Analysis of production problems in the construction of space truss steel structure:

1 component production

The panel for portal frames is thin enough to 4 mm. When cutting multiple sheets, the cutting method should be selected to avoid flame cutting. Because the flame cutting will cause a lot of wave deformation at the edge of the plate. At present, H-beam welding manufacturers mostly use submerged arc welding or semi-automatic welding. If the control is not good, it will produce welding deformation and make the component bend or twist.

2. Installation of column base

(1) Problems and phenomena of embedded parts (anchor bolts): overall or layout deviation; incorrect elevation; no protective measures for thread. The bolt hole of steel column bottom plate is not directly aligned, and the thread length is not enough.

Measures: the steel structure construction unit shall cooperate with the civil construction unit to complete the embedded parts before concrete pouring and tamping. Check relevant dimensions and fix firmly.

(2) The anchor rod is not vertical: the levelness of the base plate of the frame column foundation is poor, the anchor rod is not vertical, and the horizontal error of the embedded anchor rod after the foundation construction is too large. The column is not straight after installation, which makes the appearance of the house very ugly, brings errors to the steel column installation, affects the structural stress, and does not meet the requirements of the construction acceptance specification.

Measures: when installing the anchor bolts, the bottom plate shall be leveled with the lower adjusting bolts first, and then the non shrinkage mortar shall be used for secondary grouting. Therefore, steel bar or angle steel can be used to fix the bolt during the construction of the bolt. The anchor bolt should be welded in the cage, the support should be improved, or some other good measures should be taken when pouring the foundation concrete to avoid the anchor bolt moving a position.

(3) Anchor bolt connection phenomenon: the anchor bolt of column base is not tightened, the base plate is not welded with the base plate; some 2-3 thread anchor bolts are not exposed.

Measures: adopt welding bolts and nuts, thicken external chemical anchor bolts, fireproof coating and heat preservation treatment to prevent the influence of fire on anchorage performance; supplement foundation settlement observation data.