龙陵地震震害与地质

前言1976年5月29日20点23分与22点00分,在我国云南省龙陵县境内,连续发生了7.5和7.6级两个强烈地震,震中烈度为9度。由于这次地震之前曾经有过预报,因此伤亡极少,但是地面建筑物却遭到严重破坏。破坏比较严重的地区是龙陵县,特别是龙陵县东部的几个公社,如镇安、勐冒、朝阳、平达等公社。在上述公社境内,房屋破坏严重,地面开裂,出现大量的剥落(当地群众称之为山扒皮)、崩塌、滑坡、滚石和地裂缝。

THE GEOLOGY OF EARTHQUAKE DISASTER CAUSED BY LONGLING EARTHQUAKE

On May 29, 1976 (at Beijing time 20h23m and 20hOOm) two strong earthquakes of magnitude 7.5 and 7.6 respectively occurred in Longling of Yunnan province, with intensity Ⅸ in the epicentral area. The eastern part of Longling district has severely been damaged, causing rock-falls, land collapse, landslides, debris flows and ground fissures in a large scale. Investigations of earthquake disaster and intensity in the earthquake region show that several points with higher intensity occur mostly in a Quaternary subsidence basin. Here the iso-intensity line agrees very well with the shape of the basin, reflecting the apparent influence of regional geological and geomorphological background. In general, buildings collapsed more in the Quaternary basin than in the mountainous areas with bed rock. And, for the intermontane basins the degree of collapsing of houses in woodframework increases with the decreasing compaction of the ground and increasing thickness of strata.The damage caused by earthquake seems to be more severe in convex narrow strips of land and steeper slopes than in concave open and lowlying relief.