings (houses with a rectangular configuration, corner, stepped, with a shift in plan, shamrock, etc.).

For the Catalog, the most rational economic and at the same time promising designs and design schemes of industrial panel and frame residential buildings, public and industrial buildings were selected.

The idea of ​​a single catalog "from product to project" allows such methods standard design, as block-sectional, block-apartment, etc. In the enlarged space-planning elements (KOPE), products and methods of the Unified Catalog were used (see below).

Monolithic and prefabricated-monolithic residential buildings are recommended to be designed on the basis of wall structural systems. In the course of a feasibility study, the use of barrel and frame-barrel structural systems is allowed.

For monolithic and precast-monolithic buildings with monolithic or prefabricated-monolithic external walls, it is recommended to use a cross-wall structural system with load-bearing transverse and longitudinal walls, including external ones. Monolithic and precast-monolithic floors are considered as pinched along the contour.

Prefabricated floors are considered as pinched by walls and supported on two or three sides.

For prefabricated-monolithic buildings with prefabricated external walls in the presence of through internal longitudinal walls, it is recommended to adopt a cross-wall system with non-load-bearing external walls. In the presence of separate longitudinal stiffening diaphragms, a cross-wall structural system is used, in which the ceilings are considered as pinched by walls on two opposite sides.

For prefabricated monolithic buildings with monolithic ceilings pinched on both sides, it is allowed to use a cross-wall structural system with a flat frame or a radial arrangement of walls.

Depending on the purpose and size of the premises located on the ground floors of monolithic and precast-monolithic buildings, wall or frame structural systems can be used:

wall systems with full coincidence of the axes of the lower and upper floors;

wall systems with incomplete (partial) coincidence of the axes of the walls of the lower and upper floors;

frame systems with full coincidence of the axes of the frame of the lower and walls of the upper floors;

frame systems with incomplete (partial) coincidence of the axes of the frame of the lower and walls of the upper floors.

Wall systems with full coincidence of the axes of the walls of the lower and upper floors should be used if enterprises that do not require large premises are located on the lower floors of residential buildings.

Wall systems with incomplete (partial) coincidence of the axes of the walls of the lower and upper floors should be used if the lower floors have large rooms (span of 9 m or more) and the presence of supports in the form of pylons, columns of complex profile, arches, walls, stairs is allowed. lift nodes.

Monolithic and precast-monolithic buildings according to the method of their construction, it is recommended to use the following types:

with monolithic external and internal walls erected in a sliding formwork (Fig. 2, a) and monolithic ceilings erected in a small-panel formwork by the "bottom-up" method (Fig. 2, b), or in a large-panel formwork of ceilings by the "top-down" method ( Fig. 2, c);

with monolithic internal and end external walls, monolithic ceilings erected in a volumetric-adjustable formwork, removed onto the facade (Fig. 2, d), or in large-panel formwork of walls and ceilings (Fig. 2, e). In this case, the outer walls are made monolithic in large-panel and small-panel formwork after the construction of internal walls and ceilings (Fig. 2, e) or from prefabricated panels, large and small blocks of brickwork;

with monolithic or prefabricated-monolithic external walls and monolithic internal walls erected in adjustable formwork, removed upwards (large-panel or large-panel in combination with block) (Fig. 2, g, h). The ceilings in this case are prefabricated or prefabricated-monolithic using prefabricated shell slabs that act as a fixed formwork;

with monolithic external and internal walls erected in a volume-movable formwork (Fig. 2, i) by the method of tiered concreting, and prefabricated or monolithic ceilings;

with monolithic internal walls erected in large-panel wall formwork. Ceilings in this case are made of prefabricated or precast-monolithic slabs, external walls - from prefabricated panels, large and small blocks, brickwork;

with monolithic stiffening cores erected in adjustable or sliding formwork, prefabricated wall and ceiling panels;

sliding formworkcalled formwork, consisting of panels mounted on jacking frames, a working floor, jacks, pumping stations and other elements, and intended for the construction of vertical walls of buildings. The entire system of sliding formwork elements is lifted up by jacks at a constant speed as the walls are concreted.

Shallow formworkcalled formwork, consisting of sets of panels with an area of ​​\u200b\u200babout 1 m2 and other small elements weighing no more than 50 kg. It is allowed to assemble panels into enlarged elements, panels or spatial blocks with a minimum number of additional elements.

Large-panel formworkcalled formwork, consisting of large-sized panels, elements of connection and fastening. Formwork boards take all technological loads without installing additional load-bearing and supporting elements and are equipped with scaffolds, struts, adjustment and installation systems.

Volumetric mobile formworkformwork is called a formwork, which is a system of vertical and horizontal panels hinged into a U-shaped section, which in turn is formed by connecting two L-shaped half-sections and, if necessary, inserting a floor shield.

Volumetric mobile formwork is a formwork, which is a system of external panels and a folding core moving vertically in tiers along four racks.

Block formwork is a formwork consisting of a system of vertical panels and corner elements, hingedly connected by special elements into spatial block forms.

Stone buildings may have masonry walls or prefabricated elements (blocks or panels).

Masonry is made of bricks, hollow ceramic and concrete stones (made of natural or artificial materials), as well as lightweight brickwork with slab insulation, backfill of porous aggregates or polymer compositions foamed in the masonry cavity.

Large blocks of stone buildings are made of bricks, ceramic blocks and natural stone (sawn or pure tesque).

