Steel structure processing needs to pay attention to what aspects

Before the steel structure is processed and installed, the positioning control line, foundation axis, elevation, anchor bolt position, elevation and foundation concrete quality of the building should be checked in advance. If the out-of-tolerance is found to be within the allowable deviation range of the specification, corrective and adjustment measures shall be taken. In elevation inspection, the measured data should be compared with the pre-measured data of steel column size and elevation one by one, and the error between the two should be eliminated when adjusting the base plate or anchor bolt and nut. The allowable deviation of supporting surface, anchor bolt position and bottom plate should conform to the requirements stipulated in the code. The quality problem of foundation concrete should be dealt with according to relevant regulations.

Before processing and installation of steel structure, the overall size of steel members shall not be checked, and deformation and quality defects of members shall be dealt with. Although the steel members have passed the quality inspection before leaving the factory, they may miss the inspection, or they may have new deformation and damage during transportation and stacking. If there is no recheck before installation, these problems will not be dealt with in time before the processing and installation of Tonghua steel structure, which will affect the installation quality of steel structure, resulting in installation difficulties or quality defects. Preventive measures:

(1) Steel column assembly and welding should take anti-deformation measures, deformation in production should be timely corrected. When transporting and stacking steel columns, supporting points should be appropriate to prevent bending and deformation under the action of dead weight. Because of the poor out-of-plane stiffness of the long column, the lifting point should be selected at 2/3 of the column length to prevent deformation. Steel roof span is too large, should be corrected before installation to prevent forced connection and bending deformation of the column.

(2) When the steel column is hoisted to the foundation plane in place, the vertical and horizontal axes on the column bottom plate should be aligned with the foundation line to prevent the size deviation of the span, resulting in horizontal tension or thrust when the column head is installed and the roof truss is connected, resulting in bending deformation of the column body, and appropriate control.

(3) When the steel column and the tailstock are connected and installed, the roof board shall be lifted from the edge of the two inclined planes on the upper chord to the middle in symmetrical synchronization, to prevent a inclined plane from producing lateral concentrated pressure, resulting in bending deformation of the steel column. Without design permission, heavy components and equipment shall not be horizontally dragged or vertically hoisted using steel columns and other connectors to prevent bending deformation of steel columns or damage to the connection structure.

(4) Correction of out-of-tolerance fixed verticality of the frame steel column. If it is elastic deformation, it can be restored to original state without external force correction after eliminating external pressure; In the case of plastic deformation, before correction, temporary support should be added above or at the top of the bending part of the steel column to reduce gravity, and then a transverse reaction frame is fixed in the bending part and corrected with a jack. If the steel column is rigid, the curved convex surface can be heated with an oxyacetylene flame and corrected by applying a jacking force.