深埋隧道软弱围岩拱顶三维渐进性塌落机制上限分析  

Upper bound analysis of three-dimensional progressive collapse mechanism ofdeep tunnel roof with weak surrounding rock

作　　者：孙闯[1] 兰思琦 陶琦 关喜彬 韩希平 SUN Chuang;LAN Si-qi;TAO Qi;GUAN Xi-bin;HAN Xi-ping(School of Civil Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China;China Railway 19th Bureau Group Sixth Engineering Co.Ltd.,Wuxi,Jiangsu 214000,China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]中铁十九局集团第六工程有限公司,江苏无锡214000

出　　处：《岩土力学》2023年第9期2471-2484,共14页Rock and Soil Mechanics

基　　金：国家重点研发计划资助项目(No.2017YFC1503101);国家自然科学基金资助项目(No.51704144);辽宁省“兴辽英才计划”资助项目(No.XLYC1807107)。

摘　　要：隧道拱顶塌方是一个渐进性破坏的过程,为研究深埋隧道软弱围岩拱顶渐进性塌落特征,基于极限分析上限定理和非线性Hoek-Brown破坏准则,建立了深埋隧道三维渐进性塌落机制,推导了考虑孔隙水压力作用下的塌方全过程塌落体曲面解析解,绘制了拱顶渐进性塌落形态三维曲面图,分析了相关参数单一变化时塌落体形态特征以及不同孔隙水压力作用下各参数对塌落体重力和隧道支护力的影响规律。结果表明:表征岩体特征的无量纲参数、重度、孔隙水压力和岩体抗拉强度对渐进性塌方塌落体形态、重力和支护力有显著影响;深埋隧道围岩物理力学参数在渐进性塌方过程中逐渐减弱,主要体现为岩体强度随变形的发展逐渐衰减直至一个残余值,围岩强度的衰减情况和残余强度大小对塌落体重力和隧道支护力有一定影响。理论计算得到的隧道拱顶塌落形态与实际隧道工程F3断层破碎带隧道拱顶塌方范围基本吻合,验证了理论计算结果对预测隧道拱顶渐进性塌方塌落体范围的适用性,研究成果可为软弱围岩深埋隧道施工设计及安全防护提供理论依据。Tunnel roof collapse is a progressive failure process.In order to study the progressive collapse characteristics of deep tunnel roof with weak surrounding rock,based on the limit analysis upper bound theorem and nonlinear Hoek-Brown failure criterion,the three-dimensional progressive collapse mechanism of deep tunnel is established.The analytical solution of collapse surface in the whole process considering pore water pressure is derived.The three-dimensional surface diagram of roof progressive collapse is drawn.The influence law of the shape characteristics of the collapse body with single change of related parameters and each parameter on the collapse gravity and tunnel support force under different pore water pressure were analyzed.The results show that the dimensionless parameters characterizing the rock mass,unit weight,pore water pressure and tensile stress have significant effects on the shape and gravity of progressive collapse.In the process of progressive collapse of deep tunnel,the physical and mechanical parameters of surrounding rock gradually weaken,it is mainly reflected that the strength of rock mass gradually decreases with the development of deformation until it reaches a residual value.The attenuation of the strength of surrounding rock and the residual strength have a certain influence on the collapse gravity and tunnel support force.The collapse shape of tunnel roof obtained by theoretical calculation is basically consistent with the collapse range of tunnel roof in the F3 fault fracture zone of actual tunnel engineering,which verifies the applicability of the theoretical calculation results for predicting the collapse range of tunnel roof progressive collapse.The research results can provide a theoretical basis for the construction design and safety protection of deep tunnel with weak surrounding rock.

关 键 词：隧道工程 软弱围岩 渐进性破坏 三维塌落机制 上限分析 

分 类 号：U451[建筑科学—桥梁与隧道工程]