降水对陇西黄土滑坡的诱发作用及时空影响分析
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摘要
以现场调查、试验测试数据为依据,从降水(主要指大暴雨或连阴雨)改变地形地貌促使滑坡形成、改变滑坡土的成分构成、改变滑坡的土体结构及稳定性、改变滑坡土的力学强度4个方面阐述了对黄土滑坡的诱发作用。选择典型城市的系列降水资料及发生滑坡数量,从多年降水、年内降水过程及降水的空间变化3个方面阐述了对黄土滑坡的时空影响。年际上,同一区域滑坡发生的频次与多年降水过程呈现良好的相关性,存在丰水年发生滑坡次数多、规模大而枯水年发生滑坡次数少、规模小的规律,丰水年发生滑坡数量一般是枯水年的3~5倍、平水年的1~2倍;年内滑坡集中出现于6-9月份和2-3月份,占全年滑坡数量的80%以上;不同区域,年降水量及降水强度越大,黄土滑坡发生频率越高,规模也越大;自东南向西北,随着降水量及降水强度的递减,依次划分为黄土滑坡强发育区、较强发育区和一般发育区。
In this paper,based on in-situ investigation and test data,the landslide type and characteristics in the Longxi Loess Plateau of Gansu Province were summarized,the formation mechanisms of the loess landslide were analyzed from four aspects: change in topography,change in landslide composition,change in landslide soil structure and change in landslide mechanical strength,which were all caused by atmospheric precipitation(mainly by heavy rain or continuous rain).According to precipitation and the number of landslide event in some typical areas,the impact and effect of atmospheric precipitation upon the landslide were described from three aspects(including annual precipitation,precipitation process and precipitation space-time change features).In the same area,it was found that there was a good correlation between the landslide frequency and annual precipitation,for instance,in wet years the number of landslide event was 3 ~ 5 times than that in dry years and 1 ~ 2 times than ordinary year.During a year,the landslide concentrated from June through September and from February through March,when the number of landslide event accounted for more than 80% of the total.In various regions,the larger the precipitation and rainfall intensity,the higher the loess landslide occurrence frequency and the larger the landslide scale.From southeast to northwest,with decreasing precipitation and rainfall intensity,there were,in turn,loess landslide stronger development areas,strong development areas and general development areas.
In this paper,based on in-situ investigation and test data,the landslide type and characteristics in the Longxi Loess Plateau of Gansu Province were summarized,the formation mechanisms of the loess landslide were analyzed from four aspects: change in topography,change in landslide composition,change in landslide soil structure and change in landslide mechanical strength,which were all caused by atmospheric precipitation(mainly by heavy rain or continuous rain).According to precipitation and the number of landslide event in some typical areas,the impact and effect of atmospheric precipitation upon the landslide were described from three aspects(including annual precipitation,precipitation process and precipitation space-time change features).In the same area,it was found that there was a good correlation between the landslide frequency and annual precipitation,for instance,in wet years the number of landslide event was 3 ~ 5 times than that in dry years and 1 ~ 2 times than ordinary year.During a year,the landslide concentrated from June through September and from February through March,when the number of landslide event accounted for more than 80% of the total.In various regions,the larger the precipitation and rainfall intensity,the higher the loess landslide occurrence frequency and the larger the landslide scale.From southeast to northwest,with decreasing precipitation and rainfall intensity,there were,in turn,loess landslide stronger development areas,strong development areas and general development areas.
引文
[1]Ding Hongwei,Li Li,Yao Xingrong,et al.The impact and control of atmospheric precipitation of loess landslides[J].Gansu Geology,2013,22(1):55-60.[丁宏伟,李莉,姚兴荣,等.大气降水对黄土滑坡的影响和控制[J].甘肃地质,2013,22(1):55-60.]
[2]Dai Fuchu.Analysis of landslide initiative mechanism based on stress-strain behavior of soil[J].Chinese Journal of Geotechnical Engineering,2000,22(1):127-130.[戴福初.从土的应力应变特征性探讨滑坡发生机理[J].岩土工程学报,2000,22(1):127-130.]
[3]Yan Shaojun,Tang Huiming,Xiang Wei.Effect of rainfall on the stability of landslides[J].Hydrology and Engineering Geology,2007,34(2):33-36.[严绍军,唐辉明,项伟.降雨对滑坡稳定性影响过程分析[J].水文地质工程地质,2007,34(2):33-36.]
[4]Ning Shejiao,Kang Jinshuan,Tao Hong,et al.Big terrace landslide successful forecast method[J].Hydrology and Engineering Geology,2006,33(6):110-112.[宁社教,康金栓,陶虹,等.黄土塬边大型滑坡成功预报的基本做法[J].水文地质工程地质,2006,33(6):110-112.]
