Seismic Performance of a New Type Steel-Concrete Composite Shear Wall

Abstract

Using steel-concrete composite section is an efficient method for improving the behaviour of shear wall under seismic action. In consideration of the complex configuration of traditional composite shear wall and the time-consuming constructing process, based on the existing research, partially encased composite section was introduced into shear wall system. The partially encased composite shear wall (PECSW) is composed of a steel bone, some horizontal links and a group of concrete columns. The steel bone is a steel web, welded with vertical ribs and flanges in both side at certain interval. The horizontal links connect the flanges (or vertical ribs) and vertical ribs. Concrete is poured on both sides of steel web, between flanges (or vertical ribs) and vertical ribs, formulating several independent long concrete columns. The PECSW can be bulk prefabricated in the factory and transported to the site to install. Because of no vertical rebar in PECSWs, the PECSW structure, which consists of PECSWs and other precast concrete structural elements, can be assembled quickly. This paper reports an experimental study on the seismic behaviour of the PECSW under cyclic lateral loading. Two full-scale single-bay, single-story specimens were constructed. The bearing capacity, energy consumption, stiffness and other performance data had been discussed based on the results of experiment. To explore the possibility of simplifying configuration of PECSW, the web of one specimen was welded with stud shear connectors on both side while the web of another specimen wasn’t. The test results show that the PEC shear wall has a good seismic behaviour. Both specimens followed bending failure mode. The concrete columns offered the vertical bearing capacity as well as the flexural bearing capacity. The concrete and the horizontal links between flanges and ribs provided effective support against local buckling of the flanges, once broken occurred between the links and the flanges, the flanges buckled severely, and the bearing capacity of PECSW fell accordingly. The initial stiffness, yield drift, peak point bearing capacity, accumulated energy dissipation of the PECSW specimens with and without stud shear connectors was basically identical. Then, parametric studies were conducted through numerical simulation so that the contribution of links and the stud shear connectors can be evaluated. According to the research above, the concrete part in the PECSW can postpone local buckling of steel sheet. The horizontal links in the PECSW support interaction between steel and concrete, provide concrete anchorage to steel bone. In general, the PECSW has commendable seismic behaviours and deserve further study.