Seismic performance of precast concrete bridge columns with quasi-static cyclic shear test for high seismic zones

摘要

In this study, six 1/3-scale short bridge column specimens are investigated for shear strength under the same quasi-static cyclic loading protocol. The specimens consist of one cast-in-place (CIP) reference column and five precast columns, and the precast columns are designed with different connection approaches. The test includes the comparison between the specimens with or without shear keys, bonded or unbonded prestressing tendons, and column or footing embedment. Test results show that the shear strengths of precast columns using only mild reinforcement are emulative of the CIP column. Shear keys employed in the connection do not retain significant improvement in terms of hysteretic behavior, while specimens with prestressing tendons possess higher shear strength but lower ductility. The unbonded prestressing tendon provides unique self-centering capability with good energy dissipation. Finite element models of the columns were created with ANSYS by considering the bond-slip effect between reinforcement and concrete, contact behavior of connection surface, and material nonlinearity, depending on different structural details. The models can effectively simulate damage development under monotonic loading, and the load-displacement curves are in good agreement with the backbone curves of the test results.