Extra-large-span cross-section-variable pre-stressed normally placed evacuating quadrangular pyramid space grid and manufacturing method thereof

Abstract

The invention discloses an extra-large-span cross-section-variable pre-stressed normally placed evacuating quadrangular pyramid space grid and a manufacturing method thereof, wherein pre-stressed space trusses (2) are arranged at about 1 / 3 parts of two sides of a normally placed evacuating cross-section-variable bi-layer grid (1) along an x direction and a y direction, and the bottom chord of each pre-stressed space truss (2) is provided with a steel cable steering support rack (5); the upper end of a support node (6) of each pre-stressed space truss (2) is provided with a steel cable supportsteel frame (7), and the outer side of the upper part of a frame column (3) is provided with a horizontal stay bar (8); and one end of the pre-stressed steel cable (4) slopes downwards to the span centre around the top end of the steel cable support steel frame (7) and the other end of the pre-stressed steel cable (4) is fixed on the lower part of the frame column (3) after bypassing a fixed pulley on the end part of the horizontal stay bar (8). The extra-large-span cross-section-variable pre-stressed normally placed evacuating quadrangular pyramid space grid disclosed by the invention is applied to square or rectangular extra-large-span (L is greater than or equal to 120m and smaller than or equal to 180m) roofs and has the advantages of low steel consumption, simple structure, low manufacturing and installing cost, excellent mechanical property, and the like.

Description

technical field [0001] The invention relates to a steel grid roof structure, in particular to a super-large-span (120m≦L≦180m) variable-section prestressed positive-release evacuated quadrangular pyramid grid structure and a manufacturing method thereof, belonging to the technical field of building steel structures. Background technique [0002] It has been more than 40 years since the flat-plate steel grid was introduced from abroad in 1965. Because of its three-dimensional space force, factory manufacturing, on-site installation, simple process, and less steel consumption, it is widely used in single-storey industrial plants and public building roofs. up to tens of millions of square meters. However, the span (18m-60m) accounts for more than 90%, and there are as many as 13 types of grid structures. No matter which form, they have a common feature that the planes of the upper chord grid layer and the lower chord grid layer are parallel to each other. (equal height), the s...

AI Technical Summary

Problems solved by technology

[0003]There are as many as thirteen kinds of traditional flat steel grid structures. The rigidity of the quadrangular pyramid grid is the best, and it is the most widely used when the span is between 18m and 60m. When the span is greater than 60m, it is commonly known as a super-large span, especially for square or rectangular flat roofs with a span of 120m to 180m. The conventional practice is to use three layers. , consisting of two quadrangular pyramids at the center of the height of the grid. When the span is 155m×155m, the structural height reaches 12m. When the roof drainage slope i=0.07, the maximum column height reaches 5.45m. The height of the whole structure reaches 17.65m. Like a six-story residential building, the roof structure accounts for 51% of the total volume of the building. In addition to doubling the building’s surrounding enclosure materials, the power of the indoor air conditioner must be more than doubled. The amount of steel is large, the cost is high, and it is extremely unfavorable to the "energy saving and emission reduction" of the building

It is difficult for the existing technology to meet the design requirements of "safety, rationality, advancedness and economy" for the super-long-span rigid grid structure

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