Panels of stone buildings are made of vibro-brick masonry or ceramic blocks. Exterior wall panels may have a layer of slab insulation.

Structural system	The distance between the temperature-shrinkage seams, m, for ceilings
		monolithic	prefabricated
Cross-wall with load-bearing external and internal walls, longitudinal-wall
Cross-wall with non-load-bearing outer walls, cross-wall with separate longitudinal diaphragms
Cross-wall without longitudinal diaphragms

Monolithic concrete walls

External and internal walls made of cast-in-situ concrete, when using floating formwork, are erected simultaneously or sequentially (first the internal walls, and then the external ones, or vice versa).

For the construction of load-bearing walls from monolithic concrete, it is recommended to use heavy concrete of a class not lower than B7.5 and light concrete of a class not lower than B5. In buildings with a height of four or less floors, it is allowed to use lightweight concrete of class B3.5 in load-bearing walls. For internal walls, the density of lightweight concrete must be at least 1700 kg/m3.

Monolithic single-layer external walls are recommended to be designed from lightweight concrete of a dense structure. With an intergranular porosity of concrete of not more than 3% and a concrete class of at least B3.5 in normal and dry zones, it is allowed to design external walls without a protective and decorative layer. External lightweight concrete walls without a protective and decorative layer should be painted with hydrophobic compounds.

External single-layer walls are recommended to be designed from lightweight concrete with a density of not more than 1400 kg/m3. During a feasibility study, it is allowed to use lightweight concrete with a density of more than 1400 kg/m3 in single-layer external walls.

Layered exterior walls can be designed with two or three base layers. Double-layer external walls can have an insulating layer on the outside or inside. In three-layer exterior walls, the insulation layer is located between the concrete layers.

Two-layer external walls with insulation on the outside can be monolithic and prefabricated-monolithic.

Monolithic walls are erected in two stages. At the first stage, the inner layer of the wall is erected in adjustable formworks from heavy concrete, at the second - the outer layer of heat-insulating lightweight monolithic concrete.

A prefabricated monolithic wall consists of an inner monolithic layer made of heavy concrete and an outer layer made of prefabricated elements.

A two-layer outer wall with insulation on the inside consists of an outer monolithic concrete layer, an inner insulation layer made of aerated concrete blocks no more than 5 cm thick or rigid plate insulation (for example, expanded polystyrene) no more than 3 cm thick and an inner finishing layer (Fig. 26a).

The limitation of the thickness of the insulating layers is associated with the provision of a normal heat and moisture regime of the walls.

It is expedient to use heavy concrete at calculated winter temperatures not exceeding minus 7°C. In other cases, lightweight concrete should be used.

first, a layer of insulation is laid on the inner shield of the formwork, then the formwork is assembled and a layer of monolithic concrete is concreted. In this case, it is possible to use insulation boards that are not calibrated in thickness;

insulation boards are installed after concreting the walls.

In this case, it is necessary to use insulation boards calibrated in thickness.

When designing two-layer walls with insulation on the inside, it should be taken into account that the construction of such walls is easier than walls with insulation on the outside, but their use is limited by the condition that there is no dew point within the thickness of the insulation layer.

Three-layer external walls are recommended to be designed as prefabricated-monolithic, consisting of an inner bearing layer of monolithic heavy concrete and an insulated prefabricated shell panel installed from the outside. The shell panel can be installed before and after the erection of the monolithic part of the wall (Fig. 26, b).

It is allowed to design three-layer external walls with external and internal layers of monolithic concrete and an insulating layer of rigid plate insulation (Fig. 26, c).

Monolithic buildings definition according to SNiP 2.08.01.-85

Monolithic and precast-monolithic buildingsaccording to the method of their construction, it is recommended to use the following types:

with monolithic external and internal walls erectedin sliding formworkand monolithic ceilings erectedin small-panel formwork by the “bottom-up” method, or in large-panel formwork of ceilings by the “top-down” method;

with monolithic internal and end external walls, monolithic ceilings,erected in a three-dimensional formwork, extracted to the facade, orin large-panel formwork of walls and ceilings. External walls in this case are made monolithicin large-panel and small-panel formworkafter the construction of internal walls and ceilings or from prefabricated panels, large and small blocks of brickwork;

with monolithic or prefabricated-monolithic external walls and monolithic internal walls erected in adjustable formwork, removed upwards (large-panel or large-panel in combination with block). Overlappings in this case are made prefabricated or prefabricated-monolithic using prefabricated slabs - shells that act as a fixed formwork;

with monolithic external and internal walls erected in volumetricmobile formwork by layered concreting, and prefabricated or monolithic ceilings;

with monolithic internal walls erectedin large-panel formwork walls . Ceilings in this case are made of prefabricated or precast-monolithic slabs, external walls - from prefabricated panels, large and small blocks, brickwork;

with monolithic stiffening coreserected in adjustable or sliding formwork, prefabricated panels of walls and ceilings;

with monolithic stiffening cores, prefabricated frame columns, prefabricated panels of external walls and ceilings erected by the lifting method.

Monolithic buildings

The load-bearing CS of a monolithic reinforced concrete building consists of a foundation, vertical load-bearing elements (columns and walls) resting on it and combining them into a single spatial system of horizontal elements (floor slabs and roofing).