[5]Wu Weijiang,Wang Nianqin.Basic types and active features of loess landslide[J].The Chinese Journal of Geological Hazard and Control,2002,13(2):36-40.[吴玮江,王念秦.黄土滑坡的基本类型与活动特征[J].中国地质灾害与防治学报,2002,13(2):36-40.]
[6]Chen Shanxiong,Chen Shouyi.Analysis of stability of unsaturated soil slope due to permeation of rainwater[J].Rock and Soil Mechanics,2001,22(4):447-450.[陈善雄,陈守义.考虑降雨的非饱和土坡稳定性分析方法[J].岩土力学,2001,22(4):447-450.]
[7]Wang Jianhua,Huang Nuan.Reliability analysis of stability for unsaturated loess slopes under the condition of rainfall infiltration[J].Water Power,2006,32(10):38-40.[王建华,黄暖.降雨入渗条件下非饱和黄土边坡的可靠度分析[J].水力发电,2006,32(10):38-40.]
[8]Wu Lizhou,Huang Runqiu.Numerical analysis of seepage flow and its parameters in unsaturated soils[J].Hydrology and Engineering Geology,2011,38(1):94-98.[吴礼舟,黄润秋.非饱和土渗流及其参数影响的数值分析[J].水文地质工程地质,2011,38(1):94-98.]
[9]Long Wanxue,Wu Ju,Fu Helin.Research on on-site simulation test of landslide by artificial rainfall[J].Journal of Guizhou University of Technology(Natural Science Edition),2008,37(3):20-24.[龙万学,吴俊,傅鹤林.降雨型滑坡现场模拟试验研究[J].贵州工业大学学报(自然科学版),2008,37(3):20-24.]
[10]Tian Dongfang,Liu Defu,Zhou Mingtao.Sensitivity analysis on the influence factors of slope runoff and rainfall infiltration[J].Water Power,2010,36(4):11-13.[田东方,刘德富,周明涛.边坡降雨入渗与坡面径流影响因素敏感性分析[J].水力发电,2010,36(4):11-13.]
[11]Li Xi'an,Peng Jianbing,Chen Zhixin,et al.On the infiltration modes of surface runoff in the loess layer and geological hazards[J].Journal of Engineering Geology,2007,15(4):495-499.[李喜安,彭建兵,陈志新,等.黄土地层地表径流下潜模式与地质灾害[J].工程地质学报,2007,15(4):495-499.]
[12]Zheng Zhiyong.Analysis on the formative mechanism of the loess landslides in Tongchuan[J].Journal of Xian University of Sciedce and Technology,2008,28(4):694-697.[郑志勇.黄土滑坡的形成机理[J].西安科技大学学报,2008,28(4):694-697.]
[13]Atkinson J H,Farrar D M.Stress path tests to measure soil strength parameters for shallow landslips[C]//Proceedings of the11th International Conference on Soil Mechanics and Foundation Engineering.1985,2:983-986.
[14]Zhu J H,Anderson S A.Determination of shear strength of Hawaiian residual soil subjected to rainfall-induced landslides[J].G otechnique,1998,48(1):73-82.
[15]Brand E W.Some thoughts on rain-induced slope failures[C]//Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering,Stockholm.1981,3:373-376.
[16]Anderson S A,Riemer M F.Collapse of saturated soil due to reduction in confinement[J].Journal of geotechnical engineering,1995,121(2):216-220.
[17]Jin Yanli,Dai Fuchu.Study on the mechanism of loess landslide induced by irrigation[J].Chinese Journal of Geotechnical Engineering,2007,29(10):1493-1499.[金艳丽,戴福初.灌溉诱发黄土滑坡机理研究[J].岩土工程学报,2007,29(10):1493-1499.]
[18]Krahn J,Fredlund D G,Klassen M J.Effect of soil suction on slope stability at Notch Hill[J].Canadian Geotechnical Journal,1989,26(2):269-278.
[19]Fredlund D G.Bringing unsaturated soil mechanics into engineering practice[C]//Proceedings of the 2nd international conference on unsaturated soils.1998:1-35.
[20]Wu Weijiang.Seasonal freezing and thawing effect on shaping of slope[J].The Chinese Journal of Geological Hazard and Control,1996,7(4):59-64.[吴玮江.季节性冻融作用与斜坡整体变形破坏[J].中国地质灾害与防治学报,1996,7(4):59-64.]
[2]Dai Fuchu.Analysis of landslide initiative mechanism based on stress-strain behavior of soil[J].Chinese Journal of Geotechnical Engineering,2000,22(1):127-130.[戴福初.从土的应力应变特征性探讨滑坡发生机理[J].岩土工程学报,2000,22(1):127-130.]
[3]Yan Shaojun,Tang Huiming,Xiang Wei.Effect of rainfall on the stability of landslides[J].Hydrology and Engineering Geology,2007,34(2):33-36.[严绍军,唐辉明,项伟.降雨对滑坡稳定性影响过程分析[J].水文地质工程地质,2007,34(2):33-36.]
