Three-dimensional displacement characteristics of adjacent pile induced by shield tunneling under influence of multiple factors

Shield tunneling inevitably passes through a large number of pile foundations in urban areas. Thus, an accurate assessment of tunneling-induced pile displacement and potential damage becomes a critical part of shield construction. This study presents a mechanism research of pile-soil-tunnel interaction through Pasternak-based two-stage analysis method. In the first stage, based on Mindlin's solution, the soil displacement fields induced by shield thrust force, cutterhead frictions, shield shell frictions and grouting pressure are derived. The analytical solution of three-dimensional soil displacement field is established by introducing Pinto's three-dimensional volume loss formula, which solves the problems that shield construction factors are not taken into account in Loganathan's formula and only two-dimensional soil displacement field can be obtained. In the second stage, based on Pasternak's two-parameter foundation model, the analytical solution of pile displacement induced by shield tunneling in layered soil is derived. A case was found in the project of interval tunnels from Wanjiali Square to Furong District Government of Changsha Metro Line 5, where the shield tunnels were constructed near viaduct piles. The reliability of the analytical solution proposed in this study is verified by comparing with the field measured data and the results of finite element method (FEM). In addition, the comparisons of longitudinal, horizontal and vertical displacements of soil and pile foundation analyzed by the analytical solution and FEM provide corresponding theoretical basis, which has significant engineering guidance for similar projects.

Automated summary

This study presents a mechanism research of pile-soil-tunnel interaction through Pasternak-based two-stage analysis method. The reliability of the analytical solution proposed in this study is verified by comparing with the field measured data and the results of finite element method (FEM). The comparisons of longitudinal, horizontal and vertical displacements of soil and pile foundation analyzed by the analytical solution and FEM provide corresponding theoretical basis, which has significant engineering guidance for similar projects.