Space frame construction process quality control points (installation points of attention)

1.Quality control before construction

Rods and bolts and balls and other materials into the field, must check the quality of materials and factory certificate of conformity, and according to the requirements of the design drawings for the appearance of the quality, type specifications, signs and marking and transportation damage scratches and other serious acceptance. According to the provisions of the rod, bolt ball, welding materials and welding with a certain number of steel plate sampling for inspection batch re-inspection. The surface of bolts, rods and steel components should be treated by sand blasting to remove rust, clean the surface of rust, dirt, paint, oxides, corrosion and other substances, and then painted, painted with two primers and two top coats, and the painting must meet the requirements of the design drawings. Bolt balls, rods and steel components are tested by instruments for film thickness and recorded after entering the site, and can be used only after meeting the design. Before the construction, the technicians will carry out technical briefing according to the drawings, construction program and corresponding specification requirements, and according to the installation drawings, the bolts and balls and rods that need to be assembled will be classified and screened according to the number, and the number of rods must correspond to the drawings when installing, and the size of rods will be checked. Before the installation of steel space frame, review the axis of foundation column and pop up control line at the position of embedded parts on the top of the column, check whether the elevation of embedded parts is consistent with the drawings, determine the accurate position of the base of steel space frame on the top of foundation column, and correct the embedded parts that do not meet the accuracy requirements.

2.Quality control of assembling

The assembling precision of the rods affects whether the overall space frame can be accurately and smoothly completed, so the quality of rod assembling is especially important. Rod assembly must be installed correctly according to the installation drawings, space frame rod number, bolt ball number should be one-to-one correspondence with the drawings, and must not be mixed, otherwise it will result in not being able to close the situation. If found assembled space frame rod error, should stop the installation in time, and the installation of the wrong rod removed to replace the correct rod. High-strength bolts should be fully tightened in place during the assembly process of rods and bolt balls, and there shall be no loosening. After the installation of the small unit space frame is completed, it is necessary to do the corresponding check to prevent the accumulation of errors and retighten the loose bolts to ensure the quality of installation.

3.Lifting, docking quality acceptance points

Starting space frame lifting, docking is completed to carry out quality acceptance, acceptance of key points are as follows: ① installers in the space frame docking is completed, must check whether all the bolts are screwed into the checking method: will continue to tighten the top wire, can be screwed into the indication of high-strength bolts have been screwed into the high-tension bolt, such as the top wire can not be screwed into the high-strength bolts, it should continue to tighten the high-strength bolts. ② Each small unit should be used after the completion of docking latitude and longitude to check the axis deviation, axis deviation should be re-adjusted to ensure that each unit to meet the requirements, to avoid cumulative deviation caused by the subsequent rework of large areas. ③After material checking, all the components in the docking position should be preassembled to ensure that all the bolts can be completely tightened. When the pre-installed buttresses are lifted together with the structure, unloading measures should be taken to prevent the bolts from being subjected to bending stress. ④ Deflection test shall be carried out in the process of assembling, before lifting and after installation to ensure that the deflection of the steel Space frame is within the design range before the next step of installation. ⑤ After the docking is completed, the quality inspection personnel will check the quality of docking, and the crane will be released only after it is qualified, and the lifting work will be completed.

4.Quality control after installation

After the installation of Space frame is completed, the length deviation in longitudinal and transverse direction, height deviation and deflection value of steel space frame should be measured. Longitudinal and transverse length deviation is not more than 1/2000, and not more than 30mm, support center displacement deviation is not more than 1/3000, and should not be more than 30mm, adjacent support height difference is not more than 15mm, the highest point and the lowest point of the support height difference is not more than 30mm. and the overall deflection value of the Space frame to determine the measured deflection value shall not exceed the design of the 1.15 times, the deflection observation point should be in accordance with the requirements of the specification. The deflection observation point should be arranged according to the specification requirements, and the measured deflection curve should be archived and preserved.