1、Manufacturing problem of components

The plate used for the portal steel frame is very thin, the thinnest can be up to 4 mm. The cutting of thin sheets should be preferred to cut and avoid cutting with flame. Because flame cutting will cause great wave deformation on the edge of the board. At present, most manufacturers of H-beam welding use submerged arc automatic welding or semi-automatic welding. If the control is not good, the welding deformation should occur, and the components will be bent or twisted.。

2. Anchor Bolt Assembly Questions

（1）Anchor Bolt：
Overall or layout offset; the elevation is incorrect; the thread is not protected. Directly causing the bolt holes in the steel column bottom plate to be misaligned, resulting in insufficient thread length。

Measure：The steel structure construction unit should cooperate with the civil construction unit to complete the work of the embedded parts before the concrete is poured. Both parties must review the relevant dimensions and fix it firmly。Anchor bolt is not straight：
The anchor bolts are not vertical. After the pillars are installed, they are not in a straight line. The appearance of the house is not beautiful. The structural strong is affected and does not meet the requirements of the construction acceptance specification.

Measure: The anchor bolt should be installed and the bottom plate should be leveled with the lower adjusting bolt, then Refilling with non-shrinking mortar for secondary grouting

3. Linking problems

High Strength Bolt

1）Bolt equipment surface does not meet the requirements, which will result in poor bolt installation, or the degree of bolt fastening does not meet the design requirements。

Cause Analysis：

①Surface has rust, oil and other impurities, bolt holes, burrs, welding, etc.。

②Bolt mounting surface is still defective after being processed。

Solution：

①High-strength bolt surface rust, oil and bolt hole defects should be cleaned one by one. It must be rust-proofed before use, so that the bolts for assembly should not be used in the formal assembly. Bolts should be kept and issued by special personnel。

②Handling the assembly surface should take into account the construction and installation sequence, prevent repeated, and try to handle before lifting.