Please wait a minute...
Journal of ZheJiang University (Engineering Science)  2020, Vol. 54 Issue (9): 1715-1726    DOI: 10.3785/j.issn.1008-973X.2020.09.007
    
Experimental and numerical study on slurry fracturing of shield tunnels in sandy stratum
Jing-jing LIU1(),Tie-lin CHEN1,*(),Mao-hong YAO1,Yu-xin WEI2,Zi-jian ZHOU1
1. Key Laboratory of Urban Underground Engineering of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China
2. Beijing Urban Rapid Transit Development Co. Ltd, Beijing 100027, China
Download: HTML     PDF(1876KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

A series of 2D model tests on slurry fracturing of shield tunnels in the sandy stratum with different cover depths were conducted to investigate the slurry fracturing mechanism, the displacements of the ground surface, and the earth pressure distribution in the stratum. According to the test results, the slurry fracturing mechanism is that the dense sandy stratum and the filter cake on its surface (the filter cake-sandy stratum) is formed due to the pressurized slurry penetrating into the sandy stratum around excavation space, and then the filter cake-sandy stratum is pushed by the slurry to tensile and shear failure. The fracture pressure increases linearly with the increase of the cover depth. The fracture initiates on the top edge of the cutter head and propagates up to the ground surface in acclivitous direction directly, or first in straight and then in acclivitous direction. Based on a self-developed finite element program for simulating slurry fracturing, the 2D numerical models were established referring to the model tests, the numerical results including the morphology of the fracture propagation which agreed with the test results, and the vertical and horizontal displacements in the stratum were obtained. The numerical results show that the vertical displacement mainly distributes in a triangle region bounded by the fracture surface above the cutter head, while the horizontal displacement mainly distributes in the excavation face.



Key wordssandy stratum      slurry shield      slurry fracturing      filter cake      model test method      finite element method (FEM)     
Received: 17 January 2020      Published: 22 September 2020
CLC:  U 45  
Corresponding Authors: Tie-lin CHEN     E-mail: 13115305@bjtu.edu.cn;tlchen1@bjtu.edu.cn
Cite this article:

Jing-jing LIU,Tie-lin CHEN,Mao-hong YAO,Yu-xin WEI,Zi-jian ZHOU. Experimental and numerical study on slurry fracturing of shield tunnels in sandy stratum. Journal of ZheJiang University (Engineering Science), 2020, 54(9): 1715-1726.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2020.09.007     OR     http://www.zjujournals.com/eng/Y2020/V54/I9/1715


砂层盾构隧道泥水劈裂试验与数值研究

开展砂层盾构隧道泥水劈裂平面模型试验,研究不同覆土厚度条件下的泥水劈裂破坏机制、土体表面竖向位移和土体内部土压力变化规律. 结果显示,劈裂机制为加压泥浆向掘削空间表面砂层渗透形成致密砂层及其表面泥膜(泥膜-砂层结构),泥膜-砂层结构在泥浆挤压作用下发生拉剪破坏. 劈裂压力随覆土厚度的增加呈近似线性增大. 劈裂扩展从刀盘顶部起始分别呈“斜直线”或“先竖直后斜线”型向上扩展. 基于自主开发的模拟泥水劈裂的有限元计算程序,参照模型试验建立二维数值模型,计算获得与模型试验较一致的劈裂扩展形态以及土体内部竖向位移与水平位移的变化规律. 结果表明,土体竖直向位移主要分布在刀盘上方以劈裂面为边界的“三角形”区域内,土体水平位移主要分布在掘削面土层.


