Experimental study of end-plate joints with box columns

Abstract

Bolted joints between I-section beams and I-section columns have been widely adopted in prefabricated steel frames to avoid field welding, but it is difficult to use bolted beam-to-column joints when box columns are used because of the lack of constructional spaces and the absence of practical design methods. In order to solve this problem, a new end-plate joint form with box columns and I-section beams, as well as three prefabrication techniques for this connection form, are proposed in this paper. Four full-scale specimens were tested: one of the specimens was subjected to monotonic loads, and the other three, constructed with different prefabrication techniques, were subjected to cyclic loads. On the basis of the test results, the resistance, stiffness, rotation capacity, energy dissipation capacity and failure modes of the end-plate joints with box columns were analyzed, and the influences of different prefabrication techniques on the seismic behaviours of the joints were compared. Parametric analysis was conducted with finite element models. The joint specimens prefabricated with different techniques showed similar macro-mechanical properties, and the joint rotations were mainly caused by bulges of the column flanges. All the specimens showed satisfactory deformability and ductility, developing storey drift angles of >0.07rad before initial fractures. The prefabrication techniques notated XW and NW were recommended as preferred because of their superior seismic performance compared to that of the technique notated YW.