Full-scale test of a steel moment-resisting frame with composite floor under a penultimate edge column removal scenario

Abstract

This study investigates the structural behavior and load-resisting mechanism of a typical composite floor system subjected to the penultimate edge column removal scenario. A 2 × 1 bay full-scale composite floor system is quasi-statically pushed down to failure under the displacement loading scheme. Full scale, moment-resisting connection, and continuous steel deck are three main features of this test. Based on this test, load-deflection responses, load-carrying mechanisms, deformation manners, and failure modes are discussed. The maximum load-carrying capacity was achieved at the flexural stage before the fracture of the girder-to-column connection, after that, the resistance decreased slightly and plateaued. The maximum static and dynamic load carrying capacities of the tested specimen is 4.2 times and 3.6 times of the ASCE load combination for accidental events, respectively. The damaged area of the composite floor is concentrated neighboring to the removed column, which is caused by the girder-to-column connection failure. Yield line method is used to predict the load-carrying capacity of this composite floor system, and the prediction agrees well with the maximum resistance measured in the test. After the failure of the girder-to-column connection in the removed column area, the measured loads are 15.9% ∼ 24.5% higher than the predicted values. This is because the yield line method does not count the contribution of the tensile membrane action in the slab. By comparing with the results from previous experimental studies, the effectiveness of the moment-resisting connection and the continuous steel deck on improving the load-carrying capacity of the composite floor system has been validated.