Construction quality control of space frame assembly and hoisting

(1) In order to ensure that the space frame construction is correct, pre-assembly should be carried out. During pre-assembly, the site should be leveled and compacted, and the stake should be accurately set out (a shelf platform should be set up for high-altitude assembly, and the stake should be set out on the platform). The position of the pressure rod is wrong. When assembling, generally assemble the lower chord first, after correcting the elevation and axis of the lower chord, after all bolts are tightened and positioned, connect the web rod, and then assemble the chord; when connecting the ball and the rod, a special wrench should be used to properly tighten the bolts, but It should be prevented that it is too tight or too loose, which will cause accumulated errors and generate residual stress in the assembly.

(2) General assembly of the steel space frame. After the space frame is assembled as a whole, a comprehensive inspection must be carried out to check whether the bolts are tightened, carefully review each node and member, measure the allowable deviation value of each node and member, and whether the member is deformed and whether the deflection meets the design requirements, and keep records. Where the overall assembly of the ground is used, it should be hoisted into place only after the review is accurate.

(3) Hoisting and installation of steel space frame. The fixed position of each lifting point should be correct, firm and reliable, and the distance from the lifting point to the top surface of the embedded part of the support should be measured to determine the lifting height. When using synchronous hydraulic jacks for lifting, the accurate lifting height of each boom should be calculated, the rising rate of each lifting point should be determined, and the lifting should be balanced slowly; The hanging point penetration method is adopted, and the speed is adjusted by the pulley block. Prevent the problem of unbalanced rising speed of diagonal lifting points or single-point lifting points, resulting in uneven local stress in the hoisting of the frame, resulting in stress redistribution.

(4) Handling of the steel space frame in place. After the hoisting is in place, the support plate and the embedded parts should be welded or bolted firmly. When there is an oblique gap between the embedded part of the support and the flatness of the support plate, the wedge-shaped steel sheet plug should be used tightly, and then welded or bolted to fix it. The form of the support must meet the design requirements.

(5) Comprehensively review the steel space frame. After fixing in place, measure the allowable deviation and deflection value of each rod again, and check whether each rod is deformed. Keep records for reference in the design review