Experiments and numerical simulations on pressure-arch effect for a tunnel in loose deposits
ZAN Wen-bo1,2, LAI Jin-xing1, QIU Jun-ling1, CAO Xiao-yong3, FENG Zhi-hua1,4, SONG Fei-ting1,5
1. School of Highway, Chang'an University, Xi'an 710064, China; 2. School of Civil Engineering, Shaanxi Polytechnic Institute, Xianyang 712000, China; 3. CCCC First Highway Consultants Co., Ltd., Xi'an 710075, China; 4. Hebei Provincial Communications Planning and Design Institute, Shijiazhuang 050011, China; 5. A Traffic Department of the Second Mobile Brigade of the Armed Police, Nyingchi 860000, China
Abstract：A tunnel in loose deposits, located in the National Highway No. 318, is referenced to investigate the stress disturbance characteristics and mechanism of pressure arch through a combination of physical tests and numerical simulations. The radial and circumferential stresses, formation and stability mechanism of the pressure arch are analyzed. The results show that the loose zone and extent of rock mass are larger and extend to the surface at tunnel arch, whereas a smaller zone and a larger extent are observed at tunnel sidewall. The rock mass within 120° at the arch shows an obvious radial loosing and circumferential arching effect. The rock mass within the range of 0~0.55 times the excavation span is identified to be the pressure-arch zone at the sidewall where the radial and circumferential stresses obviously increase, resulting in a high-stress concentration zone to bear the load of pressure arch and its surrounding rock. The arching coefficient has a significant spatial variation, meanwhile, it increases linearly with tunnel excavation and has the largest value at the vault, followed by that at the sidewall, in which the excavation space effect shows a marginal influence. The arching coefficient within the range of 30°~60° increases greatly when excavating within the range of 6 m before and behind the tunnel face, but it tends to be stable sooner. Both the experimental and calculated pressure arches exhibit pointed-arch shapes. Their formation is of great significance to maintaining the tunnel stability and reducing the stress of support structure.
昝文博, 赖金星, 邱军领, 曹校勇, 冯志华, 宋飞庭. 松散堆积体隧道压力拱效应试验与数值模拟[J]. 岩土工程学报, 2021, 43(9): 1666-1674.
ZAN Wen-bo, LAI Jin-xing, QIU Jun-ling, CAO Xiao-yong, FENG Zhi-hua, SONG Fei-ting. Experiments and numerical simulations on pressure-arch effect for a tunnel in loose deposits. Chinese J. Geot. Eng., 2021, 43(9): 1666-1674.
[1] 谢亦朋, 杨秀竹, 阳军生, 等. 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 Yi-peng, YANG Xiu-zhu, YANG Jun-sheng, et al.Mesoscopic characteristics of deformation and failure on surrounding rocks of tunnel through loose deposits[J]. Rock and Soil Mechanics, 2019, 40(12): 4925-4934. (in Chinese)) [2] 杨建周. 穿越松散堆积体围岩加固与隧道施工技术[J]. 铁道科学与工程学报, 2019, 16(5):1266-1273. (YANG Jian-zhou.Reinforcement of surrounding rock and tunnel construction through loose deposits[J]. Journal of Railway Science and Engineering, 2019, 16(5): 1266-1273. (in Chinese)) [3] XIAO J Z, DAI F C, WEI Y Q, et al.Cracking mechanism of secondary lining for a shallow and asymmetrically-loaded tunnel in loose deposits[J]. Tunnelling and Underground Space Technology, 2014, 43: 232-240 [4] 钟祖良, 别聪颖, 范一飞, 等. 土石混合体注浆扩散机制及影响因素试验研究[J]. 岩土力学, 2019, 40(11): 4194-4202. (ZHONG Zu-liang, BIE Cong-ying, FAN Yi-fei1, et al. Experimental study on grouting diffusion mechanism and influencing factors of soil-rock mixture[J]. Rock and Soil Mechanics, 2019, 40(11): 4194-4202. (in Chinese)) [5] 杨继红, 董金玉, 黄志全, 等. 不同含石量条件下堆积体抗剪强度特性的大型直剪试验研究[J]. 岩土工程学报, 2016, 38(增刊2): 161-166. (YANG Ji-hong, DONG Jin-yu, HUANG Zhi-quan, et al.Large-scale direct shear tests on accumulation body with different stone contents[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(S2): 161-166. (in Chinese)) [6] WANG S R, LI C L, WANG Y G, et al.Evolution characteristics analysis of pressure-arch in a double-arch tunnel[J]. Tehnicki Vjesnik-Technical Gazette, 2016, 23: 181-189. [7] KONG X X, LIU Q S, ZHANG Q B, et al.A method to estimate the pressure arch formation above underground excavation in rock mass[J]. Tunnelling and Underground Space Technology, 2018, 71: 382-390. [8] WANG X Q, KANG H P, GAO F Q.Numerical study on the formation of pressure arch in bolted gravel plate[J]. Computers and Geotechnics, 2021, 130: 1-10. [9] 朱合华, 黄锋, 徐前卫. 