非均质地基中平面应变隧道开挖面稳定上限分析  

Upper bound analysis of plane strain tunnel in nonhomogeneous clays

作　　者：宋春霞[1,2] 黄茂松[1,2] 吕玺琳[1,2] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土力学》2011年第9期2645-2650,2662,共7页Rock and Soil Mechanics

基　　金：上海市优秀学科带头人计划项目(No.09XD1403900);国家自然科学基金项目(No.50908171);国家杰出青年科学基金项目(No.50825803)

摘　　要：非均质是软黏土地基中比较普遍的现象,而目前隧道开挖面稳定研究中比较成熟的理论主要是针对均质土体。因此,从塑性极限分析上限法的基本原理出发,采用平面应变隧道刚体平动破坏模式(多块体上限法),考虑软黏土地基的非均质性,推导了平面应变隧道极限支护压力关于隧道埋深、土体重度及土体强度的上限公式。通过与其他方法的比较分析,证明了极限分析方法在隧道开挖面稳定性方面的可行性;利用该方法的计算结果详细探讨了隧道开挖面稳定的影响因素;而且由计算结果可知,地基土的非均质性在影响隧道开挖面极限支护压力的同时,也影响着隧道开挖破坏面的位置和形状,为工程实践提供重要的理论依据。The heterogeneity of soil in geotechnical engineering is relatively common,while the analysis method for the face stability of tunnel in nonhomogeneous clays is not well established so far.A simple method for evaluating the undrained stability of plane strain heading tunnel in soft clays is presented.Rigorous upper bounds on the loads required to resist collapse are derived using a rigid block translational collapse mechanism on the basis of plastic limit analysis.The variation of shear strength with depth and the gravity of soil are considered in the study.To verify the quality of the upper-bound solutions,the results are compared with those obtained from the finite element limit analysis.It can be proved that the upper-bound method of limit analysis is a feasible approach for the face stability analysis of tunnel;and it also provides an important theoretical basis for the practical geotechnical engineering.

关 键 词：平面应变隧道 开挖面稳定 上限极限分析 非均质黏土 

分 类 号：TU43[建筑科学—岩土工程]