为了研究单层衬砌结构力学特征，采用了FLAC3D有限差分软件，利用软件内置的接触面单元（interface单元）对不同结构层的层间接触效应进行了模拟。以巴哈高速公路东天山隧道2#斜井工程为工程背景，建立了不同衬砌结构型式下考虑层间接触效应的数值仿真模型，分析了现场Ⅳ级围岩条件下的单层衬砌结构力学特征及其围岩稳定性，并与原复合式衬砌支护设计方案进行了对比。研究结果表明：（1）FLAC3D模拟计算中采用接触面单元（interface单元）施加于不同结构层之间，可模拟衬砌结构不同层间接触形式的相互作用，较好地反映层间接触面的力学特征及位移特性；（2）对于受力性能而言，单层衬砌结构以组合梁承载模式进行承载，衬砌结构内力呈现"小弯矩、大轴力"的分布特征，衬砌结构截面应力以压应力为主，可充分发挥混凝土材料的受压性能；（3）由于单层衬砌结构具有良好的层间接触性能，不同结构层可实现"协同受力、共同变形"，使其承载模式优于复合式衬砌，能以较小的结构厚度满足隧道支护要求，因此单层衬砌具有较高的经济性；（4）单层衬砌隧道拱腰、拱脚及边墙底部YAI值较小，围岩稳定性较差，易发生失稳，现场施工时应对上述部位加以防范。
In order to study the mechanical characteristics of single-layer lining structure, the interlayer contact effects of different structural layers are simulated by using FLAC3D finite difference software and its built-in interface elements. Based on the engineering background of the No.2 inclined shaft project of the Dongtianshan tunnel of Baliku-Hami expressway, the numerical simulation models of different lining structure types considering the interlayer contact effect are established. The mechanical characteristics of single-layer lining structure and the stability of surrounding rock under the condition of grade IV surrounding rock are analyzed, and the analysis result is compared with the design scheme of original composite lining support. The result shows that (1) in the FLAC3D simulation, the interface element is applied to different structural layers, which can simulate the interaction between different interlayer contacts of the lining structure, and better reflect the mechanical characteristics and displacement characteristics of the interlayer contact surface; (2) for the mechanical performance, the single-layer lining structure is loaded by the composite beam bearing mode, and the internal force of the lining structure presents the distribution characteristics of "small bending moment, large axial force", and the section stress of the lining structure is mainly compressive stress, which can give full play to the compressive performance of concrete materials; (3) because the single-layer lining structure has good interlayer contact performance, different structural layers can achieve "cooperative forced and common deformation", which makes its bearing mode better than the composite lining, and can meet the requirements of tunnel support with smaller structural thickness, so the single-layer lining has higher economy; (4) the single-layer lining tunnel has small YAI values at the arch hance, the arch foot and the bottom of the side wall, which needs to be paid more attention to prevent the surrounding rock instability and damage of the above locations.
[1] 毛光宁. 选择挪威法还是新奥法取决于岩体状态[J]. 现代隧道技术, 1995(5):25-31. MAO Guang-ning. Choice of NTM or NATM Depends on State of Rock Mass[J]. Modern Tunnelling Technology, 1995(5):25-31.
[2] 王彬. 费尔艾那隧道工程情况[J]. 现代隧道技术, 1994(7):22-26. WANG Bin. Engineering Situation of Vereina Tunnel[J]. Modern Tunnelling Technology, 1994(7):22-26.
[3] 陈智. 秦岭隧道喷射钢纤维混凝土衬砌抗压、抗拉强度分析[J]. 岩土工程界, 2001(11):57-59. CHENG Zhi. Analysis of Compressive and Tensile Strengths of Sprayed Steel Fiber Concrete Lining of Qinling Mountain Tunnel[J]. Geological Exploration for Non-ferrous Metals, 2001(11):57-59.
[4] 梁国臣. 西康铁路高碥沟隧道湿喷钢纤维混凝土施工[J]. 施工技术, 2001, 30(5):23-39. LIANG Guo-chen. Construction of Wet-spray Steel Fiber Concrete in Gaobiangou Tunnel Project of Xikang Railway[J]. Construction Technology, 2001, 30(5):23-39.
[5] 刘新荣, 祝云华, 李晓红,等. 隧道钢纤维喷射混凝土单层衬砌试验研究[J]. 岩土力学, 2009, 30(8):2319-2323. LIU Xin-rong, ZHU Yun-hua, LI Xiao-hong, et al. Experimental Research on Single-layer Tunnel Lining of Steel Fiber Shotcrete[J]. Rock and Soil Mechanics, 2009, 30(8):2319-2323.
[6] 陈雪峰, 毛金龙, 袁立,等. 单层衬砌在梨花井隧道中的应用[J]. 中外公路, 2018,38(2):182-185. CHEN Xue-feng, MAO Jin-long, YUAN Li, et al. Application of Single Layer Lining in Lihuajing Tunnel[J]. Journal of China & Foreign Highway, 2018,38(2):182-185.
