CN200964645Y - Large span large cantilever roof oblique-pulling type double-layer prestress steel grid roof - Google Patents

Abstract

The utility model discloses a cable-stayed double-layer prestressed steel grid frame roof with a large span and large overhang roof, which comprises a double-layer steel grid frame (1), which is on the upper chord node of the support of the steel grid frame (1). A support frame (2) is provided, a fixed pulley (3) is provided on the top of the support frame (2), a force transmission device (5) is provided on the lower chord node in the middle of the steel grid frame (1), and the prestressed steel cable After the two ends of (4) pass through the fixed pulley (3) and the force transmission device (5), they are respectively fixed on the lower chord nodes of the large overhanging grid of the steel grid (1); 100m≤L<160m) and a roof structure with a double-layer space grid structure with large overhangs, which can not only greatly improve the overall rigidity of the steel grid, but also effectively reduce the amount of steel used and the construction cost.

Description

Long-span and large overhang roof cable-stayed double-layer prestressed steel grid roof

Technical field:

The utility model relates to a roof, in particular to a large-span (100m≤L≤160m) large cantilever (L≥12m) roof cable-stayed double-layer prestressed steel grid roof.

Background technique:

For large buildings with large spans (100m≤L≤160m) and large overhangs (L≥12m), when the roof is designed as a flat roof, due to the large span, if a general flat steel grid is used, the height of the grid is relatively high. The length of the diagonal web bars of the grid frame is too long, resulting in an increase in steel consumption; in order to reduce the steel consumption, at present, three-layer steel grid frames are generally used for large-scale building roofs with large spans and large overhangs to reduce the amount of diagonal webs. However, one layer of the three-layer steel grid is in the neutral layer of the structure, which contributes almost zero to the bending stiffness of the structure, and the increase of the grid members and nodes of the neutral layer is about 1/3 of that of the double-layer grid. It uses a large amount of steel, which has been proved by engineering practice.

Invention content:

The purpose of this utility model is to provide a cable-stayed roof with large span and large cantilever, which can not only reduce the amount of steel used, but also reduce the cost of the project, and can make the roof of the large-span and large-cantilever steel grid frame possible. The double-layer prestressed steel mesh frame roof is used to solve the problems existing in the prior art.

The utility model is constituted as follows: it includes a double-layer steel grid frame, a supporting frame is arranged on the supporting upper chord node of the steel grid frame, a fixed pulley is arranged on the top of the supporting frame, and a fixed pulley is arranged on the middle lower chord node of the steel grid frame. There is a force transmission device, and the two ends of the prestressed steel cable pass through the fixed pulley and the force transmission device, and are respectively fixed on the lower chord nodes of the large cantilevered grid of the steel grid.

The prestressed steel cables are arranged orthogonally in pairs in the steel grid body, the distance between the prestressed steel cables in one direction is 1 to 2 grids, and the distance between the prestressed steel cables in the other direction The spacing is 3 to 4 grids.

The steel grid frame is composed of square pyramids placed upright.

The force transmission device is composed of a steel box, a fixed pulley installed in the steel box and a tie rod fixed at the bottom of the steel box. The other end of the tie rod is fixed at the center of the four oblique web bars of the lower chord ball node of the quadrangular cone.

The force transmission devices in the two orthogonal directions are of the same height, and the horizontal sections of the prestressed steel cables in the two orthogonal directions do not collide or engage.

The utility model is specially aimed at the roof structure of a double-layer space grid structure with a large span (100m≤L<160m) and a large overhang. Compared with the prior art, it can not only greatly improve the overall rigidity of the steel grid , and can effectively reduce the amount of steel used and reduce the cost of the project.

Description of drawings:

Accompanying drawing 1 is the planar structural representation of the utility model;

Accompanying drawing 2 is A-A sectional view of accompanying drawing 1;

Accompanying drawing 3 is the B-B sectional view of accompanying drawing 1;

Accompanying drawing 4 is the structure diagram of the force transmission device of the present utility model.