Depending on the type of vertical load-bearing elements (columns and walls), structural systems are divided into (Fig. 5.1, a, b, c):

Columns, where the main bearing vertical element are columns;

Wall, where the main load-bearing element is the wall;

Column-wall, or mixed, where columns and walls are vertical bearing elements.

Fragments of building plans:

a - column CS; b - wall CS; c - mixed CS;

1 - floor slab; 2 - columns; 3 walls

The lower floors are often solved in one constructive system, and the upper floors in another. The structural system of such buildings is combined.

Depending on the engineering and geological conditions, loads and design assignment, the foundations are made in the form of separate slabs of variable thickness under the columns (Fig. 5.2, a), tape slabs under the columns and the wall (Fig. 5.2, b) and a common foundation slab over the entire area constructive system (Fig. 5.2, c). With a large thickness of the plates, more economical than solid, ribbed and box-shaped plates are used (Fig. 5.2, d, e). With weak soils, pile foundations are arranged.

Rectangular columns (pylons) with an elongated cross section have ratios b/a<4 или hэт/b>4. More elongated columns should be referred to as walls.

Beamless floors: a - smooth slab; 6 - plate with capitals

In multi-storey buildings, mixed column-wall CSs are most often used.

It is recommended to design the load-bearing structural system in such a way that the vertical load-bearing elements (columns, walls) are located from the foundation one above the other along the height of the building, i.e. were congruent. In cases where the columns and walls are not made along the same axis, stiffening ribs and wall beams should be provided under the "hanging" columns and walls.

The structural system of buildings is recommended to be separated by settlement joints at different heights of the building, and also, depending on the length of the building, by temperature-shrinkage joints. The required distances between expansion joints along the length of the building should be determined by calculation. During the construction period, it is possible to arrange temporary expansion joints, which are then eliminated.

Modern systems facade glazing

Heat transfer in translucent enclosing structures can occur with the help of radiation, convection and thermal conductivity. You can change the heat-shielding properties by influencing these components of heat transfer.

There are several ways to influence the thermal characteristics of window structures:

─ increase in the number of glazing layers, which is not effective enough, because

how it reduces the penetration of visible light through window structures;

─ change in the thickness of the gap between the stelae of the double-glazed window (thermal resistance of the air gap gradually increases to a certain thickness, and then practically does not change);

─ the use of filling the inter-pane space with various gases

or gas mixtures (today, air is replaced by gases: argon, krypton, xenon, or gas mixtures formed in combination with air; when replacing air with argon, the thermal resistance of the layer increases by 10%);

─ the use of vacuum insulating glass units (the design of a vacuum insulating glass

consists of two sheets of glass soldered together with a small gap.

This design is highly durable. The use of special glasses with a low-emissivity heat-reflecting coating to influence the radiant component of heat transfer and the combined use of a coating and gas filling (when using heat-reflecting coatings, there is a significant reduction in the amount of thermal energy lost in the form of infrared radiation through the surface of a window glass that transmits visible and reflects infrared radiation. For By reducing the value of the radiant component of heat transfer, heat loss through windows is significantly reduced, however, heat-reflecting coatings reduce the coefficient of light transmission through windows.Coatings based on various metals are widely used as heat-reflecting coatings: silver, gold, copper with a system of antireflection oxides, semiconductor oxides of tin and indium) ; the use of electrically heated glazing (heating of either the glass surface or the air space between the panes of a double-glazed window.

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In the regions of the Urals and Siberia, the most widely used modification of KUB-type systems, called "Structures without crossbars" or KBK. The structures of the Crossbarless Frame (KBK) were developed in 2006 by OAO 12 Voenproekt jointly with the Central Production Association at Spetsstroy of Russia by order of PC KUB-Sibir LLC. As a result, a completely new set of documentation for the structural system was born, which in 2007 was certified by the Federal State Unitary Enterprise TsPP, Moscow for compliance with the requirements normative documents in the field of construction. KBK simultaneously combines all the advantages and effective features of the prefabricated monolithic systems "USMBK", "KUB-1", "KUB-2", "KUB-3" based on their implementation in construction, as well as applied innovative developments, confirmed by experimental work .

KBK is a universal system used for the construction of almost the entire range of urban structures: residential, socio-cultural, administrative and household buildings, multi-level parking lots, warehouses, and some industrial buildings. A domestic development was chosen as the basis for the CSC - the KUB-2.5 frameless frame system. It has been used in our military construction complex for many years, has been worked out from a design point of view and adapted to the existing Russian technological culture in the construction industry. A modification of the KUB system under the abbreviation USMBK was used in the construction of objects of the Ministry of Defense in various countries.

In terms of construction time frameless systems can only compete with buildings erected from reinforced concrete panels. But the quality of panel housing does not meet modern requirements. In particular, many buyers are not satisfied with the impossibility of redevelopment and the inevitable uniformity of the buildings under construction.

The advantage of the KBK frameless frame, first of all, lies in a limited set of constituent elements, on the one hand, and in the wealth of possibilities for internal planning solutions, the creation of a non-repeating set of apartments from rooms and volumes, the use of local materials for the construction of external enclosing walls and internal partitions, on the other hand sides. The problem of redevelopment of internal spaces is easier to solve.

The advantages of the KBK prefabricated transomless system from an economic point of view are confirmed by the fact that in Siberia and the Urals there are not isolated cases when contractors using a constructive transomless construction system won tenders from companies building in a "monolith".

