地质条件不确定性下TBM管片结构失事概率计算  

Breakage probability assessment of TBM construction tunnel lining segments considering geologic uncertainty

作　　者：刘东海[1] 黄培志[1] 冯守中 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]武汉广益工程咨询有限公司,武汉430000

出　　处：《岩土力学》2010年第4期1181-1186,1192,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金青年基金资助项目(50709024);教育部新世纪优秀人才支持计划资助

摘　　要：不良地质条件是影响TBM施工隧洞管片结构安全的重要因素。综合考虑围岩地质条件和衬砌结构的不确定性,提出了一种定量分析TBM管片结构失事概率的新方法。在基于Markov过程估计隧洞沿程地质岩性变化概率的基础上,建立了隧洞任意位置处管片选型不匹配的概率模型;考虑围岩和管片参数的不确定性,采用随机有限元方法计算某一类型管片在不同围岩下的失事概率;由此,采用全概率公式,可计算隧洞沿程任意位置处管片结构的失事概率。结合实际工程,针对施工期工况,确定了该隧洞管片沿程的失事概率、最大失事概率及其所对应的位置等,为管片选型、优化设计及TBM施工期的风险防范提供了依据。Geologic failure is one of the most important impacts for the safety of lining segments in TBM construction tunnel. A new assessment method is proposed to analyze the risk of segments breakage more quantitatively considering geologic uncertainty. Firstly, probability model of segment type incorrect selection is established after the probability of geologic distribution aligning tunnel is estimated based on Markov process. Secondly, considering the mechanical parameter＇s uncertainties of surrounding rock and segments, the breakage probabilities of different segments under a certain rock type are calculated respectively using stochastic finite element method. Then, segment breakage probability aligning tunnel is obtained from the former two probabilities using total probability formula. Finally, the method is applied to a real project. We obtain the segment breakage probability at anywhere along the tunnel, the maximum breakage probability and the related locations under the construction conditions （loads）. The results provide a great support to lining structure optimal design, segments type selection and risk prevention during TBM construction.

关 键 词：地下工程 管片结构 TBM施工 风险分析 随机有限元 地质条件不确定性 

分 类 号：U451[建筑科学—桥梁与隧道工程]