基于Timoshenko-Pasternak模型的盾构下穿既有隧道沉降简化计算方法  

Simplified Calculation Method for Existing Tunnel Settlement Caused by Shield Under-passing Based on Timoshenko-Pasternak Model

作　　者：王亮 潘彬涛 江杰[2,3] 龙逸航 WANG Liang;PAN Bintao;JIANG Jie;LONG Yihang(China Railway First Bureau Group Third Engineering Co.,Ltd.,721006,Baoji,China;School of Civil Engineering and Architecture,Guangxi University,530004,Nanning,China;Key Laboratory of Engineering Disaster Prevention and Structural Safety of Ministry of Education,530004,Nanning,China)

机构地区：[1]中铁一局集团第三工程有限公司,宝鸡721006 [2]广西大学土木建筑工程学院,南宁530004 [3]工程防灾与结构安全教育部重点实验室,南宁530004

出　　处：《城市轨道交通研究》2024年第10期21-29,38,共10页Urban Mass Transit

基　　金：国家自然科学基金项目(52068004)。

摘　　要：[目的]旨在解决在盾构下穿既有隧道沉降计算中,传统Euler-Bernoulli梁与Winkler地基模型精度不足问题。[方法]基于Timoshenko梁理论和Pasternak地基理论引入同时考虑土体剪切效应和隧道整体剪切变形的Timoshenko-Pasternak模型,通过推导盾构下穿既有隧道的沉降控制方程,并使用有限差分法对其进行求解,得到沉降计算结果。之后将这些结果与有限元数值模拟解、实际工程监测数据及传统Euler-Bernoulli-Winkler模型的理论解进行详细对比。[结果及结论]基于Euler-Bernoulli-Winkler模型的计算结果在既有隧道沉降值上存在低估现象,而在既有隧道沉降槽宽度和管片张开量上存在高估现象,且无法计算既有隧道管片的错台量。相较之下,基于Timoshenko-Pasternak模型的计算结果与数值模拟及实际监测值更为一致。该模型能够较为准确地估计既有隧道沉降、沉降槽宽度及管片张开量,并提供了可靠的隧道管片的错台量计算结果。这对实际工程具有重要的指导意义,为实际工程提供了可靠的参考依据。[Objective]It is aimed to tackle the inefficient accuracy of traditional Euler-Bernoulli beam and Winkler foundation model in calculating settlement induced by shield under-passing existing tunnels.[Method]Based on the Timoshenko beam theory and Pasternak foundation theory,the Timoshenko-Pasternak model,which simultaneously considers the soil shear effect and the tunnel overall shear deformation,is introduced.Settlement control equations for shield under-passing existing tunnels are derived and solved using finite difference method to obtain settlement calculation results.These results are then compared in detail with finite element numerical simulation solutions,actual engineering monitoring data,and theoretical solutions from traditional Euler-Bernoulli-Winkler model.[Result&Conclusion]Research results show that the Euler-Bernoulli-Winkler model tends to underestimate settlement values and overestimate settlement trough width and segment opening amount for existing tunnels.Additionally,it fails to calculate the segment misalignment amount of existing tunnels.In contrast,the calculation results from Timoshenko-Pasternak model are more consistent with the numerical simulation and actual monitoring values.The model can accurately estimate settlement,settlement trough width,and segment opening amounts for existing tunnels,and provides reliable calculation results for tunnel segment misalignment.The findings are of significant practical value,offering a reliable reference for engineering applications.

关 键 词：盾构 下穿既有隧道 沉降变形 简化计算方法 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]