The KBK system makes it possible to build both comfortable and "elite" and "social" housing on a single industrial, technological basis. Moreover, the “social” or “elite” purpose of housing is realized at the expense of volume, decoration, etc. At the same time, the KBK system allows (if necessary) without demolition, by redevelopment, to turn a previously “social” house into an “elite” one, or vice versa.

The KBK system is much better adapted to difficult construction conditions. It is more industrial: less in-situ concrete is used per construction site, which means that there are fewer difficulties in winter. There is no need to attract a large staff of qualified employees and special equipment. Thus, the bulk of the problems are transferred to the plant. Ensuring the quality of the carcass largely lies at the plant and depends on the quality of the metal molds. Such a system is less time-consuming and surpasses almost any other in terms of the speed of building construction. So, a team of 5-6 people quietly mounts 200 sq. m (in the presence of reinforced concrete).

If we talk about the technical side of the technology, it can be noted that the structural system provides for the use of continuous (multi-storey) columns with a section of 400 (mm) x 400 (mm) with a maximum length of 9900 (mm). At the junction of columns, forced installation is provided, consisting in pairing the fixing rod of the upper column with the branch pipe of the upper end of the lower column. At the junction of the ceilings (at the height of the floor), the columns are provided with dowel-shaped cutouts, within which the column reinforcement is exposed.

The system of structures of the “KBK” frameless frame provides for the use of prefabricated floor panels maximum dimensions 2980 (mm) x 2980 (mm) x 160 (mm).

Floor panels, depending on the location in the frame, can be over-column (NP), inter-column (MP) and middle (SP).

Installation of structures is carried out in the following order: columns are mounted and embedded in the foundation; above-column panels are installed and welded to the reinforcement of the columns; then inter-column and middle panels are mounted. When installing the panels, the reinforcing outlets of the ends are combined in such a way that a loop is formed into which the reinforcement is inserted.

The system of structures of the beamless frame is intended for the construction of a wide range of urban structures (residential, public and auxiliary buildings for administrative purposes). Not only high-rise buildings, but also schools, kindergartens, etc. are being built using a prefabricated monolithic girderless system.

Such versatility of the "KBK" system is ensured by a combination of the following properties:
a) The supporting basis of the building frame in the "KBK" is made up of columns and floor slabs that act as crossbars, ties or diaphragms are used for stiffening elements, which makes it possible to provide spans of 3.0, 6.0 m in buildings, floor heights in buildings of 2.8, 3.0, 3.3 and 3.6 with the main grid of columns 6 x 6 m.
The bearing capacity of the floors allows the use of the frame in buildings with an intensity of design loads per floor up to 1200 (kg / m2).
b) The design of the walls assumes that they perform only an enclosing function. Walls can be designed with floor-by-floor cutting, i.e. rest on the floor slabs and transfer the vertical load from its own weight to the floor slabs of each floor; mounted or self-supporting, which makes it possible to maximize the use of local non-structural materials for enclosing structures, including monolithic walls.
c) In buildings with a height of up to 5 floors, under normal construction conditions, a frame structural scheme is used without the use of additional stiffening elements;

The system is designed for the construction of buildings up to 25 floors (up to 75 meters) under normal construction conditions. In areas with seismicity up to 9 points inclusive on a 12-point scale, the use of "KBK" is limited by the requirements of Table 8 * SNiP II-7-81 * "Construction in seismic regions" for frame buildings.

Structural elements of the KBK are manufactured and assembled using a single process equipment. The frame is assembled completely from prefabricated products, followed by monolithic knots; at the final stage, the structure is monolithic.

Thus, the shaping possibilities of the frame in the "KBK" system have a wide range of the number of floors and architectural and spatial solutions. The KBK system allows you to use a wide range of facade plastics, create spatially interesting non-standard layouts that meet the task.

The calculation of the parameters of a beamless frame with flat ceilings is carried out using calculation models implemented by software systems using software products high level(PC SKAD; PC ING+; PC LIRA and others).

One of the main differences between the KBK system and the KBK 2.5 system is the adaptation of the system to the requirements of the current legislation and the receipt of the necessary certificates.

Firstly, the "KBK" system is completed with a separate package of documentation - "Design of a beamless frame for multi-storey residential and public buildings." This set of documentation is certified by the Federal State Unitary Enterprise "TsPP" Moscow for compliance with the requirements of regulatory documents in the field of construction. Certificate No. POCCRU.CP48.C00047 dated April 5, 2007 issued.

Secondly, in order to confirm the fire resistance of building frame elements based on "KBK" in 2008, CJSC "CSN "Fire Resistance-TsNIISK", Moscow, carried out certification tests of the above-column (NP 30-30-8, TU 5842-001-08911161- 2007) and medium (SP 30-30-6, TU 5842-001-08911161-2007) reinforced concrete floor slabs (manufacturer of slabs is FGUP DOKSI pri Spetsstroy Rossii).

Tests of the above-column reinforced concrete slab were carried out under a uniformly distributed load of 700 kg/m2. The heated surface of the above-column slab - the side of the slab with working reinforcement did not reach the limit states and corresponds to a fire resistance limit of at least REI 180. For an average reinforced concrete floor slab, the fire resistance limit was REI 120.

On the basis of the test results obtained, the certification body ZAO TsSN Fire Resistance-TsNIISK, Moscow, issued certificates fire safety for the entire range of floor panels of the KBK frameless frame.

