非线性破坏准则下深埋小净距隧道围岩压力研究  

Study on Surrounding Rock Pressure of Deep Buried Tunnel with Small Clear Distance Under Nonlinear Failure Criterion

作　　者：安永林[1] 谭格宇 李佳豪 朱铁环 郭晋东 岳健[1] AN Yonglin;TAN Geyu;LI Jiahao;ZHU Tiehuan;GUO Jindong;YUE Jian(Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]湖南科技大学,湖南湘潭411201

出　　处：《灾害学》2023年第1期18-24,共7页Journal of Catastrophology

基　　金：湖南省自然科学基金资助项目(2021JJ30248);湖南省教育厅资助科研项目(20A1873)。

摘　　要：围岩压力大小是影响隧道稳定性的重要因素,也是进行合理支护设计与安全施工的前提。考虑围岩破坏的非线性特征,基于极限分析上限法推导深埋小净距隧道围岩压力公式,给出优化求解的过程,并与规范法进行验证对比,最后就相关影响因素做参数分析。结果表明:该方法与公路隧道设计规范的方法计算结果相对误差较小,且表现的规律一致,即两隧道内侧围岩压力大于外侧的围岩压力,也即中夹岩受力大,验证了本文计算方法的合理性;增大水平方向支护力,可有效减少隧道顶部的压力,提高隧道稳定性;竖向平均围岩压力随着净距的增大而增大,两者大致呈非线性相关的关系,增大幅度逐渐减小;围岩压力随着非线性Hoek-Brown准则中参数GSI、m_(i)、σ_(ci)增大而减小,所以对于软弱围岩,可以进行加固,改善自身力学性质,从而提高围岩自身承载力,减少隧道承受的围岩压力。The surrounding rock pressure is an important factor affecting the stability of the tunnel,and it is also the premise of reasonable support design and safe construction.The nonlinear characteristics of surrounding rock failure are considered,based on the upper bound method of limit analysis,the surrounding rock pressure formula of deep-buried neighborhood tunnel is deduced,and the optimization process of solution is given,which is verified and compared with the method in Specifications for Design of Highway Tunnel.Finally,the parameter analysis of related influencing factors is carried out.The results show that the relative error of the calculation results between this method and the standard method is small,and the law is consistent.The pressure of the inner surrounding rock of the two tunnels is greater than that of the outer surrounding rock,that is,the stress of the middle rock is large,which verifies the rationality of the calculation method in this paper.Increasing the horizontal support force is effective to reduce the pressure on the top of the tunnel and improve the stability of the tunnel.The vertical average surrounding rock pressure is increased with the increase of clear distance,the two are roughly nonlinearly correlated,and the increase amplitude is gradually reduced.Rock pressure is decreased with the increase of parameters GSI,mi andσci in nonlinear Hoek-Brown criterion.Therefore,for weak surrounding rock,reinforcement can be carried out,and its mechanical properties can be improved,so that the bearing capacity of surrounding rock is improved,and the surrounding rock pressure borne by the tunnel is reduced.

关 键 词：深埋隧道 围岩压力 小净距 极限分析 

分 类 号：X9[环境科学与工程—安全科学] X915.5X43