Study on the difference of seismic responses of liquefied horizontal and inclined site-pile foundation-bridge structures under bidirectional earthquake excitations

According to the completed large-scale shaking table test of the liquefied lateral extension site-pile group foundation-superstructure system, the finite element model of the shaking table test of the liquefiable inclined site is established in the finite element software OpenSees. The reliability of the numerical model is verified by comparing with the experimental results. Based on this, numerical models of typical horizontal and inclined liquefaction site-pile foundation-bridge structural systems are established, and the difference in seismic response of horizontal and inclined site under bidirectional seismic excitation is discussed. The water pressure fluctuates more at the peak stage, and the lateral displacement of the soil increases significantly, especially in the middle of the saturated sand. The damage degree of the pile foundation in the inclined field is greater, and the maximum curvature of the pile foundation in the middle of the liquefiable layer can be increased by about approximately 13 times. The horizontal displacement of the pile body increases significantly. However, the curvature of the pier in the horizontal site is larger than that in the inclined site. It is suggested that the influence of the site inclination should be considered in the pile foundation design of the liquefaction site.