受库水位周期性变化影响，水库运行期间时常会发生滑坡等地质灾害，对岸坡周边环境造成严重后果，因此深入研究水位升降变化对岸坡稳定性的影响意义重大。土质岸坡稳定性与坡内渗流场的变化密切相关，而渗流场的变化受水位升降外因及土体渗透特性内因共同作用。为了对渗流场变化影响下的岸坡稳定性进行深入研究，本文以水库岸坡土体为研究对象，通过室内试验及数值模拟的研究手段分析水位升降作用对岸坡稳定性的影响。现将本文的主要研究成果总结如下：

（1）库水位升降下岸坡土体渗透特性及力学特性变化分析。设计干湿循环试验模拟岸坡土体受库水位升降的影响，利用渗透仪及压力板仪分析随干湿循环次数增加土体的渗透特性变化规律，结果表明随饱水失水循环次数的增加，土体渗透系数随循环次数的增加呈先快后慢逐渐趋于稳定的变化趋势。利用直剪仪分析随干湿循环次数增加土体的抗剪强度变化规律，结果表明随着干湿循环次数的增加，土体抗剪强度参数出现明显下降，其中内摩擦角随干湿循环次数的增加呈线性降低，但下降幅度较小，黏聚力随干湿循环次数的增加下降幅度呈先快后慢逐渐趋于稳定的变化规律，通过室内试验得到的土体参数变化为后文进行模型试验及数值模拟稳定性预测分析提供数据支撑。

（2）运用有限元分析软件，深入研究岸坡渗流场随水位升降的变化规律。通过模拟库水位的变化，发现随库水位升降变化，坡体内的渗流场会发生规律性的改变。当库水位上升时，地下水渗流方向由坡外指向坡内，浸润线由水平直线转变为下凹曲线；当库水位下降时，地下水的渗流方向会从坡内指向坡外，浸润线形态呈现上凸的曲线。建立物理模型试验模拟水位升降变化下的土质岸坡，研究了在库水位多次周期性升降作用下岸坡的孔隙水压力变化规律，试验结果表明坡体的孔隙水压力受库水位升降作用明显，且前缘、中部和后缘的影响效果不同，距离坡面位置越远，受库水位影响的滞后性越明显，随着水位升降次数的增加，坡体不同部位受水位变化影响的差异逐渐减小，对比模型试验结果，验证库水位周期循环作用下坡体渗流规律的合理性。

（3）依据工程实例对岸坡进行稳定性分析。岸坡的稳定系数在库水位波动下会发生显著变化，当库水位由低水位上升至高水位蓄水状态时，滑坡的稳定系数经历先快速增大后逐渐减小的过程，在库水位达到最高水位时，稳定系数达到最大值；当库水位由高水位下降至低水位运行阶段时，稳定系数经历先快速减小后逐渐增大的变化过程，滑坡最危险的时刻出现在库水位下降至低水位阶段附近。岸坡在多次水位升降作用下的动态稳定性变化规律与土体性质及水位密切相关，在水位升降作用下，岸坡土体的力学性质发生劣化，相同工况下的岸坡稳定性呈缓慢降低趋势，可能诱发坡体内部发生滑坡破坏。

Due to the repeated rise and fall of reservoir water, geological disasters such as landslides often occur during the operation of the reservoir, which can endanger the surrounding environment and cause serious consequences. Therefore, it is of great significance to conduct in-depth research on the stability of reservoir bank slopes. Due to the significant effect of water on soil bank slopes, the soil will inevitably undergo corresponding changes under the periodic rise and fall of reservoir water level, which may ultimately lead to geological disasters such as landslides. This article takes the soil of the reservoir bank slope as the research object, and analyzes the impact of water level rise and fall on the stability of the bank slope through theoretical analysis, indoor experiments, and numerical simulation. The main research results of this article are summarized as follows:

