2025-09-04    143

The connections of steel frame supports in multi-story steel structure factory buildings may use welded or high-strength bolted connections.

The arrangement of longitudinal inter-column bracing should meet the following requirements:

• Longitudinal inter-column bracing should be arranged near the middle of the column row.

• Longitudinal inter-column bracing may be installed in the same bay and run continuously from top to bottom within the same column section.

• Roof-level horizontal bracing and top-story inter-column bracing should be arranged in the same column section at the end of the building unit. For longer building units, such bracing should be installed every 3 to 5 column sections.

When the horizontal stiffness of each frame varies significantly and vertical bracing is irregular, floor-level horizontal bracing should be provided according to Table 6.2.1. The configuration should adhere to the following rules:

• Horizontal bracing may be installed at the bottom of secondary beams, with the ends of the bracing members connected to both the web and the bottom flange of the longitudinal and transverse beams at the floor level.

• The arrangement of floor-level horizontal bracing should be coordinated with the location of vertical bracing.

• Beams along the floor axis may serve as chord members in the horizontal bracing system, with diagonal braces forming an angle of 30° to 60° with the chord members.

• When secondary beams within the column grid area bear significant equipment loads, rigid tie members should be added to transfer the seismic action of the equipment weight to the chord members (beams along the axis) or nodes of the horizontal bracing system.