Experimental and theoretical studies on steel-concrete hybrid structures

Abstract

The behaviors of steel frame and concrete tube hybrid structures for tall buildings are studied in this chapter. Shaking table tests are conducted on a scale down model of a typical steel-concrete hybrid tall building. The chapter observes and analyses the dynamic properties, seismic responses, and damage features of the model. It develops a simplified approach for elasto-plastic analysis of hybrid structure subjected to earthquakes. In the proposed model, the external steel frames are treated as a series of half frames while the concrete tube is modeled as a two-spring bending and shear system on each storey. The two parts are connected with horizontal rigid bars on floor levels and work cooperatively to resist horizontal loads. The proposed analytical model has been verified to be effective and accurate by comparing experimental and theoretical results of the tested model subjected to simulated earthquakes. According to the proposed simplified approach, the hybrid structure is firstly simplified as a parallelly connected half frames and multiple-spring wall system. Compared with the complete FE model, this simplified model can reduce degrees of freedom of hybrid structures dramatically and hence it reduces much computational efforts. The proposed approach can predict the elasto-plastic responses of steel-concrete hybrid structures subjected to earthquakes with satisfactory precision.