关键词: 砂层,  泥水盾构,  泥水劈裂,  泥膜,  模型试验法,  有限元法(FEM) 
Fig.1 Schematic diagram of model test device for slurry fracturing of shield tunnels
Fig.2 Model test device for slurry fracturing of shield tunnels
Fig.3 Shield model and open pore of cutter head
C/cm p1 / kPa p2 / kPa p3 / kPa
4.5 120 82 186
9.0 142 219 149
18.0 450 417 344
27.0 501 426 248
Tab.1 Experimental value of slurry fracture pressure under different cover depths conditions
Fig.4 Slurry fracture morphology under different cover depths conditions
Fig.5 Process chart of slurry fracturing of shield tunnels in sandy stratum
Fig.6 Filter cake and fracture morphology on excavation face
Fig.7 Top-view images of slurry fracture morphology in stratum above shield model under smaller cover depths (C=0.5 D, 1.0 D) conditions
Fig.8 Top-view images of slurry fracture morphology in stratum above shield model under larger cover depths (C=2.0 D, 3.0 D) conditions
Fig.9 Mechanical analysis for direction of fracture propagation
Fig.10 Uplift displacement of ground surface varying with time
Fig.11 Uplift displacement of ground surface at moment of fracture propagating to ground surface under different cover depths conditions
Fig.12 Curves of variations in earth pressure during slurry fracturing process
Fig.13 Photo of slurry fracture propagating to earth pressure sensor #3
材料 ρ / (kg·m?3) e Sr k / (m·s?1) 邓肯-张模型参数
K Kur n c/kPa $\phi $ Rf Kb m
砂土 1 560 0.80 0.20 1×10?10 276 552 0.57 1 31.88 0.87 50 0.2
泥膜-砂层结构 2 000 0.50 1.00 1×10?20 500 1 000 0.60 500 30.00 0.90 100 0.3
Tab.2 Material parameters in numerical simulation
Fig.14 Schematic diagram of numerical model of slurry fracturing of shield tunnels in sandy stratum
Fig.15 Numerical results of slurry fracture morphology under different cover depths conditions
Fig.16 Distribution of experimental and numerical slurry fracture pressure under different cover depths conditions
Fig.17 Numerical results of horizontal displacement at moment of slurry fracture propagating to ground surface under different cover depths conditions
Fig.18 Numerical results of vertical displacement at moment of slurry fracture propagating to ground surface under different cover depths conditions
[1]   朱金才, 卢珂, 杨进超, 等 砂土地层中隧道失稳机理验证[J]. 地下空间与工程学报, 2015, 11 (5): 1175- 1179
ZHU Jin-cai, LU Ke, YANG Jin-cao, et al Verification of the failure mechanism of tunnel in sandy soil[J]. Chinese Journal of Underground Space and Engineering, 2015, 11 (5): 1175- 1179
[2]   朱永全, 宋玉香. 隧道工程: 第2版[M]. 北京: 中国铁道出版社, 2007: 30.
[3]   王梦恕 中国盾构和掘进机隧道技术现状、存在的问题及发展思路[J]. 隧道建设, 2014, 34 (3): 179- 187
WANG Meng-shu Tunneling by TBM/shield in China: state-of-art, problems and proposals[J]. Tunnel Construction, 2014, 34 (3): 179- 187
doi: 10.3973/j.issn.1672-741X.2014.03.001
[4]   闵凡路, 宋航标, 柏煜新, 等 泥水盾构隧道开挖面被动破坏研究进展[J]. 隧道建设, 2018, 38 (4): 575- 581
MIN Fan-lu, SONG Hang-biao, BAI Yu-xin, et al Research progress of passive failure of excavation face during slurry shield tunneling[J]. Tunnel Construction, 2018, 38 (4): 575- 581
doi: 10.3973/j.issn.2096-4498.2018.04.007
