四川汶川七盘沟“7·11”泥石流破坏建筑物的特征与力学模型  

Characteristics and Mechanism of Buildings Damaged by Debris Flows on 11 July,2013 in Qipangou of Wenchuan,Sichuan

作　　者：曾超[1,2,3] 崔鹏[1,2] 葛永刚[1,2] 张建强[1,2] 雷雨[1,2,3] 严炎[1,2,3] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院山地灾害与地表过程重点实验室,四川成都610041 [3]中国科学院大学,北京100049

出　　处：《地球科学与环境学报》2014年第2期81-91,共11页Journal of Earth Sciences and Environment

基　　金：中国科学院重点部署项目(KZZD-EW-05-01);国家自然科学基金项目(41030742;41190084)

摘　　要：2013年7月11日,四川省汶川县威州镇七盘沟暴发大规模泥石流。通过实地调查和测量,获取了98份建筑物破坏样本。泥石流中大石块、漂木和生活废弃物是参与破坏的主要介质;建筑物长轴方向与流向垂直时,更易遭受破坏;而长轴方向与流向平行且规则分布时,首个遭遇泥石流的建筑物会严重破坏,但也起到阻挡泥石流和耗能的作用,较好地保护了其后的建筑物;当建筑物分布不规则时,首个和凸出的建筑物均遭受冲击破坏;距泥石流出口和主流线越近,建筑物破坏越严重。分析建筑物破坏特征发现:受损建筑物表现的破坏模式因结构类型不同而异;若以梁和柱为承重构件,其破坏主要因柱体受冲后产生塑性铰或被剪断,致建筑物倾斜或倒塌,而以砌体为承重构件者,其破坏表现为承重墙体产生裂缝或垮塌致建筑物整体倒塌。参照建筑物破坏模式,以静力学极限平衡理论为基础,提出建筑物柱体和墙体破坏的临界条件计算公式。最后,依据泥石流的破坏方式和建筑物受损模式,将七盘沟建筑物的破坏划分为5个等级,并讨论了甘肃舟曲泥石流和本次灾害期间建筑物破坏特征的异同。本研究从案例分析的角度,为泥石流危险区城镇及居民点建筑物规划布局和结构设计提供参考。A destructive debris flow hazard occurred in Qipangou of Wenchuan county,Sichuan province on July 11,2013.The debris flow resulted in 350buildings destroyed,more than 2 000buildings buried or flooded and 15 people dead or missing.98 damaged buildings were investigated and measured in details to study the characteristic and patterns of buildings damaged by debris flow.Big boulder,drift logs and waste mixed in debris flow are the mainly contribute to the destruction of building;buildings are more vulnerable when the longitudinal axis（major axis）of them is perpendicular to the flow direction of debris flow;if the longitudinal axis is parallel to the flow direction,the first exposed building is damaged severely,but the buildingblocks debris flow with a lot of energy,so as to protect the subsequent buildings from the direct impact of debris flow;for some buildings with irregular distribution,both the first building and protruding part are damaged;the closer the buildings locate to the mainstream and outlet of debris flow,the more serious the buildings are damaged.The characteristics of buildings damaged show that the patterns of debris flow damaging buildings are not the same because of the different structures;if the load-bearing elements of buildings are beams and columns,the collapses of buildings are mainly due to the destruction of columns by the formation of plastic hinges or clipping,while the cracks or collapses of bearing walls are responsible for the collapse of buildings with masonry structure.According to the patterns of buildings damaged,the formulas to calculate the critical condition of building damaged by debris flow were proposed based on the limit equilibrium theory.Finally,the destruction of buildings in Qipangou could be classified into five levels based on the characteristics and collapse patterns of building damaged,and the characteristics of buildings managed by debris flow in Qipangou were compared with that in Zhouqu of Gansu.The case study will improve the land use planning for debris flo

关 键 词：泥石流 建筑物 破坏特征 力学模型 极限平衡理论 临界条件 汶川 四川 

分 类 号：P642.23[天文地球—工程地质学]