四川盆地典型地震灾区居民住房受损影响因素及特征分析

Influencing factors and characteristics of residential housing damage in typical earthquake-stricken areas of the Sichuan Basin

摘要:

2021年9月16日,四川泸县发生 M_S6.0地震,导致泸县18个乡镇不同程度受灾。通过现场的调查资料,定量统计出灾区居民住房损坏情况,评估房屋结构、震中距离同居民住房损坏程度间的关系,并建立四川盆地典型地震灾区不同地震烈度下的居民住房易损性矩阵。在此基础上,比较此次地震与同震级下其他地震平均震害指数的差异,进而探讨研究区居民住房破坏程度的特征及原因,得出以下结论:(1)住房易损性由高到低为砖混结构、砖木及其他结构(土木、木、石砌结构)、钢混结构;(2)泸县地震中90%的住房损坏出现在震中距6 600 m内的区域;(3)比较同震级两次地震发现,盆地对居民住房造成的损坏比山地低1~2倍。研究结果可为四川盆地及其他地震多发地区震后灾损快速评估、居民住房规划重建提供科学参考依据。

Abstract:

An M_S6.0 earthquake occurred on September 16th, 2021, and affected 18 towns in Luxian County, Sichuan Province, with varying degrees. The seismic damage of residential houses in these areas is quantitatively analyzed through an onsite survey, and the relationship among house structures, epicentral distance, and degree of residential damage is assessed. A matrix of residential housing vulnerability in typical earthquake-stricken areas of the Sichuan Basin with different intensities is then established. Considering this matrix, the difference in average earthquake damage indexes between the affected areas and other regions that previously experienced earthquakes of the same magnitude is compared. Furthermore, the characteristics and factors that contribute to the residential housing damage in the study area are discussed, and the following conclusions are drawn: (1) The vulnerability of houses from high to low is brick-concrete structures, brick-wood and other structures (civil, wood, and stone structures), and steel-concrete structures; (2) 90% of the housing damage during the Luxian earthquake occurred in the area within 6 600 m from the epicenter; (3) Under two earthquakes with the same magnitude, the damage to residential houses in the basin is 1-2 times lower than that in the mountains. The results of this study can be used as a scientific reference for the rapid assessment of damages, planning, and reconstruction of residential housing after earthquakes in the Sichuan Basin and other earthquake-prone areas.