Analysis on the mechanism of bank slope sliding considering the effect of reservoir water fluctuation and sliding zone weakening
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摘要:
以三峡库区凉水井滑坡为研究对象，采用理论分析与数值模拟的研究手段，构建了滑带强度弱化模型，提出了渗流驱动的滑坡启滑判据，应用Geo-studio有限元程序分析了库水不同升降速率对滑坡稳定性的影响，揭示了库水升降作用下岸坡渗流场演变规律和渗流驱动下的启滑机制。研究表明：（1）渗透压力与渗透时间的变化是滑带土强度弱化的关键因素，弱化到临界强度时，在渗流驱动下发生压剪破坏而启滑，由局部向整体以渐进模式破坏失稳；（2）库水升降过程中，坡体内孔隙水压力滞后性较明显，水位升降速率会影响坡体地下水响应时程，升降速率越大，孔隙水压力变化越大，渗流驱动力越大，滑坡稳定性变化越快，越趋近于渐进破坏；（3）库水位从175 m降到145 m，凉水井滑坡滑面法向应力最大降低了38.19%，剪应力最大降低了22.20%，有效法向应力最大落差为168.64 kPa，抗剪强度最大落差为63.45 kPa。以上分析结论与规律可为涉水滑坡启滑机制分析、库岸山体滑坡失稳研究及应急防治工程等提供科学依据和理论方法。
Abstract:This study focuses on the Liangshuijing landslide in the Three Gorges Reservoir area, using theoretical analysis and numerical simulations methods to construct a strength weakening model for the sliding zone and proposes a criterion for seepage-driven landslide initiation. The influence of different water level rise and fall rates on landslide stability is analyzed using the finite element program Geo-Studio, and the evolution laws of bank slope seepage field under the rise and fall of reservoir water and the starting and sliding mechanism caused by seepage are revealed. The research finds that changes in seepage pressure and time are crucial in weakening the strength of sliding zone soil. Once it reaches the critical strength, seepage causes pressure shear failure, leading to the initiation of the landslide, which progresses from local to overall failure. During the reservoir water level rise and fall process, the hysteresis of pore water pressure in the slope body is evident, and the rate of water level change affects the response time of groundwater in the slope. A faster rate of water level change leads to a greater change in pore water pressure, more driving force from seepage, and a faster change in landslide stability and a closer approach to progressive failure. When the reservoir water level drops from 175 m to 145 m, the normal stress on the sliding surface of the Liangshuijing landslide decreases by 38.19%, and the shear stress decreases by 22.20%. The maximum decrease in the effective normal stress is 168.64 kPa and the maximum decrease in shear strength is 63.45 kPa. The above findings provide a scientific basis and theoretical methods for the analysis of landslide initiation and sliding mechanisms, instability research of reservoir bank landslides, and emergency prevention and control engineering.
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表 1 滑坡计算参数一览表
Table 1. List of calculation parameters for Liangshuijing landslide
岩土体 弹性模量/GPa 泊松比 重度/（kN·m−3） 黏聚力/kPa 内摩擦角/（°） 天然 饱和 天然 饱和 天然 饱和 滑床 24 0.2 25.1 25.3 5650 5420 47.04 43.80 滑带 3 0.4 23.0 23.8 19.17 14.41 25.03 24.29 滑体 3 0.4 23.0 23.8 21.48 19.29 34.83 27.68 
