Experimental study on steel-plate composite wall-to-foundation connections subjected to combined axial compression and cyclic lateral-force

Abstract

Nowadays, great attention has been arisen on steel-plate composite (SC) walls, but studies on SC wall-to-foundation connections were rarely reported. In this paper, eight large-scale specimens were designed and tested to investigate the in-plane and out-of-plane behavior of SC wall-to-foundation connections subjected to combined axial compression and cyclic lateral-force. Test parameters mainly included the loading direction (in-plane and out-of-plane), construction detail of the connection (lap-splice and embedding) and the aspect ratios or height-to-thickness ratios of SC walls. The effects of test parameters on SC wall-to-foundation connection performance were discussed. For test specimens subjected to in-plane loading, results showed that the specimens all failed by flexure. For specimens subjected to out-of-plane loading, the specimens with the wall height-to-thickness ratio of 1.33 and 2.5 failed by shear and flexure-splitting, respectively. The lap-splice connection could be regarded as an over-strength connection since failure usually occurs on the connection while the embedding connection could be designed as a full-strength connection where the SC wall itself fails, according to AISC N690s1-15. The lap-splice connections had better ductility than embedding connections. The specimens with larger SC-wall aspect ratios or height-to-thickness ratios had better ductility. The current expressions for the in-plane and out-of-plane load-carrying capacities of SC walls were evaluated based on the test results. The comparison showed that the current expressions generally underestimated the load-carrying capacities of the specimens. Since both construction details of lap-splice and embedding had been proven feasible for practical use in SC wall-to-foundation connections, further studies on the design of both connection types were recommended.