摩岗岭滑坡成因机理
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摘要
摩岗岭滑坡位于泸定县境内的大渡河右岸一级支流磨西河口,为18世纪四川西部强震诱发的巨型地震高位滑坡.研究揭示,该滑坡发育于高烈度区的康定杂岩中,河谷走向与区域最大主应力方向垂直,河谷下切过程中斜坡经历了强烈的浅表生卸荷回弹,形成高陡斜坡后,谷坡在河谷应力场(重力场)的长期作用下坡体浅表层沿与缓倾坡外的结构面、走向北北西的陡倾结构面(与坡面走向一致)分别发生滑移和拉裂,当河谷切穿得妥断裂后,断裂带塑性变形,牵动上部坡体表层发生压缩-剪胀错动变形;周期性强震的反复作用,滑移和拉裂成脉动式和累进性式发展,最终使上述两组结构面接近贯通状态,上下游北东和北向侧裂面的切割,为坡体大规模失稳奠定了基本条件.1786年强烈的地震、高位地形放大效应、背坡效应等因素叠加最终触发摩岗岭滑坡的发生.
Mogangling landslide,located on the right bank of Daduhe River,is a seismic landslide with high location,which triggered by strong earthquake in 18th century at western Sichuan Basin.Research reveals that,the landslide is developed in the Kangding complex strata,where the flow direction of Daduhe Rive is perpendicular to the regional maximum geo-stress.During the cutting of the Daduhe River,the slope underwent the epigenetic unloading and elastic rebounding,forming high slope,furthermore,under the river stress field time-dependent action,the slope began the slip-crack in tension by the action of structural planes and the slope surface,when the Daduhe River cut through the Detuo fault,plastic deformation happened in the fault zone,and compression-dilatancy deformation emerged in the slope upon the faul.As the periodicity strong earthquake action,the slip-crack in tension developed in progressivity and in pulsating movement made the steep structural plane nearly through.For the lateral edge structural planes exist,presenting the condition for a huge high-locality landslide.As expected,the earthquake in 1786 triggered the Mogangling high-locality landslide under the co-action of strong earthquake,topography amplification and opponent slope effect.
Mogangling landslide,located on the right bank of Daduhe River,is a seismic landslide with high location,which triggered by strong earthquake in 18th century at western Sichuan Basin.Research reveals that,the landslide is developed in the Kangding complex strata,where the flow direction of Daduhe Rive is perpendicular to the regional maximum geo-stress.During the cutting of the Daduhe River,the slope underwent the epigenetic unloading and elastic rebounding,forming high slope,furthermore,under the river stress field time-dependent action,the slope began the slip-crack in tension by the action of structural planes and the slope surface,when the Daduhe River cut through the Detuo fault,plastic deformation happened in the fault zone,and compression-dilatancy deformation emerged in the slope upon the faul.As the periodicity strong earthquake action,the slip-crack in tension developed in progressivity and in pulsating movement made the steep structural plane nearly through.For the lateral edge structural planes exist,presenting the condition for a huge high-locality landslide.As expected,the earthquake in 1786 triggered the Mogangling high-locality landslide under the co-action of strong earthquake,topography amplification and opponent slope effect.
引文
[1]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分析[J].地质力学学报,2008,14(2):109-114.Zhang Y S,Lei W Z,Shi J S,et al.General characteristics of 5.12earthquake induced geohazards in Sichuan[J].Journal ofGeomechanics,2008,14(2):109-114.
[2]吴树仁,石菊松,姚鑫,等.四川汶川地震地质灾害活动强度分析评价[J].地质通报,2008,27(11):1900-1906.Wu S R,Shi J S,Yao X,et al.Analysis and evaluation ofgeohazard intensity of the Wenchuan earthquake,Sichuan,China[J].Geological Bulletin of China,2008,27(11):1900-1906.
[3]王涛,马寅生,龙长兴,等.四川汶川地震断裂活动和次生地质灾害浅析[J].地质通报,2008,27(11):1913-1922.Wang T,Ma Y S,Long C X,et al.Fault activity of the Wenchuanearthquake in Sichuan,China and seismic-secondary geohazards[J].Geological Bulletin of China,2008,27(11):1913-1922.
