汶川地震大型滑坡成因模式
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摘要
"5.12"汶川地震诱发了数以万计的滑坡灾害,其中仅大型滑坡就上百处.通过对汶川地震诱发的20余处大型滑坡的变形破坏特征进行深入调研,结合振动台试验和数值模拟等手段,发现汶川地震诱发大型滑坡的变形破坏模式和内在力学机制与常规重力作用下滑坡机制具有显著的不同.在强震条件下,斜坡中上部地震水平加速度可超过1g,其地震水平惯性力远远超过岩体的抗拉强度,地震作用首先在坡体后缘形成与坡面平行且陡倾坡外的深大拉裂缝,随后拉裂岩体的底部产生剪切滑移,最终形成滑坡.在强震条件下,斜坡岩体最基本的变形破坏单元就是拉裂和剪切滑移,且以拉裂占主导.不同的斜坡结构,其底部剪切滑移会沿不同的结构面发生.根据滑源区所处的地质环境条件、坡体结构以及岩性组合特征,将汶川地震诱发的大型滑坡划分为五类成因模式:拉裂—顺走向滑移型、拉裂—顺层(倾向)滑移型、拉裂—水平滑移型、拉裂—散体滑移型、拉裂—剪断滑移型.
The "5·12" Wenchuan earthquake induced thousands of landslides,including hundreds of large-scale ones.The deformation and destroy characteristics of 20 large-scale landslides induced by Wenchuan earthquake found in our in-depth investigation and extensive survey,combined with the tools of shaking table test and numerical simulation,we find that their deformation and destroy model and intrinsic mechanical mechanism Wenchuan earthquake are significantly different from those of landsides induced by routine gravity.On the condition of strong shock,the earthquake-horizontal acceleration on the middle-top of the declivity can exceed 1g,and its earthquake horizontal inertia enormously exceeds the tension strength of the rock mass.Seismic action firstly shaped a deep large fissure which was parallel to the clinohedron on the back of the slope,and then the bottom of the pull-apart rock mass engendered shearing glide,finally,there induced landslide.On the condition of strong shock,the most essential deformation and destroy element of the slope rock mass are tension-cracks and shearing glide,and mainly dominated by tension-cracks.With different slope structures,the bottom shearing glide occurs with different discontinuities.According to the geological environment of the landsliding source region as well as the characteristics of the slope form and lithological association,this paper divides the large-scale landslides induced by Wenchuan earthquake into five genetic types,namely,tension-cracking and consequent sliding,tension-cracking and bedding sliding,tension-cracking and horizontal sliding,tension-cracking and scattering sliding and tension-cracking and shearing sliding.
The "5·12" Wenchuan earthquake induced thousands of landslides,including hundreds of large-scale ones.The deformation and destroy characteristics of 20 large-scale landslides induced by Wenchuan earthquake found in our in-depth investigation and extensive survey,combined with the tools of shaking table test and numerical simulation,we find that their deformation and destroy model and intrinsic mechanical mechanism Wenchuan earthquake are significantly different from those of landsides induced by routine gravity.On the condition of strong shock,the earthquake-horizontal acceleration on the middle-top of the declivity can exceed 1g,and its earthquake horizontal inertia enormously exceeds the tension strength of the rock mass.Seismic action firstly shaped a deep large fissure which was parallel to the clinohedron on the back of the slope,and then the bottom of the pull-apart rock mass engendered shearing glide,finally,there induced landslide.On the condition of strong shock,the most essential deformation and destroy element of the slope rock mass are tension-cracks and shearing glide,and mainly dominated by tension-cracks.With different slope structures,the bottom shearing glide occurs with different discontinuities.According to the geological environment of the landsliding source region as well as the characteristics of the slope form and lithological association,this paper divides the large-scale landslides induced by Wenchuan earthquake into five genetic types,namely,tension-cracking and consequent sliding,tension-cracking and bedding sliding,tension-cracking and horizontal sliding,tension-cracking and scattering sliding and tension-cracking and shearing sliding.
引文
Hu,X.W.,Huang,R.Q.,Shi,Y.B.,et al.,2009a.Analysis of blocking river mechanism of Tangjiashan landslide and dam-breaking mode of its barrier dam.Chinese Journal of Rock Mechanics and Engineering,28(1):181-189(in Chinese with English abstract).
Hu,X.W.,Luo,G.,Huang,R.Q.,et al.,2009b.Study of stability of remnant mountain body in back scarp of Tangjiashan landslide after“5.12”Wenchuan earthquake.Chinese Journal of Rock Mechanics and Engi-neering,28(11):2349-2359(in Chinese with English abstract).
