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摘要:
近年来，随着“治沟造地”和“固沟保塬”等工程在黄土高原的陆续开展，出现了许多直线型黄土填方边坡。降雨是诱发边坡失稳的重要因素，但对降雨诱发直线型黄土填方边坡变形演化特征和破坏模式的研究较少。以直线型黄土填方边坡为研究对象，通过传感器监测、三维激光扫描和人工降雨，开展室内降雨模型试验，记录了降雨入渗下边坡内部水文响应特征和边坡失稳破坏过程，并对湿润锋、土颗粒运移、坡体内部变形响应、裂缝演化特征及破坏模式进行了分析。试验结果表明：随着降雨入渗，湿润锋达到后，体积含水率增加，并在峰值后保持稳定，而基质吸力则减小，到达最低点后保持稳定。冲沟对填方边坡的影响较大，它的发育改变了坡体内含水率特征，同时也是控制边坡整体滑动的边界；边坡变形响应区域主要是以填方边坡前缘堆积区和后缘滑塌区为主；裂缝演化方向由边坡前缘向后缘发展，它的发育为雨水入渗提供优势通道，同时也加剧边坡的变形破坏；降雨形成的水动力驱使坡体中细颗粒从填方边坡后缘向前缘流失，减弱了土体颗粒之间的胶结能力，使其抗剪强度降低，进而使边坡失稳破坏。因此，在降雨入渗下，直线型黄土填方边坡的变形破坏模式为：坡顶冲沟破坏、坡脚软化→局部牵引坍塌、整体失稳→块体分割、流滑破坏。研究结果可为直线型黄土填方边坡的工程建设和滑坡灾害防治提供理论参考。
Abstract:In recent years, many linear loess fill slopes have appeared with the continuous development of “Governing valleys” and “Retaining plateau” projects in the Loess Plateau. Slope instability is induced by rainfall, which is an important factor. However, there are few studies on the deformation evolution characteristics and failure modes of rainfall-induced linear loess fill slopes. In this paper, the linear loess fill slope is taken as the research object, and the indoor rainfall model test is carried out through sensor monitoring, three-dimensional laser scanning technology and artificial rainfall system. The hydrological response characteristics and failure process of slope under rainfall infiltration are recorded, and the wetting front, soil particle migration, internal deformation response, fracture evolution characteristics and failure mode are analyzed. The test results show that with the infiltration of rainfall, when the wetting front is reached, the volumetric moisture content increases and remains stable at the maximum, while the matric suction decreases and remains stable at the minimum. The gully has a greater impact on the fill slope. The development of slope changes the characteristics of the water content in the slope, and at the same time it is the boundary that controls the overall sliding of the slope. The deformation response area of the slope is mainly the front accumulation area and the back slide area of the filling slope. The cracks evolve from the leading to the trailing edge, and its development offers preferential seepage channels for the infiltration of rainwater. At the same time, the cracks also intensifies the deformation and failure of the slope. The hydrodynamic force formed by rainfall drives the loss of fine particles in the slope from the rear edge of the fill slope to the front edge, weakens the cementation among the soil particles, reduces the shear strength, and causes the slope instability and failure. Therefore, under the rainfall infiltration, the deformation and failure modes of the linear loess fill slope are: gully failure at the top of slope and toe softening →local traction collapse and overall instability → block segmentation and at last the flow slip failure. The research results can provide a theoretical reference for the engineering construction of linear loess fill slope and the prevention and control of landslide disaster.
