Characteristics of Seepage Field and Structural Safety Analysis of Small Interval Tunnels with Asymmetric Seepage Boundaries
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摘要:
为探究非对称渗流边界条件下小净距隧道渗流-应力场特征及衬砌结构的安全性,以深圳莲塘隧道为工程背景,开展小净距隧道渗流模型实验,并结合模型试验与相似模拟的方法,分析单侧水源条件下小净距隧道围岩渗流水压力分布规律,并揭示不同补水距离条件下渗流场的演化规律和衬砌的安全性. 结果表明:在单侧水源条件下,小净距隧道围岩渗流场呈现出显著的非对称分布,从补水边界到另一侧水位面呈非线性降低,在隧道附近的围岩中水压力在水平方向呈非对称的“W”形分布;围岩渗流场的非对称分布导致了左右洞水压力、排水量和安全系数的非对称;与远离水源的隧道相比,靠近水源的隧道平均水压力和排水量分别增大10.4%和5.5%,安全系数减小3.0%,并且水压力非对称性更显著;从施工期到运营期,围岩和衬砌水压力分布的非对称性有小幅度增大;随着补水距离的增大,衬砌水压力线性减小,安全系数增大,水压力非对称系数增大;研究结果可为富水地区非对称渗流边界隧道的施工和运营提供一定的参考.
Abstract:To study the characteristics of the seepage-stress field and the safety of the lining structure of small interval tunnels under asymmetric seepage boundary conditions, based on the Liantang Tunnel in Shenzhen, China, a seepage model experiment for the small interval tunnels was developed. In addition, through model experiment and analog simulation, the distribution law of seepage water pressure in the surrounding rock of the small interval tunnels under unilateral water source conditions was analyzed, and the evolution law of the seepage field and the safety of the lining at different distances from the water sources were revealed. The results indicate that the surrounding rock seepage field of the small interval tunnels exhibits a significant asymmetric distribution under unilateral water source conditions. The water level decreases nonlinearly from the water replenishment boundary to the other side. Besides, the water pressure in the surrounding rock near the tunnels is distributed in an asymmetric “
W ” shape. The asymmetric distribution of the surrounding rock seepage field leads to the asymmetry of water pressure, water inflow, and safety coefficient in the left and right tunnels. Compared with the tunnel farther from the water source, the average water pressure and water inflow of the tunnel closer to the water source increases by 10.4% and 5.5%, respectively, and the safety coefficient decreases by 3.0%. Moreover, the water pressure asymmetry of the tunnel closer to the water source is more significant. The asymmetry of water pressure distribution in the surrounding rock and lining slightly increases from the construction period to the operation period. As the distance from the water sources increases, the water pressure of the lining linearly decreases, and the safety coefficient and the asymmetry coefficient of the water pressure increase. The research results can provide a reference for the construction and operation of tunnels with asymmetric seepage boundaries in water-rich areas. -
表 1 围岩与注浆材料参数
Table 1. Material parameters of surrounding rock and grouting
材料 E/MPa γ/(kN·m−3) φ/(°) c/MPa K/(m·d−1) 围岩 3 000.0 23.7 34.6 0.130 0.20 模型围岩相似材料 29.0 23.9 34.0 0.001 0.20 注浆圈 7 800.0 24.4 0.02 模型注浆圈相似材料 76.6 24.2 0.02 初期支护 22 000.0 24.0 0.04 表 2 模型材料参数
Table 2. Model material parameters
材料 密度/(kg·m−3) E/GPa 泊松比 黏聚力/MPa 内摩擦角/(°) K/(m·s−1) 围岩 2300 3.0 0.34 0.13 33.00 2×10−6 注浆圈 2420 7.8 0.32 0.45 36.00 2×10−7 初期支护 2400 24 0.23 4×10−7 二次衬砌 2500 32.5 0.20 排水盲管 2400 24.0 0.20 0.05 -
[1] NIKVAR HASSANI A, FARHADIAN H, KATIBEH H. A comparative study on evaluation of steady-state groundwater inflow into a circular shallow tunnel[J]. Tunnelling and Underground Space Technology, 2018, 73: 15-25. doi: 10.1016/j.tust.2017.11.019 [2] LI S C, LIU C, ZHOU Z Q, et al. Multi-sources information fusion analysis of water inrush disaster in tunnels based on improved theory of evidence[J]. Tunnelling and Underground Space Technology Incorporating Trenchless Technology Research, 2021, 113: 103948.1-103948.11. [3] LI L Y, YANG J S, FU J Y, et al. Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology[J]. Journal of Rock Mechanics and Geotechnical Engineering, 2022, 14(5): 1470-1485. doi: 10.1016/j.jrmge.2021.12.013 [4] 李术才,王康,李利平,等. 岩溶隧道突水灾害形成机理及发展趋势1)[J]. 力学学报,2017,49(1): 22-30. doi: 10.6052/0459-1879-16-345LI Shucai, WANG Kang, LI Liping, et al. Mechanical mechanism and development trend of water-inrush disasters in karst tunnels[J]. Chinese Journal of Theoretical and Applied Mechanics, 2017, 49(1): 22-30. doi: 10.6052/0459-1879-16-345 [5] 张顶立,孙振宇,宋浩然,等. 