隧道分级让压支护作用下围岩弹塑性变形全过程解析  

Elastic-plastic deformation of surrounding rocks under graded yielding support of tunnel

作　　者：董建华[1,2] 徐斌[1,2] 吴晓磊 连博 DONG Jian-hua;XU Bin;WU Xiao-lei;LIAN Bo(Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;Western Engineering Research Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou,Gansu 730050,China)

机构地区：[1]兰州理工大学甘肃省土木工程防灾减灾重点实验室,甘肃兰州730050 [2]兰州理工大学西部土木工程防灾减灾教育部工程研究中心,甘肃兰州730050

出　　处：《岩土力学》2022年第8期2123-2135,共13页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52178335);中央引导地方科技发展资金(No.YDZX20216200001739);陇原青年创新创业人才(团队)项目(No.2020RCXM120);兰州市十大科技创新项目(No.2020-2-11);甘肃省知识产权局高价值专利培育和转化项目(No.20ZSCQ034);甘肃省基础研究创新群体项目(No.20JR10RA205)。

摘　　要：为了解决高地应力软岩隧道支护结构失效等问题,基于合理释放围岩应力、减小支护结构受力等原理,提出了液压式隧道分级让压支护结构。考虑开挖面的空间效应及围岩应变软化条件,通过分析虚拟支护力的衰减规律,建立了围岩压力、虚拟支护力与支护反力的静力平衡方程,研究了各阶段支护结构与围岩的协同作用,得到了围岩在支护结构变形全过程的位移与应力变化关系,揭示了该支护结构的支护效果。通过算例分析与数值模拟,结果表明:围岩应力在两次让压阶段显著释放,围岩变形特点与结构让压特性保持一致;理论计算值与模拟值的变化趋势一致,验证了理论分析的合理性;所提出结构能有效释放围岩应力,减小支护结构受力,避免了支护结构的屈服破坏,解决了高地应力软岩隧道支护难题,为该支护结构的应用与发展提供了理论支持。In order to solve the failure of support structure of tunnel in high stress soft rock,based on the principle of reasonably releasing the stress in surrounding rocks and reducing the stress of support structure,a hydraulic tunnel graded yielding support structure is proposed.Considering the spatial effect of the excavation surface and the strain softening condition of the surrounding rocks,by analyzing the attenuation law of the virtual supporting force,the static balance equation of stress in the surrounding rocks,the virtual support force and the support reaction force is established.The synergy between the supporting structure and the surrounding rocks at each stage is studied to generate the relationship between the displacement and stress of the surrounding rocks in the whole deformation process of the support structure.The supporting effect of the proposed graded yielding support structure is revealed.The results show that the stress of surrounding rocks is significantly released at the two yielding stages and the deformation characteristics of surrounding rocks are consistent with the yielding characteristics of structure.The simulation results show the consistent variation trend with that of the theoretical values,which verifies the rationality of the theoretical analysis.The proposed yielding support structure can effectively release the stress in the surrounding rocks and reduce the stress of the supporting structure.It can avoid the yield failure of the support structure,solving the support problem of the tunnel in the soft rock with high stress,which can provide theoretical support for the application and development of the support structure.

关 键 词：隧道工程 应力释放 全过程解析 虚拟支护力 应变软化 

分 类 号：TU448[建筑科学—岩土工程]