作　　者： ; ; ; ; ;

机构地区： 成都理工大学环境与土木工程学院

出　　处： 《灾害学》 2014年第2期182-187,共6页

摘　　要： 研究发现在地震较为平静的则木河断裂带中段，分布有数个上亿立方米的超大型山体滑坡，这些滑坡均沿断裂带分布、规模巨大，具有高速远程碎屑流等地震滑坡特征，应是强烈古地震所触发。离散元数值模拟分析显示，在该特定的斜坡岩体力学条件下，高速远程碎屑流启动的临界加速度应该不低于1．6g，与此相对应的地震烈度不低于Ⅺ度。进一步的研究证实，大型古地震滑坡的形成时代在一级阶地形成之前、二级阶地形成之后，距今约1～2万年左右。这表明全新世初期是则木河断裂带中段活动性极为强烈的时期。我们认为，大规模古地震滑坡集中分布且地震活动相对较平静的断裂带中段，目前极有可能正处于构造应力的积累过程，是否是未来强烈地震的潜在震源部位，应予以重视。 Study found that in the relatively calm earthquake belt Zemuhe fault, several billion cubic meters of large landslides are distributed, which have characteristics of seismic landslide debris flows like distributing along the fault zone, large scale, with high speed remote debris flow, and so on. Therefore these landslides should have been triggered by strong ancient earthquakes. Bases on analysis of discrete element numerical simulation, the initi- ate critical acceleration of high speed debris flow is not lower than 1. 6g, and the corresponding seismic intensity is not lower than XI degree in this special rock mechanics. With the further investigation, the huge landslides hap- pened before first terrace formed and after the second terrace formed, when is between one thousand and two thou- sand years. It demonstrates the early Holocene is the periods when Zemuhe fault zone~ new activity is strong ex- tremely. We believe that the fault~ middle part with few strong earthquakes may be in the process of tectonic stress accumulation gradually, where huge seismic landslides are located. It indicates whether the middle of the fault is the potential earthquake focus, which we should pay more attention to.

关 键 词： 则木河 断裂带 古地震 滑坡 碎屑流

领　　域： [天文地球] [天文地球] [天文地球] [环境科学与工程]