摘要：Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is *** passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunnels will suffer serious asymmetric *** is no available support design method for tunnels under such a situation in existing studies to clarify the support time and support *** study first analyzed the mechanical behavior of tunnels in non-hydrostatic in-situ stress field and derived the theoretical equations of the ground squeezing curve(GSC)and ground loosening curve(GLC).Then,based on the convergence confinement theory,the support design method of deep soft-rock tunnels under non-hydrostatic high in-situ stress field was established considering both squeezing and loosening *** addition,this method can provide the clear support time and support stiffness of the second layer of initial *** proposed design method was applied to the Wanhe tunnel of the China-Laos railway in *** data indicated that the optimal support scheme had a good effect on controlling the tunnel deformation in non-hydrostatic high in-situ stress *** applications showed that the secondary lining could be constructed properly.

摘要：隧道穿越高地应力深埋软岩地层时,开挖卸荷扰动会引发围岩产生严重的挤压变形和松动破坏,导致支护结构出现大变形。以玉磨铁路万和隧道穿越高地应力花岗岩构造破碎带为工程依托,首先基于经典Kastner公式和Caquot公式确定考虑松动效应的高地应力构造破碎带围岩特征曲线;然后基于收敛约束理论分析围岩与支护结构的稳定性,明确考虑围岩松动效应和控制支护让压程度的必要性;最后通过多工况比选确定第二层增设钢拱架的支护时机和支护参数。研究结果表明:高地应力环境下,前期作用于支护结构的围岩压力以形变压力为主。随着应力的释放,断面变形达0.8 m时的松动压力占比已超过30%,此时考虑松动效应的围岩对支护结构产生1.094 MPa的围岩压力,不考虑松动效应的围岩压力仅为0.765 MPa。因此在进行隧道稳定性分析及支护设计时,不能忽视围岩松动效应的影响;在第一层初期支护让压至一定程度后应及时增设第二层钢拱架抵抗围岩变形。以断面变形达到0.45 m时设置第二层钢拱架作为最优支护时机,以间距为0.6 m的I22b型钢拱架作为最佳支护参数,现场监测数据表明该大变形支护方案取得了良好的控制效果。研究成果能准确反映高地应力构造破碎带隧道大变形灾变过程,对类似工程的支护设计优化有明确的指导意义。