Thirdly, in order to confirm the seismic resistance and assess the suitability of the system of structures of a girderless frame for construction in seismic areas, from August 22 to August 29, 2008, by order of PC KUB-Siberia LLC in Perm, static and dynamic tests of building fragments were successfully carried out. Two experimental three-story fragments of a building made of elements of the "KBK" system were tested in full size with an imitation of the workload in order to justify its use in construction on sites with seismicity up to 7-9 points on the MSK-64 scale. In the construction of the first fragment of the building, ties were used as stiffening elements, in the construction of the second, reinforced concrete diaphragms.

Tested non-profit organization"Russian Association for earthquake-resistant construction and protection from natural and man-made impacts" (NO RASS) with the participation of OJSC "12 Voenproekt" (Novosibirsk), LLC "KBK-Ural" (Perm), FGUP "TsPO" at Spetsstroy of Russia (Voronezh).

According to the test results, the seismic resistance of the KBK frame was confirmed up to 9 points - when using reinforced concrete diaphragms as stiffeners, up to 7 points - when using ties. The Russian Association for Earthquake Resistant Construction and Protection from Natural and Technogenic Impacts (RASS) issued a conclusion dated 06.11.2008:

“The KBK building system based on the structures of the Beamless frame is RECOMMENDED for use in the construction of buildings on sites with a seismic activity of 7-9 points on the MSK-64 scale, subject to the restrictions established by the requirements of Table 8* SNiP II -7-81* “Construction in seismic regions” for frame buildings."

The foregoing allows us to draw a number of conclusions.

1. Compliance of BCM technology with the current legislation allows it to be used without any restrictions and difficulties in any regions of our country, including earthquake-prone ones, while expertise project documentation in authorized federal bodies executive power and authorities of the constituent entities of the Russian Federation passes without any special features.

2. KBK technology provides complete and reliable predictability of the terms of erection of the building frame. So, already at the stage of the preliminary design, after agreeing on the floor plans, the developer can conclude an agreement with the reinforced concrete plant for the manufacture of structural elements of the building frame, and the extremely limited use of monolithic concrete at the construction site minimizes seasonal changes in the pace of construction, or its suspension. All this allows the developer to correctly assess its capabilities and meet the deadlines and costs specified by the contract, which is especially important when performing work on government orders.

In preparing the article, materials from the sites www.kub-sk.ru, www.12voenproekt.ru were used

One of the modifications frameless frame is a prefabricated monolithic frame or frame-braced frame with flat floor slabs, including multi-storey columns with a maximum length of 13 m of square section 40x40 cm, above-column, inter-column floor panels and insert panels of the same size in terms of 2.8x2.8 m and a single thickness of 160 and 200 mm, as well as diaphragm stiffness.

frame designed for the construction of relatively simple buildings in terms of composition, up to 9 floors high with a frame scheme and 16 ... 20 floors with a frame-braced scheme with cells in a 6x6 plan; 6x3 m, and with the introduction of metal sprengels on cells 6x9; 6x12 m at a height of 3.0; 3.6 and 4.2 m with full vertical load up to 200 kPa and horizontal seismic load up to 9 points.

The foundations are monolithic and prefabricated glass type. External enclosing structures are self-supporting and hinged from various materials or standard industrial products of other structural systems. Stairs are mainly made of stacked steps on steel stringers. The joints of the frame elements are monolithic, forming a frame system, the crossbars of which are the ceilings.

Installation of structures is carried out in the following order: they are mounted and embedded in the glasses of the column; mount over-column panels with high accuracy, on which the quality of installation of the entire ceiling depends; intercolumn panels are installed on the above-column panels. Then the insert panels are mounted. After alignment, straightening and fixing of the floor, reinforcement is installed in the seams of monolithic and the seams between the panels and joints of panels with columns throughout the floor are installed.

frame calculated on the action of vertical and horizontal loads by the method of replacing frames in two directions. In this case, a slab with a width equal to the pitch of the columns of the perpendicular direction is taken as the crossbar of the frame.

When calculating the system for the action of horizontal forces in both directions, the full design load is taken, the bending moments from which are introduced in full value into the design combinations. When calculating the system for the action of vertical forces, the work of the frame is taken into account in two stages: installation and operational. At the installation stage, hinged support of floor panels is taken in places of special mounting devices, except for above-column panels, which are rigidly connected to the column. In the operational stage, the frames are calculated for the full vertical load in two directions. The design bending moments are distributed in a certain ratio between the spans and the overstring strips.

Force effects on the columns at the bottom level of the floor panel are determined by formulas that take into account the two-stage operation of the structure. Elements of the structural system are prepared from concrete of class B25 and reinforced with steel reinforcement of classes A-I; A-II and A-III.

A characteristic feature of the system is the junction of the above-column panel with the column. To effectively transfer the load from the panels to the column, the column is trimmed along the perimeter at the level of the floor with four bare corner rods exposed. The collar of the above-column panel in the form of angle steel is connected to the rods with the help of mounting parts and welding.

The node for connecting floor panels of the Perederiya joint type, in which longitudinal reinforcement 0 12-A-P is passed and embedded in bracket-shaped reinforcement outlets. For efficient transfer of vertical load in the panels, longitudinal triangular grooves are provided, which form with the concrete of the monolithic seam (200 mm wide) a kind of key that works well for shearing.

The specified constructive system is designed for use in areas with an underdeveloped precast concrete industry for buildings for various purposes with relatively low requirements for the indicator of industriality (degree of factory readiness) of the system. Principal solutions of a prefabricated monolithic frame without crossbars.

