考虑孔隙水压力作用下浅埋黄土隧道稳定性的上限分析  

Upper Bound Analysis of Stability of Shallow-buried Tunnel in Loess Considering Pore Water Pressure

作　　者：于丽[1,2] 吕城 夏鹏曦 王明年[1,2] YU Li;LV Cheng;XIA Pengxi;WANG Mingnian(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of Traffic Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《铁道学报》2021年第11期153-159,共7页Journal of the China Railway Society

基　　金：中国铁路总公司科技研究开发计划(2017G007-G-2)。

摘　　要：由于黄土垂直节理发育导致浅埋黄土隧道的破坏模式不同于普通隧道,垂直节理的发育破坏了围岩的完整性和连续性从而降低隧道的稳定性,同时黄土的水敏性强,浅埋黄土隧道的稳定性受地下水的影响,目前研究浅埋黄土隧道稳定性问题的理论不够成熟。结合浅埋黄土隧道实际破坏形式构建二维有限多块体平动破坏模式,基于极限分析上限法和强度折减法同时考虑孔隙水压力的作用,利用Matlab软件求解浅埋黄土隧道的安全系数及破裂面范围。将求解的安全系数和既有的研究进行对比,验证了计算安全系数的合理性。分析不同参数对安全系数和破裂面范围的影响,研究结果表明:孔隙水压力对隧道稳定性和破裂面范围的影响显著,且不同孔隙水压力作用下浅埋黄土隧道的安全系数随参数变化的规律基本一致。可为浅埋黄土隧道的支护设计提供重要的参考依据。Due to the vertical joint development of loess,the failure mode of shallow-buried tunnel in loess is different from that of ordinary tunnel.The development of vertical joints destroys the integrity and continuity of surrounding rock and reduces the stability of the tunnel.At the same time,due to the strong water sensitivity of loess,the stability of the shallow buried tunnel in loess is affected by groundwater.Currently,further study is required for the theory regarding the stability of shallow-buried tunnels in loes.In this paper,the two-dimensional finite multi-block translational failure mode was constructed based on the actual failure mode of shallow-buried tunnel in loess.Based on the limit analysis upper bound method,the strength reduction method,and the effect of pore water pressure,the safety factor and the range of the fracture surface of shallow buried tunnel in loess was solved by Matlab software.By comparing the calculated safety factor n with the existing research,the rationality of the safety factor calculated by the method was verified.The influence of different parameters on the safety factor and the range of the fracture surface was analyzed.The results show that the pore water pressure has a significant influence on the stability of the tunnel and the range of the fracture surface,and the safety factor of the shallow buried tunnel in loess with different pore water pressure changes with the parameters.This paper can provide an important reference for the support design of shallow buried tunnels in loess.

关 键 词：上限分析 浅埋黄土隧道 孔隙水压力 稳定性 

分 类 号：U459[建筑科学—桥梁与隧道工程]