考虑轴向力时圆形隧道围岩稳定性线性与非线性分析

发布时间：2018-05-12 12:49

本文选题：圆形隧道 + 平面外应力　；参考：《中南大学》2014年硕士论文

【摘要】：在进行应力应变状态的理论研究时,地下工程通常被简化为无限各向同性均匀岩土介质中静水压力作用下圆形截面隧洞的平面应变问题。目前的大多数研究假定平面外应力为中主应力,不考虑平面外应力对隧道围岩应力位移的影响,这显然不满足复杂地应力条件下工程实际的要求。本文基于圆形隧道平面应变问题,在广义非线性Hoek-Brown强度准则的基础上,对地下洞室开挖过程中的应力和位移进行弹塑性分析；基于岩石的弹-脆-塑性模型和非相关联流动法则,研究轴向地应力作用下隧道应力、位移及塑性区半径的非线性理论解,并通过简化获得理想弹塑性模型下的相应理论解；考虑岩体的应变软化特性,建立考虑轴向应力作用下软化围岩的应力与位移的线性和非线性数值解。取得了如下主要成果： (1)基于广义Hoek-Brown屈服准则,建立了考虑渗透水压力下的柱孔和球孔硐室围岩的应力、位移和塑性区半径的解。理论成果具有一定的工程实用价值。 (2)基于广义Hoek-Brown强度准则和非相关联流动准则,考虑轴向地应力作用,建立了弹-脆-塑性围岩的应力、位移及塑性区半径的理论解。将该理论解中的残余强度值用岩体的峰值强度值替换,获得了基于广义非线性Hoek-Brown强度准则并考虑轴向地应力作用下理想弹塑性围岩的应力、位移及塑性区半径的理论解。采用强度参数等效转换技术和Wang(2012)的理论方法,验证了本文理论的正确性和可靠性。 (3)构建了考虑轴向力作用下软化围岩应力应变特性的逐步求解方法,基于Mohr-Coulomb和广义Hoek-Brown强度准则,建立了考虑轴向应力作用下软化围岩的应力与位移的数值解。
[Abstract]:In the theoretical study of stress-strain state, underground engineering is usually simplified as the plane strain problem of circular section tunnel under hydrostatic pressure in infinite isotropic homogeneous rock and soil media. At present, most researches assume that the out-of-plane stress is the middle principal stress, and do not consider the influence of the out-of-plane stress on the stress and displacement of the surrounding rock of the tunnel, which obviously does not meet the practical requirements of the engineering under the complex geostress condition. Based on the plane strain problem of circular tunnel and the generalized nonlinear Hoek-Brown strength criterion, the stress and displacement during the excavation of underground cavern are analyzed by elastic-plastic analysis. Based on the elastic-brittle plastic model of rock and the non-correlated flow rule, the nonlinear theoretical solutions of tunnel stress, displacement and plastic zone radius under axial stress are studied, and the corresponding theoretical solutions under ideal elastic-plastic model are obtained by simplification. Considering the strain softening characteristics of rock mass, the linear and nonlinear numerical solutions of stress and displacement of softening surrounding rock under axial stress are established. The following main results have been achieved: 1) based on the generalized Hoek-Brown yield criterion, the stress, displacement and plastic zone radius of the surrounding rock of the cylindrical and spherical caverns under permeable water pressure are established. The theoretical results have certain engineering practical value. 2) based on the generalized Hoek-Brown strength criterion and the non-associated flow criterion, the theoretical solutions of stress, displacement and radius of plastic zone of elastic-brittle plastic surrounding rock are established considering the action of axial in-situ stress. The residual strength value in the theoretical solution is replaced by the peak strength value of the rock mass, and the theoretical solutions of the stress, displacement and radius of the plastic zone of the ideal elastoplastic surrounding rock under the action of axial in-situ stress are obtained based on the generalized nonlinear Hoek-Brown strength criterion. The validity and reliability of this theory are verified by using the equivalent conversion technique of strength parameters and Wangwei 2012). Based on Mohr-Coulomb and generalized Hoek-Brown strength criterion, the numerical solution of stress and displacement of softening surrounding rock under axial stress is established.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451.2

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