云南鲁甸5.1、5.0级地震震害分析

通过对鲁甸5.1、5.0级两次地震后112个居民点的震害调查,分别给出了5.1级地震等烈度分布图及5.1、5.0级地震等烈度综合分布图;分析了场地条件及其震害、各类房屋的震害特征、典型结构房屋的震害原因以及生命线工程震害。结果表明,两次地震形成较大范围的7度破坏区和少数调查点有8度破坏现象的主要原因是:震源浅,地表振动强烈;盆地区广泛分布有煤层、膨胀土、淤泥土和松散的粉砂、粉土等不良影响地层,且埋藏浅;震区建筑结构简易,抗震能力极差;两次地震震害叠加。最后对灾区恢复重建提出了4条建议。

Analysis of the Disaster Caused by M5.1 and M5.0 Earthquake in Ludian County, Yunnan

Based on the investigation on the earthquake disaster in 112 residential quarters caused by M5.1 and M5.0 earthquakes occurred successively in Ludian County, the coseismic distribution of M5.1 earthquake and the synthetic coseismic distribution of M5.1 and M5.0 earthquakes are put forward. Further, the field condition and related earthquake disaster, the characteristics of the earthquake-disaster of different kinds of structures, as well as the cause of the earthquake disaster for the typical-structure buildings and life-line construction are analyzed. The conclusions show that two earthquakes gave rise to a large-scale disaster area with the intensity of Ⅶ. But there are a few spots at which the intensity reached Ⅷ and caused destruction. The reasons can be concluded as the following four points: ①The focuses of the two earthquakes are shallow, so the ground motion is strong. ②The shallo-imbeded loose layers like coal bed, expansive soil, silt, incompact silty sand and silty soil are widely distributed in the Ludain Basin. ③The construction in the earthquake-striken area is rough and the aseismic ability is very poor. ④The two earthquakes-disasters are superpositional. Finally, four suggestions are bring for ward for the recovery and reconstruction in the disaster area.