天水黄土结构性变化诱发滑坡敏感性分析
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摘要
黄土高原地区黄土滑坡频频发生,尤其是近年来极端气候条件增多,集中强降雨导致甘肃天水地区黄土滑坡群发.2013年8月,在经历一周持续降雨之后,天水地区产生了大量的黄土滑坡以及黄土-泥岩接触面滑坡.黄土地区滑坡发生后一些滑坡的复活往往与黄土的结构性存在紧密联系.选取天水花南村滑坡后壁黄土为研究对象,利用GDS三轴仪对滑坡区黄土原状样和重塑样进行了固结不排水三轴压缩试验.试验结果表明,原状黄土表现出明显的应变软化特征,而重塑黄土的应变软化现象急剧减小,二者的孔隙水压力变化特征也有差异.同时基于三轴试验结果,绘制了原状黄土和重塑黄土的应力路径图,应力路径图再次证实了重塑样应变软化减小的现象.孔隙水压力随轴向应变变化图中可见,剪切初始阶段,重塑样的孔隙水压力增加较原状样更为迅速,对于滑坡的诱发更加敏感.
The loess landslide occurred frequently in the region of loess plateau in recent years. The extreme weather conditions and the heavy rainfall made the loess landslide become more than before in Tianshui,Gansu Province. A mass of loess landslide and loess-mudstone interface landslide triggered in Tianshui after a weekly continuous rainfall in August 2013. The resurrection of the loess landslide is often closely linked with the structure of loess. The undisturbed loess and remolded loess samples were chosen in the scarp of Huanancun landslide to operate consolidated undrained triaxial test by GDS triaxial apparatus. The results showobviously that the strain of undisturbed samples were strain softening,and the strain softening in remolded samples were weakened sharply. The result of strain softening was also undertaken by the stress path. The changes of pore water pressure in undisturbed and remolded samples were different from each other. At the beginning of shearing,the pore water pressure in the undisturbed samples increased slower than in the remolded samples. So the remolded loess was more sensitivity to the landslide than the undisturbed loess.
The loess landslide occurred frequently in the region of loess plateau in recent years. The extreme weather conditions and the heavy rainfall made the loess landslide become more than before in Tianshui,Gansu Province. A mass of loess landslide and loess-mudstone interface landslide triggered in Tianshui after a weekly continuous rainfall in August 2013. The resurrection of the loess landslide is often closely linked with the structure of loess. The undisturbed loess and remolded loess samples were chosen in the scarp of Huanancun landslide to operate consolidated undrained triaxial test by GDS triaxial apparatus. The results showobviously that the strain of undisturbed samples were strain softening,and the strain softening in remolded samples were weakened sharply. The result of strain softening was also undertaken by the stress path. The changes of pore water pressure in undisturbed and remolded samples were different from each other. At the beginning of shearing,the pore water pressure in the undisturbed samples increased slower than in the remolded samples. So the remolded loess was more sensitivity to the landslide than the undisturbed loess.
引文
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[15]Zhang Maosheng,Li Tonglu.Triggering factors and forming mechanism of loess land-slides[J].Journal of Engineering Geology,2011,19(4):530-540.[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.]
[16]Wu Weijiang,Su Xing,Liu Wei,et al.Loess-mudstong interface landslides:characteristics and causes[J].Journal of Glaciology and Geocryolog,2014,36(5):1167-1175.[吴玮江,宿星,刘伟,等.黄土-泥岩接触面滑坡的特征与成因[J].冰川冻土,2014,36(5):1167-1175.]
[17]Wu Weijiang.Slide accelerated by water entrapment due to seasonal freezing[J].Journal of Glaciology and Geocryolog,1997,19(4):359-365.[吴玮江.季节性冻结滞水促滑效应:滑坡发育的一种新因素[J].冰川冻土,1997,19(4):359-365.]
[18]Wang Nianqin,Yao Yong.Characteristics and mechanism of landslides in loess during freezing and thaw ing periods in seasonally frozen ground regions[J].Journal of Disaster Prevention and M itigation Engineering,2008,28(2):163-166.[王念秦,姚勇.季节冻土区冻融期黄土滑坡基本特征与机理[J].防灾减灾工程学报,2008,28(2):163-166.]
[19]Deng Guohua,Shao Shengjun.Research on change structural characteristics of loess based on true triaxial tests[J].Rock and Soil M echanics,2013,34(3):679-684.[邓国华,邵生俊.基于真三轴试验的黄土结构性变化规律研究[J].岩土力学,2013,34(3):679-684.]
