考虑锚固支护对层面剪切特性影响的隧道变形破坏特征  

Deformation and failure characteristics of tunnels considering effect of anchorage support on layer shear characteristics

作　　者：朱珍德 舒晓云 陈卫忠[2] 宋广骞 田洪铭[2] 田云 ZHU Zhende;SHU Xiaoyun;CHEN Weizhong;SONG Guangqian;TIAN Hongming;TIAN Yun(College of Civil and Transportation Engineering,Hohai University,Nanjing 210024,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China;Jinan Municipal Public Assets Management and Operation Co.Ltd.,Jinan 250000,China;Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province,Shaoxing University,Shaoxing 312000,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210024 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [3]济南市政公用资产管理运营有限公司,山东济南250000 [4]绍兴文理学院岩石力学与地质灾害浙江省重点实验室,浙江绍兴312000

出　　处：《中南大学学报（自然科学版）》2023年第3期895-907,共13页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51991392,5217090638,52179113,41831278)。

摘　　要：本文基于对ABAQUS有限元软件切向接触模型的二次开发,研究层状软岩隧道在不同层面倾角条件下的稳定性变化规律,分析层面抗剪强度与锚固支护之间的关系,揭示锚固支护强度对层状软岩隧道围岩变形破坏的影响规律。研究结果表明:在层面抗剪强度较低时,围岩变形可分为基岩变形与层面剪切滑移变形;不同地应力条件下,基岩变形在层面倾角为45°时最小,且随层面倾角的变化呈“U”形分布;在地应力较小时,层面剪切滑移变形显著,围岩发生层面剪切滑移变形与基岩屈曲变形的复合破坏模式;锚固加固后,随着层面黏聚力增加,层面剪切滑移与基岩变形均呈指数减小,基岩塑性区分布由“纺锤形”逐步过渡为均匀分布,基岩的塑性破坏区显著减小;层状软岩隧道开挖后,垂直层面正应力分布沿层面可分为应力降低区与应力增强区,锚固支护可减小层面正应力的降低幅度,抑制基岩的屈曲变形。层状软岩隧道变形破坏本身具有明显的非对称性,锚固支护可协调层面与基岩之间的变形差异性,使围岩变形区域更均匀,有效提升围岩整体承载力。Based on the secondary development of the tangential contact model in finite element software ABAQUS,the stability variation law of layered soft rock tunnels at different layer dip angles was studied.The relationship between layer shear strength and anchorage support was analyzed and the influence of anchorage support strength on the surrounding rock deformation of layered soft rock tunnels was revealed.The results show that at low layer shear strength,the surrounding rock deformation is divided into layer shear slip and bedrock deformation.Under different in-situ stress conditions,the bedrock deformation is the smallest when the dip angle is 45°,and there occus"U"shape distribution as the dip angle changes.When the in-situ stress is small,the layer shear slip is obvious,which result in composite surrounding rock failure of layer shear slip and bedrock buckling deformation.After anchorage reinforcement,with the increase of layer cohesive strength,the layer shear slip and bedrock deformation exponentially decrease.The plastic zone of bedrock gradually transitions from"fusiform"to uniform distribution,and the plastic failure of bedrock significantly decreases.After excavation of layered soft rock tunnels,the normal stress along the vertical layer can be divided to stress reduction zone and stress enhancement zone.Anchorage support can decrease the reduction degree of layer normal stress and inhibit the buckling deformation of bedrock.The deformation and failure of excavated layered soft rock tunnels is inherently and significantly asymmetric.In addition,anchorage support can effectively coordinate the deformation variability between layers and bedrock,making the deformation distribution area of the surrounding rock more uniform and improving the overall bearing capacity of the surrounding rock.

关 键 词：锚固支护 层状软岩隧道 数值模拟 变形破坏 

分 类 号：TD353[矿业工程—矿井建设]