Detailed ways:

Embodiment of the present utility model: as shown in accompanying drawing 1, it comprises the double-deck plate type steel network frame 1 that is formed by the quadrangular pyramid connection that puts upright, is provided with support frame 2 on the supporting upper chord node of steel network frame 1, supports The height of the frame 2 needs to be determined after calculation according to the prestressed size of the steel cables of the steel grid frame 1; fixed pulleys 3 are arranged on the top of the support frame 2; Each force transmission device 5 is composed of a steel box 6, a fixed pulley 7 installed in the steel box 6, and a pull rod 8 fixed at the bottom of the steel box 6. The other end of the pull rod 8 is fixed on the lower string ball of the square cone. The center of the four diagonal bars of the node (as shown in Figure 4). Two prestressed steel cables 4 are arranged orthogonally in the steel grid frame 1. The distance between the two prestressed steel cables 4 perpendicular to the span direction is 1 to 2 grids, and the two prestressed steel cables 4 in the other span direction The distance between the steel cables 4 is 3 to 4 grids, and each prestressed steel cable 4 passes through the fixed pulley 3 and the fixed pulley 7 of the force transmission device 5, and the two ends are fixed on the large cantilever net of the steel grid frame 1 On the lower chord node of the frame, the prestressed steel cable 4 at the force transmission device 5 turns to be a horizontal section. The force transmission devices 5 in the two orthogonal directions are of the same height, and the horizontal sections of the prestressed steel cables 4 in the two orthogonal directions do not collide or engage.

In the utility model, the support frame 2 is arranged at the supporting upper chord node of the steel grid frame 1, so that the angle between the horizontal section of the prestressed steel cable 4 and the inclined line section is multiplied, and the force transmission device 5 acts on the steel grid frame 1. doubled, the effect of prestress is obvious, and the prestressed steel cable 4 is anchored outward to the lower chord node of the large cantilever. The component force can improve the force bearing effect of the large overhang, and in the prestressed "formed state", the internal force of each member of the steel grid 1 is mostly opposite to the internal force of each rod of the "loaded state" steel grid 1, which can be greatly improved. Reduce the internal force of each rod of the steel grid 1, reduce the amount of steel used, and increase the structural rigidity.

In the utility model, the anchor point of the large cantilever lower chord node of the force transmission device 5 and the prestressed steel cable 4 is equivalent to the elastic support point of the steel grid 1 at this position, which can greatly improve the overall rigidity of the steel grid 1, so that The height of the double-layer steel grid frame 1 is 25-35% lower than that of the conventional steel grid frame, which effectively saves the building height and reduces the amount of steel used. When the utility model establishes the prestress, it is realized by setting the oblique cable parts on both sides of the support frame 2, just like the positive and negative threaded "screw tensioners" used by the electric power department to tension the cables, and determine the rotation through calculation. After the number of turns, the tensile force of the cable is obtained.

Claims (5)

1. large-span large-cantilever roofing cable-stayed type double-layer prestressed steel grid roof, it comprises clad steel rack (1), it is characterized in that: the bearing of steel mesh frame (1) node that winds up is provided with bracing frame (2), the top of bracing frame (2) is provided with fixed pulley (3), the middle part lower-chord panel point of steel mesh frame (1) is provided with load transfer device (5), after fixed pulley (3) and load transfer device (5) are passed in the two ends of prestressed cable (4), be separately fixed on the lower-chord panel point of the rack of encorbelmenting greatly of steel mesh frame (1).

2. large-span large-cantilever roofing cable-stayed type double-layer prestressed steel grid roof according to claim 1, it is characterized in that: prestressed cable (4) pairwise orthogonal is arranged in steel mesh frame (1) body, spacing between the prestressed cable of one of them direction (4) is 1～2 grid, and the spacing between the prestressed cable of another direction of quadrature (4) is 3～4 grids with it.

3. large-span large-cantilever roofing cable-stayed type double-layer prestressed steel grid roof according to claim 1 is characterized in that: steel mesh frame (1) is connected and composed by the quadrangular pyramid of just putting.

4. large-span large-cantilever roofing cable-stayed type double-layer prestressed steel grid roof according to claim 1, it is characterized in that: load transfer device (5) by steel case (6), be contained in the fixed pulley (7) in the steel case (6) and be fixed on pull bar (8) formation of steel case (6) bottom, the other end of pull bar (8) is fixed on the central authorities of four diagonal web members of quadrangular pyramid lower edge ball node.

5. large-span large-cantilever roofing cable-stayed type double-layer prestressed steel grid roof according to claim 1 and 2, it is characterized in that: the load transfer device of two orthogonal directions (5) is contour, and the horizontal segment of the prestressed cable of two orthogonal directions (4) is not collided, not interlock.

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