[7] 李云鹏. 公路隧道锚喷单层衬砌支护参数设计与结构受力特性分析[D]. 长沙:中南大学, 2017. LI Yun-peng. Design of Anchor-shotcrete Single-layer Lining Support Parameters and Structural Force Analysis for Road Tunnel[D]. Changsha:Central South University, 2017.
[8] 邹逸伦,周健,方勇. 高地应力下隧道单层衬砌受力特性研究[J]. 现代隧道技术, 2018, 55(增2):129-137. ZOU Yi-lun, ZHOU Jian, FANG Yong. Study on Mechanical Characteristics of Single-layer Lining under High Geo-stress Conditions[J]. Modern Tunnelling Technology, 2018, 55(S2):129-137.
[9] SU J, BLOODWORTH A. Interface Parameters of Composite Sprayed Concrete Linings in Soft Ground with Spray-applied Waterproofing[J]. Tunnelling and Underground Space Technology, 2016, 59:170-182.
[10] 周平, 王志杰, 徐海岩,等. 考虑层间效应的钢纤维混凝土隧道单层衬砌受力特征模型试验研究[C]//中国土木工程学会2017年学术年会论文集. 北京:中国城市出版社, 2017:395-420. ZHOU Ping, WANG Zhi-jie, XU Hai-yan, et al. Experimental Study on Mechanical Characteristics Model of Steel Fiber Reinforced Concrete Single-layer Lining Considering Interlayer Effect[C]//Proceedings of the China Civil Engineering Society 2017 Annual Conference. Beijing:China City Press, 2017:395-420.
[11] 张俊儒, 仇文革, 郭宏博,等. 隧道单层衬砌受力机理研究[C]//2006中国高速铁路隧道国际技术交流会论文集. 北京:中国铁道出版社, 2006:422-427. ZHANG Jun-ru, QIU Wen-ge, GUO Hong-bo, et al. Study on Stress Mechanism of Single-layer Lining of Tunnel[C]//2006 International Technical Exchange Meeting of China High Speed Railway Tunnel. Beijing:China Railway Publishing House, 2006:422-427.
[12] VOGEL F, SOVJÁK R, PEŠKOVÁ Š. Static Response of Double Shell Concrete Lining with a Spray-applied Waterproofing Membrane[J]. Tunnelling & Underground Space Technology, 2017, 68:106-112.
[13] 宋玉香,刘勇,齐键旭.铁路隧道复合衬砌内力计算方法研究[J]. 铁道工程学报, 2015, 32(8):73-75, 110. SONG Yu-xiang, LIU Yong, QI Jian-xu. Research on the Calculation Method of Composite Lining Internal Force for Railway Tunnel[J]. Journal of Railway Engineering Society, 2015,32(8):73-75,110.
[14] 陈育民, 徐鼎平. FLAC/FLAC3D基础与工程实例[M]. 北京:中国水利水电出版社, 2013. CHEN Yu-min, XU Ding-ping. Basis of FLAC/FLAC3D and Engineering Examples[M]. Beijing:China Water and Power Press, 2013.
[15] Itasca. FLAC3D User's Manual[M]. Ver. 5.0. Mineapolis:Itasca Consulting Group, Inc., 2012.
[16] 郑文华, 刘德军. 基于FLAC3D二次开发的不连续变形模拟方法探讨[J]. 岩土工程学报, 2013,35(增1):197-202. ZHENG Wen-hua, LIU De-jun. Discussion of Discontinuous Deformation Simulation Method Based on Secondary Development of FLAC3D[J]. Chinese Journal of Geotechnical Engineering, 2013,35(S1):197-202.
[17] 李术才, 王书法, 朱维申,等. 台湾软弱岩盘隧道变形预估系统数值模拟研究[J]. 岩土工程学报, 2001, 23(5):540-543. LI Shu-cai, WANG Shu-fa, ZHU Wei-shen, et al. Research on Numerical Simulation of Deformation of Soft Rockmass Tunnels in Taiwan[J]. Chinese Journal of Geotechnical Engineering, 2001, 23(5):540-543.
[18] 叶果. 新老混凝土界面抗剪性能研究[D]. 重庆:重庆大学, 2011. YE Guo. Study on Anti-shear Behavior of Bond-interface between New and Old Concrete[D]. Chongqing:Chongqing University, 2011.
[19] 关宝树, 国兆林. 隧道及地下工程[M]. 成都:西南交通大学出版社, 2000. GUAN Bao-shu, GUO Zhao-lin. Tunnel and Underground Engineering[M]. Chengdu:Southwest Jiaotong University Press, 2000.
[20] 张俊儒. 隧道单层衬砌作用机理及设计方法研究[D]. 成都:西南交通大学, 2007. ZHANG Jun-ru. Study on Action Mechanism and Design Methodology of Tunnel Single Shell Lining[D]. Chengdu:Southwest Jiaotong University, 2007.
[21] 周辉, 张传庆, 冯夏庭,等. 隧道及地下工程围岩的屈服接近度分析[J]. 岩石力学与工程学报, 2005, 24(17):3083-3087. ZHOU Hui, ZHANG Chuan-qing, FENG Xia-ting, et al. Analysis of Rock Mass Stability in Tunnel and Underground Engineering Based on Yield Approach Index[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(17):3083-3087.
