Seismic Performance of Prestressed High Strength Concrete Pile to Pile Cap Connections

Six pile-cap connections were tested to evaluate performance of prestressed high-strength concrete piles (PHC pile)-cap connection under cyclic loading. The failure modes, hysteretic performance, ductility and bearing capacity were observed and analyzed. In addition, the seismic performance of pile-cap connection with different connections and cutting-off pile was studied. The test results showed that the connections appear to be bending damage. The two flexural modes were tensile rupturing of prestressed bar and yielding of anchor bars. The connections were severely damaged because of the yielding of anchor bars and appearing of the plastic hinge. The bond slippage failure of anchor bars was not observed in the cap, and the length of anchor bars meet requirements. It shows that the bearing capacity and energy dissipation capacity increased with the rotation capacity of pile connection. Nonlinear finite element models were established to analyze the mechanical properties of these connections using ABAQUS. The moment-displacement curves obtained from the numerical analysis compared well with the experimental results. The effects of parameters on the behavior of the connections were conducted based on the numerical model.