海底隧道突水演化机制与过程控制方法[J]. 岩石力学与工程学报,2020,39(4): 649-667.ZHANG Dingli, SUN Zhenyu, SONG Haoran, et al. Water inrush evolutionary mechanisms of subsea tunnels and process control method[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(4): 649-667. [6] ZHAO J P, TAN Z S, MA N. Development and application of a new reduction coefficient of water pressure on sub-sea tunnel lining[J]. Applied Sciences, 2022, 12(5): 2496. doi: 10.3390/app12052496 [7] 刘立鹏,汪小刚,贾志欣,等. 水岩分算隧道衬砌外水压力折减系数取值方法[J]. 岩土工程学报,2013,35(3): 495-500.LIU Lipeng, WANG Xiaogang, JIA Zhixin, et al. Method to determine reduction factor of water pressure acting on tunnel linings using water-rock independent calculation methodology[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(3): 495-500. [8] HARR M E. Groundwater and seepage[M]. New York: McGraw-Hill, 1962. [9] 王建宇. 再谈隧道衬砌水压力[J]. 现代隧道技术,2003,40(3): 5-10. doi: 10.3969/j.issn.1009-6582.2003.03.002WANG Jianyu. Once more on hydraulic pressure upon lining[J]. Modern Tunnelling Technology, 2003, 40(3): 5-10. doi: 10.3969/j.issn.1009-6582.2003.03.002 [10] 朱成伟,应宏伟,龚晓南. 任意埋深水下隧道渗流场解析解[J]. 岩土工程学报,2017,39(11): 1984-1991. doi: 10.11779/CJGE201711005ZHU Chengwei, YING Hongwei, GONG Xiaonan. Analytical solutions for seepage fields of underwater tunnels with arbitrary burial depth[J]. Chinese Journal of Geotechnical Engineering, 2017, 39(11): 1984-1991. doi: 10.11779/CJGE201711005 [11] MENG Wei, HE Chuan, ZHOU Zihan, et al. Influence of constant total hydraulic head on pore pressure and water inflow of grouted tunnel calculated by complex variable method[J]. Tunnelling and Underground Space Technology, 2023, 136: 105071.1-105071.11. [12] LI Z, HE C, CHEN Z Q, et al. Study of seepage field distribution and its influence on urban tunnels in water-rich regions[J]. Bulletin of Engineering Geology and the Environment, 2019, 78(6): 4035-4045. doi: 10.1007/s10064-018-1417-0 [13] 马少坤,陈彩洁,段智博,等. 基于镜像法的有限含水层内隧道渗流场解析解及其验证[J]. 工程力学,2023,40(5): 172-181. doi: 10.6052/j.issn.1000-4750.2021.10.0838MA Shaokun, CHEN Caijie, DUAN Zhibo, et al. Analytical solution and verification on seepage field of tunnel in finite aquifer based on image method[J]. Engineering Mechanics, 2023, 40(5): 172-181. doi: 10.6052/j.issn.1000-4750.2021.10.0838 [14] 杜朝伟,王梦恕,谭忠盛. 水下隧道渗流场解析解及其应用[J]. 岩石力学与工程学报,2011(增2): 3567-3573.DU Chaowei, WANG Mengshu, TAN Zhongsheng. Analytic solution for seepage field of subsea tunnel and its application[J]. Chinese Journal of Rock Mechanics and Engineering, 2011(S2): 3567-3573. [15] LI Z, CHEN Z Q, HE C, et al. Seepage field distribution and water inflow laws of tunnels in water-rich regions[J]. Journal of Mountain Science, 2022, 19(2): 591-605. doi: 10.1007/s11629-020-6634-x [16] 齐春,何川,封坤. 考虑流固耦合效应的水下盾构隧道受力特性[J]. 西南交通大学学报,2015,50(2): 306-311,330. doi: 10.3969/j.issn.0258-2724.2015.02.015QI Chun, HE Chuan, FENG Kun. Fluid-solid interaction-based mechanical characteristics of underwater shield tunnel[J]. Journal of Southwest Jiaotong University, 2015, 50(2): 306-311,330. doi: 10.3969/j.issn.0258-2724.2015.02.015 [17] FAN H B, ZHU Z G, SONG Y X, et al. Water pressure evolution and structural failure characteristics of tunnel lining under hydrodynamic pressure[J]. Engineering Failure Analysis, 2021, 130: 105747.1-105747.17. [18] ZHANG Z Q, CHEN B K, LI H Y, et al. The performance of mechanical characteristics and failure mode for tunnel concrete lining structure in water-rich layer[J]. Tunnelling and Underground Space Technology, 2022, 121: 104335.1-104335.19. [19] CHEN Z Q, LI Z, HE C, et al. Investigation on seepage field distribution and structural safety performance of small interval tunnel in water-rich region[J]. Tunnelling and Underground Space Technology, 2023, 138: 105172.1-105172.23. [20] 张治国,汪嘉程,赵其华,等. 富水山岭地区邻近补水断层隧道结构上的水头分布解析求解[J]. 岩石力学与工程学报,2020,39(增2): 3378-3394.ZHANG Zhiguo, WANG Jiacheng, ZHAO Qihua, et al. Analytical solution of head distribution on tunnel structure adjacent water-filled fault in water-enriched mountain region[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(S2): 3378-3394.