Effect of Mechanical Splice to Seismic Performance of Precast Column-Foundation Connection

Identifying plastic hinge property is one of key the factors in successful modeling and subsequent seismic performance evalmechanical splices are also essentially required in precast connections, and its residual slip can greatly affect the plastic hinge length and finally the emulative performance level of PC seismic forceresisting system (SFRS). However, most of the existing models are not directly applicable in current forms to estimate the plastic hinge length of precast connections with mechanical splices. To address the effects of the residual slip induced in the mechanically spliced reinforcement system and its nonuniform stiffness due to splicing device (or coupler), a detailed nonlinear finite element (FE) analysis model was developed in this study, where plasticity-based constitutive models and a unique connector element were adopted for concrete and mechanically spliced reinforcements, respectively. Existing test results of column-foundation connections were used to verify the analytical approach. On this basis, a robust macro modeling method was also proposed for nonlinear cyclic analysis of PC moment frame systems with mechanical splices in this study. It appears that the magnitude of the residual slip in mechanical splices can greatly undermine the lateral stiffness, energy dissipation capacity, and equivalent viscous damping ratio of PC moment connections, and the proposed macro modeling approach can reasonably capture their behavioral characteristics.