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[1] 谭淋耘,黄润秋,裴向军. 库水位下降诱发的特大型顺层岩质滑坡变形特征与诱发机制[J]. 岩石力学与工程学报,2021,40(2):302 − 314. [TAN Linyun,HUANG Runqiu,PEI Xiangjun. Deformation characteristics and inducing mechanisms of a super-large bedding rock landslide triggered by reservoir water leve l decline in Three Gorges Reservoir area[J]. Chinese Journal of Rock Mechanics and Engineering,2021,40(2):302 − 314. (in Chinese with English abstract)
[2] 肖捷夫,李云安,胡勇,等. 库水涨落和降雨条件下古滑坡变形特征模型试验研究[J]. 岩土力学,2021,42(2):471 − 480. [XIAO Jiefu,LI Yunan,HU Yong,et al. Model tests on deformation characteristics of ancient bank landslide under water level fluctuation and rainfall[J]. Rock and Soil Mechanics,2021,42(2):471 − 480. (in Chinese with English abstract)
[3] 李跃,徐卫亚,易魁,等. 堆积体滑带土非饱和-饱和渗透特性试验研究[J]. 岩土力学,2021,42(5):1355 − 1362. [LI Yue,XU Weiya,YI Kui,et al. Experimental study of unsaturated-saturated permeability characteristics of slip soil in landslide deposits[J]. Rock and Soil Mechanics,2021,42(5):1355 − 1362. (in Chinese with English abstract)
[4] HE Chuncan,HU Xinli,XU Chu,et al. Model test of the influence of cyclic water level fluctuations on a landslide[J]. Journal of Mountain Science,2020,17(1):191 − 202. doi: 10.1007/s11629-019-5713-9
[5] TU Guoxiang,DA Huang,DENG Hui. Reactivation of a huge ancient landslide by surface water infiltration[J]. Journal of Mountain Science,2019,16(4):806 − 820. doi: 10.1007/s11629-018-5315-5
[6] CAO Chunhui,FENG Jili,TAO Zhigang. Start-up mechanism and dynamic process of landslides in the full high waste dump[J]. Water,2020,12(9):2543. doi: 10.3390/w12092543
[7] 陈小平,黄勋. 强度折减中滑坡启动阶段的动力分配原理[J]. 岩石力学与工程学报,2018(4):809 − 819. [CHEN Xiaoping,HUANG Xun. Mechanism of dynamic distribution in the stage of landslide initiation with shear strength reduction[J]. Chinese Journal of Rock Mechanics and Engineering,2018(4):809 − 819. (in Chinese with English abstract) doi: 10.13722/j.cnki.jrme.2017.0758
[8] 刘梦琴,陈勇. 基于直剪试验的滑带土强度再生特征研究[J]. 人民长江,2018,49(18):92 − 96. [LIU Mengqin,CHEN Yong. Strength regeneration characteristics of sliding zone soil based on direct shear test[J]. Yangtze River,2018,49(18):92 − 96. (in Chinese with English abstract)
[9] 高玮,冯威,王家超,等. 一种基于滑动带的土坡稳定分析方法研究[J]. 水利与建筑工程学报,2017,15(6):1 − 6. [GAO Wei,FENG Wei,WANG Jiachao,et al. Stability analysis method of soil slope based on sliding zone[J]. Journal of Water Resources and Architectural Engineering,2017,15(6):1 − 6. (in Chinese with English abstract)
[10] ZHU Feng,DUAN Zhongyuan,WU Zhenyu,et al. Experimental study on direct shear creep characteristics and long-term strength of red layer sliding zone soil in southern Hunan[J]. Advanced Materials Research,2013,842:782 − 787. doi: 10.4028/www.scientific.net/AMR.842.782
[11] LIU Q B,WANG S,XIA D S,et al. Experimental study of residual-state creep behavior of intact sliding-zone soil[J]. Yantu Lixue/Rock and Soil Mechanics,2017,38(5):1305 − 1313.