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Key words:
- linear loess fill slope /
- rainfall infiltration /
- failure mode /
- model test
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表 1 试验用土不同粒径体积百分比
Table 1. Volume percentage of different particle sizes in the test soils
成分 砂粒 粉粒 黏粒 粒径/mm >0.075 0.005～0.075 <0.005 体积分数/% 8.64 90.00 1.36 
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表 2 试验用土的基本物理指标
Table 2. Basic physical indicators of the test soils
名称 比重 液限/% 塑限/% 塑性指数 孔隙比 饱和渗透系数/（m·s−1） 延安黄土 2.70 30.6 21.4 9.2 0.853 1.26×10−6
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表 3 模型填筑后不同层位的密实度
Table 3. Density of different layers after model filling
填筑层号 含水率/% 密度/（g·cm−3） 干密度/（g·cm−3） 压实度 1 14.5 1.79 1.56 0.90 2 15.6 1.79 1.55 0.89 3 16.4 1.81 1.55 0.89 4 15.2 1.80 1.56 0.90 5 15.6 1.79 1.54 0.89 6 14.2 1.77 1.55 0.89
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表 4 降雨方案
Table 4. Rainfall schemes
降雨次数 起止时刻 降雨时间/min 降雨强度/（mm·h−1） 第1次 14:24—15:34 70 18 第2次 16:14—16:24 10 18 第3次 16:34—16:44 10 18 第4次 16:54—17:04 10 18 第5次 17:14—17:29 15 18 第6次 17:44—18:04 20 18 第7次 18:24—18:44 20 18 第8次 18:59—19:14 15 18 第9次 19:29—19:39 10 18 第10次 19:49—22:29 160 18
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表 5 降雨过程中不同监测点含水率响应时间
Table 5. Response time of water content at different monitoring points during rainfall
传感器编号 EC-1 EC-2 EC-3 EC-4 EC-5 埋设深度/cm 10 10 10 10 20 响应时间/min 43 74 72 33 59
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表 6 降雨过程中不同监测点基质吸力响应时间
Table 6. Response time of matric suction at different monitoring points during rainfall
传感器编号 MPS-1 MPS-2 MPS-3 MPS-4 MPS-5 埋设深度/cm 10 10 10 10 20 响应时间/min 63 54 66 40 158
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表 7 湿润锋平均运移速率
Table 7. Average velocity of the wetting front
传感器编号 EC-1 EC-2 EC-3 EC-4 EC-5 湿润锋运移速率/（10−6 m·s−1） 26.43 15.36 15.79 50.51 38.53
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表 8 填方边坡不同位置处颗粒级配参数
Table 8. Gradation parameters of particles at different positions of the fill slope
取土位置 D10/mm D60/mm D30/mm Cc Cu 原始 0.009 0.037 0.022 1.453 4.111 坡顶 0.012 0.040 0.025 1.302 3.333 坡中 0.010 0.038 0.023 1.392 3.800 坡脚 0.008 0.044 0.023 1.503 5.500 堆积体 0.006 0.035 0.016 1.219 5.833
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[1] 张茂省, 李同录. 黄土滑坡诱发因素及其形成机理研究[J]. 工程地质学报,2011,19(4):530 − 540. [ZHANG Maosheng, LI Tonglu. Triggering factors and forming mechanism of loess landslides[J]. Journal of Engineering Geology,2011,19(4):530 − 540. (in Chinese with English abstract) doi: 10.3969/j.issn.1004-9665.2011.04.014
[2] 张茂省, 胡炜, 孙萍萍, 等. 黄土水敏性及水致黄土滑坡研究现状与展望[J]. 地球环境学报,2016,7(4):323 − 334. [ZHANG Maosheng, HU Wei, SUN Pingping, et al. Advances and prospects of water sensitivity of loess and the induced loess landslides[J]. Journal of Earth Environment,2016,7(4):323 − 334. (in Chinese with English abstract) doi: 10.7515/JEE201604001
[3] 吴玮江, 王念秦. 甘肃滑坡灾害[M]. 兰州: 兰州大学出版社, 2006.
