Nonlinear Finite Element Analysis Of Behavior Of High-low Double-rowed Retaining Piles

A plane finite element model of high-low double-rowed retaining piles considering the pile-soil interaction is proposed in this paper. In this model, the finite element software ABAQUS is used, and soil nonlinearity is modeled using Modified Cam-clay constitutive relationship. The lateral deformation, the moment and the earth pressure of the pile at any point can be calculated with this model. Some factors which have influences on the retaining character of double-row piles are analyzed, such as the excavation depth, width, the array pitch of the double-row piles, the pile stiffness. Through the comparison of the analysis result, some stress characters of the double-row piles are concluded, and some reference results are summarized for engineering practice and theory study.The main conclusions are the following:1.As the excavation depth is increasing, the positive earth pressure gets smaller and smaller. The positive earth pressure on the pile above the excavation face is almost equal to the academic positive earth pressure. And when under the excavation face, the earth pressure on the pile is between the academic positive earth pressure and the static earth pressure.2.As the excavation depth is increasing, the negative earth pressure gets larger and larger, but it has a big different comparing with the academic negative earth pressure. The negative earth pressure is bigger on the middle of the front pile than on the head and the bottom of the front pile. The negative earth pressure on the back pile is almost equal to the academic static pressure.Through the conclusions above, when design the double-row pile retaining structure, we should enhance the positive earth pressure and reduce the negative earth pressure.Using the method described in this paper, some project cases are analyzed. The rationality and applicability of the model are validated.