Seismic behavior and reliability of variable friction damped self-centering prestressed concrete frames considering bolt bearing

Abstract

This study comprehensively studied the bolt bearing behavior on the influence of friction based self-centering prestressed concrete (SCPC) frames. Based on the mechanism and test results of a SCPC connection with variable friction dampers (VFD), the theoretical analyses for the VFD-SCPC connection considering the whole procedure of friction bolts ranging from bearing to failure were carried out. The numerical model of the VFD-SCPC connection considering the bolt bearing behavior was proposed and the incremental dynamic analyses were carried out to obtain the seismic behavior of the VFD-SCPC frames when the friction bolts in the VFD ranged from bearing to failure. Taking the inter-story drift corresponding to the initiation of friction bolt bearing as variation, the fragility analyses for the SCPC frames with VFD and common constant friction dampers (CFD) were conducted to acquire the reliable design for the allowed bearing of friction bolts. The analyses results shown that to obtain the balance between the acceptable damage and expected reliability, the inter-story drift corresponding to the initiation of friction bolt bearing should be ranged from 2.0% to 2.5% for the VFD-SCPC frames and less than 2.0% for CFD-SCPC frames.