Experimental Study on the U-Shaped Steel Box Girders Using 1/4 Scale Test Specimen - I : Lateral-Torsional Buckling Behavior -

The objective of the present study is to understand the lateral torsional buckling behavior of the U-type girder system by structural tests before it is combined with concrete slab. In the present study, the test result for the U-shaped girders with upright webs reveals that both the buckling load and its mode are influenced by the geometrical type of the web system and by the initial geometrical imperfection. The pure bending tests to observe the lateral torsional buckling behavior are performed for the U-shaped girder stiffened by upper lateral bracings without vertical stiffeners on webs. It is observed that the W-type bracing system is more efficient than the X-type bracing system when the same volume of steel is used.