盾构隧道围岩与衬砌协同作用纵向位移计算法  

Calculation Method of Longitudinal Displacement of Shield Tunnel Surrounding Rock and Lining in Cooperation

作　　者：李东彪 曾志康 沈才华[3] 李菁文 姜育科 LI Dong-biao;ZENG Zhi-kang;SHEN Cai-hua;LI Jing-wen;JIANG Yu-ke(CCCC Tunnel&Bridge(Nanjing)Technology Co.,Ltd.,Nanjing 211800,China;Tunnel Maintenance Technology R&D Center of CCCC Infrastructure Maintenance Group Co.,Ltd.,Nanjing 211800,China;School of Civil Engineering and Transportation,Hohai University,Nanjing 210098,China)

机构地区：[1]中交隧桥(南京)技术有限公司,南京211800 [2]中交基础设施养护集团有限公司隧道养护技术研发中心,南京211800 [3]河海大学土木与交通学院,南京210098

出　　处：《科学技术与工程》2023年第11期4841-4848,共8页Science Technology and Engineering

基　　金：国家自然科学基金(41830110,52278400);中交养护集团2020年重大科技研发项目(27100020Y251,27100020Y249);浙江省交通运输厅科技计划(2022-GCKY-12)。

摘　　要：盾构机掘进过程中,千斤顶顶进力的不均匀引起的纵向位移是管片间初始错台的主要原因之一;基于Timoshenko梁理论的隧道纵向位移计算方法,未能考虑隧道开挖后围岩卸载破坏的变形特征及围岩与衬砌结构的协同作用效应,预测误差较大。建立了考虑围岩卸载扩容效应的等效地基抗力系数计算方法,提出了能考虑螺栓个数的等效抗剪刚度计算公式,建立一种基于Timoshenko梁理论的改进管片拼装式隧道纵向位移理论计算方法。实际工程案例分析表明:考虑围岩开挖卸载过程中围岩的非线性体积相关塑性变形(即扩容效应)更合理;考虑壁后注浆液固化过程的时效性,采用改进的滑移边界条件计算的纵向位移最大值是传统的固定端边界的计算值的2.3倍,边界条件对计算结果影响较大,本文计算方法更符合实际情况,也更安全。In the process of shield tunneling,the longitudinal displacement caused by the uneven jacking force of jack is one of the main reasons for the initial dislocation between segments.The calculation method of tunnel longitudinal displacement based on Timoshenko beam theory fails to consider the deformation characteristics of unloading failure of surrounding rock after tunnel excavation and the synergistic effect of surrounding rock and lining structure,so the prediction error is large.The calculation method of equivalent foundation resistance coefficient considering the unloading and expansion effect of surrounding rock was established,and the calculation formula of equivalent shear stiffness considering the number of bolts was put forward.An improved theoretical calculation method of longitudinal displacement of segment-assembled tunnel based on Timoshenko beam theory was established.The analysis of practical engineering cases show that it is more reasonable to consider the nonlinear volume-dependent plastic deformation(ie dilatancy effect)of surrounding rock during excavation and unloading.Considering the timeliness of the curing process of grout behind the wall,the maximum longitudinal displacement calculated by the improved sliding boundary condition is 2.3 times that of the traditional fixed end boundary,and the boundary condition has a great influence on the calculation results.The calculation method is more in line with the actual situation and safer.

关 键 词：隧道纵向位移 地基抗力系数 TIMOSHENKO梁理论 等效抗剪刚度 

分 类 号：U455[建筑科学—桥梁与隧道工程]