考虑湿度应力的深部软岩隧道大变形控制研究  

Research on Large Deformation Control of Deep Soft Rock Tunnel Considering Humidity Stress

作　　者：张建俊[1] 王洋 孙闯[1] 裴文强[2] 张馨[2] Zhang Jianjun;Wang Yang;Sun Chuang;Pei Wenqiang;Zhang Xin(School of Civil Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,P.R.China;China Railway Eighteenth Bureau Group Co.,Ltd.,Tianjin 300350,P.R.China)

机构地区：[1]辽宁工程技术大学土木工程学院,辽宁阜新123000 [2]中铁十八局集团有限公司,天津300350

出　　处：《地下空间与工程学报》2024年第1期230-240,共11页Chinese Journal of Underground Space and Engineering

基　　金：国家重点研发项目(2017YFC1503101);辽宁工程技术大学学科创新团队资助项目(LNTU20TD08)。

摘　　要：为探明深部高地应力软岩隧道大变形产生机理,制定适应大变形控制措施,以月直山隧道为工程依托,首先明确求解围岩形变压力与松动压力的Kastner与Caquot公式,基于岩体弹塑性力学与连续介质理论建立围岩湿度应力解析解,采用收敛-约束法绘制出3种围岩应力作用下围岩与初期支护特征曲线,分析断面变形过程中围岩与支护结构相互作用规律及3种应力占比演化规律。分别以混凝土与型钢钢架作为二衬支护结构对月直山隧道围岩稳定性进行计算分析,明确考虑湿度应力与松动压力条件下隧道二衬最优支护时机与支护参数,以支护结构安全系数FS评判出最优支护方案并对隧道软岩大变形进行治理。结果表明:当围岩径向位移达到550 mm时,仅考虑形变压力Pi时围岩对支护结构的压力P仅为0.813 MPa,考虑湿度应力Pw与松动压力Pa时P增大为1.372 MPa,湿度应力与松动应力总占比达40.7%,仅考虑形变压力而设计的支护结构不满足围岩稳定性要求;根据“卸压支护”理念,确定以“位移释放峰值upeak=0.325 m”与“间距d=0.7 m”作为增设第二层钢架的最佳支护时机与支护参数,现场二次钢架设置24天后使围岩变形收敛于50.8 mm,围岩大变形得到控制,研究成果可为今后相关隧道工程设计与施工提供参考。In order to explore the mechanism of large deformation of deep high-in-situ stress soft rock tunnel and formulate control measures to adapt to large deformation,taking Yuezhishan Tunnel as an engineering background,the Kastner and Caquot formula of deformation pressure and loosening pressure of surrounding rock was first solved,and the analytical solution of moisture stress of surrounding rock was established based on elastoplastic mechanics of rock mass and continuum theory.The convergent constraint method was used to draw the characteristic curves of surrounding rock and initial support under the action of three kinds of surrounding rock stresses,and the interaction law of surrounding rock and supporting structure and the evolution law of the three kinds of stress proportion in the process of section deformation were analyzed.Considering the humidity stress and loosening pressure conditions,the optimal supporting time and supporting parameters of the second lining of Zhishan tunnel are clearly considered,and the optimal supporting scheme is judged by the safety factor FS of the supporting structure,and the large deformation of soft rock of the tunnel is treated.The results show that:When the radial displacement of surrounding rock reaches 550mm,the pressure P of surrounding rock on the supporting structure is only 0.813 MPa when the deformation pressure Pi is taken into account,and the pressure P increases to 1.372 MPa when the humidity stress Pw and the loosening pressure Pa are taken into account,accounting for 40.7%of the total.The support structure designed only considering the deformation pressure cannot meet the requirements of surrounding rock stability.According to the concept of"pressure relief support","displacement release peak upeak=0.325 m"and"spacing D=0.7 m"were determined as the best supporting time and parameters for adding the second layer of steel frame.After 24 days of setting the second steel frame on site,the deformation of surrounding rock converged to 50.8mm,and the large deformation of

关 键 词：隧道工程 软岩大变形 湿度应力 收敛-约束法 支护优化 

分 类 号：U452.2[建筑科学—桥梁与隧道工程]