Construction Method For High Strength Bolts (Construction Method Of Steel Structure-Part 7)

When installing high-strength bolts for steel beams and columns in a steel structure project, make sure the friction surface is clean and dry, not wet. The screwed tightening sequence should be from the center to the edge of the gusset plate, for two connections, from the major to the secondary, for H-shaped steel members, the order is the edge of the upper flange, the edge of the lower flange, duplicate plate, for beam-column nodes on the same section of the column, the screwed tightening sequence should be nodes at the upper beam and column first, then nodes at the lower beam and column, finally nodes at the intermediate beam-column joints. The fastening degree of high-strength bolts is controlled by an electric wrench, and the final tightening torque to achieve an acceptable quality level, for the ordinary bolt connecting wall beam purlin, each bolt without two mat washers. All mounting screw holes are not permitted to use gas cutting holes; however, when the stack pin hole exceeds allowable deviation, preventing connecting bolts from being penetrated, a reamer may be used for adjustment.

The purlin and supporting system installation

The hoisting of steel structure, cross operation, and line construction should all be coordinated with the purlin and supporting system.

The installation of steel purlins necessitates screw position alignment and reasonable tightening.

Immediately after hoisting is completed, re-adjust the verticality and level degree between members to ensure proper alignment between continuous members, and install and adjust supports and level supports between columns. To adjust them, lock one side of the column support and relax the other. Once the column has reached verticality, lock the support to "tightening" status, but not so tight that it damages the members. Use the ridge point as the center point for adjusting the horizontal support from the roof to the ridge, and align the house top beam to keep the roof vertical. In other words, only by adjusting the verticality of all members can the brace be locked.

Before installation, correct any bending deformation caused by purlin transportation or stacking; during installation, use a wall tie and a pull rod to adjust the degree of purlin level.