Effect of Rainfall Patterns on Stability of Shallow Landslide
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摘要: 在降雨与浅层滑坡稳定性关系的研究中, 目前的研究往往忽略了降雨类型的影响.因此, 选取4种具有代表性的降雨类型: 均匀型、递增型、递减型以及峰值型为对象, 基于Rosso提出的降雨强度与地下水关系模型, 构建考虑降雨类型的浅层滑坡地下水位高度随降雨时间的变化关系, 研究不同降雨类型对浅层滑坡地下水位变化的影响.进而, 结合无限边坡理论, 建立浅层滑坡的稳定性计算模型, 研究不同降雨类型对浅层滑坡稳定性的影响.研究结果表明: 降雨类型对浅层滑坡稳定性的影响是明显的, 递增型降雨作用下的浅层滑坡安全系数最小, 其次是均匀型降雨, 再次是峰值型降雨, 最大的是递减型降雨; 同时在确定浅层滑坡临界降雨量和进行区域浅层滑坡易发性研究时降雨类型的影响不容忽视.Abstract: The effect of the rainfall patterns is often ignored in studies of the relationship of rainfall versus shallow stability of landslide. This paper takes four representative rainfall patterns including uniform, delayed, advanced and central ones as the object of study to explore the effect of the rainfall patterns on the height of ground water, based on the hillslope hydrological model proposed by Rosso. And then the infinite slope failure model is applied to establish the stability calculation model for shallow landslide, and the effect of the rainfall patterns on shallow landslide stability is analyzed. Results show that rainfall patterns have strong effect on the stability of shallow landslide, with the delayed rainfall having the lowest safety factor for shallow landslide, followed by uniform rainfall, then central rainfall, and lastly the advanced rainfall. It is found necessary to consider the effect of rainfall patterns for determining of the critical rainfall and analyzing of the susceptibility of shallow landslide in a region.
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Key words:
- underground water /
- shallow landslide /
- rainfall patterns /
- stability /
- infinite slope /
- geologic hazard
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表 1 各岩组的物理力学指标参数
Table 1. The physical-mechanical properties of each petrofabric
岩土类别 天然密度P(kN/m3) 导水率T(m2/d) 内摩擦角φ(°) 三叠系上统须家河组 21.0 70 40 泥盆系中统养马坝组 19.6 95 38 震旦系下统 17.6 75 33 表 2 不同降雨类型下, 浅层滑坡不稳定区的面积比
Table 2. The ratio of the unstable area to the total area under the different rainfall patterns
降雨类型 递减型 递增型 峰值型 均匀型 面积比 0.182 7 0.242 3 0.183 8 0.189 0 -
[1] Casadei, M., Dietrich, W.E., Miller, N.L., 2003. Testing a Model for Predicting the Timing and Location of Shallow Landslide Initiation in Soil-Mantled Landscapes. Earth Surface Processes and Landforms, 28(9): 925-950. doi: 10.1002/esp.470 [2] Chang, K., Chiang, S., 2009. An Integrated Model for Predicting Rainfall-Induced Landslides. Geomorphology, 105(3-4): 366-373. doi: 10.1016/j.geomorph.2008.10.012 [3] Guo, X., Zhao, C.G., Yu, W.W., 2005. Stability Analysis of Unsaturated Soil Slope and Its Progress. China Safety Science Journal, 15(1): 14-18 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZAQK200501004.htm [4] Li, T.B., Chen, M.D., Wang, L.S., 1999. Real-Time Tracing Prediction of Landslides. Chengdu University of Scicene & Technology Press, Chengdu (in Chinese). [5] Li, Y., Meng, H., Dong, Y., et al., 2004. Main Types and Characteristics of Geo-Hazard in China-Based on the Results of Geo-Hazard Survey in 290 Counties. The Chinese