青藏高原东缘理塘乱石包高速远程滑坡发育特征与形成机理
Huge long-runout landslide characteristics and formation mechanism: A case study of the Luanshibao landslide, Litang County, Tibetan Plateau
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摘要: 青藏高原复杂的地质构造背景，导致该区地震频发，加之该区异常的气候变化，大型乃至巨型地质灾害发育多，危害大。在遥感解译、野外地质调查、物探、槽探和地质测年资料分析的基础上，论述了乱石包滑坡的发育特征，并对其形成机理进行分析探讨。认为乱石包高速远程滑坡具有如下特征：①乱石包滑坡的滑动方向垂直于理塘-德巫断裂的北西段，乱石包滑坡顶部接近于现代雪线；②乱石包滑坡最大滑行距离达3.83km，滑坡后壁与前缘堆积区的高差约820m，滑体方量0.64×108~0.94×108m3，平均滑动速度约53.25m/s；③测年资料表明，乱石包滑坡形成1980±30a BP左右；④组成滑坡体的岩性主要为花岗岩，在长期构造活动和冷冻风化作用下，节理裂隙发育，呈碎裂岩体。分析表明，乱石包滑坡受断裂构造、地形地貌和古气候变化影响较大，形成机理复杂：①理塘-德巫断裂全新世以来活动强烈，具有强震地质背景，由该断裂活动形成的强震可能是乱石包滑坡形成的主要因素之一，在地震作用下，坡顶部地震波放大，垂直加速度大于水平加速度，岩体发生震胀和抛掷，从而形成高速远程滑动；②距今1800~2000a BP左右时，青藏高原地区的温度变化较大，该时期发生的大规模冰川活动可能是乱石包滑坡发生的主要因素之一；③地震、气候变化的组合也是引起乱石包滑坡发生的成因之一，并形成一个完整的地质灾害链：地震→雪崩→岩崩→高速碎屑流。Abstract: In the Tibetan Plateau, the complex geological tectonic background causes frequent earthquakes, together with the abnormal climate change, there are many large or even huge geological hazards, causing serious consequences. In this paper, based on the interpretation of remote sensing and the analysis of field geological survey, geophysical prospecting, trenching, and geological dating data, the authors studied the development characteristics of the Luanshibao landslide and investigated its formation mechanism. The Luanshibao long-runout landslide has the following features① The Luanshibao landslide is located on the northeastern margin of the Maoyaba Basin in Litang County, western Sichuan. The sliding direction of the landslide is perpendicular to the northwestern segment of the Litang-Dewu fault, with the top part of the Luanshibao landslide approaching the current snow line. ②The maximum sliding distance of the Luanshibao landslide is 3.83km; the elevation difference between the back wall of the landslide and the accumulation zone at the leading edge is approximately 820m, with a sliding body volume of approximately 0.64×108~0.94×108m3 and an average sliding velocity of approximately 53.25m/s. ③ The dating data indicate that the Luanshibao landslide occurred at about 1980±30a BP. ④ The compositional lithology of the landslide rocks is mainly granite, and the joint fractures are developed as cracked rocks under the impact of long-term tectonic dynamics and freezing weathering. The analysis indicates that the Luanshibao landslide has been substantially affected by the fault structure, terrain topography, and ancient climate change, and its formation mechanism is complicated① Since the Holocene, the Litang-Dewu fault has experienced frequent, strong earthquake activity. The strong earthquakes resulting from the fault activity might have been one of the main factors for the formation of the Luanshibao landslide. Under the impact of earthquakes, the seismic wave at the top of the slope would be "amplified", producing a vertical acceleration greater than the horizontal acceleration. The rock bodies experienced shock expansion and were thrown, forming the longrunout landslide. ② Dating back to approximately 2000a BP, the temperature change in the Tibetan Plateau area was relatively large, and the large-scale glacial activity occurring in this period was most likely one of the main factors behind the formation of the Luanshibao landslide. ③ The combination of earthquakes and climate change seems to have been one of the conditions causing the occurrence of the Luanshibao landslide, forming a complete chain of geological disasters, i.e., earthquake→avalanche→rockfall→ high speed debris flow.
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[1] Voight B,Faust C.Frictional heat and strength loss in some rapid landslides:error correction and affirmation of mechanism for the Vaiont landslide[J].Geotechnique,1992,42:641-643.