Huang,R.Q.,2009.Mechanism and geomechanical modes of landslide hazards triggered by Wenchuan 8.0earthquake.Chinese Journal of Rock Mechanics and Engineering,28(6):1239-1249(in Chinese with English abstract).
Huang,R.Q.,Pei,X.J.,Li,T.B.,2008.Basic characteris-tics and formation mechanism of the largest scale land-slide at Daguangbao occurred during the Wenchuan earthquake.Journal of Engineering Geology,16(6):730-741(in Chinese with English abstract).
Huang,R.Q.,Pei,X.J.,Zhang,W.F.,et al.,2009.Futher examination on characteristics and formation Mechanism of Daguangbao Landslide.Journal of Engineering Geology,17(6):725-736(in Chinese with English abstract).
Keeper,D.V.,1984.Landslides caused by earthquakes.Geological Society of America Bulletin,95(4):406-421.doi:10,1130/0016-7606(1984)95<406:LCBE>2.0.CO;2
Liu,C.Z.,2010.Mechanism analysis on the Jiweishan rock-fall disaster happened in Wulong,Chongqing,June 5,2009.Journal of Engineering Geology,18(3):297-304(in Chinese with English abstract).
Sun,P.,Zhang,Y.S.,Yin,Y.P.,et al.,2009.Discussion on long run-out sliding mechanism of Donghekou landslide debris flow.Journal of Engineering Geology,17(6):737-744(in Chinese with English abstract).
Xu,Q.,Chen,J.J.,Feng,W.K.,et al.,2009a.Study of the seismic response of slopes by physical modeling.Journal of Sichuan University(Engineering Science Edition),41(3),266-272(in Chinese with English abstract).
Xu,Q.,Pei,X.J.,Huang,R.Q.,et al.,2009b.Large-scale landslides induced by the Wenchuan earthquake.Science Press,Beijing(in Chinese).
Xu,Q.,Fan,X.M.,Huang,R.Q.,et al.,2010.A catastrophic rockslide-debris flow in Wulong,Chongqing,China in 2009:background,characterization,and causes.Landlides,7(1):75-87.doi:10.1007/s10346-0090179-y
Yin,Y.P.,2010.Mechanism of apparent dip slide of inclined bedding rockslide-a case study of Jiweishan rockslide in Wulong,Chongqing.Chinese Journal of Rock Mechanics and Engineering,29(2):217-226(in Chinese with English abstract).
Zheng,Y.R.,Ye,H.L.,Huang,R.Q.,2009.Analysis and discussion of failure mechanism and fracture surface of slope under earthquake.Chinese Journal of Rock Mechanics and Engineering,28(8):1714-1723(in Chinese with English abstract).
胡卸文,黄润秋,施裕兵,等,2009a.唐家山滑坡堵江机制及堰塞坝溃坝模式分析.岩石力学与工程学报,28(1):181-189.
胡卸文,罗刚,黄润秋,等,2009b.唐家山滑坡后壁残留山体震后稳定性研究.岩石力学与工程学报,28(11):2349-2359.
黄润秋,2009.汶川8.0级地震触发崩滑灾害机制及其地质力学模式.岩石力学与工程学报,28(6):1239-1249.
黄润秋,裴向军,李天斌,2008.汶川地震触发大光包巨型滑坡基本特征及形成机理分析.工程地质学报,16(6):730-741.
黄润秋,裴向军,张伟锋,等,2009.再论大光包滑坡特征与形成机制.工程地质学报,17(6):725-736.
刘传正,2010.重庆武隆鸡尾山危岩体形成与崩塌成因分析.工程地质学报,18(3):297-304.
孙萍,张永双,殷跃平,等,2009.东河口滑坡-碎屑流高速远程运移机制探讨.工程地质学报,17(6):737-744.
许强,陈建君,冯文凯,等,2009a.斜坡地震响应的物理模拟试验研究.四川大学学报(工程科学版),41(3):266-272.
许强,裴向军,黄润秋,等,2009b.汶川地震大型滑坡研究.北京:科学出版社.
殷跃平,2010.斜倾厚层山体滑坡视向滑动机制研究——以重庆武隆鸡尾山滑坡为例.岩石力学与工程学报,29(2):217-226.
郑颖人,叶海林,黄润秋,2009.地震边坡破坏机制及其破裂面的分析探讨.岩石力学与工程学报,28(8):17141723.
