【作者】 李凤涛； 俞悦； 唐晓武；

【Author】 LI Fengtao;YU Yue;TANG Xiaowu;The Third Railway Survey and Design Institute Group Corporation;Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University;

【机构】 铁道第三勘察设计研究院集团城交分院； 浙江大学滨海与城市岩土工程研究中心；

【摘要】 盾构掘进时,密封舱支护压力需要维持在合理范围来保持开挖面稳定,支护压力过大则会引起开挖面被动失稳造成地表隆起破坏。近来研究表明浅埋隧道首先发生局部失稳破坏而非整体破坏,而针对掘进面被动失稳局部破坏模式尚没有相关的理论分析,本文提出三维局部破坏上限分析模型并进行上限分析,分析表明:浅埋隧道条件下,掘进面首先发生局部失稳破坏;随着覆土厚度和土体摩擦角增大,局部失稳高度增大直至掘进面整体失稳。本文极限支护压力解位于经典解之间,为确定极限支护压力的大小提供了合理的参考。更多还原

【Abstract】 An appropriate range of support pressure in the chamber should be controlled in the slurry shield tunneling to sustain the stability of tunnel face.However,the passive instability can occur suddenly bringing the blow-out damage of ground surface.According to the former literatures,the local instability on the up part of face is more occurred than the whole instability of tunnel face.There is no theoretical analysis applied to investigate the local passive instability of face.Furthermore,by proposing a 3D kinematically admissible mechanism for the partial blow-out instability,the upper bound solution of support pressure is derived.The analytical solution show that the local instability on the up part of face occur first.The height of this failureis increased with cover depth ratio and the friction angle increasing.The support pressure given in this research is in agreement with the classical solution.By reference to this study,the design of support pressure in tunneling will be performed more reasonable.更多还原