The technical and economic indicators of the system are characterized by a somewhat lower consumption of metal than frame-panel systems for the same cell parameters, but by a higher consumption of concrete and significant construction labor intensity.

The structural system of the building is a set of interconnected load-bearing structures of the building, ensuring its strength, spatial rigidity and reliability in operation. The choice of the structural system of a building determines the static role of each of its structures. The material of structures and the technique of their construction are determined when choosing the building system of the building.

The load-bearing structures of a building consist of interconnected vertical and horizontal elements.

Horizontal load-bearing structures - perceive all the vertical loads falling on them and transfer them floor-by-floor to vertical load-bearing structures (walls, columns). Vertical structures, in turn, transfer the load to the foundation of the building.

Since antiquity, floor systems have been designed from a stereotypical approach to the layout of a beam cage, i.e. consisted of beams (crossbars) and flooring, so wooden floors are also constructively solved. Then there are reinforced concrete ribbed floor slabs, in which this approach is already merged into one structural element. The flat hollow core slabs that appeared later are a significant step in the design of new types of building systems.

In industrial residential buildings, compared with traditional structures that had mixed coatings, including fragments of wooden floors, horizontal load-bearing structures for the first time begin to play the role stiffness diaphragms In addition, floors perceive horizontal loads and impacts (wind, seismic, etc.) and transfer forces from these impacts to vertical structures.

The transfer of horizontal loads and impacts is carried out in two ways: either with their distribution to all vertical structures of the building, or to individual special vertical stiffeners (walls, stiffening diaphragms, lattice wind braces or stiffeners). The industrial type of buildings also provides intermediate solutions - load transfer is possible with the distribution of horizontal loads in various proportions between stiffeners and structures that work to absorb vertical loads.

Ceilings - stiffening diaphragms ensure the compatibility of horizontal movements of vertical load-bearing structures from wind and seismic effects. The possibility of compatibility and alignment of movements is achieved by rigid coupling of horizontal load-bearing structures with vertical ones.

As noted earlier, with a reduction in the construction volume of buildings, the horizontal load-bearing structures of residential buildings with a height of more than two floors, in accordance with the requirements of fire safety standards, are made difficult to combust or fireproof. These requirements, as well as the requirements of the economic stratum, are most fully met by reinforced concrete structures, which determined their mass use as horizontal load-bearing elements of all types of buildings. Overlappings are usually a reinforced concrete slab - prefabricated, prefabricated-monolithic or monolithic.

Vertical load-bearing structures are distinguished by the type of structures, which serves as a defining feature for the classification of structural systems. On the rice. 2 the main typological features of a residential building are given, the vertical load-bearing structures of which are continuous the vertical plane of the walls. When using columns as the main vertical load-bearing structural elements, already at the first stage of industrialization, it was possible to obtain four structural schemes of a serial residential building: with a transverse arrangement of crossbars; with a longitudinal arrangement of crossbars; with a cross arrangement of crossbars; a no-brainer solution.

Industrialization made it possible not only to look at the work of floors from a new point of view, but also to significantly expand the typology of vertical load-bearing structures. With the development of serial housing construction, the following types of vertical load-bearing structures are distinguished by separate groups:

planar (walls);

solid section rods (frame racks);

volume-spatial (volumetric blocks);

volumetric-spatial internal load-bearing structures to the height of buildings in the form of thin-walled rods of an open or closed profile (stiffeners). The stiffening shaft is usually located in the central part of the building; elevator, ventilation shafts and other communications are placed in the internal space of the shaft. In long buildings, several stiffeners are provided;

volume-spatial external load-bearing structures to the height of the building in the form of a thin-walled shell of a closed profile, which simultaneously forms the outer building envelope. Depending on the architectural solution, the outer load-bearing shell may have a prismatic, cylindrical, pyramidal or other shape.

According to the types of vertical load-bearing structures, five main structural systems of buildings are distinguished: frame, frameless (wall), volume-block, trunk and shell, otherwise called peripheral

The choice of vertical load-bearing structures, the nature of the distribution of horizontal loads and effects between them is one of the main issues in the layout of a structural system. It also influences the planning decision, architectural composition and economic feasibility of the project. In turn, the choice of the system is influenced by the typological features of the building being designed, its number of storeys and engineering and geological conditions of construction.

The frame system with a spatial frame frame is mainly used in the construction of multi-storey earthquake-resistant buildings with a height of more than nine floors, as well as in normal construction conditions in the presence of an appropriate production base. The frame system is the main one in the construction of public and industrial buildings. In housing construction, the volume of its application is limited not only for economic reasons. The basis of fire safety requirements in the design of residential buildings is the consistent creation of vertical fire barriers - firewalls. In a frame-type structure, the creation of firewalls was carried out by embedding fireproof vertical stiffening diaphragms between the columns. Thus, the possibilities of spatial planning, the main advantage of frame systems, were limited in advance.

The frameless system is the most common in residential construction; it is used in buildings of various planning types with a height of one to 30 floors.

The volumetric-block system of buildings in the form of a group of individual bearing pillars of volumetric blocks installed on top of each other was used for residential buildings up to 12 floors high in normal and difficult soil conditions. The pillars were connected to each other by flexible or rigid connections.