(1) Analysis of water permeability and mechanical properties of soil. The dry-wet cycle test was designed to simulate the influence of the rise and fall of the reservoir water level on the soil of the bank slope. The permeability characteristics of the soil with the increase of the number of dry-wet cycles were analyzed by using the permeameter and the pressure plate instrument. The results show that with the increase of the number of cycles of saturated water loss, the permeability coefficient of the soil increases with the number of cycles. The trend of fast and then slow gradually tends to be stable. Through the shear strength analysis of the direct shear apparatus, it is found that the shear strength of the soil changes with the increase of the number of dry and wet cycles. The results show that the shear strength parameters of the soil decrease significantly with the increase of the number of dry-wet cycles. Specifically, the internal friction angle decreases linearly, and the decrease is relatively small ; the decrease of cohesion shows a trend of fast first and then slow, and gradually tends to be stable. The changes of soil parameters obtained by laboratory tests provide data support for the prediction and analysis of bank slope stability.

(2) The finite element analysis software is used to study the seepage characteristics of the bank slope.By simulating the change of reservoir water level, it is found that with the change of reservoir water level,the seepage field in the slope will change regularly. When the reservoir water level rises, the groundwater seepage direction points from the outside of the slope to the inside of the slope, and the saturation line changes from a horizontal straight line to a concave curve;when the reservoir water level drops, the seepage direction of groundwater will point from the inside of the slope to the outside of the slope, and the shape of the saturation line presents a convex curve. A physical model test is established to simulate the soil bank slope under the change of water level fluctuation, and the variation law of pore water pressure of bank slope under the action of multiple periodic fluctuation of reservoir water level is studied. The test results show that the pore water pressure of the slope is obviously affected by the fluctuation of the reservoir water level, and the influence of the front, middle and rear edges is different. The farther away from the slope position, the more obvious the hysteresis of the influence of the reservoir water level. With the increase of the number of water level fluctuation, the difference of the influence of water level change on different parts of the slope gradually decreases.The rationality of the seepage law of the slope under the periodic circulation of the reservoir water level is verified.

(3) According to the engineering example, the stability analysis of the bank slope is carried out. The stability coefficient of bank slope will change significantly under the fluctuation of reservoir water level. When the reservoir water level rises from low water level to high water level, the stability coefficient of landslide increases rapidly and then decreases gradually. When the reservoir water level reaches the highest water level, the stability coefficient reaches the maximum value. When the reservoir water level drops from the high water level to the low water level operation stage, the stability coefficient undergoes a process of rapid decrease and then gradual increase. The most dangerous time of the landslide occurs near the reservoir water level drop to the low water level stage. The dynamic stability of the bank slope under the action of multiple water level fluctuations is closely related to the soil properties and water level. Under the action of water level fluctuations, the mechanical properties of the bank slope soil deteriorate, and the stability of the bank slope under the same working conditions decreases slowly, which may induce landslide damage inside the slope.

[1] 李广信,张丙印,于玉贞.土力学[M].北京:清华大学出版社,2013:169-178.

[2] 唐晓松,郑颖人,叶海林.涉水岸坡稳定性分析相关问题的研究[J].合肥工业大学学报(自然科学版),2009,32(10):1585-1589.

[3] 张景昱,宛良朋,潘洪月等.考虑水–岩作用特点的典型岸坡长期稳定性分析[J].岩土工程学报,2017,39(10):1851-1858.

[4] Lu H, Li J, Wang W, et al. Cracking and water seepage of Xiashu loess used as landfill coverunder wetting-drying cycles[J]. Environmental Earth Sciences, 2015,74(11):1-10.

[5] Louati F,TrabelsiH,Jamei M,et al.Impact of wetting-drying cycles and cracks on the permeability of compacted clayey soil[J].European Jourmal of Environmental & Civil Enginecring,2018:1-26.

[6] Albrecht B A,Benson C H.Effect of Desiccation on Compacted Natural Clays[J].Journal of Geotechnical & Geoenvironmental Engineering,2001,128(1):67-75.

[7] 张国栋,邓全胜,李泯蒂,等.干湿循环对水库滑坡渗透系数影响的试验研究[J].人民长江,2016.47(22):82.