[2] Plafker G,Ericksen G E,Concha J F.Geological aspects of the May 31,1970 Peru earthquake[J].Seismological Society of America Bulletin,1971,61(3):543-578.
[3] 黄润秋,许强.中国典型灾难性滑坡[M].2008,北京:科学出版社.
[4] Weidinger J T.Landslide Dams in the High Mountains of India,Nepal and China-Stability and Life Span of Their Dammed Lakes[J].Italian Journal of Engineering Geology and Environment,2006,Special Issue (1):67-80.
[5] 吕艳,王根龙,张新社.翠华山山崩地质遗迹景观离散元数值模拟[J].工程地质学报,2013,21(3):443-449.
[6] 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.
[7] 刘伟.西藏易贡巨型超高速远程滑坡地质灾害链特征研析[J].中国地质灾害与防治学报,2002,13(3):9-18.
[8] 吕杰堂,王治华,周成虎.西藏易贡大滑坡成因探讨[J].地球科学(中国地质大学学报),2003,28(1):107-110.
[9] Yin Y P,Xing A G.Aerodynamic modeling of the Yigong gigantic rock slide-debris avalanche,Tibet,China[J].Bulletin of Engineering Geology and the Environment,2011,71:149-160.
[10] Xu Q,Shang Y J,van Asch T,et al.Observations from the large,rapid Yigong rock slide-debris avalanche,southeast Tibet[J].Canadian Geotechnical Journal,2012,49:589-606.
[11] Shang Y J,Yang Z F,Li L,et al.A super-large landslide in Tibet in 2000:background,occurrence,disaster,and origin[J].Geomorphology,2003,54:225-243.
[12] 黄润秋,裴向军,李天斌.汶川地震触发大光包巨型滑坡基本特征及形成机理分析[J].工程地质学报,2008,16(6):730-742.
[13] 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] 张永双,雷伟志,石菊松,等.四川5.12地震次生地质灾害的基本特征初析[J].地质力学学报,2008,14(2):109-116.
[15] 张永双,石菊松,孙萍,等.汶川地震内外动力耦合及灾害实例[J].地质力学学报,2009,15(2):131-142.
[16] 张永双,苏生瑞,吴树仁,等.强震区断裂活动与大型滑坡关系研究[J].岩石力学与工程学报,2011,28(s2):3503-3513.
[17] 王秀英,聂高众,王登伟.四川汶川地震诱发滑坡与地震动峰值加速度对应关系研究[J].岩石力学与工程学报,2010,29(1):159-165.
[18] 张明,殷跃平,吴树仁,等.高速远程滑坡-碎屑流运动机理研究发展现状与展望[J].工程地质学报,2010,18(6):805-818.
[19] 程谦恭,王玉峰,朱圻,等.高速远程滑坡超前冲击气浪动力学机理[J].2011,29(1):70-80.
[20] Scheidegger A E.On the prediction of the reach and velocity of catastrophic landslides[J].Rock Mechanics,1973,5:231-236.
[21] 殷跃平,朱继良,杨胜元.贵州关岭大寨高速远程滑坡-碎屑流研究[J].工程地质学报,2010,18(4):445-455.
[22] 唐川.昭通头寨沟特大型灾害性滑坡研究[J].云南地理环境研究,1991,2(2):64-71.
[23] Sassa K.The mechanism starting liquefied landslides and debris flows[C]//Proceedings of the 4th International Symposium on Landslides.Rotterdam:Balkema A A,1984,2:349-354.
[24] Sassa K,Fukuoka H,Wang G,et al.Undrained dynamic-loading ring-shear apparatus and its application to landslide dynamics[J].Landslides,2004,1:7-19.
[25] 汪发武.高速滑坡形成机制:土粒子破碎导致超孔隙水压力的产生[J].长春科技大学学报,2001,1(31):64-69.
[26] Wang F W,Sassa K,Wang G H.Mechanism of a long-runout landslide triggered by the August 1998 heavy rainfall in Fukushima Prefecture,Japan[J].Engineering Geology,2002,(63):169-185.
[27] 邢爱国.云南头寨大型高速岩质滑坡流体动力学机理的研究[J].岩石力学与工程学报,2002,21(4):614-614.
