Experimental and Finite Element Analysis of Shear Behavior of Prestressed High-Strength Concrete Piles

Abstract

Previous earthquake damage investigations in Japan have shown that prestressed high-strength concrete (PHC) piles experience shear failure in the event of an earthquake. To investigate the shear behavior of PHC piles, tests were conducted by varying the shear span-effective depth ratio and deformed bars. By verifying the correctness of an ABAQUS model, a finite element model of a pile was established and the effects of the shear span-effective depth ratio, axial load, concrete strength, and deformed bars on the shear capacity were studied. The results indicate that reducing the shear span-effective depth ratio and increasing the prestressing bar ratio and concrete strength can improve the shear capacity of PHC piles. Compared to a common PHC pile, a prestressed high-strength concrete pile reinforced with deformed bars (PRC piles) has higher shear capacity. As the shear span-effective depth ratio increases from 1.0 to 2.0 in steps of 0.25, the shear capacity decreases by 31.73%, 18.45%, 18.73%, and 16.09% in order. When the diameter of the prestressing bar increases from 7.1 to 9.0, 10.7, and 12.6 mm, the shear capacity increases by 19.25%, 9.32%, and 7.35% in order. When the diameter of the deformed bar increases from 12 to 18 mm in steps of 2 mm, the shear capacity increases by 7.2%, 7.4%, and 7.5% in order. As the axial compression ratio increases from 0 to 0.45 in steps of 0.15, the shear capacity of the PHC pile increases by 27.01%, 17.75%, and 12.27% in order, whereas the shear capacity of the PRC pile increases by 17.93%, 13.43%, and 9.77% in order. As the concrete strength increases from 60 to 80 and 100 MPa, its shear capacity increases by 6.30% and 5.87%, respectively.