Seismic performance of multiple hardening wall: macro-element modelling, parametric analysis, and design

Steel-concrete composite bolted connections (SCCBCs) are frequently used for the horizontal connections of precast concrete (PC) walls, which makes the walls resilient and easy to replace after earthquakes. In a newly developed PC wall named as the multiple hardening PC shear wall (MHPCW), the SCCBCs are extended to vertical connections and are characterized by limited travel behavior, referred to as friction bearing devices (FBDs). The FBD plays a crucial role in the multiple hardening behavior by leveraging the longitudinal elongation, and friction and limited travel are identified as key factors in design. Although previous experimental results have demonstrated the promising seismic performance of the MHPCW, a deeper understanding of the multiple hardening mechanism is still needed. This study introduces a macro element modeling approach for the MHPCW. The validation of various failure modes and both lateral and longitudinal responses is conducted through experimental results. A parametric analysis of the MHPCW is conducted to explore the influence of key parameters, including the limited travel of the FBD, FBD friction, stiffness of end column, and axial load ratio. Furthermore, design recommendations for the FBD are proposed and validated by both experimental and numerical results, with failure modes fully considered, thus advancing the understanding of MHPCW.