SU1622545A1 - Ferroconcrete roof - Google Patents

Abstract

The invention relates to building structures. The purpose of the invention is to increase the carrying capacity by enhancing the effect of spatial work when used in hip hyp ceilings. The overlap includes central plates, contour elements I of the T-section, supported on columns 3 and prestressed reinforcement arranged along the axes of the supports for the entire length and width of the building. This is achieved by performing in the walls of the contour elements of longitudinal discontinuous channels 4 having through holes 6 in the interrupting channels edges. Reinforcement is passed through the last and holes in the columns, and the grooves are embedded. Contour elements can be made in the form of annular plates with cantilever trapezoidal in plan shelves of variable thickness increasing to wall 6 or

Description

6-6

(/

WITH

ig /; /

-ShCHGz

The invention relates to building structures and can be used for floors in industrial and civil buildings.

The purpose of the invention is to increase the carrying capacity by increasing the effect of spatial overlap work when used in tent-type floors.

Fig 1 shows an overlap, plan view; in fig. 2 shows section A-A in FIG. one; On fig 3 - section BB in FIG. one; in fig. 4, node I in FIG. one; in fig. 5 shows section B - B in FIG. four; in fig. 6 is a diagram of the interface unit of the contour elements with the column.

The overlap includes prefab slabs consisting of T-shaped contour elements 1 and a central plate 2. Contour elements 1 are supported on columns 3 In the walls of the contour elements 1 longitudinal channels 4 are made, in which reinforcement 5 is placed across the entire length and width of the building Armature 5 is passed through openings 6 formed in the ribs and columns interrupting the channels. After tensioning the reinforcement 5, the grooves 4 and the aperture 6 are monolithic.

With a sufficient level of reduction of the overlap by the tension of the reinforcement 5 along the planes of the abutment of the contour elements 1 to the columns 3, frictional forces arise, significantly exceeding in size the vertical support reactions of the overlap. This makes it possible, similarly to the well-known constructive solution using the same principle, to exclude consoles of columns as a structural element. In order to ensure the reliability of the joint on the mating surfaces of the contour elements 1 and columns 3, keyed slots 7 can be made filled with concrete when monolithing the joints of prefabricated elements.

The installation of the ceiling is carried out in the following sequence.

Contour elements 1 are installed on temporary support tables on columns 3. Central plates are mounted in openings between contour elements I with support on the latter. Laying and tension are made on the reinforcement concrete 5. Channels 4 and seams between prefabricated elements are embedded. After a set of fie rumble monolithing the required strength, the temporary support tables on the columns can be removed.

The contour element 1 with a length of span is made, for example, in the form of an annular plate with cantilever shelves on one or both sides of the rib. For matching the annular plates between themselves and with the central plates, the 2 shelves of annular plates have a trapezoidal shape in plan.

In order to carry out the overlap in order to involve all the overlap elements in the joint spatial work, the shelves have a variable section height, decreasing with distance from the edge of the annular plate and equal in place to the edge not less

half its height. The change in the height of the section of the shelves can be either linear or non-linear or stepwise. The interface of the plates 2 with the shelves of the annular plates can be arranged both in one and in different levels. The upper surface of the shelves can be non-horizontal with a slope to the edge in order to organize the construction of the cell overlap. The central plates 2 can be flat, ribbed or vaporized (step-blown) with the transfer of thrust to the shelves of annular plates and, in addition, can be assembled from several mounting elements. The operation of the structure under the action of a vertical load is characterized as follows.

The reinforcement 5 within each cell of the building forms a contour closed around the perimeter of the cell, the center of gravity of which vertically is substantially below the level of the middle surface of the floor of the plates 2.

0 This, provided that the transfer of forces from the floor of the plates 2 to the contour element 1 is ensured, the occurrence of a thrust force in a closed contour is determined, which, with a sufficient cross section of the reinforcement 5, can be completely perceived by it. Broadcast

The forces on the rib of the annular plate and the reinforcement 5 contained therein is carried out through the shelves of the plate, which have a variable thickness increasing towards the rib. Such an outline of the lower surface of the structure (punctured) provides a stressful state characterized by small values of bending moments. The presence of reinforcement 5 capable of performing the tightening function determines the spatial nature of the work.

5 design, what caused the effective use of the strength properties of materials.

In the proposed construction, the dimensions of the overlapped cell are not related to the width of the annular plate, since the position of the junction along the contour of the plates 2 along the span is not significant due to a different principle of work to overlap under load. An overlapped cell can be either square or direct coal with a ratio of side lengths of up to 1.7. Since the reinforcement 5 passes along the axis of the columns 3 over the entire length and width of the building, then after embedding the seams and pa

Call 4 contour elements 1 together with the columns of the framework form a multi-span spatial system. The indeterminacy of the junction points of the contour elements I with columns 3 in combination with the rigidity of the spatial structure of the overlap, as well as an increase in the rigidity of the compression of the whole disc of the overlap during tension of the reinforcement 5, allows to achieve high seismic resistance of the overlap of the frame as a whole.

To implement rational reinforcement of the contour elements 1, the reinforcement part 5 smoothly changes its position along the section height of the contour elements 1 in accordance with the plots of bending moments arising in the contour element 1 as a continuous crossbar of the frame frame. Thus, in the support zones of the contour elements 1, part of the reinforcement 5 is retracted to the upper surface of the structure for perception in the reference sections of the moments of the negative sign.

Due to the fact that the reinforcement 5 is passed through specially provided holes in the columns 3, the design of the interfacing node with the column 3 is simplified and there is no need for welding work on the installation, which significantly reduces the labor intensity of installation

The proposed shape of the contour element 1 in the form of an annular plate with cantilever shelves makes it possible to easily solve the design of the facade contour element with the exception of one of the shelves in the manufacture of the annular front plate in opo

splint of the series annular plate. The installation of the front annular slab can also be carried out without the use of intermediate mounting supports, provided that it is supported on previously mounted adjacent row annular plates.

The use of the invention allows to expand the scope of application of spatial structures in prefabricated floors of frame buildings, including with enlarged grid of columns and in areas of high seismicity.

Claims (1)

Invention Formula Reinforced concrete slab, including prefabricated slabs, placed in a stack with columns by increasing the effect of spatial work overlap when used in tent-type overlaps, prefabricated plates with prestressed reinforcement are made of a T-section with a decrease in the thickness of the shelves and intermittent channels are formed in the wall of the T-shaped plate and have a depth exceeding the thickness of the shelf, while 0, the overlap is made with additionally linear fittings placed along the bottom of the channel in the same vertical plane with the corresponding bent reinforcement. / 0 l t ZTird, FIG. g Figm AT 6 FIG. five