汶川大地震诱发地质灾害主要类型与特征研究
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摘要
"5.12"汶川大地震诱发了数以万计的次生地质灾害,对灾区人民生命财产安全构成严重威胁,并成为影响灾区灾后恢复重建的重要因素之一。本文在对汶川地震区地质灾害进行大量现场调查的基础上,结合室内分析模拟,对汶川地震诱发的滑坡、崩塌、不稳定斜坡(震裂山体)和泥石流等主要次生地质灾害的主要类型及特征进行了较系统地分析研究。结果表明,强震诱发滑坡灾害发生特点与岩性结构和地形条件有较明显的关系,在硬岩、软岩和松散堆积物分布区,滑坡的启动、运动和停积形式有较大的差别,但总体上都具有高速、高动能、强大动力等特征。强震诱发的崩塌主要包括高位大型崩塌;小规模块石崩落、抛射;崩塌诱发大规模滑坡3类。强震条件下大多数崩塌都表现出一定的水平抛射特征。强烈的地震动力使极震区众多山体大范围震裂松动,形成了大量震裂山体。这些震裂山体的地表裂缝具体又可细分为断裂裂缝、震裂裂缝和滑裂裂缝3类。汶川地震形成了巨量泥石流物源,再加上震后泥石流爆发的临界降雨量大大降低,其启动和运动方式发生明显改变,在今后数年内,泥石流将是影响灾区恢复重建的最大地质灾害隐患,应高度重视,采取切实有效措施加以防范。
Great amount of geo-hazards have been triggered by the Wenchuan Earthquake on May 12,2008.It made a serious threaten to the properties of the people who live in those regions and it become a main factor which need to be considered during the remediation project after the earthquake.The paper based on lots of site-investigations of the regions and did some related indoor simulations to provide a systematic research on the main types and characteristic of earthquake triggered landslide,collapse,unstable slopes and debris flow.To conclude,the regions where the geo-hazards developed have a close relationship with the rock structures and the topography condition.The critical,initiate and slide phases of landslide were different when it occurred in hard rock region,soft rock region and the loose accumulation.In general,the movement has the characteristic of high speed,high energy released.The collapses which triggered by the earthquake can be distinguished into three types: the high altitude large collapse;the rock burst in small scale and the large landslide triggered by collapse.In the high magnitude earthquake,the rock burst always moved horizontally.There are also some cracked mountains after the strong shocks.It can be sub-distinguished into three types: cracks due to the broken rock,cracks due to the shaking affect and cracks due to the tension sliding.The quake also provide a large amount of loose materials for the future debris flow which become a great potential threaten to the upcoming remediation plan.Early warning should be given as well as the related counter measures.
Great amount of geo-hazards have been triggered by the Wenchuan Earthquake on May 12,2008.It made a serious threaten to the properties of the people who live in those regions and it become a main factor which need to be considered during the remediation project after the earthquake.The paper based on lots of site-investigations of the regions and did some related indoor simulations to provide a systematic research on the main types and characteristic of earthquake triggered landslide,collapse,unstable slopes and debris flow.To conclude,the regions where the geo-hazards developed have a close relationship with the rock structures and the topography condition.The critical,initiate and slide phases of landslide were different when it occurred in hard rock region,soft rock region and the loose accumulation.In general,the movement has the characteristic of high speed,high energy released.The collapses which triggered by the earthquake can be distinguished into three types: the high altitude large collapse;the rock burst in small scale and the large landslide triggered by collapse.In the high magnitude earthquake,the rock burst always moved horizontally.There are also some cracked mountains after the strong shocks.It can be sub-distinguished into three types: cracks due to the broken rock,cracks due to the shaking affect and cracks due to the tension sliding.The quake also provide a large amount of loose materials for the future debris flow which become a great potential threaten to the upcoming remediation plan.Early warning should be given as well as the related counter measures.
引文
[1]黄润秋,许强.中国典型灾难性滑坡[M].北京:科学出版社,2008.
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[3]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.
[4]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.
[5]马贵生,罗小杰.唐家山滑坡形成机制与堰塞坝工程地质特征[J].人民长江,2008,39(22):46-85.
[6]唐春安,左宇军,秦泗凤,等.汶川地震中的边坡浅层散裂与抛射模式及其动力学解释[A].纪念汶川地震一周年论文集[C].北京:科学出版社,2009.
[7]徐锡伟,闻学泽,叶建青,等.汶川M-S 8.0地震地表破裂带及其发震构造[J].地震地质,2008,30(3):597-629.
[8]唐川,梁京涛.汶川震区北川“9.24”暴雨泥石流特征研究[J].工程地质学报,2008,16(6):751-758.
[2]许强,黄润秋.“5.12”汶川大地震诱发大型崩滑灾害动力学特征初探[J].工程地质学报,2008,16(6):721-729.
[3]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.
[4]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.
[5]马贵生,罗小杰.唐家山滑坡形成机制与堰塞坝工程地质特征[J].人民长江,2008,39(22):46-85.
[6]唐春安,左宇军,秦泗凤,等.汶川地震中的边坡浅层散裂与抛射模式及其动力学解释[A].纪念汶川地震一周年论文集[C].北京:科学出版社,2009.
[7]徐锡伟,闻学泽,叶建青,等.汶川M-S 8.0地震地表破裂带及其发震构造[J].地震地质,2008,30(3):597-629.
[8]唐川,梁京涛.汶川震区北川“9.24”暴雨泥石流特征研究[J].工程地质学报,2008,16(6):751-758.
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