[5]   LV X L, ZHOU Y C, HUANG M S, et al Experimental study of the face stability of shield tunnel in sands under seepage condition[J]. Tunnelling and Underground Space Technology, 2018, 74: 195- 205
doi: 10.1016/j.tust.2018.01.015
[6]   WONG K S, Ng C W W, Chen Y M, et al Centrifuge and numerical investigation of passive failure of tunnel face in sand[J]. Tunnelling and Underground Space Technology, 2012, 28: 297- 303
doi: 10.1016/j.tust.2011.12.004
[7]   李昀. 软土中超大直径泥水平衡盾构开挖面稳定性研究[D]. 上海: 同济大学, 2008: 53.
LI Yun. Stability analysis of large slurry shield-driven tunnel in soft clay [D]. Shanghai: Tongji University, 2008: 53.
[8]   袁大军, 黄清飞, 小泉淳, 等 水底盾构掘进泥水喷发现象研究[J]. 岩石力学与工程学报, 2007, 26 (11): 2296- 2301
YUAN Da-jun, HUANG Qing-fei, XIAO Quan-chun, et al Study on slurry-water gushing during underwater shield tunnel construction[J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26 (11): 2296- 2301
doi: 10.3321/j.issn:1000-6915.2007.11.016
[9]   LIU X Y, YUAN D J An in-situ slurry fracturing test for slurry shield tunneling[J]. Journal of Zhejiang University-SCIENCE A: Applied Physics and Engineering, 2014, 15 (7): 465- 481
[10]   ADACHI J, SIEBRITS E, PEIRCE A, et al Computer simulation of hydraulic fractures[J]. International Journal of Rock Mechanics and Mining Sciences, 2007, 44 (5): 739- 757
doi: 10.1016/j.ijrmms.2006.11.006
[11]   KUMAR S, ZIELONKA M, SEARLES K, et al Modeling of hydraulic fracturing in ultra-low permeability formations: the role of pore fluid cavitation[J]. Engineering Fracture Mechanics, 2017, 184: 227- 240
doi: 10.1016/j.engfracmech.2017.08.020
[12]   CHEN T L, PANG T Z, ZHAO Y, et al Numerical simulation of slurry fracturing during shield tunnelling[J]. Tunnelling and Underground Space Technology, 2018, 74: 153- 166
doi: 10.1016/j.tust.2018.01.021
[13]   MIN F L, ZHU W, HAN X R Filter cake formation for slurry shield tunneling in highly permeable sand[J]. Tunnelling and Underground Space Technology, 2013, 38: 423- 430
doi: 10.1016/j.tust.2013.07.024
[14]   尹鑫晟. 泥水盾构成膜规律及开挖面稳定性[D]. 杭州: 浙江大学, 2017: 27.
YIN Xin-sheng. Cake filtration and face stabilitv of slurry shield tunnel[D]. Zhejiang: Zhejiang University, 2017: 27.
[15]   XU T, BEZUIJEN A. Bentonite slurry infiltration into sand: filter cake formation under various conditions[J]. Geotechnique. 2019, 69(12): 1095-1106.
[16]   CUI W, LIU D, SONG H F, et al Development and experimental study on environmental slurry for slurry shield tunneling[J]. Construction and Building Materials, 2019, 216: 416- 423
doi: 10.1016/j.conbuildmat.2019.04.265
[17]   阮文军, 王文臣, 胡安兵 新型水泥复合浆液的研制及其应用[J]. 岩土工程学报, 2001, 23 (2): 212- 216
RUAN Wen-jun, WANG Wen-chen, HU An-bing Development and application of new kind of cement composite grout[J]. Chinese Journal of Geotechnical Engineering, 2001, 23 (2): 212- 216
doi: 10.3321/j.issn:1000-4548.2001.02.018
[18]   闵凡路, 魏代伟, 姜腾, 等 泥浆在地层中的渗透特性试验研究[J]. 岩土力学, 2014, 35 (10): 2801- 2806
MIN Fan-lu, WEI Dai-wei, JIANG Teng, et al Experimental study of law of slurry infiltration in strata[J]. Rock and Soil Mechanics, 2014, 35 (10): 2801- 2806
[19]   陈仲颐, 周景星, 王洪瑾. 土力学[M]. 北京: 清华大学出版社, 1994: 164-165.
