Experimental study on full-scale steel moment-resisting frames with nonstructural walls subjected to multiple earthquakes

Abstract

A cyclic loading test of a steel moment-resisting frame (SMRF) with nonstructural components was conducted to evaluate the seismic performance of steel buildings subjected to multiple earthquakes. The specimen is a single-floor, one-span substructure of the intermediate story of typical current middle- or low-rise steel building in Japan. Two specimens were tested. The structural systems of these two specimens were the same, but the nonstructural components attached to the steel frame were different. The light gauge steel (LGS) partition wall and the autoclaved lightweight concrete (ALC) exterior wall were used as the nonstructural components of each specimen. One typical set of loading history that corresponds to one earthquake was created based on the response analysis results, and multiple sets of loadings with various levels were loaded to consider the effect of multiple earthquakes. Based on the observed visible damages, it was found that the structural component performed well under multiple earthquakes with a maximum story drift angle less than 1/50, while for the nonstructural component, the ALC wall performed better than the LGS wall. From the obtained load–deformation relationship, it was found that the strength of the structural component and the strength contribution of the LGS wall gradually decreased when subjected to multiple earthquakes, while the strength contribution of the ALC wall fluctuates within a close range. Moreover, the elastic stiffness of the structural component subjected to multiple earthquakes was almost constant, while the stiffness contribution of the nonstructural components decreased.