[8] 刘宏泰,张爱军,段涛,等.干湿循环对重塑黄土强度和渗透性的影响[J].水利水运工程学报,2010(004）:38-42.

[9] 陈彬,王宝,许健,等.冻融-干湿循环作用下土工合成黏土衬垫防渗性能变化规律[J].新型建筑材料, 2019,046(001):128-133.

[10] 景静,孙文, 江肖鹏.干湿循环对非饱和黄土渗透系数的影响研究[J]. 水资源与水工程学报, 2020,31(06):224-229.

[11] 张家俊.干湿循环下膨胀土裂隙、体变与渗透特性研究[D].华南理工大学,2010.

[12] 万勇,薛强,吴彦,等.干湿循环作用下压实黏土力学特性与微观机制研究[J].岩土力学,2015,36(10):2815-2824.

[13] 慕焕东,邓亚虹,李荣建,等.砂粒含量对砂质黄土力学性质影响试验研究[J].水利与建筑工程学报, 2018,16(06):36-39+44.

[14] 丑亚玲,张庆海,郏书胜.基于冻融-干湿作用的非饱和重塑黄土强度试验[J].兰州理工大学学报, 2019,45(03):118-125.

[15] 李丽,张坤,张青龙,等.干湿和冻融循环作用下黄土强度劣化特性试验研究[J].冰川冻土, 2016,38(04):1142-1149.

[16] 叶万军,李长清,马伟超.干湿循环作用下黄土节理裂隙发育扩张的机制研究[J].科学技术与工程,2016,16(30): 122-127.

[17] 刘禹阳,王耕,来弘鹏等.干湿循环作用下原状黄土宏-微观参数关系研究[J].水利学报,2022,53(04): 421-432.

[18] 李彤.干湿循环条件下非饱和黄土持水特性与边坡稳定性研究[D].兰州:兰州交通大学,2019.

[19] 卞明智.干湿循环对非饱和土力学性质影响研究[J].安徽建筑,2019,26(09):243-244.

[20] 张芳枝,陈晓平.反复干湿循环对非饱和土的力学特性影响研究[J]. 岩土工程学报, 2010,32 (01):41-46.

[21] 陈洪凯,翁其能,袁建议,等.重庆库区典型松散土体的岩土力学参数敏感性试验分析[J]. 重庆大学学报(自然科学版),2000,23:203-206.

[22] 杨和平,肖夺.干湿循环效应对膨胀土抗剪强度的影响[J].长沙理工大学学报（自然科学版）,2005, (02):1-5+12.

[23] 吕海波,曾召田,赵艳林,等.膨胀土强度干湿循环研究[J].岩土力学,2009,30(12):3797-802.

[24] 蒋佳莉,张卫兵,王红雨.干湿循环作用下银川地区重塑粉质黏土强度劣化试验研究[J].公路交通科技,2020,37(05):33-42.

[25] Richards LA.Capillary Conduction of Liquids Through Porous Mediums[J].Physics,1931,1(5):318-333.

[26] J.Jiang, D.Ehret, W.Xiang, et al.Numerical simulation of Qiaotou Landslide deformation caused by drawdown of the Three Gorges Reservoir,China[J]. Environment Earth Sciences,2011, 62(2):411-419.

[27] G Hossein, G Soheil. Stability of sandy slopes under seepage conditions[J]. Landslides, 2008,5:397-406.

[28] Asch Th W J, Malet J P , Bogaard T A. The effect of groundwater fluctuations on the velocity pattern of slow-moving landslides[J]. Natural Hazards and Earth System Sciences, 2009,9(3):939-749.

[29] Shen J H, Gao Y H, Wen L W, et al. Deformation response regularity of Liujiaba landslide under fluctuating reservoir water level condition[J]. Natural Hazards, 2018,94(1):151-166.

[30] Tang MG, Xu Q, Yang H, et al. Activity law and hydraulics mechanism of landslides with different sliding surface and permeability in the Three Gorges Reservoir area,China[J].EngineeringGeology,2019,260:150212.

