超大埋深软岩隧道中导洞合理超前距离研究  

Research on the Reasonable Advance Distance of Middle Pilot Tunnel in Super Deep Buried Soft Rock

作　　者：谭忠盛[1] 张宝瑾 卫鹏 林克 赵金鹏 Tan Zhongsheng;Zhang Baojin;Wei Peng;Lin Ke;Zhao Jinpeng(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,P.R.China;The 3rd Engineering Co.,Ltd.,of China Railway 16th Bureau Group,Huzhou,Zhejiang 313000,P.R.China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中铁十六局集团第三工程有限公司,浙江湖州313000

出　　处：《地下空间与工程学报》2025年第2期563-571,599,共10页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51978041)。

摘　　要：在超大埋深软岩中修建隧道,由于地应力高、围岩软弱,常常导致隧道产生大变形灾害。采用超前中导洞应力释放技术释放部分地应力,可使围岩中高地应力场转变为低地应力场,降低正洞扩挖时围岩作用于支护结构上的力,从而减小隧道变形,保证支护结构的安全。本文以滇藏铁路丽香段哈巴雪山隧道为依托,分析中导洞不同超前距离工况下隧道的变形量、初期支护结构受力及围岩塑性区大小,提出中导洞合理超前距离,并通过现场监测对其应用效果进行分析。结果表明:中导洞超前距离为2倍中导洞洞径时,隧道变形及围岩塑性区较小,支护结构受力较为合理,且现场实测隧道变形平均可减小44.52%,初期支护结构围岩压力、钢筋应力及喷混应力平均降低32%、35%、31%。When tunnels are built in super deep soft rock,due to high geo-stress and weak surrounding rock,large deformation disasters often occur in tunnels.The middle pilot tunnel stress release technology is used to release part of the crustal stress,which can transform the high-ground stress field in the surrounding rock into the low-ground stress field,reduce the stress of the surrounding rock on the support structure when the main tunnel is expanded,thus reducing the tunnel deformation and ensuring the safety of the support structure.Therefore,relying on the Haba Snow Mountain Large Deformation Tunnel in the Lixiang section of the Yunnan Tibet Railway,literature research,numerical simulation,and on-site tests are used to study the tunnel deformation,initial support structure stress,and distribution of the loose zone of the surrounding rock under different advance distance conditions of the middle pilot tunnel.Finally,a reasonable advance distance for the middle pilot tunnel was proposed,and its application effect was analyzed through on-site monitoring.The results show that when the leading distance of the middle pilot tunnel is twice the diameter of the middle pilot tunnel,the deformation and plastic zone of the tunnel and surrounding rock are relatively small,and the stress on the support structure is relatively reasonable.Moreover,the average deformation of the tunnel measured on site can be reduced by 44.52%.The initial support structure reduces the surrounding rock pressure,steel stress,and shotcrete stress by an average of 32%,35%,and 31%.

关 键 词：超大埋深 大变形隧道 应力释放技术 中导洞 超前距离 

分 类 号：U25[交通运输工程—道路与铁道工程]