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1.
Preliminary investigation of some large landslides triggered by the 2008 Wenchuan earthquake, Sichuan Province, China 总被引：14，自引：5，他引：9
Fawu Wang Qiangong Cheng Lynn Highland Masakatsu Miyajima Huabin Wang Changgen Yan 《Landslides》2009,6(1):47-54
The M
s 8.0 Wenchuan earthquake or “Great Sichuan Earthquake” occurred at 14:28 p.m. local time on 12 May 2008 in Sichuan Province, China. Damage by earthquake-induced landslides was an important part of the
total earthquake damage. This report presents preliminary observations on the Hongyan Resort slide located southwest of the
main epicenter, shallow mountain surface failures in Xuankou village of Yingxiu Town, the Jiufengchun slide near Longmenshan
Town, the Hongsong Hydro-power Station slide near Hongbai Town, the Xiaojiaqiao slide in Chaping Town, two landslides in Beichuan
County-town which destroyed a large part of the town, and the Donghekou and Shibangou slides in Qingchuan County which formed
the second biggest landslide lake formed in this earthquake. The influences of seismic, topographic, geologic, and hydro-geologic
conditions are discussed. 相似文献
2.
Vertical acceleration effect on landsides triggered by the Wenchuan earthquake,China 总被引：3，自引：0，他引：3
Yueping Yin 《Environmental Earth Sciences》2014,71(11):4703-4714
The 2008 Wenchuan earthquake with Ms8.0 triggered extensive throwing-pattern landslides in the area within or near the seismic faults. The resultant landslides from this earthquake brought to the fore the effect of vertical earthquake acceleration on landslide occurrence. The pseudostatic analysis and the dynamic response on landslide stability due to the Wenchuan earthquake are studied with the Chengxi (West Town) catastrophic landslide used as a case study. The results show that the epicenter distance is an important factor which affects the vertical acceleration and thus the stability of landslide. Also, the vertical acceleration was found to have a significant impact on the FOS of landslide if the earthquake magnitude is quite large. Within the seismic fault, the amplitude effect of vertical acceleration is very dominant with the FOS of landslide, for vertical acceleration ranging from positive to negative, having a variation of 25 %. The variation of FOS of landslide for vertical acceleration ranging from positive to negative are 15 and 5 % for landslides near seismic fault and outside seismic fault, respectively. For landslide with a slope angle <45°, the FOS of landslide with both horizontal and vertical accelerations is significantly greater than the one without vertical acceleration. Further, the results computed from both the pseudostatic method and dynamic analysis reveal that the FOS during the earthquake varied significantly whether vertical acceleration is considered or not. The results from this study explain why lots of throwing-pattern catastrophic landslides occurred within 10 km of the seismic fault in the Wenchuan earthquake. 相似文献
3.
汶川8级地震地质灾害的类型及实例 总被引：11，自引：2，他引：9
龙门山地区活动断裂右旋斜冲运动与汶川8级强烈地震存在成因联系。汶川8级地震造成了惨重的人员伤亡和巨大的财产损失,地震地质灾害主要类型有地震灾害、地震触发地质灾害和地震引发地质灾害隐患。严重地震灾害包括房屋倒塌与部分坍塌、房屋平移、房屋倾斜变形、墙体破裂与结构破坏、桥梁垮塌等。地震触发严重地质灾害包括山体滑坡、山体滑塌、岩块崩塌,局部产生泥石流与沙土液化。地震引发地质灾害隐患包括潜在滑坡、不稳定边坡与滑塌隐患、危岩体与崩塌隐患及泥石流灾害隐患。地震地质灾害分布与活动断层存在密切关系,沿北川映秀断裂地震地质灾害最为严重,沿汉旺漩口断裂、茂县汶川断裂、青川断裂地震地质灾害也比较严重。在活动断裂之间相对稳定地块远离活动断裂超过3~5 km,地震灾害和地震触发地质灾害显著减轻。 相似文献
4.
汶川八级地震滑坡高速远程特征分析 总被引：21，自引：3，他引：18
汶川地震触发的高速远程滑坡主要沿龙门山主中央断裂带汶川映秀安县高川北川县城平武南坝青川一线地震破裂带展布。由于获得了1.5g以上的抛掷加速度，具有明显的气垫效应，估计最大滑动速度一般大于70ms-1，滑动距离一般为滑体启动时长度的数倍甚至10多倍，堆积成坝形成多处堰塞湖，最大滑行距离达3.2km。本文重点解剖了位于地震破裂带南西段(初始震中)的汶川映秀牛圈沟滑坡碎屑流、位于地震破裂带中段的北川城西滑坡和位于地震破裂带北东段青川东河口滑坡碎屑流3个典型实例，认为具有如下特征:(1）岩性条件:母岩遭受长期构造动力作用，呈碎裂岩体，后期被强烈风化，岩体极为破碎；(2）抛掷效应:位于汶川地震主断裂带或附近，垂直加速度大于水平加速度，强地面运动持时长，岩体发生振胀和抛掷；(3）碰撞效应:上部滑坡体发生高位剪出和高位撞击，致使岩体碎屑化；(4）铲刮效应:撞击作用导致下部山体被铲刮，形成次级滑坡，为碎屑流体提供了足够展翼和抛洒物源体积；(5）气垫效应:碎屑化岩体快速抛掷导致下部沟谷空气迅速谷状圈闭和向下紊流，形成气垫效应，或者，在下部地形开阔地带压缩空气呈层流状态致使滑体凌空飞行。 相似文献
5.