[28] 邢爱国,高广运,陈龙珠,等.大型高速滑坡启程流体动力学机理研究[J].岩石力学与工程学报,2004,23(4):607-613.
[29] Muller L.New considerations on the Vaiont slide[J].Rock Mechanics&Engineering Geology,1968,6(1/2):4-91.
[30] 孙萍,张永双,殷跃平,等.东河口滑坡-碎屑流高速远程运移机制探讨[J].工程地质学报,2009,17(6):737-744.
[31] Sun P,Zhang Y S,Shi J S,et al.Analysis on the dynamical process of Donghekou rockslide-debris flow triggered by 5.12 Wenchuan earthquake[J].Journal of Mountain Science,2011,8(2):140-148.
[32] 胡明鉴,程谦恭,汪发武.易贡远程高速滑坡形成原因试验探索[J].岩石力学与工程学报,2009,28(1):138-143.
[33] Skempton,A W.Residual strength of clays in landslides,folded strata and the laboratory[J].Geotechnique,1985,35(1):3-18.
[34] 龙建辉.高速远程黄土滑坡预测预报方法研究[D].长安大学博士学位论文,2008.
[35] 许强,董秀军.汶川地震大型滑坡成因模式[J].地球科学——中国地质大学学报,2011,36(6):1134-1142.
[36] 徐峻龄.中国的高速滑坡及其基本类型[J].中国地质灾害与防治学报,1994,5(s):24-29.
[37] 黄润秋,裴向军,张伟锋,等.再论大光包滑坡特征与形成机制[J].工程地质学报,2009,17(6):725-12.
[38] 岳中琦.汶川地震与山崩地裂的极高压甲烷天然气成因和机理[J].地学前缘,2013,20(6):15-20.
[39] 岳中琦.汶川地震成因的龙门山断裂带异常高压天然气体力源简述[J].岩石力学与工程动态,2009,2:45-51.
[40] 赵京轶,汤倩,兰晓雯,等.地下高压气体对汶川地震灾害的作用分析[J].震灾防御技术,2009,4(4):406-416.
[41] Zhang Y S,Zhao X T,Lan H X,et al.A Pleistocene landslidedammed lake,Jinsha River,Yunnan,China[J].Quaternary International,2011,233:72-80.
[42] Kent P E.The transport mechanism in catastrophic rock falls[J].Geology,1966,74:79-83.
[43] 龙德雄,黄辅琼,官致君,等.四川理塘毛垭温泉地质构造环境及成因分析[J].四川地震,2006,1:34-40.
[44] 徐锡伟,闻学泽,于贵华,等.川西理塘断裂带平均滑动速率、地震破裂分段与复发特征[J].中国科学(D辑),2005,35(6):540-551.
[45] 王治华,吕杰堂.从卫星图像上认识西藏易贡滑坡[J].遥感学报,2001,5(4):312-317.
[46] 杨保.青藏高原地区过去2000年来的气候变化[J].地球科学进展,2003,18(2):285-292.
[47] Schneider D,Huggel C,Haeberli W,et al.Unraveling driving factors for large rock-ice avalanche mobility[J].Earth Surface Processes and Landforms,2011,36:1948-1966.
[48] 刘嘉麒,倪云燕,储国强.第四纪的主要气候事件[J].第四纪研究,2001,21(3):239-248.
[49] O'Connor J E,Costa J E.Geologic and hydrologic hazards in glacierized basins in North America resulting from 19th and 20th century global warming[J].Natural Hazards,1993,8(2):121-140.
[50] Haeberli W,Hohmann R.Climate,glaciers and permafrost in the Swiss Alps 2050:scenarios,consequences and recommendations[C]//Kane D L,Hinkel K M.Ninth International Conference on Permafrost,University of Alaska,Fairbanks:Fairbanks,Alaska,2008:607-612.
[51] Hewitt K,Clague J J,Orwin J F.Legacies of catastrophic rock slope failures in mountain landscapes[J].Earth-Science Reviews,2008,87:1-38.
[52] Radic V,Hock R.Regionally differentiated contribution of mountain glaciers and ice caps to future sea-level rise[J].Nature Geoscience,2011,4(2):91-94.
[53] Chen J,Dai F C,Lv T Y,et al.Holocene landslide-dammed lake deposits in the Upper Jinsha River,SE Tibetan Plateau and their ages[J].Quaternary International,2013,298:107-113.
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