Design and Numerical Investigation of Novel Self-Centering Precast Concrete Beam-Column Joints with Replaceable Damage-Controllable Hinges

Abstract To minimize the seismic damage to the beam-column joint and facilitate post-earthquake repair, an innovative precast concrete (PC) beam-column joint (SCPJ) with self-centering and damage-controllable capacities was proposed. In the proposed SCPJ, the steel connector which was made up of two splice plates and an X-shaped plate, can form a rotational hinge at the joint and can be readily replaced after seismic damage. Also, unbonded post-tensioned (PT) tendons were used as self-centering elements. A design method was first developed for SCPJ to control damage within the dog-bone-shaped steel plates (DSP) and provide a comparable load-carrying capacity to a cast-in-place (CIP) joint. Afterward, numerical models for the proposed SCPJ were established using ABAQUS. The comparison between a CIP joint and a counterpart SCPJ (namely SCPJ-1) confirmed the validity of the design method. The damage was primarily localized in the DSP, while the PC components remained almost intact. Specimen SCPJ-1 showed a 30% lower residual drift ratio at the ultimate displacement than the CIP joint, demonstrating excellent self-centering capacity. Further, the systematic parametric analysis indicated that the increase of the DSP material strength and prestress level of PT tendons substantially improved the self-centering capability. The variations of the DSP thickness, the width of weakened section of DSP, and the thickness of XSP can shift the failure from DSP to XSP or PC components.