The trunk system is used in buildings with a height of more than 16 floors. It is most expedient to use the trunk system for multi-storey buildings that are compact in plan, especially in earthquake-resistant construction, as well as in conditions of uneven base deformations (on subsiding soils, above mine workings, etc.).

The shell system is inherent in unique high-rise buildings for residential, administrative or multifunctional purposes.

Along with the main structural systems, combined systems are widely used, in which vertical supporting structures are assembled from various elements - rod and planar, rod and barrel, etc.

Partial framing system based on a combination of load-bearing walls and a framing supporting all vertical and horizontal loads. The system was used in two versions: with load-bearing outer walls and an inner frame, or with an outer frame and inner walls. The first option was used with increased requirements for freedom of planning decisions of the building, the second - with the expediency of using non-load-bearing lightweight structures of the outer walls and in the design of buildings of medium and high storeys.

The frame-diaphragm system is based on the division of static functions between wall (coupling) and rod elements of load-bearing structures. All or most of the horizontal loads and impacts are transferred to the wall elements (vertical stiffening diaphragms), and mainly vertical loads are transferred to the rod (framework). The system has been most widely used in the construction of multi-storey frame-panel residential buildings under normal conditions and in earthquake-resistant construction.

The frame-barrel system is based on the division of static functions between the frame, which perceives vertical loads, and the shaft, which perceives horizontal loads and impacts. It was used in the design of high-rise residential buildings.

The frame-block system is based on a combination of a frame and three-dimensional blocks, the latter being used in the system as non-bearing or load-bearing structures. Non-bearing three-dimensional blocks are used for floor-by-floor filling of the frame's load-bearing lattice. The carriers are installed each other in three to five tiers on horizontal carrier platforms (ceilings) of the frame, located in increments of three to five floors. The system was used in buildings above 12 floors.

The block-wall (block-panel) system is based on a combination of load-bearing columns made of three-dimensional blocks and load-bearing walls, floor-by-floor connected to each other by floor disks. It was used in residential buildings up to 9 floors in normal soil conditions.

The shaft-wall system combines load-bearing walls and a shaft with the distribution of vertical and horizontal loads between these elements in various ratios. It was used in the design of buildings above 16 floors.

The shaft-shell system includes an outer load-bearing shell and a load-bearing shaft inside the building, working together to absorb vertical and horizontal loads. Consistency of movements of the shaft and shell is ensured by horizontal load-bearing structures of individual grillage floors located along the height of the building. The system was used in the design of high-rise buildings.

The frame-shell system combines the outer load-bearing shell of the building with the inner frame when the shell works for all types of loads and impacts, and the frame - mainly for vertical loads. The compatibility of horizontal displacements of the shell and frame is ensured in the same way as in buildings of the shell-barrel system. Used in the design of high-rise buildings.

The concept of "constructive system" is a generalized constructive-static characteristic of a building, independent of the material from which it is being built and the method of construction. For example, on the basis of a frameless structural system, a building with chopped wooden, brick, concrete (large-block, panel or monolithic) walls could be designed.

In turn, the frame system can be implemented in wooden, steel or reinforced concrete structures. Variants also arose when using various materials for filling cells formed by load-bearing elements in frame or shaft buildings. For this purpose, any elements were used - from small-sized to volume-block.

The bearing part of the shell building can be a diagonal or non-braced spatial steel truss, a monolithic reinforced concrete shell with regularly spaced openings, a prefabricated monolithic reinforced concrete lattice, and so on. Combined structural systems were also multivariate. The areas and scales of application in the construction of individual structural systems were determined by the purpose of the building and its number of storeys.

Along with the basic and combined systems, mixed structural systems are used in design, in which two or more structural systems are combined in height or length of the building. This decision is usually dictated by functional requirements. For example, if it was required to perform a transition from a frameless system in the upper typical floors to a frame system on the first floors, i.e. if necessary, the device of a fine-mesh planning structure of standard floors above the hall planning structure in non-standard ones. Most often, this need arises when arranging large stores on the first floors of residential buildings.

The structural scheme is a variant of the structural system according to the characteristics of the composition and type of placement in space of the main load-bearing structures, for example, in the longitudinal or transverse directions. The structural scheme, as well as the system, is chosen at the initial stage of design, taking into account space-planning design and technological requirements. In residential frame buildings, four structural schemes are used: with transverse or longitudinal crossbars, cross-bar arrangement and without crossbars.

When choosing a constructive frame scheme, economic and architectural requirements are taken into account: frame elements should not bind the planning solution; frame crossbars should not cross the ceiling surface in living rooms, etc. Therefore, a frame with a transverse arrangement of crossbars is used in multi-storey buildings with a regular planning structure (mainly hostels and hotels), combining the step of the transverse partitions with the step of the supporting structures. A frame with a longitudinal arrangement of crossbars was used in residential buildings apartment type.

A girderless (beamless) frame in residential buildings was used only in the absence of an appropriate production base and large house-building factories in a particular region, since for prefabricated housing construction such a scheme is the least reliable and most expensive. The beamless frame was mainly used in the manufacture of monolithic and precast-monolithic structures of the building by raising the floors.

The building system is a complex characteristic constructive solution buildings according to the material and technology of erection of the main load-bearing structures.

Building systems for buildings with load-bearing walls made of bricks and small blocks of ceramics, lightweight concrete or natural stone are traditional and prefabricated.

