Analytical Prediction for Tunnel-Soil-Pile Interaction Mechanics based on Kerr Foundation Model

Abstract

Existing analytical method to predict tunneling-induced pile deformation is generally based on the Winkler foundation model that neglects shear effects of soil, which is not sufficient for engineering practice. A simplified solution based on Kerr foundation model is presented in this study to investigate the tunnel-soil-pile interaction. In order to improve the accuracy of the prediction for tunneling-induced free-field movements, the cavity contraction theory is utilized in the first stage which received a higher accuracy than the previous solution. In the second stage, the soil free-field displacement is imposed on the existing pile, and the simplified solution for pile deformation governed by the disturbance of passive displacement is established based on the Kerr foundation model, which can take account of the soil shear effects. The applicability and accuracy of the simplified solution are then verified by several cases including the reported analytical solution, centrifuge modeling tests and observed data in situ. Good agreements are obtained in the comparative analyses, which demonstrates that the proposed solution can serve as an alternative approach for conservatively estimating tunneling-induced pile deformation in the preliminary design in clay. Furthermore, the parametric analysis associated with the pile deformation has also been performed. As a result, it is of primarily theoretical and practical significance to investigate the influence of soil shear effects on the tunnel-soil-pile interaction mechanics.