[31] Yang H, Tang M G, Xu Q, et al.Characteristics and hysteresis of saturated-unsaturated seepageof soil landslides in the Three Gorges Reservoir,China[J].Open Geosciences,2019,11(1):298-312

[32] Wang S M, Pan Y C, Wang L, et al. Deformation characteristics, mechanism and influencing Factors of hydrodynamic pressure landslides in the Three Gorges Reservoir: A case study and model test study[J].Bulletin of Engineering Geology and the Environment,2021,80(4):3513-3533.

[33] 胡修文,唐辉明,刘佑荣.三峡库区赵树岭滑坡稳定性物理模拟试验研究[J].岩石力学与工程学报,2005(12):2089-2095.

[34] 罗先启.滑坡模型试验理论及其应用[D],三峡大学,2008.

[35] 罗先启,程圣国,牛恩宽.滑坡物理模型试验畸变修正及应用研究[J].岩石力学与工程学报2009,28(S1):3082-3088.

[36] 罗先启,刘德富,吴剑,等.雨水及库水作用下滑坡模型试验研究[J].岩石力学与工程学报.2005(14):2476-2483.

[37] 张均锋,孟祥跃,朱而千.水位变化引起分层边坡滑坡的实验研究[J].岩石力学与工程学报,2004(16):2676-2680.

[38] 杜锋,许模,肖先煊,等.顺层缓倾型水库滑坡稳定性物理模拟试验研究－以向家坪滑坡为例[J].工程地质学报,2018,26(03):694-702.

[39] 任俊谦.三峡库区不同成因类型老滑坡体渗透特性及水位升降速率对其稳定性影响[D].成都理工大学,2016.

[40] 张文杰,陈云敏,凌道盛.库岸边坡渗流及稳定性分析[J].水利学报,2005(12):1510-1516.

[41] 毛昶熙,段祥宝.关于渗流的力及其应用[J].岩士力学,2009,30(6):156930(6):1569-1574.

[42] 王冬林,李宗利,张洪泉.库水位骤降对均质土坝坝坡稳定的影响分析[J].人民黄河,2011,33(04):147-149.

[43] 陈勇,杨贝贝.基于ABAQUS的非饱和边坡流-固耦合分析[J].地下空间与工程学报,2016,12(04):938-945.

[44] 王锦国,周云,黄勇,等. 三峡库区猴子石滑坡地下水动力场分析[J].岩石力学与工程学报, 2006, 25(S1):2757-2762.

[45] 罗红明,唐辉明,章广成,等.库水位涨落对库岸滑坡稳定性的影响[J].地球科学(中国地质大学学报),2008(05):115-120.

[46] 郑颖人,时卫民,孔位学.库水位下降时渗透力及地下水浸润线的计算[J].岩石力学与工程学报,2004(9):3203-3210.

[47] 冯文凯,石豫川,柴贺军.降雨及库水升降作用下地下水浸润线简化求解[J].成都理工大学学报(自然科学版),2006, 33(1): 90-94.

[48] 林雪松,陈殿强,何峰.基于简化边界的尾矿坝浸润线解析解[J].中国地质灾害与防治学报,2015, 26(01):56-61.

[49] 李建习,唐利苗,曹园园.水库水位非均匀下降情况下库岸浸润线求解[J].人民长江, 2018,49(12):55-58+92.

[50] 李强,高松,牛红凯等.尾矿库浸润线解析解及适用性分析[J].岩土力学,2020,41(11):3714-3721.

[51] 胡庆,李漪,李恒,等.库水波动下库岸边坡地下水浸润线解析解及误差分析[J].长江科学院院报,2013,30(03):44-48.

[52] 郑晓晶,殷坤龙.基于非饱和渗流的水库库岸滑坡稳定性计算[J].水文地质工程地质,2007,2:39-42.

[53] 杨何,汤明高,许强.库水位升降下三峡库区滑坡堆积体渗流滞后性研究[J].水利水电技术,2020,51 (12):9-15.

[54] 马春驰,李天斌,陈国庆,等.地下水与开挖作用下堆积层滑坡体滑动机制分析[J]. 工程地质学报, 2013,21(6):878-884.

