四川芦山7.0级地震中非抗震设防民居震害特征

Seismic damages of non-seismic design residential houses in the M7. 0 Lushan Earthquake

发生于2013年4月20日的芦山7.0级地震波及川西地区多个县市,造成大量人员伤亡和经济损失。与震害较轻的钢筋混凝土和约束砌体结构相比,大量非抗震设防的无约束砌体结构和穿斗木构架民居建筑受损严重。在简要描述无约束砌体结构震害特征的基础上,介绍了川西穿斗木构架的结构组成,总结了其柱脚滑移、纤榫脱出、整体歪斜、填充墙倒塌等典型震害,分析了穿斗木构架中砌体填充墙的结构作用,并给出综合考虑木构架和砌体填充墙的损伤状态以确定整体结构破坏等级的建议。通过对某高烈度区域穿斗木构架和无约束砌体结构民居建筑的破坏等级统计数据的比较,认为穿斗木构架具有更高的抗震性能。

The M7. 0 Lushan Earthquake affected a large area in western Sichuan,resulting in large fatalities and economic losses. As compared with reinforced concrete structures and confined masonry structures,non-seismic design structures including unconfined masonry structures and Chuandou-type timber frames that are most common structural systems for the local residential houses suffered from various levels of seismic damages during the earthquake. A brief introduction to typical damage in unconfined masonry structures is followed by a description of typical damage patterns observed in Chuandou-type timber frames. Focus is given to the role of masonry infills as secondary structural components. Taking the timber frame and the masonry infills as primary and secondary structural components,a classification criterion of damage levels in accordance with the Chinese seismic intensity scale was proposed for Chuandou-type timber houses. The comparison of the statistics of damage levels of Chuandou-type timber frames and unconfined masonry structures in a high intensity area shows that the former exhibits much better seismic performance and is a promising earthquake-resistant system for residential houses in south weatern China.