General structure construction technology of space frame bolt ball

1. Production of hollow steel balls and steel pipe rods

In order to ensure the installation and quality of space frame and space frame bolt ball processing, all hollow steel ball nodes and steel pipe rods are processed centrally in the factory. The steel ball is processed by tire film, and the raw material is No. 45 steel. The edge is trimmed by a lathe, and the processing tolerance is: diameter deviation ± 1mm, ball ellipticity deviation < 1mm. The allowable deviation of the length of the steel pipe member is ±1mm, the end face of the member must be perpendicular to the axis of the rod, the allowable deviation is 0.5% R (R is the radius of the steel pipe), and the maximum bending of the steel pipe member shall not exceed 1/1000 of the rod length.

2. Installation of steel space frame

Based on and guided by computer simulation theory, a detailed assembly plan has been formulated. According to the characteristics of the project structure and the layout of the construction site, a scaffolding work platform is set up on the ground, planks are laid flat on the scaffold, and then the space frame and the space frame bolt balls are assembled on the scaffold work platform. The space frame is assembled using the air bulk method. construction. According to the actual situation of the space frame structure and the characteristics of left-right symmetry, in order to reduce the error accumulation of the space frame during the assembly project, the assembly of the overall space frame should start between the 8th and 9th axes of the starting unit, and assemble the starting unit first. Vertical and horizontal axes, correct the size at any time, and only after the space frame of the starting unit is considered correct can it be expanded from the center to both sides. During the assembly process, the rods are hoisted in place by the pick-up rod, and assembled and bolted at the designed position.

3. Assembly of starting units

Directly assemble a single rod and a single node into a space frame, and the position of each node should be measured and checked during the assembly process. After the space frame installation of the starting unit is completed, conduct a self-inspection immediately to ensure that the bolts at all nodes are fastened in place. Carry out positioning electric welding (3 welding points at each support) to ensure that the space frame will not be displaced during the subsequent installation process. Then assemble them in two directions at the same time with the starting unit as the center.

Assembling the basic unit, the space frame other than the starting unit is assembled by the air bulk method. Firstly, the small unit is assembled, and then the space frame is assembled. When assembling, the space frame is reasonably divided into small units according to the actual situation, and finally the whole space frame. First, select a top-chord triangular cone, and use a top-chord horizontal rod, 3 web rods and a top-chord ball to spell out a unit cone that meets the design requirements. When assembling, all the bolts at the node ball of the unit cone should be screwed in place. After assembling the cone, it should be calibrated. The error of the diagonal line of the lower chord rectangle should not exceed 1mm.