The traditional system is based on the construction of walls using hand-masonry techniques, as was done in all traditional buildings since ancient times. It should be noted that in an industrial building, only enclosing structures, ceilings and other internal load-bearing structures remain traditional - they are completely identical to prefabricated structures.

The prefabricated system is based on the mechanized installation of walls from large blocks or panels, made in the factory from brick, stone or ceramic blocks. With the introduction of new housing series, the large-block system almost everywhere gives way to the panel one.

The traditional system (with wooden floors), which for a long time was considered the main type of a capital civil building of medium and high storeys, is a thing of the past. As it has been repeatedly emphasized, "traditional" buildings were called according to the fire scenario. Only for the convenience of classifying the huge variety of industrial structures, traditional buildings stand out in them, only in appearance resembling the former brick structures built before the end of the 50s.

By the mid-80s of the last century, based on the application traditional system building envelopes, about 30% of the volume of residential construction and 80% of mass public buildings were erected. Of course, the level of industrialization of building structures of the "traditional" building system as a whole is quite high due to the massive use of large-sized prefabricated products of ceilings, stairs, partitions, and foundations.

The industrial traditional system had significant architectural advantages. Due to the small size of the main structural element of the wall (brick, stone), this system allows you to design buildings of any shape with different floor heights and openings of various sizes and shapes.

The use of the traditional system was considered the most appropriate for buildings that dominate the development. Building structures with hand-made walls are reliable in operation - high-tech firing brick did not require the installation of busy, short-lived plaster in operation, the fire resistance of industrial brick walls was significantly increased. When designing them, new approaches were used to ensure durability and heat resistance.

Along with the architectural and operational advantages, manual laying of walls is the cause of the main technical and economic disadvantages of stone buildings: the complexity of erection and the instability of the strength characteristics of the masonry, depending on different batches of bricks, in case of minor deviations in technological process in brick factories. The quality and strength of the masonry depended on the season of construction and the skill of the mason.

The large-block construction system was used for the construction of residential buildings up to 22 floors high. The mass of prefabricated elements was 3-5 tons. The installation of large blocks was carried out according to the basic principle of erecting stone walls - in horizontal rows, on mortar, with mutual dressing of the seams.

The advantages of a large-block building system are: the simplicity of the construction technique, due to the self-sustainability of the blocks during installation, the possibility of a wide imputation of the system in conditions of a different raw material base. A flexible block nomenclature system made it possible to build various types of residential buildings with a limited number of standard sizes of products. This system required less capital investment in the production base compared to panel and block housing construction due to the simplicity and lower metal consumption of the molding equipment, and the limited mass of prefabricated products made it possible to use common low-capacity assembly equipment.

The creation of a large-block building system was the first stage in the mass industrialization of building structures with concrete walls. The large-block system, compared to the traditional stone system, reduced labor costs by 10% and construction time by 15-20%. As the more industrial panel system is introduced, the use of the large-panel system is gradually decreasing. By the mid-70s of the last century, the large-block system in mass housing construction occupies the third place in terms of application volume after panel and traditional stone systems.

The panel building system is used in the design of buildings up to 30 floors in normal soil conditions and up to 14 floors in seismic areas. The introduction of the panel system into housing construction began in the late 1940s simultaneously in the USSR and France. In 1967, GOST 11309-65, developed by the USSR State Construction Committee, came into effect for all types of large-panel houses, which defines all the requirements for their quality, joint arrangement and the degree of accuracy in the production and installation of products.

The walls of such buildings are assembled from concrete panels a floor high, weighing up to 10 tons and 1-3 structural and planning steps long.

The technical advantage of panel structures is their significant strength and rigidity. This determined the widespread use of panel structures for high-rise buildings in difficult soil conditions (on subsidence and permafrost soils, above mine workings). For the same reason, panel structures exhibit greater seismic resistance compared to other building systems.

In other economic developed countries the volume of panel construction is also growing rapidly, which is explained by the high economic efficiency building system. However, it should be noted that by the beginning of the 80s no country had such a powerful industrial base for the construction industry, and by the mid-80s most Western countries were affected by a serious economic crisis.

The frame-panel building system with a load-bearing prefabricated reinforced concrete frame and external walls made of concrete or non-concrete panels is used in the construction of buildings up to 30 floors high. Introduced in the USSR along with the panel at the end of the 1940s, until the beginning of the 90s, about 15% of the volume of public buildings were erected on its basis annually. In housing construction, the system was used to a limited extent, since it was inferior to the panel one in terms of technical and economic indicators.

The volume-block building system was also first introduced by Soviet builders. Volumetric-block buildings are erected from large volumetric-spatial reinforced concrete elements weighing up to 25 tons, containing a living room or another fragment of the building. Volumetric blocks, as a rule, were installed on top of each other without dressing the seams.

Volumetric-block construction can significantly reduce the total labor costs in construction (by 12-15% compared to panel construction) and obtain a progressive structure of these costs. If in panel construction the ratio of labor costs at the factory and the construction site is on average 50 to 50%, then in volume-block construction it approaches from 80% of factory production to 20% of labor costs at the construction site. Due to the complexity of the technological equipment, capital investments in the creation of volume-block housing construction plants are 15% higher compared to panel housing construction plants.

The volume-block system is used for the construction of residential buildings up to 16 floors high in normal and difficult soil conditions and for residential buildings of low and medium-rise buildings with a seismicity of 7-8 points. The most effective volume-block housing construction with a significant concentration of construction, the need for its implementation in a short time, with a shortage of labor.