Numerical simulation of shotcrete-anchor support for duplex arch tunnel in soft rock based on shear-slip line theory
ZUO Shuangying1, FU Li1, LI Haoyi1, LIU Bo1, PENG Muwen1, SONG Xiong2
1. College of Resources and Environment Engineering, Guizhou University, Guiyang 550025, Guizhou, China; 2. Guangzhou Branch, China Railway First Group Co., Ltd., Guangzhou 511492, Guangdong, China
摘要 软弱围岩隧道开挖卸荷形成楔形塑性区,基于RABCEWICZ L V等提出的剪切滑移线理论,计算锚杆、喷层、钢筋网、钢拱架等一次支护结构在剪切区高度上提供的支护抗力,反向施加在开挖轮廓面上;对贵阳轨道交通2#线某段连拱隧道进行数值建模,采用中导洞+台阶法施工方案,模拟其开挖支护过程,得出变形破坏效应,并与现场监测的典型断面地表沉降、边墙收敛及顶拱沉降等数据进行对比。计算结果表明:喷锚支护措施使得围岩及地表沉降、水平变形减小,有效缓解隧道开挖后的应力集中现象,重力式中隔墙在隧道开挖过程中的连拱效应明显,支护结构与围岩一起发挥了共同承载圈作用,隧道的整体稳定可以得到保证。
Abstract: Excavation unloading of tunnels in soft weak surrounding rock forms a wedge-shaped plastic zone. Based on the shear-slip line theory proposed by RABCEWICZ L V et al, the supporting resistance provided by the anchor bar, shotcrete layer, steel mesh, and steel arch at the shear height was calculated and applied to the excavation outline in reverse. The numerical model of the double-arch tunnel of a section of Guiyang rail transit line 2# was built, and the construction scheme of middle guide hole-stairs method was used to simulate the excavation and support process, and the deformation and damage effect could be obtained, which were compared with the monitored data of the typical cross-section such as settlement, side wall convergence and roof arch settlement. The research results showed that the shotcrete-anchor support measures reduced the deformation of the surrounding rock, effectively relieved the stress concentration phenomenon after excavation, and the multi-arch effect of mid-partition wall was very obvious. The supporting structure and surrounding rock together layed an important role of common bearing circle, which may keep the whole tunnel stable.
左双英,付丽,李豪逸,刘博,彭木文,宋雄. 基于剪切滑移线理论的软岩连拱隧道喷锚支护数值模拟[J]. 隧道与地下工程灾害防治, 2020, 2(4): 44-51.
ZUO Shuangying, FU Li, LI Haoyi, LIU Bo, PENG Muwen, SONG Xiong. Numerical simulation of shotcrete-anchor support for duplex arch tunnel in soft rock based on shear-slip line theory. Hazard Control in Tunnelling and Underground Engineering, 2020, 2(4): 44-51.
[1] 王后裕, 陈上明, 言志信. 地下工程动态设计原理[M]. 北京: 化学工业出版社, 2008. [2] 李志业, 曾艳华. 地下结构设计原理与方法[M]. 成都: 西南交通大学出版社, 2003. [3] 中国冶金建设协会.岩土锚杆与喷射混凝土支护工程技术规范:GB50086—2015[S].北京: 中国计划出版社, 2015. [4] LIU W P, WAN S F, FU M F. Limit support pressure on tunnel face at different construction line slopes by slip line method[J]. Tunnelling and Underground Space Technology, 2020, 106: 103619. [5] 肖明清, 封坤, 李策,等. 复合地层盾构隧道围岩压力计算方法研究[J].岩石力学与工程学报, 2019,38(9):1836-1847. XIAO Mingqing, FENG Kun, LI Ce, et al. A method for calculating the surrounding rock pressure of shield tunnels in compound strata[J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(9):1836-1847. [6] 孙雁军, 阳军生, 罗静静,等. 隧道工作面稳定性与滑移线网破坏模式研究[J]. 岩土工程学报, 2019,41(7):1374-1380. SUN Yanjun, YANG Junsheng, LUO Jingjing, et al. Stability and mesh-like collapse mechanism of tunnel face[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(7):1374-1380. [7] 王永甫, 王成, 唐晓松. 基于非关联流动法则的圆形隧洞滑移线解答[J]. 应用数学和力学, 2013,34(12):1285-1290. WANG Yongfu, WANG Cheng, TANG Xiaosong. Slip line solution for circular tunnels based on the non-associated flow rule[J]. Applied Mathematics and Mechanics, 2013, 34(12):1285-1290. [8] 孟波, 靖洪文, 陈坤福, 等. 软岩巷道围岩剪切滑移破坏机理及控制研究[J]. 岩土工程学报, 2012,34(12):2255-2262. MENG Bo, JING Hongwen, CHEN Kunfu, et al. Shear and slip failure mechanism and control of tunnels with weak surrounding rock[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(12):2255-2262. [9] 谢亦朋, 杨秀竹, 阳军生. 松散堆积体隧道围岩变形破坏细观特征研究[J]. 岩土力学, 2019,40(12):4925-4934. XIE Yipeng, YANG Xiuzhu, YANG Junsheng. Mesoscopic characteristics of deformation and failure on surrounding rocks of tunnel through loose deposits[J]. Rock and Soil Mechanics, 2019, 40(12):4925-4934. [10] 程良奎, 杨志银. 喷射混凝土与土钉墙[M]. 北京: 中国建筑工业出版社, 1998. [11] 赵宇飞.加锚结构面剪切特性及锚固岩体综合力学模型研究[D].北京: 中国水利水电科学研究院, 2013. ZHAO Yufei. Research on the shear properties of bolted rock joints and the mechanical model of anchoring rock mass[D]. Beijing: China Institute of Water Resources and Hydropower Research, 2013. [12] 左双英, 肖明, 来颖. 基于FLAC3D的某水电站大型地下洞室群开挖及锚固效应数值分析[J]. 武汉大学学报(工学版), 2009,42(4):432-436. ZUO Shuangying, XIAO Ming, LAI Ying. Numerical analysis of excavation and anchorage effect on complex underground caverns of a hydropower station with FLAC3D[J]. Journal of Wuhan University(Engineering Science), 2009, 42(4):432-436. [13] Itasca Consulting Group Inc. FLAC3D(fast lagrangian analysis of continua in 3 dimension)user's manuals[Z]. 2.1ed.. Minnesota, USA:Mineapolis, 2002. [14] 李树忱, 晏勤, 谢璨, 等. 膨胀性黄土隧道钢拱架-格栅联合支护力学特性研究[J]. 岩石力学与工程学报, 2017, 36(2):446-456. LI Shuchen, YAN Qin, XIE Can, et al. The mechanical behavior of composite supports of steel-grid in loess tunnel[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(2):446-456.
2020, Vol. 2 
