Influences of vertical drainage wells on stability of expansive soil canals in North Xinjiang
DENG Ming-jiang1, CAI Zheng-yin2,3, GUO Wan-li3, HUANG Ying-hao2,3, ZHANG Chen3
1. State Key Laboratory of Eco-Hydraulics in Northwest Arid Region of China, Xi'an 710048, China; 2. Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam of the Ministry of Water Resources, Nanjing 210024, China; 3. Geotechnical Engineering Department, Nanjing Hydraulic Research Institute, Nanjing 210024, China
Abstract：The water conveyance canal in North Xinjiang is a periodic water supply canal, and the “wetting-drying” circulation caused by canal water leakage may significantly reduce the strength of expansive soils and further affect the stability of the expansive soil canals. In order to reduce the threat of canal leakage to the stability of canal slopes, the Construction and Management Department has carried out the transformation of the seepage quick drainage system. Based on this, the stability characteristics of the canals before and after the reform are analyzed through numerical calculation. The results show that if the water level behind the membrane of the leakage section is reduced to 0 m by the vertical drainage well pumping operation, the stability factor of the section under the most dangerous condition is greater than 1.35, which means the canal slope is stable. If the seepage pumping is not carried out, when the section with water level greater than 1 m after membrane is operated for more than 10 years, the stability factor will be less than 1.05, and the canal slope is understable or unstable. Only the function of the vertical drainage wells as the anti-slide piles is analyzed, then the function can be ignored, and the sliding arc will appear in front of the drainage wells. If the location of a drainage well is moves forward, the maximum protection range of a single pile is 44 meters when the drainage well moves to the edge of the canal.
邓铭江, 蔡正银, 郭万里, 黄英豪, 张晨. 竖向排水井对北疆膨胀土渠道稳定性的作用分析[J]. 岩土工程学报, 2020, 42(s2): 1-6.
DENG Ming-jiang, CAI Zheng-yin, GUO Wan-li, HUANG Ying-hao, ZHANG Chen. Influences of vertical drainage wells on stability of expansive soil canals in North Xinjiang. Chinese J. Geot. Eng., 2020, 42(s2): 1-6.
 张良以, 陈铁林, 张顶立. 降雨诱发膨胀土边坡渐进破坏研究[J]. 岩土工程学报, 2019, 41(1): 70-77. (ZHANG Liang-yi, CHEN Tie-lin, ZHANG Ding-li.Progressive failure of expansive soil slopes under rainfall[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(1): 70-77. (in Chinese))  孔令伟, 陈正汉. 特殊土与边坡技术发展综述[J].土木工程学报, 2012, 45(5): 141-161. (KONG Ling-wei, CHEN Zheng-han.Advancement in the techniques for special soils and slopes[J]. China Civil Engineering Journal, 2012, 45(5): 141-161. (in Chinese))  殷宗泽, 袁俊平, 韦杰, 等. 论裂隙对膨胀土边坡稳定的影响[J].岩土工程学报, 2012, 34(12): 2155-2161. (YIN Zong-ze, YUAN Jun-ping, WEI Jie, et al.Influences of fissures on slope stability of expansive soil[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(12): 2155-2161. (in Chinese))  唐朝生, 施斌. 干湿循环过程中膨胀土的胀缩变形特征[J]. 岩土工程学报, 2011, 33(9): 1376-1384. (TANG Chao-sheng, SHI Bin.Swelling and shrinkage behaviour of expansive soil during wetting-drying cycles[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(9): 1376-1384. (in Chinese))  OH S, NING L.Slope stability analysis under unsaturated conditions: Case studies of rainfall-induced failure of cut slopes[J]. Engineering Geology, 2015, 184: 96-103.  陈善雄, 戴张俊, 陆定杰, 等. 考虑裂隙分布及强度的膨胀土边坡稳定性分析[J]. 水利学报, 2014, 45(12): 1442-1449. (CHEN Shan-xiong, DAI Zhang-jun, LU Ding-jie, et al.Stability analysis of expansive soil slope considering fracture distribution and strength[J]. Journal of Hydraulic Engineering, 2014, 45(12): 1442-1449. (in Chinese))  周跃峰, 程展林, 龚壁卫, 等. 新疆某渠道边坡填料的剪胀特性与变形失稳研究[J]. 岩石力学与工程学报, 2018, 37(增刊2): 4406-4414. (ZHOU Yue-feng, CHENG Zhan-lin, GONG Bi-wei, et al.The dilatancy and instability of an infilled material in a canal slope in Xinjiang[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(S2): 4406-4414. (in Chinese))  岑威钧, 王蒙, 石从浩, 等. 降雨条件下多裂隙膨胀岩渠坡稳定性分析[J]. 郑州大学学报(工学版), 2014, 35(2): 10-14. (CENG Wei-jun, WANG Meng, SHI Cong-hao.Stability analysis of multi-fissure expansive rock canal slope under rainfall conditions[J]. Journal of Zhengzhou University (Engineering Science), 2014, 35(2): 10-14. (in Chinese))  温世亿. 膨胀土渠坡若干关键技术问题研究[D]. 武汉: 武汉大学, 2010. (WEN Shi-yi.Research on Several Key Teehnieal Problems of Expansive Soil Canal Slopes[D]. Wuhan: Wuhan University, 2010. (in Chinese))  KHAN M S, HOSSAIN S, AHMED A, et al.Investigation of a shallow slope failure on expansive clay in texas[J]. Engineering Geology, 2016, 219: S0013795216304616.  郑颖人, 赵尚毅. 有限元强度折减法在土坡与岩坡中的应用[J]. 岩石力学与工程学报, 2004, 23(19): 3381-3388. (ZHENG Ying-ren, ZHAO Shang-yi.Application of strength reduction FEM in soil and rock slope[J]. Chinese Journal of Rock Mechanics and Engineering, 2004, 23(19): 3381-3388. (in Chinese))  邓铭江, 蔡正银, 郭万里, 等. 北疆白砂岩特殊物理力学性质试验研究[J]. 岩土工程学报, 2020, 42(增刊1): 1-5. (DENG Ming-jiang, CAI Zheng-yin, GUO Wan-li[J]. Experimental study on special physical and mechanical properties of white sandstone in North Xinjiang[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(S1): 1-5. (in Chinese))  陈皓. 膨胀土渠道在干湿循环作用下的稳定性研究[D]. 南京: 南京水利科学研究院, 2019. (CHEN Hao.Study on Stability of Canal Slope of Expensive Soil under Drying-wetting Cycles[D]. Nanjing: Nanjing Hydraulic Research Institute, 2019. (in Chinese))