[20]Sun Mingxiang,Yang Lei,Fan Yaowu,et al.Study on loess structure w ith different test methods[J].Journal of Railw ay Engineering Society,2011(3):24-31.[孙明祥,杨磊,樊耀武,等.基于不同试验手段对黄土的结构性研究[J].铁道工程学报,2011(3):24-31.]
[21]Cheng Xiaoyong,Xiang Wei,Liu Jianping,et al.Structural parameter system of loess based on Bertalanffy[J].Chinese Journal of Geotechnical Engineering,2008(S1):252-256.[程小勇,项伟,刘建平,等.基于贝塔朗菲的黄土结构性参数理论体系研究[J].岩土工程学报,2008(S1):252-256.]
[22]Liao Hongjian,Li Tao,Peng Jianbing.Study of strength characteristics of high and steep slope landslide mass loess[J].Rock and Soil M echanics,2011,32(7):1939-1944.[廖红建,李涛,彭建兵.高陡边坡滑坡体黄土的强度特性研究[J].岩土力学,2011,32(7):1939-1944.]
[23]Shao Shengjun,Tao Hu,Xu Ping.Discussion on research of mechanical characteristics of loess considering structural behavior and its application[J].Rock and Soil M echanics,2011(S2):42-50.[邵生俊,陶虎,许萍.黄土结构性力学特性研究与应用的探讨[J].岩土力学,2011(S2):42-50.]
[2]Li Tonglu,Long Jianhui,Li Xinsheng.Types of loess landslides and methods for their movement forecast[J].Journal of Engineering Geology,2007,15(4):500-505.[李同录,龙建辉,李新生.黄土滑坡发育类型及其空间预测方法[J].工程地质学报,2007,15(4):500-505.]
[3]Xu Ling,Dai Fuchu,Kuang Guolin,et al.Types and characteristics of loess landslides at Heifangtai loess plateau,China[J].Journal of M ountain Science,2008,26(3):364-371.[许领,戴福初,邝国麟,等.黑方台黄土滑坡类型与发育规律[J].山地学报,2008,26(3):364-371.]
[4]Xu Ling,Dai Fuchu,Min Hong,et al.Loess landslide types and topographic features at south Jingyang plateau,China[J].Earth Science:Journal of China University of Geosciences,2010,35(1):155-160.[许领,戴福初,闵弘,等.泾阳南塬黄土滑坡类型与发育特征[J].地球科学:中国地质大学学报,2010,35(1):155-160.]
[5]Li Bin,Yin Yueping,Wu Shuren,et al.Basic types and characteristics of multiple rotational landslides in loess[J].Journal of Engineering Geology,2011,19(5):703-711.[李滨,殷跃平,吴树仁,等.多级旋转黄土滑坡基本类型及特征分析[J].工程地质学报,2011,19(5):703-711.]
[6]Wang Gongxian.Sliding mechanism and prediction of critical sliding of Huangci landslide in Yongjing county,Gansu province[J].Journal of Catastrophology,1997,12(3):23-27.[王恭先.甘肃省永靖县黄茨滑坡的滑动机理与临滑预报[J].灾害学,1997,12(3):23-27.]
[7]Ni Weida,Yong Rui,Ge Yunfeng.Quantitative research on the liquefaction-vaporization effect of high-speed loess landslides[J].Safety and Environmental Engineering,2010,17(5):4-7.[倪卫达,雍睿,葛云峰.高速黄土滑坡液化-汽化效应定量研究[J].安全与环境工程,2010,17(5):4-7.]
[8]Wang Jiading,Xiao Shufang,Zhang Zhuoyuan.The mechanism for movement of irrigation-induced highspeed loess landslide[J].Journal of Engineering Geology,2001,9(3):241-246.[王家鼎,肖树芳,张倬元.灌溉诱发高速黄土滑坡的运动机理[J].工程地质学报,2001,9(3):241-246.]
[9]Wu Caixia,Xu Ling,Dai Fuchu,et al.Topographic features and initiation of earth flow s on Heifangtai loess plateau[J].Rock and Soil M echanics,2011,32(6):1767-1773.[武彩霞,许领,戴福初,等.黑方台黄土泥流滑坡及发生机制研究[J].岩土力学,2011,32(6):1767-1773.]
[10]Wu Weijiang,Wang Guoya,Ren Lubin,et al.Characteristics and causes of the mudflow-landslides in loess[J].Journal of Glaciology and Geocryolog,2015,37(1):138-146.[吴玮江,王国亚,任路滨,等.泥流型黄土滑坡的特征与成因[J].冰川冻土,2015,37(1):138-146.]
