In order to understand the influence of seismic response on the pile foundation of large cantilever pier bridge in deep soft soil area, a typical structural model of large cantilever pier bridge is established by using finite element software. Considering earthquake, the seismic response of large cantilever pier structure in deep soft soil area is numerically simulated. The results show that: for the seismic response of large cantilever pier pile foundation, when considering the liquefaction of surface soft soil, due to the large mass of bridge deck above the pier, no matter whether considering the liquefaction of soft soil or not, the peak moment appears at the pile foundation near the ground and the bottom of soft soil; in the case of liquefaction, the variation of pile shear force with depth is similar to that of pile bending moment, that is, when the liquefaction of surface soft soil is considered, the pile bending moment and shear force at the interface of pier bottom and pile top and at the interface of soft and hard soil appear obvious peaks; using the time history analysis method of bedrock input seismic wave, we can know that when the surface soil liquefies, the dynamic response of pile foundation is small, and the peak point of surface soil moves down, and its inertial force causes the bending moment of pier plus pile to increase, so there is a double peak situation. When the liquefaction of soil layer is not considered, the ground motion can be transmitted from the bottom to the top of the soil layer. Because the bending moment at the top of the pile caused by the mass of the bridge deck system is large, the peak value at the top of the pile is larger than that at the interface of the soft and hard soil layers. The analysis results have important theoretical significance and guiding role for the design of bridge pile foundation in deep soft soil area.
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