不同大变形等级下层理角度对层状软岩隧道的影响  

Effect of bedding angle of layered soft rock tunnels with different large deformation grades

作　　者：潘文韬 何川[1] 吴枋胤 徐迪 王飞 杨文波[1] 寇昊 PAN Wentao;HE Chuan;WU Fangyin;XU Di;WANG Fei;YANG Wenbo;KOU Hao(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,P.R.China;Sichuan Mianjiu Expressway Co.,Ltd,Jiangyou 621700,Sichuan,P.R.China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]四川绵九高速公路有限责任公司,四川江油621700

出　　处：《土木与环境工程学报（中英文）》2023年第5期94-105,共12页Journal of Civil and Environmental Engineering

基　　金：四川省科技计划(2019YFG0001)。

摘　　要：为探究不同大变形等级下层理角度对层状软岩隧道的影响,依托九绵高速全线软岩大变形隧道,通过岩石力学试验确定遍布节理模型参数,基于数值模拟,探究不同软岩大变形等级(轻微、中等、强烈)下层理角度对层状软岩大变形隧道围岩及支护体系受力变形的影响,并通过现场统计的层理角度与大变形情况对数值模拟结果进行验证。结果表明:1)层理小角度(0°、15°)与大角度(90°)围岩变形、支护结构受力变形较大,随着大变形等级的增大,层理角度引起的围岩支护变化效果越明显。2)随着层理角度的增大,围岩变形从拱底逐渐转移到右拱腰。围岩变形主要发生在隧道轮廓与层理面相切位置,其中拱底及左拱脚对层理角度变化较敏感。3)初支应力偏向及节理塑性区大致与层理弱面法向一致,随着层理角度的增大,节理的剪切塑性区由拱顶、拱底转移到左拱脚、右拱肩,最终偏移到左右拱腰上下位置;相比初支压应力,初支拉应力对层理角度更敏感,垂直节理增大了张拉剪切破坏塑性区贯通的风险,但剪切破坏塑性区半径反而有可能减小。4)现场的统计规律表现为小角度与大角度大变形等级较高,层理角度为60°以下时,岩层破坏发生在拱腰及拱肩处,随着层理角度的增大,有向拱肩发展的趋势,大角度层理时岩层破坏主要发生在拱腰处。This paper aims to explore the influence of bedding angle on layered soft rock tunnel under different deformation grades.Based on the large deformation soft rock tunnels along the Jiumian Expressway,the parameters of ubiquitous joint model were determined through rock mechanical test.Based on the numerical simulation,the influence of bedding angle on the stress and deformation of surrounding rock and supporting system of large deformation tunnel in layered soft rock was studied under different soft rock large deformation levels(slight,medium and strong).The results of numerical simulation were verified by field statistical law of bedding angle and large deformation.The results show that:1)The deformation and stress of surrounding rock and the supporting structure with small angle(0°,15°)and large angle(90°)of bedding are large,with the increase of large deformation grade,the effect of surrounding rock and support changes caused by bedding angle is more obvious.2)The deformation of surrounding rock gradually shifts from the arch bottom to the right arch waist with the increase of bedding angle.The surrounding rock deformation mainly occurs at the position where the tunnel contour is tangent to the bedding plane,and the arch bottom and left arch foot are sensitive to bedding angle.3)The deflection of the initial support stress and the plastic zone of the joint are roughly consistent with the normal direction of the weak plane of bedding.With the increase of bedding angle,the shear plastic zone of joints shifts from vault and arch bottom to left arch foot and right arch shoulder,and finally shifts to the upper and lower position of left and right arch waist.The initial support tension stress is more sensitive to the bedding angle than the compressive stress,vertical joints increase the risk of tensile and shear failure plastic zone transfixion,but the radius of plastic zone in shear failure may decrease.4)The statistical law of the site is that the large deformation grade of small angle and large angle is higher,

关 键 词：层状软岩隧道 大变形等级 层理角度 遍布节理模型 数值分析 现场实测 

分 类 号：TU457[建筑科学—岩土工程]