在收集整理四川泸定 M_S6.8 地震现场调查资料的基础上,对比九寨沟 M_S7.0 地震,分析房屋震害特征和人员伤亡情况。结果表明,相较九寨沟地震,四川泸定 M_S6.8 地震灾区房屋震害更为严重,遇难人数更多,主要原因是房屋抗震能力不足、选址不合理以及地质灾害较为发育等。灾区房屋结构类型主要有钢混结构、砖混结构、穿斗木结构、石木结构、砖木结构、土木结构等6类。对房屋平均震害指数和易损性曲线的分析表明,未设防的砖混结构、简易结构房屋抗震能力弱,震害比其他结构房屋严重; 而人员死亡主要由地震地质灾害造成,集中在高烈度区和地质灾害易发区,死亡人员以中老年为主,人员死亡率与地震烈度、人口密度有明显相关性。灾区房屋破坏及人员伤亡具有高山峡谷地区的震害特征。本文的研究结果可为进一步研究该类地区的地震灾害风险研究提供参考。

This paper analyzes the characteristics of building damage and casualties from the Luding M_S6.8 earthquake by comparing them with those of the Jiuzhaigou M_S7.0 earthquake. The results indicate that the Luding earthquake resulted in more severe building damage and a higher number of casualties than the Jiuzhaigou earthquake. This disparity is primarily attributed to the inadequate earthquake resistance of buildings,unsuitable building locations,and a relatively higher incidence of geological hazards in the affected areas. The study identifies six major types of building structures in the disaster areas:steel-concrete composite structures,concrete-masonry structures,timber frame structures,stone-timber structures,and soil-timber structures. Based on an analysis of seismic indices and fragility curves,the most severely damaged buildings were concrete-masonry structures lacking seismic fortification and simple buildings with low seismic resilience. The primary cause of fatalities was geological hazards,which predominantly occurred in regions with high earthquake intensity and significant geological vulnerability. Middle-aged and elderly individuals were found to have the highest mortality rates,which strongly correlated with the earthquake intensity and population density. The disaster area is characterized by hilly and valley landforms,which contributed to the specific patterns of building damage and casualties observed. The findings of this paper offer valuable insights for future research on earthquake disaster risks in similar regions.

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四川省科技专项(LY2208、LY2207)、四川地震科技创新团队专项(201902)、国家重点研发计划(2020YFC1511705)共同资助