[20]   孙训方, 方孝淑, 关来泰. 材料力学: 第1册[M]. 北京: 高等教育出版社, 2009: 234.
[21]   屈智炯, 刘恩龙. 土的塑性力学[M]. 北京: 科学出版社, 2011: 182-183.
[22]   工程地质手册编委会. 工程地质手册: 第5版[M]. 北京: 中国建筑工业出版社, 2018: 176.
[1] Lian-hui JIA,Tai-yun LI. Key technologies of segment erector for super-large shield machine[J]. Journal of ZheJiang University (Engineering Science), 2020, 54(4): 816-823.
[2] YU Yang-tian, ZHANG Qing, GU Xin. Hybrid model of peridynamics and finite element method under implicit schemes[J]. Journal of ZheJiang University (Engineering Science), 2017, 51(7): 1324-1330.
[3] PAN Qian, CHEN Yun min, LI Yu chao, WEN Yi duo. Hydraulic conductivity of bentonite filter cake and its impact on permeability of cutoff walls[J]. Journal of ZheJiang University (Engineering Science), 2017, 51(2): 231-237.
[4] XIAO Wen-sheng, CUI Jun-guo, LIU Jian, WU Xiao-dong, HUANG Hong-sheng. Optimization study for reducing cogging torque in permanent magnet synchronous motor used for direct-drive oil pumping[J]. Journal of ZheJiang University (Engineering Science), 2015, 49(1): 173-180.
[5] XIAO Wen-sheng, CUI Jun-guo, LIU Jian, WU Xiao-dong, HUANG Hong-sheng. ptimization study for reducing cogging torque in permanent magnet synchronous motor used for direct-drive oil pumping[J]. Journal of ZheJiang University (Engineering Science), 2014, 48(8): 1-8.
[6] PAN Xiao-yu, XIE Xu, LI Xiao-zhang, SUN Wenzhi, ZHU Han-hua. Mechanical properties and grading method of corroded high-tensile steel wires[J]. Journal of ZheJiang University (Engineering Science), 2014, 48(11): 1917-1924.
[7] ZHANG Zhong-miao, FANG Kai, LIU Xing-wang, LIN Cun-gang. Surrounding ground settlement control of special double-row
structure supported foundation pit
[J]. Journal of ZheJiang University (Engineering Science), 2012, 46(7): 1275-1280.
[8] WANG Cheng-li, GAO Hui, LU Jian-gang. Loss of damper bars in hydro-generator under different stator fault[J]. Journal of ZheJiang University (Engineering Science), 2012, 46(4): 770-776.
[9] ZHANG Zhong-miao, LIN Cun-gang,WU Shi-ming,ZOU Jian, LIU Jun-wei. Case study of ground surface consolidation settlements induced
by slurry shield tunnelling
[J]. Journal of ZheJiang University (Engineering Science), 2012, 46(3): 431-440.
[10] LIU Lian-yun, HAO Zhi-yong, QIAN Xin-yi. Simulation methods for acoustical characteristics of
air-cleaner filter element
[J]. Journal of ZheJiang University (Engineering Science), 2012, 46(10): 1784-1789.
[11] ZHONG Zhi-xian, ZHU Chang-sheng. Dynamics behavior of multi-disk flexible rotor system
with transverse crack
[J]. Journal of ZheJiang University (Engineering Science), 2012, 46(10): 1839-1845.
[12] SHEN Guo-hui, SUN Bing-nan, YE Yin, LOU Wen-juan. Broken wire analysis and broken wire load calculation of
high voltage transmission tower
[J]. Journal of ZheJiang University (Engineering Science), 2011, 45(4): 678-683.
[13] YANG De-Jun, ZHANG Cha-Jiao, ZHANG Ke-feng, et al. Simulation of dynamic root growth and water transfer in soil-crop-atmosphere system[J]. Journal of ZheJiang University (Engineering Science), 2009, 43(11): 2048-2053.