变埋深下软弱破碎隧道围岩渐进性破坏试验与数值模拟[J]. 岩石力学与工程学报, 2010, 29(6): 1113-1122. (ZHU He-hua, HUANG Feng, XU Qian-wei.Model test and numerical simulation for progressive failure of weak and fractured tunnel surrounding rock under different overburden depths[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(6): 1113-1122. (in Chinese)) [10] 黄锋, 朱合华, 徐前卫. 含软弱夹层隧道围岩松动破坏模型试验与分析[J]. 岩石力学与工程学报, 2016, 35(增刊1): 2915-2924. (HUANG Feng, ZHU He-hua, XU Qian-wei.Model test and analysis about loose failure of tunnel surrounding rock mass containing weak interlayer[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(S1): 2915-2924. (in Chinese)) [11] 房倩, 张顶立, 王毅远, 等. 圆形洞室围岩破坏模式模型试验研究[J]. 岩石力学与工程学报, 2011, 30(3): 564-571. (FANG Qian, ZHANG Ding-li, WANG Yi-yuan, et al.Model test study of failure modes surrounding rock for circular caverns[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(3): 564-571. (in Chinese)) [12] 李英杰, 张顶立, 宋义敏, 等. 软弱破碎深埋隧道围岩渐进性破坏试验研究[J]. 岩石力学与工程学报, 2012, 31(6): 1138-1147. (LI Ying-jie, ZHANG Ding-li, SONG Yi-min, et al.Experimental research of progressive damage of surrounding rock for soft fractured deep tunnel[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(6): 1138-1147. (in Chinese)) [13] 汪成兵. 均质岩体中隧道围岩破坏过程的试验与数值模拟[J]. 岩土力学, 2012, 33(1): 103-108. (WANG Cheng-bing.Laboratory and numerical investigation on failure process of tunnel constructed in homogeneous rock[J]. Rock and Soil Mechanics, 2012, 33(1): 103-108. (in Chinese)) [14] 叶飞, 毛家骅, 刘燕鹏, 等. 软弱破碎隧道围岩动态压力拱效应模型试验[J]. 中国公路学报, 2015, 28(10): 76-82. (YE Fei, MAO Jia-hua, LIU Yan-peno, et al.Model test on effect of dynamic pressure arch of tunnel in soft broken surrounding rock[J]. China Journal of Highway and Transport, 2015, 28(10): 76-82. (in Chinese)) [15] 郑康成, 丁文其, 金威, 等. 特大断面隧道分步施工动态压力拱分析研究[J]. 岩土工程学报, 2015, 37(增刊1): 72-77. (ZHENG Kang-cheng, DING Wen-ai, JIN Wei, et al.Experimental and numerical study on staged construction pressure arch of super large section tunnel[J]. China Journal of Geotechnical Engineering, 2015, 37(S1): 72-77. (in Chinese)) [16] 崔蓬勃, 朱永全, 刘勇, 等. 考虑土拱发挥过程的非饱和砂土盾构隧道极限支护力计算方法研究[J]. 岩土工程学报, 2020, 42(5): 873-881. (CUI Peng-bo, ZHU Yong-quan, LIU Yong, et al.Calculation of ultimate supporting forces of shield tunnels in unsaturated sandy soils considering soil arching effects[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(5): 873-881. (in Chinese)) [17] 曲世韡. 深埋城市地铁隧道对地层变形的影响及压力拱形成规律研究[D]. 北京: 北京交通大学, 2013. (QU Shi-fu.Study on Influence of Deep-buried Urban Subway Tunnel on Strata Deformation and Formation rule of Pressure Arch[D]. Beijng: Bejjing Jiaotong University, 2009. (in Chinese)) [18] 潘皇宋, 杜广印, 王坤, 等. 无衬砌黄土隧道压力拱模型试验及数值模拟[J]. 东南大学学报(自然科学版), 2019, 49(5): 949-955. (PAN Huang-song, DU Guang-yin, WANG Kun, et al.Model test and numerical simulation on pressure arch of unlined loess tunnel[J]. Journal of Southeast University (Natural Science Edition), 2019, 49(5): 949-955. (in Chinese)) [19] 中交第一勘察设计研究院有限公司. 国道318林芝到拉萨段公路改造工程(二期)[R]. 西安, 2015. (CCCC First Highway Consultants Co., Ltd., Reconstruction of Nyingchi-Lasa Section of National Highway 318 (Phase II)[R]. Xi'an, 2015. (in Chinese)) [20] 何珺, 张成平, 杨公标. 砂卵石地层小净距隧道渐进性破坏过程试验研究[J]. 土木工程学报, 2015, 48(增刊1): 362-367. (HE Jun, ZHANG Cheng-ping, YANG Gong-biao.Test study on progressive failure of closely spaced tunnel in sandy cobble ground[J]. China Civil Engineering Journal, 2015, 48(S1): 362-367. (in Chinese)) [21] 江权, 冯夏庭, 李邵军, 等. 高应力下大型硬岩地下洞室群稳定性设计优化的裂化-抑制法及其应用[J]. 岩石力学与工程学报, 2019, 38(6): 1081-1101. (JIANG Quan, FENG Xia-ting, LI Shao-jun.Cracking-restraint design method for large underground caverns with hard rock under high geostress condition and its practical application[J]. Chinese Journal of Rock Mechanics and Engineering, 2019, 38(6): 1081-1101. (in Chinese))
