考虑渗流影响的盾构隧道开挖面稳定上限分析  

Upper-bound limit analysis of stability of shield tunnel face considering seepage

作　　者：王浩然[1,2] 黄茂松[1,2] 吕玺琳[1,2] 周维祥[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：《岩土工程学报》2013年第9期1696-1704,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年科学基金项目(50825803);国家自然科学基金青年科学基金项目(50908171)

摘　　要：通过考虑渗流影响的弹塑性有限元分析,获得渗流条件下的开挖面破坏模式,对比无渗流条件下开挖面的破坏模式,分析渗流对开挖面破坏模式的影响。基于极限上限分析,对无渗流条件下的破坏模式进行改进,提出了适合渗流条件下盾构隧道开挖面稳定性分析的破坏模式,建立了考虑渗流影响的极限分析上限法,获得了渗流条件下维持开挖面稳定的总极限支护压力。结合算例验证了该方法的有效性,并将其用于钱江隧道工程实例分析。研究表明:渗流会影响开挖面破坏模式,但当水位线不高于地表时,这种影响可以认为是一定的与隧道直径和土体内摩擦角等因素无关。总支护压力的很大部分被用于平衡渗流力,且总支护压力值与地下水位线近似呈线性关系。Based on the plastic strain distribution obtained from elasto-plasticity FE simulation,the influence of seepage on the failure mechanism is studied through comparison of mechanism under dry or drained conditions.A new failure mechanism under seepage conditions is proposed by improving the mechanism under dry or drained conditions.The face stability of shield tunnel is studied,and the upper-bound solution of limit support pressure is calculated.The proposed method is verified through case studies and applied to the analysis of face stability for Qianjiang tunnel.The analysis shows that the seepage has influence on the failure mechanism of tunnel face,and that if the ground water table is lower than the ground,the influence will be the same and independent of the tunnel diameter and the friction angle.A large part of support pressure is used to equilibrate the seepage force,and the total support pressure almost has linear relation with the water level.

关 键 词：盾构隧道 渗流 开挖面稳定性 极限上限分析 数值模拟 

分 类 号：TU91[建筑科学—建筑理论]