WU Weijiang, WANG Nianqin. Landslide hazards in Gansu[M]. Lanzhou: Lanzhou University Press, 2006. (in Chinese)
[4] 朱晓霞, 张力, 杨树文. 降雨引发的兰州黄土滑坡时空规律分析和临界降雨量预测[J]. 中国地质灾害与防治学报,2019,30(4):24 − 31. [ZHU Xiaoxia, ZHANG Li, YANG Shuwen. Characteristics of rainfall-induced loess landslides and their threshold rainfall in Lanzhou[J]. The Chinese Journal of Geological Hazard and Control,2019,30(4):24 − 31. (in Chinese with English abstract)
[5] 黄玉华, 武文英, 冯卫, 等. 陕北延安“7.3暴雨”诱发地质灾害主要类型与特征[J]. 西北地质,2014,47(3):140 − 146. [HUANG Yuhua, WU Wenying, FENG Wei, et al. Main types and characteristics of the geo-hazards triggered by heavy rain on July 3 in Yan’an, Shaanxi[J]. Northwestern Geology,2014,47(3):140 − 146. (in Chinese with English abstract) doi: 10.3969/j.issn.1009-6248.2014.03.019
[6] 张硕, 裴向军, 黄润秋, 等. 降雨诱发黄土高填方支挡边坡失稳机理研究[J]. 工程地质学报,2017,25(4):1094 − 1104. [ZHANG Shuo, PEI Xiangjun, HUANG Runqiu, et al. Rainfall induced instability mechanism of high embankment retaining loess slope[J]. Journal of Engineering Geology,2017,25(4):1094 − 1104. (in Chinese with English abstract)
[7] 宋焱勋, 彭建兵, 张骏. 黄土填方高边坡变形破坏机制分析[J]. 工程地质学报,2008,16(5):620 − 624. [SONG Yanxun, PENG Jianbing, ZHANG Jun. Deformation mechanism of high loess embankment slope[J]. Journal of Engineering Geology,2008,16(5):620 − 624. (in Chinese with English abstract) doi: 10.3969/j.issn.1004-9665.2008.05.008
[8] 张硕, 裴向军, 黄润秋, 等. 黄土填方边坡降雨入渗特征及变形破坏模式的模型试验[J]. 中国公路学报,2019,32(9):32 − 41. [ZHANG Shuo, PEI Xiangjun, HUANG Runqiu, et al. Model test on seepage characteristics and deformation failure modes of loess fill slope under rainfall[J]. China Journal of Highway and Transport,2019,32(9):32 − 41. (in Chinese with English abstract)
[9] 高岳权. 黄土地区高填方路堤滑坡机理及控制措施研究[J]. 地下空间与工程学报,2016,12(增刊 1):393 − 399. [GAO Yuequan. Study on the landslide mechanism and control measures of high embankment in loess area[J]. Chinese Journal of Underground Space and Engineering,2016,12(Sup 1):393 − 399. (in Chinese with English abstract)
[10] 曹从伍, 许强, 亓星, 等. 黄土填方边坡物理模拟过程中微结构变形破坏特征[J]. 科学技术与工程,2017,17(33):225 − 231. [CAO Congwu, XU Qiang, QI Xing, et al. Research on the deformation and failure of microstructure during the physical simulation of loess landslides[J]. Science Technology and Engineering,2017,17(33):225 − 231. (in Chinese with English abstract) doi: 10.3969/j.issn.1671-1815.2017.33.033
[11] 魏恺泓, 裴向军, 张世殊, 等. 基于IBIS-L的某黄土高填方边坡支护结构变形特征[J]. 吉林大学学报(地球科学版),2018,48(5):1556 − 1565. [WEI Kaihong, PEI Xiangjun, ZHANG Shishu, et al. Deformation characteristics of loess high fill slope support structure based on IBIS-L[J]. Journal of Jilin University (Earth Science Edition),2018,48(5):1556 − 1565. (in Chinese with English abstract)
[12] 黄润秋. 20世纪以来中国的大型滑坡及其发生机制[J]. 岩石力学与工程学报,2007,26(3):433 − 454. [HUANG Runqiu. Large-scale landslides and their sliding mechanisms in China since the 20th century[J]. Chinese Journal of Rock Mechanics and Engineering,2007,26(3):433 − 454. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2007.03.001
[13] 吴宏伟, 陈守义, 庞宇威. 雨水入渗对非饱和土坡稳定性影响的参数研究[J]. 岩土力学,1999,20(1):1 − 14. [Ng Wang-wai Charles, Chen Shou-yi, Pang Yue-wai. Parametric study of effects of rain infiltration on unsaturated slopes[J]. Rock and Soil Mechanics,1999,20(1):1 − 14. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-7598.1999.01.001