[4]Ning Shejiao,Kang Jinshuan,Tao Hong,et al.Big terrace landslide successful forecast method[J].Hydrology and Engineering Geology,2006,33(6):110-112.[宁社教,康金栓,陶虹,等.黄土塬边大型滑坡成功预报的基本做法[J].水文地质工程地质,2006,33(6):110-112.]
[5]Wu Weijiang,Wang Nianqin.Basic types and active features of loess landslide[J].The Chinese Journal of Geological Hazard and Control,2002,13(2):36-40.[吴玮江,王念秦.黄土滑坡的基本类型与活动特征[J].中国地质灾害与防治学报,2002,13(2):36-40.]
[6]Chen Shanxiong,Chen Shouyi.Analysis of stability of unsaturated soil slope due to permeation of rainwater[J].Rock and Soil Mechanics,2001,22(4):447-450.[陈善雄,陈守义.考虑降雨的非饱和土坡稳定性分析方法[J].岩土力学,2001,22(4):447-450.]
[7]Wang Jianhua,Huang Nuan.Reliability analysis of stability for unsaturated loess slopes under the condition of rainfall infiltration[J].Water Power,2006,32(10):38-40.[王建华,黄暖.降雨入渗条件下非饱和黄土边坡的可靠度分析[J].水力发电,2006,32(10):38-40.]
[8]Wu Lizhou,Huang Runqiu.Numerical analysis of seepage flow and its parameters in unsaturated soils[J].Hydrology and Engineering Geology,2011,38(1):94-98.[吴礼舟,黄润秋.非饱和土渗流及其参数影响的数值分析[J].水文地质工程地质,2011,38(1):94-98.]
[9]Long Wanxue,Wu Ju,Fu Helin.Research on on-site simulation test of landslide by artificial rainfall[J].Journal of Guizhou University of Technology(Natural Science Edition),2008,37(3):20-24.[龙万学,吴俊,傅鹤林.降雨型滑坡现场模拟试验研究[J].贵州工业大学学报(自然科学版),2008,37(3):20-24.]
[10]Tian Dongfang,Liu Defu,Zhou Mingtao.Sensitivity analysis on the influence factors of slope runoff and rainfall infiltration[J].Water Power,2010,36(4):11-13.[田东方,刘德富,周明涛.边坡降雨入渗与坡面径流影响因素敏感性分析[J].水力发电,2010,36(4):11-13.]
[11]Li Xi'an,Peng Jianbing,Chen Zhixin,et al.On the infiltration modes of surface runoff in the loess layer and geological hazards[J].Journal of Engineering Geology,2007,15(4):495-499.[李喜安,彭建兵,陈志新,等.黄土地层地表径流下潜模式与地质灾害[J].工程地质学报,2007,15(4):495-499.]
[12]Zheng Zhiyong.Analysis on the formative mechanism of the loess landslides in Tongchuan[J].Journal of Xian University of Sciedce and Technology,2008,28(4):694-697.[郑志勇.黄土滑坡的形成机理[J].西安科技大学学报,2008,28(4):694-697.]
[13]Atkinson J H,Farrar D M.Stress path tests to measure soil strength parameters for shallow landslips[C]//Proceedings of the11th International Conference on Soil Mechanics and Foundation Engineering.1985,2:983-986.
[14]Zhu J H,Anderson S A.Determination of shear strength of Hawaiian residual soil subjected to rainfall-induced landslides[J].G otechnique,1998,48(1):73-82.
[15]Brand E W.Some thoughts on rain-induced slope failures[C]//Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering,Stockholm.1981,3:373-376.
[16]Anderson S A,Riemer M F.Collapse of saturated soil due to reduction in confinement[J].Journal of geotechnical engineering,1995,121(2):216-220.
[17]Jin Yanli,Dai Fuchu.Study on the mechanism of loess landslide induced by irrigation[J].Chinese Journal of Geotechnical Engineering,2007,29(10):1493-1499.[金艳丽,戴福初.灌溉诱发黄土滑坡机理研究[J].岩土工程学报,2007,29(10):1493-1499.]
[18]Krahn J,Fredlund D G,Klassen M J.Effect of soil suction on slope stability at Notch Hill[J].Canadian Geotechnical Journal,1989,26(2):269-278.
[19]Fredlund D G.Bringing unsaturated soil mechanics into engineering practice[C]//Proceedings of the 2nd international conference on unsaturated soils.1998:1-35.
[20]Wu Weijiang.Seasonal freezing and thawing effect on shaping of slope[J].The Chinese Journal of Geological Hazard and Control,1996,7(4):59-64.[吴玮江.季节性冻融作用与斜坡整体变形破坏[J].中国地质灾害与防治学报,1996,7(4):59-64.]