This paper presents a theoretical method for the horizontal mechanical responses of single pile due to tunnelling in multi-layered soils. Based on the homogenization theory and the integral L&P formula, ground horizontal displacements due to tunnelling in layered soils can be solved analytically. The pile-soil interaction model is established in which the pile is assumed to be an Euler-Bernoulli beam placed on the Pasternak foundation. According to the two-stage thought, the horizontal displacements and bending moments of the pile can be evaluated quantitatively if the calculated horizontal displacements are input into the interaction model. The proposed method is verified by comparing with the numerical method, field measurement and centrifugal test. Parametric analyses are also performed to investigate the influence of the parameters of the pile and excavation, especially the soil stratification on the mechanical responses of the pile. Results found that the GAP parameter, the distance of tunnel axis from pile axis, the length, the diameter and the elastic modulus of the pile all have an important influence on the horizontal displacements and bending moments of the pile. Importantly, the soil stratification has a non-negligible influence on the mechanical responses of the pile. The stiff interlayer sandwiched between the upper and lower soil layer can significantly limit the horizontal displacements of the pile but increase the bending moments.

本文为多层土中隧道开挖引起的单桩水平力学响应提出了一种理论方法。基于均质化理论和积分L＆P公式，可以解析解决层状土壤中隧道效应引起的地面水平位移。建立了桩-土相互作用模型，在该模型中，假定桩为放置在Pasternak基础上的Euler-Bernoulli梁。根据两阶段思想，如果将计算出的水平位移输入到相互作用模型中，就可以定量地评估桩的水平位移和弯矩。通过与数值方法，现场测量和离心试验的比较，对所提方法进行了验证。还进行了参数分析，以研究桩和开挖参数，特别是土壤分层对桩的力学响应的影响。结果发现，GAP参数，隧道轴线到桩轴线的距离，桩的长度，直径和弹性模量都对桩的水平位移和弯矩产生重要影响。重要的是，土壤分层对桩的机械响应的影响不可忽略。夹在上下土层之间的硬质中间层可以显着限制桩的水平位移，但会增加弯矩。隧道轴线距桩轴线的距离，桩的长度，直径和弹性模量都对桩的水平位移和弯矩产生重要影响。重要的是，土壤分层对桩的机械响应的影响不可忽略。夹在上下土层之间的硬质中间层可以显着限制桩的水平位移，但会增加弯矩。隧道轴线距桩轴线的距离，桩的长度，直径和弹性模量都对桩的水平位移和弯矩产生重要影响。重要的是，土壤分层对桩的机械响应的影响不可忽略。夹在上下土层之间的硬质中间层可以显着限制桩的水平位移，但会增加弯矩。