汶川八级地震滑坡特征分析 总被引：51，自引：8，他引：43
汶川地震诱发的15000多处滑坡明显受地震断裂控制，主要沿龙门山主中央断裂带和后山断裂带展布，沿龙门山主中央断裂带汶川映秀安县高川北川陈家坝平武南坝一线，滑坡面密度大于50%以上，最大可达70%。沿断裂带形成了大量的松动山体，在暴雨期间极易发生滑坡、泥石流灾害，对灾后重建构成严重威胁。据初步调查，汶川地震触发的体积最大的滑坡是位于主中央断裂带上的安县高川大光包滑坡，滑动距离长4500m，滑坡堆积体长2800m，宽1700~2200m，最大厚度达580m，若以平均厚度200m计，体积达11亿m3为我国已发生的单体滑坡之最。与常见滑坡明显不同的是，汶川地震极震区滑坡的滑床往往不具连续完整的滑面，剪出口滑坡特征不明显，呈现明显的尖点突起或边缘突出特征，反映出上部滑体被地震力振动解体，甚至抛掷后与下部滑床边缘发生撞击。以阶型滑坡、凸型滑坡、勺型崩滑、座落型（振胀型）滑坡和巨大滚石5种类型最为典型。根据强震地面运动纪录和大量实例调查表明，在汶川地震极震区，触发滑坡的地震竖向力作用是非常明显的，大量滑坡经历了初始斜坡（风化碎裂岩体）地震抛掷撞击崩裂高速滑流的作用过程。 相似文献
6.
Shengwen Qi Qiang Xu Bing Zhang Yuande Zhou Hengxing Lan Lihui Li 《Journal of Asian Earth Sciences》2011,40(4):896-906
The May 12, 2008 Wenchuan, China Earthquake which measured Mw = 8.3 according to Chinese Earthquake Administration – CEA (Mw = 7.9 according to the USGS) directly triggered many landslides, which caused about 20,000 deaths, a quarter of the total. Rock avalanches were among the most destructive landslides triggered by this seismic event, and have killed more people than any other type of landslide in this earthquake. The Donghekou rock avalanche, one example of a catastrophic avalanche triggered by the Wenchuan earthquake, occurred in Qingchuan and buried one primary school and 184 houses, resulting in more than 780 deaths, and in addition, caused the formation of two landslide dams, which formed barrier lakes.Combining aerial images (resolution of 0.5 m) with field investigations, this paper lists some parameters of 66 cases in one table, and details source characteristics of six typical cases. It has been found that most of the long runout rock avalanches have source areas with high relief and steep inclination, causing the debris in the travel courses to accelerate. There was also a large amount of saturated Holocene-age loose deposits formed by a river or gully that existed in the travel courses. Comparison studies indicate that saturated Holocene loose deposits in the travel courses could be the most important factor for the causes of the long runout characteristic of the rock avalanches especially when they traveled over gentle or even flat ground surfaces.Furthermore, the relationships among the relief slope gradient, runout and covered area are investigated, and a threshold line for predicting the maximum horizontal runout distance under certain change in elevation is presented. 相似文献
7.
汶川地震在龙门山地区激发了大量的次生地质灾害,其中尤以滑坡灾害分布最为广泛和严重。在所有滑坡灾害中,东河口滑坡发生在北川破裂带的北东端点,具有相当的特殊性,并造成了大量的生命财产损失。东河口滑坡是一种抛射型滑坡,具有与其他如重力或者降雨作用导致的滑坡不同的特点,即没有统一连续的滑动面,由上部比较深陡和下部比较浅缓的截然分开的两部分组成,在强地震加速度的作用下,滑坡体被抛射并在与地面发生碰撞之前沿抛物线轨迹运行。文章综合分析了东河口抛射型滑坡发生的地质地貌条件,并解释了该抛射型滑坡发生的动力源机制。结果显示,东河口滑坡区的滑坡带和翼状裂隙带在北川破裂带两侧的规则分布受控于断层的运动方式和滑坡的空间分布位置;此外,除地震动水平加速度和地质地貌条件外,垂直加速度和断层的运动方式对地震滑坡的激发也起着重要的作用。 相似文献
8.