[55] 张彦锋,铁永波,白永健,等.云南永善县上坝老滑坡复活机制及新滑坡稳定性分析[J].中国地质灾害与防治学报,2020,31(03):41-49.

[56] 唐军峰,唐雪梅,肖鹏,等.库水位升降与降雨作用下大型滑坡体渗流稳定性分析[J].地质科技通报, 2021,40(4):153-161.

[57] Morgenstern N R.Sstaility charts for earth slope during rapid drawdown[J]. Geotechnique, 1963,13(2):121-131.

[58] Griffiths D V, Lane P A. Slope stability analysis by finite elements[J]. Geotechnique,1999,49(3):387-403.

[59] Tony L. T. Zhan,Charles W. W. Ng. Analytical Analysis of Rainfall Infiltration Mechanism in Unsaturated Soils[J]. International Journal of Geomechanics,2004,4(4):273-284.

[60] Li C,Tang H,Han D,et al. Exploration of the creep properties of undisturbed shear zone soil the Huangtupo landslide[J]. Bulletin of Engineering Geology and the Environment,2019,78(2):1237-1248.

[61] Wang J, Su A, Liu Q, et al. Three-dimensional analyses of the sliding surface distribution in the Huangtupo NO.1 riverside sliding mass in the Three Gorges Reservoir area of China[J]. Landslides,2018,15(7):1425-1435.

[62] Terzaghi,K.Mechanism of landslide in paiges[J]. Application of geology to engineering practice geol.soc.of America. New York,1950:83-123.

[63] Zhou J,Deng J,Xu F. A Slope Analysis Method Combined with Limit Equilibrium and Finite Element Simulation[M]. Springer Berlin Heidelberg,2012.

[64] Dyson A.P,Tolooiyan A.Optimisation of strength reduction finite element method codes for slope stability analysis[J]. Innov. Infrastruct. Soult, 2018,3,38.

[65] Wu L M, Wang Z Q.Three Gorges Reservoir Water Level Fluctuation Influents on the Stability of the Slope’s Analysis[J]. Advanced Materials Research,2013,739:283-286.

[66] Lane P A,Griffiths D V.Assessment of stability of slopes under drawdown conditions [J].Journal Of Geotechnical and Geoenvironmental Engineering,2000,126(5):443-450.

[67] VIRATJANDR C,MICHALOWSKI R L.Limit analysis of submerged slopes subjected to waterdrawdown[J].Canadian Geotechnical Journal,2006,43(8):802-814.

[68] BERILGEN M M.Investigation of stability of slopes under drawdown conditions[J]. C omputersand Geotechincs,2007,34(2):81-91.

[69] 汪斌,杨昌斌,严绍军,等.考虑水位波动影响的剩余推力法及其在库区岸坡稳定性评价的应用[J].地质灾害与环境保护,2005,16(2):190-193.

[70] 卢博,郭永成,赵二平,等.库水位变化和降雨条件下边坡渗流特性及稳定性分析[J].三峡大学学报 (自然科学版),2017,39(02):54-59.

[71] 刘才华,陈从,冯夏庭.库水位上升诱发边坡失稳机理研究[J].岩土力学,2005,26(5):769-773.

[72] 胡亚波,王丽艳.三峡水库调度对库岸斜坡体内渗透压力与斜坡稳定性影响研究[J].岩石力学与工程学报,2005,24(16): 2994-2997.

[73] 仉文岗,王尉,高学成.库区水位下降对库岸边坡稳定性的影响[J].武汉大学学报(工学版),2019,52 (01):21-26.

[74] 李松林,许强,汤明高,等.库水位升降作用下不同滑面形态老滑坡响应规律[J].工程地质学报,2017,25(03):841-852.

[75] 曹伟.论库水位变化对土质滑坡稳定性的影响[J].山西师范大学学报(自然科学版),2017,31(04):123-128

[76] 贾灵慈,刘震,李开强等.非饱和土抗剪强度研究现状[J].土工基础,2023,37(02):275-278+283.