土压平衡盾构半舱掘进模式下的开挖面稳定性分析  

Excavation Face Stability Analysis of EPB Shield in Half-Chamber Tunneling Mode

作　　者：郑维刚 张涛 吴兴林 李海龙 张宏志 陈鹏 舒计城 ZHENG Weigang;ZHANG Tao;WU Xinglin;LI Hailong;ZHANG Hongzhi;CHEN Peng;SHU Jicheng(State Grid Liaoning Electric Power Supply Research Institute Co.,Ltd.,110006,Shenyang,China;State Grid Liaoning Electric Power Supply Co.,Ltd.,110006,Shenyang,China;China Railway 14th Bureau Group Large Shield Co.,Ltd.,211800,Nanjing,China)

机构地区：[1]国网辽宁省电力有限公司电力科学研究院,沈阳110006 [2]国网辽宁省电力有限公司,沈阳110006 [3]中铁十四局集团大盾构工程有限公司,南京211800

出　　处：《城市轨道交通研究》2025年第4期217-222,226,共7页Urban Mass Transit

基　　金：国家电网有限公司总部管理科技项目(5100-202128376A-0-0-00)。

摘　　要：[目的]在上软下硬或风化岩层等复杂地质环境下,土压平衡盾构满舱掘进模式施工时,渣土液位过高,刀盘产生过大扭矩,盾构耗能大。因此,实际常采用半舱掘进模式施工,降低开挖舱内渣土液位。然而液位过低会增加开挖面失稳风险,故有必要研究土压平衡盾构半舱掘进模式下的开挖面稳定问题。[方法]基于极限分析法上限定理,提出了一种考虑半舱支护的三维对数螺旋线失效模型。研究了支护压力分布形式与舱内渣土高度对土压平衡盾构隧道开挖面稳定性的影响。研究结合数值模拟和失稳模型探究了舱内渣土合理高度,对多种支护模式下的极限支护压力进行了比对。讨论了覆土厚度、黏聚力、内摩擦角等因素对极限支护压力的影响。[结果及结论]增加支护介质密度可显著提高开挖面稳定性,而增大隧道直径不利于开挖面稳定。土舱支护压力梯度、舱内渣土高度、黏聚力均与极限支护压力呈负相关。[Objective] In complex geological environments such as soft upper and hard lower or weathered rock layers,during the construction of EPB(earth pressure balance) full chamber tunneling mode,the slag liquid level is too high,the cutterhead generates excessive torque,causing lots of energy consumption in shield tunneling.Therefore,the half-chamber tunneling mode is often used in practice to reduce the slag liquid level in the excavation chamber.However,excessively low liquid levels will increase the risk of excavation face instability.Thus,it is necessary to study the excavation face stability issue of EPB shield in half-chamber tunneling mode.[Method] Based on the upper limit theorem of the limit analysis method,a 3D logarithmic spiral failure model considering half-chamber support mode is proposed.The influence of support pressure distribution form and in-chamber muck height on the stability of EPB shield tunnel excavation face is studied.Combined with numerical simulation and instability model,the reasonable height of muck in chamber is explored,and the limit support pressure under various support modes is compared.Factors such as cover soil thickness,cohesion,internal friction angle that influence the limit support pressure are discussed.[Result & Conclusion] The stability of the excavation face can be significantly improved by increasing the supporting medium density,while increasing the tunnel diameter is not conducive to the stability of the excavation face.The soil chamber supporting pressure gradient,the height of in-chamber muck and cohesion are all negatively correlated with the limit support pressure.

关 键 词：地铁隧道 盾构法 半舱掘进 半舱系数 支护梯度 极限分析法 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]