Journal of Geological Hazard and Control, 15(2): 29-34 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZGDH200402005.htm [6] Liu, H.D., 1996. Theory and Method of Forecasting Occurrence of Slope Failure. The Yellow River Water Conservancy Press, Zhengzhou (in Chinese). [7] Liu, X.X., Xia, Y.Y., Cai, J.J., et al., 2007. Study on Stability of High-Filled Embankment Slope of Highly Weathered Soft Rock under Rainfall Infiltration. Rock and Soil Mechanics, 28(8): 1705-1709 (in Chinese with English abstract). http://d.wanfangdata.com.cn/Periodical_ytlx200708033.aspx [8] Montgomery, D.R., Dietrich, W.E., 1994. A Physically Based Model for Topographic Control on Shallow Landsliding. Water Resources Research, 30(4): 1153-1171. doi: 10.1029/93WR02979 [9] Ng, C.W.W., Wang, B., Tung, Y.K., 2001. Three-Dimensional Numerical Investigations of Groundwater Responses in an Unsaturated Slope Subjected to Various Rainfall Patterns. Canadian Geotechnical Journal, 38(5): 1049-1062. doi: 10.1139/cgj-38-5-1049 [10] Rosso, R., Rulli, M.C., Vannucchi, G., 2006. A Physically Based Model for the Hydrologic Control on Shallow Landsliding. Water Resources Research, 42(6): w06410-1-16. doi: 10.1029/2005WR004369 [11] Tsai, T.L., 2008. The Influence of Rainstorm Pattern on Shallow Landslide. Enviornmental Geology, 53(7): 1563-1569. doi: 10.1007/s00254-007-0767-x [12] Wei, N., Qian, P.Y., Fu, X.D., 2006. Effects of Rainfall Infiltration and Evaporation on Soil Slope Stability. Rock and Soil Mechanics, 27(5): 778-781, 786 (in Chinese with English abstract). http://www.researchgate.net/publication/289545249_Effects_of_rainfall_infiltration_and_evaporation_on_soil_slope_stability [13] Wilkinson, P.L., Anderson, M.G., Lloyd, D.M., et al., 2002. Landslide Hazard and Bioengineering: Towards Providing Improved Decision Support through Integrated Numerical Model Development. Environmental Modeling and Software, 17(4): 333-344. doi: 10.1016/s1364-8152(01)00078-0 [14] Wu W., Slide, R.C., 2010. A Distributed Slope Stability Model for Steep Forested Basins. Water Resources Research, 31(8): 2097-2110. doi: 10.1029/95WR01136 [15] Xu, J.C., Shang Y.Q., Chen K.F., et al., 2005. Analysis of Shallow Landslide Stability under Intensive Rainfall. Chinese Journal of Rock Mechanics and Engineering, 24(18): 3246-3251 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-YSLX200518006.htm [16] 郭璇, 赵成刚, 于威威, 2005. 非饱和土边坡稳定的安全分析及进展. 中国安全科学学报, 15(1): 14-18. doi: 10.3969/j.issn.1003-3033.2005.01.004 [17] 李天斌, 陈明东, 王兰生, 1999. 滑坡实时跟踪预报. 成都: 成都科技大学出版社. [18] 李媛, 孟晖, 董颖, 等, 2004. 中国地质灾害类型及其特征—基于全国县市地质灾害调查成果分析. 中国地质灾害与防治学报, 15(2): 29-34. doi: 10.3969/j.issn.1003-8035.2004.02.005 [19] 刘汉东, 1996. 边坡失稳定时预报理论与方法. 郑州: 黄河水利出版社. [20] 刘新喜, 夏元友, 蔡俊杰, 等, 2007. 降雨入渗下强风化软岩高填方路堤边坡稳定性研究. 岩土力学, 28(8): 1705-1709. doi: 10.3969/j.issn.1000-7598.2007.08.033 [21] 魏宁, 茜平一, 傅旭东, 2006. 降雨和蒸发对土质边坡稳定性的影响. 岩土力学, 27(5): 778-781, 786. doi: 10.3969/j.issn.1000-7598.2006.05.019 [22] 许建聪, 尚岳全, 陈侃福, 等, 2005. 强降雨作用下的浅层滑坡稳定性分析. 岩石力学与工程学报, 24(18): 3246-3251. doi: 10.3321/j.issn:1000-6915.2005.18.007