[12] LIAO Kang,WU Yiping,MIAO Fasheng,et al. Effect of weakening of sliding zone soils in hydro-fluctuation belt on long-term reliability of reservoir landslides[J]. Bulletin of Engineering Geology and the Environment,2021,80(5):3801 − 3815. doi: 10.1007/s10064-021-02167-9
[13] ZHAO Yong,ZHU Liubing,HU Wenyi,et al. Analysis of stability factors and interaction rules of soil slope under heavy rainfall[J]. IOP Conference Series:Earth and Environmental Science,2020,546(3):032037. doi: 10.1088/1755-1315/546/3/032037
[14] 鲁文搏,吴益平,廖建民,等. 渗透作用下滑带土强度弱化规律研究[J]. 武汉理工大学学报(交通科学与工程版),2016,40(2):345 − 350. [LU Wenbo,WU Yiping,LIAO Jianmin,et al. The law of residual strength weakening of slip soil under the action of seepage[J]. Journal of Wuhan University of Technology (Transportation Science & Engineering),2016,40(2):345 − 350. (in Chinese with English abstract) doi: 10.3963/j.issn.2095-3844.2016.02.029
[15] 仵彦卿. 岩土水力学[M]. 北京: 科学出版社, 2009
WU Yan qing. Rock and Soil hydraulics[M]. Beijing: Science Press, 2009. （in Chinese）
[16] 周云涛,唐红梅,陈洪凯. 三峡水库泄水期间类土质岸坡渗流驱动压剪破坏机制研究[J]. 重庆师范大学学报(自然科学版),2016,33(6):37 − 44. [ZHOU Yuntao,TANG Hongmei,CHEN Hongkai. Study on compression-shear failure mechanism by seepage-driving for the quasi earthy bank slope during the drawdown in Three Gorges Reservoir[J]. Journal of Chongqing Normal University (Natural Science),2016,33(6):37 − 44. (in Chinese with English abstract)
[17] 重庆市高新岩土工程勘察设计院. 重庆市云阳县故陵镇凉水井滑坡应急勘查报告[R]. 重庆: 重庆市高新岩土工程勘察设计院, 2009
Chongqing Gaoxin geotechnical engineering survey and Design Institute Emergency investigation report on Liangshuijing landslide in Guling Town, Yunyang County, Chongqing [R] Chongqing: Chongqing Gaoxin geotechnical engineering survey and Design Institute, 2009. （in Chinese）
[18] 夏敏,任光明,马鑫磊,等. 库水位涨落条件下滑坡地下水渗流场动态特征[J]. 西南交通大学学报,2014,49(3):399 − 405. [XIA Min,REN Guangming,MA Xinlei,et al. Dynamic responses of groundwater seepage of landslide influenced by fluctuation of reservoir water level[J]. Journal of Southwest Jiaotong University,2014,49(3):399 − 405. (in Chinese with English abstract)
[19] 汤明高,吴川,吴辉隆,等. 水库滑坡地下水动态响应规律及浸润线计算模型—以石榴树包滑坡为例[J]. 水文地质工程地质,2022,49(2):115 − 125. [TANG Minggao,WU Chuan,WU Huilong,et al. Dynamic response and phreatic line calculation model of groundwater in a reservoir landslide:Exemplified by the Shiliushubao landslide[J]. Hydrogeology & Engineering Geology,2022,49(2):115 − 125.
[20] 王孔伟,路永强,聂进,等. 三峡库区仙女山和九畹溪断裂带水库地震变化规律[J]. 吉林大学学报(地球科学版),2021,51(2):624 − 637. [WANG Kongwei,LU Yongqiang,NIE Jin,et al. Earthquake variation law of Xiannüshan and Jiuwanxi fault zones in Three Gorges Reservoir area[J]. Journal of Jilin University (Earth Science Edition),2021,51(2):624 − 637.
[21] 王玉川,郭其峰,周延国. 中等倾角岩层顺向坡滑坡发育特征及形成机制分析—以拖担水库左岸坝肩滑坡为例[J]. 中国地质灾害与防治学报,2021,32(4):17 − 23. [WANG Yuchuan,GUO Qifeng,ZHOU Yanguo. Development characteristics and formation mechanism of the medium-dip bedding slopes:A case study of the landslide on the left bank of Tuodan Reservoir dam[J]. The Chinese Journal of Geological Hazard and Control,2021,32(4):17 − 23.
[22] 郭延辉,杨溢,杨志全,等. 国产GB-InSAR在特大型水库滑坡变形监测中的应用[J]. 中国地质灾害与防治学报,2021,32(2):66 − 72. [GUO Yanhui,YANG Yi,YANG Zhiquan,et al. Application of GB-InSAR in deformation monitoring of huge landslide in reservoir area[J]. The Chinese Journal of Geological Hazard and Control,2021,32(2):66 − 72.
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