[11]Wang Jiading,Zhang Zhuoyuan.A study on the mechanism of high-speed loess landslide induced by earthquake[J].Chinese Journal of Geotechnical Engineering,1999,21(6):670-674.[王家鼎,张倬元.地震诱发高速黄土滑坡的机理研究[J].岩土工程学报,1999,21(6):670-674.]
[12]Sun Ping,Yin Yueping,Wu Shuren,et al.An experimental study on the initiation mechanism of rapid and long run-out loess landslide caused by 1920 Haiyuan earthquake[J].Journal of Engineering Geology,2009,17(4):449-454.[孙萍,殷跃平,吴树仁,等.高速远程地震黄土滑坡发生机制试验研究[J].工程地质学报,2009,17(4):449-454.]
[13]Yin Yueping.Rapid and long run-out features of landslides triggered by the Wenchuan earthquake[J].Journal of Engineering Geology,2009,17(2):153-166.[殷跃平.汶川八级地震滑坡高速远程特征分析[J].工程地质学报,2009,17(2):153-166.]
[14]Chen Yongming,Shi Yucheng.Basic characteristics of seismic landslides in loess area of northw est China[J].Journal of Seismological Research,2006,29(3):276-280.[陈永明,石玉成.中国西北黄土地区地震滑坡基本特征[J].地震研究,2006,29(3):276-280.]
[15]Zhang Maosheng,Li Tonglu.Triggering factors and forming mechanism of loess land-slides[J].Journal of Engineering Geology,2011,19(4):530-540.[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.]
[16]Wu Weijiang,Su Xing,Liu Wei,et al.Loess-mudstong interface landslides:characteristics and causes[J].Journal of Glaciology and Geocryolog,2014,36(5):1167-1175.[吴玮江,宿星,刘伟,等.黄土-泥岩接触面滑坡的特征与成因[J].冰川冻土,2014,36(5):1167-1175.]
[17]Wu Weijiang.Slide accelerated by water entrapment due to seasonal freezing[J].Journal of Glaciology and Geocryolog,1997,19(4):359-365.[吴玮江.季节性冻结滞水促滑效应:滑坡发育的一种新因素[J].冰川冻土,1997,19(4):359-365.]
[18]Wang Nianqin,Yao Yong.Characteristics and mechanism of landslides in loess during freezing and thaw ing periods in seasonally frozen ground regions[J].Journal of Disaster Prevention and M itigation Engineering,2008,28(2):163-166.[王念秦,姚勇.季节冻土区冻融期黄土滑坡基本特征与机理[J].防灾减灾工程学报,2008,28(2):163-166.]
[19]Deng Guohua,Shao Shengjun.Research on change structural characteristics of loess based on true triaxial tests[J].Rock and Soil M echanics,2013,34(3):679-684.[邓国华,邵生俊.基于真三轴试验的黄土结构性变化规律研究[J].岩土力学,2013,34(3):679-684.]
[20]Sun Mingxiang,Yang Lei,Fan Yaowu,et al.Study on loess structure w ith different test methods[J].Journal of Railw ay Engineering Society,2011(3):24-31.[孙明祥,杨磊,樊耀武,等.基于不同试验手段对黄土的结构性研究[J].铁道工程学报,2011(3):24-31.]
[21]Cheng Xiaoyong,Xiang Wei,Liu Jianping,et al.Structural parameter system of loess based on Bertalanffy[J].Chinese Journal of Geotechnical Engineering,2008(S1):252-256.[程小勇,项伟,刘建平,等.基于贝塔朗菲的黄土结构性参数理论体系研究[J].岩土工程学报,2008(S1):252-256.]
[22]Liao Hongjian,Li Tao,Peng Jianbing.Study of strength characteristics of high and steep slope landslide mass loess[J].Rock and Soil M echanics,2011,32(7):1939-1944.[廖红建,李涛,彭建兵.高陡边坡滑坡体黄土的强度特性研究[J].岩土力学,2011,32(7):1939-1944.]
[23]Shao Shengjun,Tao Hu,Xu Ping.Discussion on research of mechanical characteristics of loess considering structural behavior and its application[J].Rock and Soil M echanics,2011(S2):42-50.[邵生俊,陶虎,许萍.黄土结构性力学特性研究与应用的探讨[J].岩土力学,2011(S2):42-50.]