Hu,X.W.,Luo,G.,Huang,R.Q.,et al.,2009b.Study of stability of remnant mountain body in back scarp of Tangjiashan landslide after“5.12”Wenchuan earthquake.Chinese Journal of Rock Mechanics and Engi-neering,28(11):2349-2359(in Chinese with English abstract).
Huang,R.Q.,2009.Mechanism and geomechanical modes of landslide hazards triggered by Wenchuan 8.0earthquake.Chinese Journal of Rock Mechanics and Engineering,28(6):1239-1249(in Chinese with English abstract).
Huang,R.Q.,Pei,X.J.,Li,T.B.,2008.Basic characteris-tics and formation mechanism of the largest scale land-slide at Daguangbao occurred during the Wenchuan earthquake.Journal of Engineering Geology,16(6):730-741(in Chinese with English abstract).
Huang,R.Q.,Pei,X.J.,Zhang,W.F.,et al.,2009.Futher examination on characteristics and formation Mechanism of Daguangbao Landslide.Journal of Engineering Geology,17(6):725-736(in Chinese with English abstract).
Keeper,D.V.,1984.Landslides caused by earthquakes.Geological Society of America Bulletin,95(4):406-421.doi:10,1130/0016-7606(1984)95<406:LCBE>2.0.CO;2
Liu,C.Z.,2010.Mechanism analysis on the Jiweishan rock-fall disaster happened in Wulong,Chongqing,June 5,2009.Journal of Engineering Geology,18(3):297-304(in Chinese with English abstract).
Sun,P.,Zhang,Y.S.,Yin,Y.P.,et al.,2009.Discussion on long run-out sliding mechanism of Donghekou landslide debris flow.Journal of Engineering Geology,17(6):737-744(in Chinese with English abstract).
Xu,Q.,Chen,J.J.,Feng,W.K.,et al.,2009a.Study of the seismic response of slopes by physical modeling.Journal of Sichuan University(Engineering Science Edition),41(3),266-272(in Chinese with English abstract).
Xu,Q.,Pei,X.J.,Huang,R.Q.,et al.,2009b.Large-scale landslides induced by the Wenchuan earthquake.Science Press,Beijing(in Chinese).
Xu,Q.,Fan,X.M.,Huang,R.Q.,et al.,2010.A catastrophic rockslide-debris flow in Wulong,Chongqing,China in 2009:background,characterization,and causes.Landlides,7(1):75-87.doi:10.1007/s10346-0090179-y
Yin,Y.P.,2010.Mechanism of apparent dip slide of inclined bedding rockslide-a case study of Jiweishan rockslide in Wulong,Chongqing.Chinese Journal of Rock Mechanics and Engineering,29(2):217-226(in Chinese with English abstract).
Zheng,Y.R.,Ye,H.L.,Huang,R.Q.,2009.Analysis and discussion of failure mechanism and fracture surface of slope under earthquake.Chinese Journal of Rock Mechanics and Engineering,28(8):1714-1723(in Chinese with English abstract).
胡卸文,黄润秋,施裕兵,等,2009a.唐家山滑坡堵江机制及堰塞坝溃坝模式分析.岩石力学与工程学报,28(1):181-189.
胡卸文,罗刚,黄润秋,等,2009b.唐家山滑坡后壁残留山体震后稳定性研究.岩石力学与工程学报,28(11):2349-2359.
黄润秋,2009.汶川8.0级地震触发崩滑灾害机制及其地质力学模式.岩石力学与工程学报,28(6):1239-1249.
黄润秋,裴向军,李天斌,2008.汶川地震触发大光包巨型滑坡基本特征及形成机理分析.工程地质学报,16(6):730-741.
黄润秋,裴向军,张伟锋,等,2009.再论大光包滑坡特征与形成机制.工程地质学报,17(6):725-736.
刘传正,2010.重庆武隆鸡尾山危岩体形成与崩塌成因分析.工程地质学报,18(3):297-304.
孙萍,张永双,殷跃平,等,2009.东河口滑坡-碎屑流高速远程运移机制探讨.工程地质学报,17(6):737-744.
许强,陈建君,冯文凯,等,2009a.斜坡地震响应的物理模拟试验研究.四川大学学报(工程科学版),41(3):266-272.
许强,裴向军,黄润秋,等,2009b.汶川地震大型滑坡研究.北京:科学出版社.
殷跃平,2010.斜倾厚层山体滑坡视向滑动机制研究——以重庆武隆鸡尾山滑坡为例.岩石力学与工程学报,29(2):217-226.
郑颖人,叶海林,黄润秋,2009.地震边坡破坏机制及其破裂面的分析探讨.岩石力学与工程学报,28(8):17141723.
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