Response of adjacent single pile due to tunnelling based on p–y curve

When analyzing the response of adjacent piles due to tunnelling, the simplified method based on the Winkler foundation beam model has a defect that it is almost impossible to reasonably determine the equivalent parameters of soil under different conditions. In order to remedy this defect, a correction method based on the nonlinear p–y curve of pile-soil interface is proposed. Combining the finite difference algorithm, the solving process of nonlinear equations by using the iterative method and the incremental method is presented. Moreover, the results obtained by the proposed method are compared with those from other existing methods, and a further study on some relevant problems is made by means of parametric analysis. The results indicate that it is necessary to take the nonlinear characteristics of pile-soil interface into account when solving the “passive” pile problem, especially in the vertical direction. The pile sequentially shows three different mechanical characters in vertical direction with the increase of the pile length. Maintaining to be constant, the maximum bending moment of the pile increases linearly with increase of the undrained shear strength .