Secondary to Primary Steel Truss Connection Detail

This is a CAD dwg drawing of a┬áSecondary to Primary Steel Truss Connection Detail. A flat slab or roof PRATT ‘N’ type secondary truss is connected to a primary steel truss with a moment resisting endplate connection.

Trusses with top and bottom chords of HEB220 section profiles. Pratt trusses with SHS100x5.0mm vertical and diagonal truss members whereas the primary truss introduces an HEB220 vertical member at the centerline of the connection. Secondary truss connection with a bolted endplate welded onto a verical HEB220 section profile, positioned at the centerline of the connection as a primary truss vertical member.

Floor or roof trusses, are commonly used in order to achieve large spans for creating large open space areas. Instead of large heavy primary girder beams, with very large profile sections, trusses also reduce the cost per steel unit weight of the construction. In cases where a grid column is to be omitted ( example large hangar door openings ), then a Primary truss needs to be introduced to support the slab or roof truss which in turn becomes a secondary truss. The primary truss needs to have at least the same or larger depth as the secondary truss and needs to carry the complete loads that are delivered through the secondary truss.

Size of the truss and truss members depend on the loading conditions, design criteria as well as architectural restrictions. By enlarging the truss overall depth, greater loads can be achieved but in some cases this is not feasible due to architectural restrictions. Variations of truss depth and truss members can achieve the desired loading requirements, th