Seismic behavior of concrete-filled double-skin steel tube/moment-resisting frames with beam-only-connected precast reinforced concrete shear walls

Concrete-filled double-skin steel tube (CFDST) attracts attention from researchers for it exhibits high strength, good ductility and energy dissipation capacity. In this paper, CFDST frame with beam-only-connected precast reinforced concrete shear wall system is proposed, and all the joints used high-strength bolt connection to realize fully-prefabricated construction. Three specimens were tested to obtain the seismic performance and cooperative mechanism of such proposed systems, and the contribution of beam-only-connected precast reinforced concrete shear wall (BRW) was quantified by comparing the results of these specimens. The results show that: (1) the BRW cooperated well with the CFDST frames, and it significant enhanced the lateral stiffness and strength of the CFDST frame; (2) all specimens tolerated more than 4% inter-story drift ratio, indicating that the specimens have good lateral deformation capacity; (3) the specimen with two pieces of BRW (BF-BRW-B) exhibited better ductility ratio by comparing with the specimen without BRW (BF) and with only one piece of BRW (BF-BRW-A); (4) relative brittle failure was occurred on the BRW in BF-BRW-A due to the shear force, which resulted in significant strength degradation and ductility reduction of the specimen, but two BRWs in BF-BRW-B could mitigate such situations. Lastly, equations were proposed to predict the lateral resistance of the test specimens.