汶川地震滑坡与地震参数及地质地貌因素之间的相关关系

STATISTICAL RELATIONS BETWEEN LANDSLIDES INDUCED BY WENCHUAN EARTHQUAKE AND EARTHQUAKE PARAMETERS,GEOLOGICAL AS WELL AS GEOMORPHOLOGICAL FACTORS

在对汶川地震诱发的典型滑坡进行野外调查和相关资料收集、分析和整理的基础上,对汶川地震滑坡与地震参数及坡度、岩土体特性等地质地貌因素之间的相关关系进行了统计分析。结果表明：（1）汶川地震滑坡主要发生在Ⅶ-Ⅺ烈度区,Ⅵ度及以下烈度区中发生的滑坡较少;（2）汶川地震滑坡主要发生在距震中300km的范围内,且距震中200km的范围内滑坡分布最为集中;（3）汶川地震滑坡的易发斜坡坡度为30°-50,°其中30°-40°是汶川地震滑坡发育最为敏感的坡度;（4）汶川地震滑坡主要发生在600-1500m的高程范围内,在600-1000m高程范围内的中低山和丘陵区滑坡分布最为集中;（5）砂泥岩、板岩、片岩、千枚岩等软岩类和土质类岩性是汶川地震滑坡的易发岩性,其次是软硬岩组合类,在统计的47个典型滑坡中,花岗岩、碳酸盐岩等硬岩类中发生的滑坡最少,而且由汶川地震直接导致复活的老滑坡也比较少。

This paper is based on investigations of the landslides induced by Wenchuan Earthquake and collection and analysis of the related data.It presents the statistical relations between the earthquake-induced landslides and other factors including earthquake parameters,geological and geomorphological factors.The results show that：（1）the landslides caused by Wenchuan earthquake mainly occurred in the Ⅶ～Ⅺ intensity districts,there were rather fewer landslides in the Ⅵ and below intensity districts;（2）the earthquake-induced landslides mainly occurred in the area 300 km from the epicenter,and intensively distributed in the area 200 km from the epicenter;（3）the slopes with the dip angle of 30°～50°,especially 30～40°,are very easy to slide during Wenchuan Earthquake;（4）the earthquake-induced landslides mainly distributed in the elevation range of 600～1500m,especially 600～1000 m;（5）soft rocks such as mudstone,shale,schist and so on,are the easiest to slide during Wenchuan Earthquake;the combination of soft and hard rocks is secondary to slide;and hard rocks such as granite and carbonate rocks are not easy to slide;only a few old landslides were re-activated by Wenchuan Earthquake.