[14] 林鸿州, 于玉贞, 李广信, 等. 降雨特性对土质边坡失稳的影响[J]. 岩石力学与工程学报,2009,28(1):198 − 204. [LIN Hungchou, YU Yuzhen, LI Guangxin, et al. Influence of rainfall characteristics on soil slope failure[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(1):198 − 204. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2009.01.026
[15] WU L Z, ZHOU Y, SUN P, et al. Laboratory characterization of rainfall-induced loess slope failure[J]. CATENA,2017,150:1 − 8. doi: 10.1016/j.catena.2016.11.002
[16] 周春梅, 王宇, 吕雷, 等. 雨滴溅蚀下压实黄土变形破坏规律研究[J]. 水文地质工程地质,2018,45(6):93 − 98. [ZHOU Chunmei, WANG Yu, LYU Lei, et al. Research on deformation of compacted loess under raindrop splash erosion[J]. Hydrogeology & Engineering Geology,2018,45(6):93 − 98. (in Chinese with English abstract)
[17] 周杨, 刘果果, 白兰英, 等. 降雨诱发黄土边坡失稳室内试验研究[J]. 武汉大学学报(工学版),2016,49(6):838 − 843. [ZHOU Yang, LIU Guoguo, BAI Lanying, et al. Model test study of loess slope instability induced by rainfall[J]. Engineering Journal of Wuhan University,2016,49(6):838 − 843. (in Chinese with English abstract)
[18] 张钧, 梁为邦, 林红, 等. 二元结构库岸边坡失稳机制试验研究[J]. 水文地质工程地质,2020,47(3):156 − 163. [ZHANG Jun, LIANG Weibang, LIN Hong, et al. An experimental study of the bank slope instability mechanism of dual structure reservoir[J]. Hydrogeology & Engineering Geology,2020,47(3):156 − 163. (in Chinese with English abstract)
[19] 罗浩, 霍宇翔, 巨能攀, 等. 弃渣场边坡的粒径分布特征及其失稳机制研究[J]. 水文地质工程地质,2020,47(1):69 − 79. [LUO Hao, HUO Yuxiang, JU Nengpan, et al. A study of the particle size distribution characteristics and instability mechanism of the slope of an abandoned slag yard[J]. Hydrogeology & Engineering Geology,2020,47(1):69 − 79. (in Chinese with English abstract)
[20] 李玉瑞, 程晓伟, 赖天文, 等. 延安北连接线黄土滑坡变形机制地质分析与模型试验研究[J]. 中国地质灾害与防治学报,2019,30(2):35 − 42. [LI Yurui, CHENG Xiaowei, LAI Tianwen, et al. Geological analysis and model test study on the deformation mechanism of loess landslide in the North connection line of Yan’an[J]. The Chinese Journal of Geological Hazard and Control,2019,30(2):35 − 42. (in Chinese with English abstract)
[21] ZHANG Shuo, ZHANG Xiaochao, PEI Xiangjun, et al. Model test study on the hydrological mechanisms and early warning thresholds for loess fill slope failure induced by rainfall[J]. Engineering Geology,2019,258:105135. doi: 10.1016/j.enggeo.2019.05.012
[22] 乔平定, 增钧. 黄土地区工程地质[M]. 北京: 水利电力出版社, 1990.
QIAO Pingding, LI Zengjun. Engineering Geology in Loess area [M]. Beijing: Water Resources and Electric Power Press, 1990. (in Chinese)
[23] 孙萍萍. 黄土水敏性与降雨诱发浅层黄土滑坡预测[D]. 西安: 西北大学, 2020.
SUN Pingping. Water sensitivity of loess and prediction of rainfall induced shallow loess landslides[D]. Xi'an: Northwest University, 2020. (in Chinese with English abstract)
[24] 许领, 戴福初, 邝国麟, 等. 台缘裂缝发育特征、成因机制及其对黄土滑坡的意义[J]. 地质论评,2009,55(1):85 − 90. [Xu Ling, Dai Fuchu, A. K. L. KWONG, et al. Characteristics and forming mechanisms of the plateau-edge cracks and their significance to loess landslides[J]. Geological Review,2009,55(1):85 − 90. (in Chinese with English abstract) doi: 10.3321/j.issn:0371-5736.2009.01.010
[25] 吴火珍, 冯美果, 焦玉勇, 等. 降雨条件下堆积层滑坡体滑动机制分析[J]. 岩土力学,2010,31(增刊 1):324 − 329. [WU Huozhen, FENG Meiguo, JIAO Yuyong, et al. Analysis of sliding mechanism of accumulation horizon landslide under rainfall condition[J]. Rock and Soil Mechanics,2010,31(Sup 1):324 − 329. (in Chinese with English abstract)
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