拱部脱空单线铁路隧道衬砌裂损机理研究  

Research on Mechanism of Lining Cracking in Single-track Railway Tunnels Influenced by Cavity within Arches Region

作　　者：易杰 赵乙丁 卞雯 孙厚超[1] YI Jie;ZHAO Yiding;BIAN Wen;SUN Houchao(College of Civil Engineering Yancheng Institute of Technology,Yancheng,China,224051;China Railway Construction Group East China Engineering Co.Ltd.,Sunzhou,China,215300)

机构地区：[1]盐城工学院土木工程学院,江苏盐城224051 [2]中铁建设集团华东工程有限公司,江苏苏州215300

出　　处：《沈阳建筑大学学报（自然科学版）》2024年第6期1038-1046,共9页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(52308420);江苏省自然科学基金项目(BK20220694);江苏省高等学校自然科学基金面上项目(21KJB560012);江苏省大学生创新创业项目(202310305081Y)。

摘　　要：目的研究脱空区域衬砌结构受力特性与裂损机理,为掌握实际工程衬砌裂损真实分布特征与设计加固补强方案提供理论依据,保障隧道健康服役。方法以某在役衬砌裂损铁路隧道为依托,采用无损检测方法,探明隧道壁后脱空几何尺寸及分布;基于扩展有限元法,建立表征脱空影响的仿真网格模型,揭示衬砌裂损机理;基于数值解析与现场监测结果,验证加筋肋锚网喷加固效果。结果无损检测结果显示,隧道存在严重脱空现象,脱空范围主要为隧道起拱线以上的拱部区域,平均深度为0.17~0.93 m。数值仿真结果显示,当衬砌拱部存在壁后脱空时,脱空环向角度对衬砌受力影响大于脱空径向深度,当脱空环向角度较小时,衬砌不易产生破坏或仅出现衬砌外表面张裂伴随内表面压溃。随着脱空角度的不断增大,衬砌内表面易出现混凝土张拉型裂缝且起裂位置向下移动。采用加筋肋锚网喷形式加固可显著提升裂损区域刚度,提高结构承载性能。结论衬砌壁后脱空环向角度对结构受力状态影响显著,所建立的数值解析方法能有效揭示衬砌拱部张拉裂缝开裂全过程及最终形态,提出的锚网喷加固方法能有效提高脱空衬砌承载性能。In order to study the stress characteristics and crack mechanism of the lining structure in the concealed cavity region,which proposes an extended finite element refined simulation method that accurately reflects the influence of lining cavity.To verify the reinforcement method of reinforced rib jointed anchor net unit.By utilizing a non-destructive testing method based on ground penetrating radar,the geometric dimensions of cavities behind the tunnel walls are accurately determined,which is based on an actual engineering project of a damaged lining railway tunnel in service.A numerical simulation mesh model is established using extended finite element to accurately represent the influence of cavities and reveal the mechanism of lining cracking.Based on numerical analysis and on-site monitoring,verify the reinforcement method of reinforced rib anchor mesh spray reinforcement.The results shows that non-destructive testing reveal the presence of severe cavity behind the arch walls of the tunnel,primarily in the arch area above the arch spring line,with an average depth ranging from 0.17m to 0.93m.The numerical simulation results demonstrate that in the presence of cavities behind the lining arch,the cavity azimuth angle has a greater impact on the lining stress compared to the void radial depth.When the cavity azimuth angle is small,the lining is less susceptible to damage or the occurrence of tensile cracks on the outer surface accompanied by internal surface crushing.With the continuous increase of the cavity angle,tensile cracks are more likely to occur on the inner surface of the lining,and the cracking position moves downwards.Reinforced rib jointed anchor net unit can significantly enhance the stiffness of the reinforcement area and improve the structural load-bearing performance.The conclusions show that the azimuth angle of cavities behind the lining has a significant influence on the stress state of the structure.The proposed numerical analysis method can effectively reflect the mechanism of lining crackin

关 键 词：壁后脱空 无损检测 扩展有限元 衬砌裂损 加筋肋锚网喷 

分 类 号：TU942[建筑科学—建筑技术科学]