西南地区节理化薄层软岩隧道大变形力学机理及支护控制方法  

Mechanical mechanism of large deformation and support control for jointed thin soft rock tunnel in Southwest China

作　　者：陶志刚[1,2] 李梦楠 张博 李慧茹[3] 史广诚 Tao Zhigang;Li Mengnan;Zhang Bo;Li Huiru;Shi Guangcheng(State Key Laboratory for Geomechanics and Deep Underground Engineering,Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Institute of Science and Technology,China University of Mining and Technology-Beijing,Beijing 100083,China)

机构地区：[1]深部岩土力学与地下工程国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083 [3]中国矿业大学(北京)科学技术研究院,北京100083

出　　处：《矿业科学学报》2023年第4期452-463,共12页Journal of Mining Science and Technology

基　　金：深部岩土力学与地下工程国家重点实验室创新基金(SKLGDUEK202201)。

摘　　要：针对西南山区高地应力软岩隧道支护结构破坏、围岩大变形等问题,以云南昌宁隧道为工程背景,分析了隧道围岩大变形破坏模式及力学机理,开展了软岩隧道NPR锚索应力补偿支护技术应用研究工作。首先采用现场勘查和室内试验的方法,对隧道地质条件及破坏成因进行分析;然后,研究了昌宁隧道影响围岩稳定性的主要控制因素和围岩破坏模式,提出了以NPR锚索为核心的应力补偿支护技术;最后,通过现场试验分析了NPR锚网耦合支护条件下昌宁隧道围岩控制效果。结果表明:岩层挤压弯折和层间剪切滑移是昌宁隧道围岩破坏的主要模式;以NPR锚索为核心的应力补偿支护技术能有效控制隧道围岩初期支护大变形,隧道围岩最大变形量从2150 mm降低到100 mm以内,效果显著。研究成果可为软岩隧道大变形的防治提供参考。This study analyzes the large deformation failure mode and mechanical mechanism of tunnel surrounding rock,with an aim to lessen the damage of high ground stress soft rock tunnel support structure and large deformation of surrounding rock in southwest mountainous area,with Yunnan Changning Tunnel as example for analysis,This paper investigates NPR anchor cable stress compensation support for soft rock tunnel.First,we analyzed the geological conditions and causes of failure of the tunnel through field survey and indoor test.Then,we looked at the main control factors affecting the stability of surrounding rock and the failure mode of surrounding rock of Changning Tunnel.Next,this study proposed the stress compensation support technology with NPR anchor cable as the core.Finally,we analyzed the control effect of surrounding rock of Changning Tunnel under the condition of NPR anchor mesh coupling support through field test.Results show that the main failure modes of the surrounding rock of Changning Tunnel are the compression bending of rock strata and the shear slip between layers.The stress compensation support technology with NPR anchor cable as the core works to effectively control the large deformation of the tunnel surrounding rock in the initial support.The maximum deformation of the tunnel surrounding rock is controlled from 2150 mm to less than 100 mm,which demonstrates significant control effect.The research results can provide reference for the prevention and control of large deformation of soft rock tunnel.

关 键 词：软岩隧道 破坏模式 恒阻大变形锚索(NPR锚索) 开挖补偿 

分 类 号：U45[建筑科学—桥梁与隧道工程]