[4]祁生文,伍法权,刘春玲,等.地震边坡稳定性的工程地质分析[J].岩石力学与工程学报,2004,23(16):2792-2797.Qi S W,Wu F Q,Liu C L,et al.Engineering geology analysis onstability of slope under earthauake[J].Chinese Journal of RockMechanics and Engineering,2004,23(16):2792-2797.
[5]邢伟.地震冲击波对坡面位移和地面形状的影响[J].水土保持应用技术,2007(4):6-8.Xun W.Influence of earthquake wallop to slope surfacedisplacement and surface shape[J],Applied Tecnnique of Soil andWater Conservation,2007(4):6-8.
[6]殷跃平.汶川八级地震地质灾害研究[J].工程地质学报,2008,16(4):433-444.Yin Y P.Researches on the geo-hazards triggered by Wenchuanearthquake,Sichuan[J].Journal of Engineering Geology,2008,16(4):433-444.
[7]江在雄.1786年大渡河地震、水患及救灾,康定-泸定磨西地震220周年[J].四川地震,2006(3):4-9.Jiang Z X.The 1786 Kangding-Ludin-Muoxi earthquake,floodand relief-220thanniversary[J].Earthquake Research in Sichuan,2006(3):4-9.
[8]黄润秋.中国西南岩石高边坡的主要特征及其演化[J].地球科学进展,2005,20(3):292-297.Huang R Q.Main characteristics of high rock slopes in southwestern china and their dynamic evolution[J].Advances in EarthScience,2005,20(3):292-297.
[9]王运生.地震高位滑坡形成条件及其抛射运动程式研究[J].岩石力学与工程学报,2009,28(11):2360-2369.Wang Y S.Study of formation conditions and toss motion program ofhigh landslides induced by earthquake[J].Chinese Journal of RockMechanics and Engineering,2009,28(11):2360-2369.
[2]吴树仁,石菊松,姚鑫,等.四川汶川地震地质灾害活动强度分析评价[J].地质通报,2008,27(11):1900-1906.Wu S R,Shi J S,Yao X,et al.Analysis and evaluation ofgeohazard intensity of the Wenchuan earthquake,Sichuan,China[J].Geological Bulletin of China,2008,27(11):1900-1906.
[3]王涛,马寅生,龙长兴,等.四川汶川地震断裂活动和次生地质灾害浅析[J].地质通报,2008,27(11):1913-1922.Wang T,Ma Y S,Long C X,et al.Fault activity of the Wenchuanearthquake in Sichuan,China and seismic-secondary geohazards[J].Geological Bulletin of China,2008,27(11):1913-1922.
[4]祁生文,伍法权,刘春玲,等.地震边坡稳定性的工程地质分析[J].岩石力学与工程学报,2004,23(16):2792-2797.Qi S W,Wu F Q,Liu C L,et al.Engineering geology analysis onstability of slope under earthauake[J].Chinese Journal of RockMechanics and Engineering,2004,23(16):2792-2797.
[5]邢伟.地震冲击波对坡面位移和地面形状的影响[J].水土保持应用技术,2007(4):6-8.Xun W.Influence of earthquake wallop to slope surfacedisplacement and surface shape[J],Applied Tecnnique of Soil andWater Conservation,2007(4):6-8.
[6]殷跃平.汶川八级地震地质灾害研究[J].工程地质学报,2008,16(4):433-444.Yin Y P.Researches on the geo-hazards triggered by Wenchuanearthquake,Sichuan[J].Journal of Engineering Geology,2008,16(4):433-444.
[7]江在雄.1786年大渡河地震、水患及救灾,康定-泸定磨西地震220周年[J].四川地震,2006(3):4-9.Jiang Z X.The 1786 Kangding-Ludin-Muoxi earthquake,floodand relief-220thanniversary[J].Earthquake Research in Sichuan,2006(3):4-9.
[8]黄润秋.中国西南岩石高边坡的主要特征及其演化[J].地球科学进展,2005,20(3):292-297.Huang R Q.Main characteristics of high rock slopes in southwestern china and their dynamic evolution[J].Advances in EarthScience,2005,20(3):292-297.
[9]王运生.地震高位滑坡形成条件及其抛射运动程式研究[J].岩石力学与工程学报,2009,28(11):2360-2369.Wang Y S.Study of formation conditions and toss motion program ofhigh landslides induced by earthquake[J].Chinese Journal of RockMechanics and Engineering,2009,28(11):2360-2369.
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