Rapid Identification and Emergency Investigation of Surface Ruptures and Geohazards Induced by the M_s 7.1 Yushu Earthquake 总被引：1，自引：0，他引：1
ZHANG Yongshuang YAO Xin XIONG Tanyu MA Yinsheng HU Daogong YANG Nong GUO Changbao 《《地质学报》英文版》2010,84(6):1315-1327
<正>The rapid identification based on InSAR technology was proved to be effective in our emergency investigation of surface ruptures and geohazards induced by the Yushu earthquake.The earthquake-generating fault of the Yushu earthquake is the Yushu section of the Garze-Yushu faults zone.It strikes NWW-NW,23 km long near the Yushu County seat,dominated by left-lateral strike slip,and appearing as a surface rupture zone.The macroscopic epicenter is positioned at Guo-yang-yan -song-duo of Gyegu Town(33°03'11"N,96°51'26"E),where the co-seismic horizontal offset measured is 1.75 m.Geohazards induced by the Yushu earthquake are mainly rockfalls,landslides,debris flows, and unstable slopes.They are controlled by the earthquake-generating fault and are mostly distributed along it.There are several geohazard chains having been established,such as earthquake,canal damage,soil liquefying,landslide-debris flow,earthquake,soil liquefying,roadbed deformation,etc.In order to prevent seismic hazards,generally,where there is a visible surface rupture induced by the Yushu earthquake,reconstruction should be at least beyond 20 m,on each side,from it.Sufficient attention should also be given to potential geohazards or geohazard chains induced by the earthquake. 相似文献
9.
汶川八级地震地质灾害研究 总被引：118，自引：15，他引：103
汶川地震触发了15000多处滑坡、崩塌、泥石流,估计直接造成2万人死亡。地质灾害隐患点达10000余多处,以崩塌体增加最为显著,反映出地震对山区高陡斜坡的影响差异性非常大,在山顶上的放大作用非常显著。通过综合分析堰塞湖库容、滑坡坝高以及坝体物质组成和结构,对地震形成的33处坝高大于10m的滑坡堰塞湖进行了评估,划分出极高、高、中和低4种溃决危险。汶川地震滑坡滑床往往不具连续平整的滑面,尖点撞击是极震区滑坡的一大共性,可以分为勺型滑床、凸型滑床和阶型滑床等类型。据实地调查,滑坡附近震毁建筑物垂向震动非常明显,具有地震抛掷撞击崩裂高速滑流三阶段特征。在高速滑流中,发生3种效应:(1)高速气垫效应,滑坡体由较大块石和土构成,具有一定厚度,飞行行程可达1~3km;(2)碎屑流效应,撞击粉碎的土石呈流动状态,特别是含水丰富时,形成长程流滑;(3)铲刮效应,巨大撞击力导致下部岩体崩裂,形成新滑坡、崩塌,但是,其厚度不大,滑床起伏不平。本文以北川城西滑坡和青川东河口滑坡为例,分析了地震滑坡高速远程滑动及成灾机理。北川县城城西滑坡导致1600人被埋死亡,数百间房屋被毁,是汶川地震触发的最严重的滑坡灾难,举世罕见。青川东河口滑坡碎屑流是汶川地震触发的较为典型的高速远程复合型滑坡,滑程约2400m,高速碎屑流冲抵清江河左岸,形成滑坡坝,致使7个村庄被埋,约400人死亡。 相似文献
10.
范宣梅 王欣 戴岚欣 方成勇 邓宇 邹城彬 汤明高 魏振磊 窦向阳 张静 杨帆 陈兰 魏涛 杨银双 张欣欣 夏明垚 倪涛 唐小川 李为乐 戴可人 董秀军 许强 《工程地质学报》2022,30(5):1504-1516
2022年9月5日四川甘孜泸定县发生6.8级地震,诱发了大量地质灾害,造成房屋损毁和多处道路阻断,并导致了严重的人员伤亡。快速预测地震诱发地质灾害空间分布对震后应急救援至关重要。为此,成都理工大学地质灾害防治与地质环境保护国家重点实验室利用已建立的地震诱发滑坡近实时预测模型,在震后2 h内,快速预测了地震诱发滑坡空间分布概率。同时,利用震后重点区域的无人机影像和国产高分六号影像,对地震诱发滑坡进行了智能识别和人工解译及现场调查复核,共解译滑坡3633处,总面积13.78 km2。研究发现本次泸定地震诱发滑坡,较2008年汶川和2017年九寨沟地震滑坡,规模相对较小。本次地震诱发滑坡主要分布于鲜水河断裂带和大渡河两侧,呈带状分布,在磨西镇、得妥镇及王岗坪彝族藏族乡等Ⅸ度烈度区相对集中。对控制滑坡空间分布的地形地貌、地质和地震3类因素9个因子进行分析,发现其主要分布在坡度35°~55°、高程1000~1800 m范围内;受断层控制强烈,主要分布在距断层1 km范围内;在花岗岩中最为发育。上述研究成果获得的地震诱发滑坡及受损道路和房屋分布情况,为震后应急救援提供了重要支撑。 相似文献