The structural system of prefabricated self-centering steel frame (PSCF) was proposed previously by the author. Experimental studies focusing on PSCF connections, plane frame, overall structures as well as the numerical simulations were conducted. Compared with the self-centering steel frame (SCF), the PSCF has avoided the onsite aerial tension of steel strands and simultaneously achieves similar seismic performance as well as selfcentering capacity. While the self-centering function of both PSCF and SCF may be restrained by conventional floor systems. Based on this thesis, a spatial PSCF with a new type of floor system containing sliding secondary beams was proposed in this paper to enable the frame expansion, and pseudo-dynamic and quasi-static tests toward it were conducted. The test results indicated that the proposed new floor system was reliable and feasible in accommodating the frame expansion. Meanwhile, the spatial PSCF with the new floor system has a favorable self-centering capacity, reliable gap-opening mechanism, superior seismic performance and enough redundancy to withstand multiple aftershocks.

Introduction

Self-centering steel frames (SCFs) can mitigate structural damage, reduce or eliminate residual deformation and are easy to repair after strong earthquakes. Since the development of SCFs in 2001, theoretical analysis, experimental testing and numerical modelling of SCFs have been extensively studied by many researchers. Ricles et al. and Garlock et al. [1–۴] conducted early experimental studies on self-centering beam-column connections with angles, developing a theoretical moment-rotation curve. Self-centering beam-column connections with Tstub devices was further researched by Aliabadi et al. [5]. And Wang et al. [6] achieved the self-centering function of SCFs by adopting shape memory alloys. Additionally, friction dampers have been introduced to self-centering connections. Various details and friction materials, including nonasbestos organic friction pads, hard steel against brass sheets, mild steel against brass sheets etc., were studied and improved continually to attain more stable energy dissipating capacity [7–۱۳]. Moreover, Belleville Springs used in friction sliding structural connections were researched to deal with the clamping force loss in seismic friction sliders [14]. The proposed self-centering connections or SCFs achieved the resilient function of the structure upon earthquake actions. While the self-centering connections proposed above required onsite aerial tension of steel strands when they are applied to multi-rise or high-rise buildings, causing great construction difficulty inevitably.