地震作用下钢筋混凝土框架结构倒塌全过程振动台试验研究  

Shaking table test on complete collapse process of RC frame structure subjected to earthquake

作　　者：骆欢[1,2] 杜轲 孙景江[1,2] 许卫晓[1,2] 丁宝荣[1,2] 

机构地区：[1]中国地震局工程力学研究所,黑龙江哈尔滨150080 [2]中国地震局地震工程与工程振动重点实验室,黑龙江哈尔滨150080

出　　处：《建筑结构学报》2017年第12期49-56,共8页Journal of Building Structures

基　　金：中国地震局工程力学研究所基本科研业务费专项(2016B04;2016A05);国家自然科学基金青年基金项目(51408563)

摘　　要：以玉树7.1级地震中某底层遭到严重破坏的钢筋混凝土(RC)框架结构为原型,设计了1个1∶5缩尺的三维模型,通过模型的倒塌全过程振动台试验,研究了汶川、玉树地震中高烈度地区RC框架结构出现的典型侧向逐层呈多米诺骨牌式连续倒塌现象的全过程和倒塌破坏机制。试验中该模型结构的倒塌过程共分为两个阶段,即侧向增量倒塌和竖向连续倒塌。当底层层间位移角达到1/19时,试验模型处于临近倒塌状态。在倒塌过程中,底层角柱C3最先丧失竖向承载力,此时竖向倒塌开始发展,结构在重力荷载及输入地震动的共同作用下,底层柱的水平侧移持续增加,造成其相邻的柱B2、B3、C2相继失效,丧失竖向承载力,模型结构的冗余度不足使结构产生更大范围的竖向倒塌,最终模型结构呈侧向逐层连续倒塌。通过对倒塌后废墟的研究,发现模型结构呈"强梁弱柱"型破坏,其破坏模式与震害调查结果一致。最后,讨论了此种废墟下人员生存空间的问题,给出了防RC框架结构倒塌的相关建议。A specimen constructed at one-five scale,whose prototype structure is a RC frame destroyed seriously at the first floor under Yushu earthquake,is used to research the complete process of the typical lateral increment collapse modes like domino and failure mechanism of RC frame structures located at high seismic intensity region induced by Wenchuan and Yushu earthquakes. Through the shaking table test,the experimental findings indicate that the complete collapse process can be divided into two parts, that is, horizontal increment collapse and vertically progressive collapse. The specimen is in a boundary collapse state when the inter-story drift at the first floor reaches 1/19. In process of collapse,the corner column named C3 loses its vertical load carrying capacity at first where the progressively vertical collapse begins to occur. The lateral displacements of columns at the first floor are constantly increased under the combination of gravity load and ground motion,causing columns named B2,B3 and C2 next to C1 to fail subsequently. After these,the damaged specimen has a deficient redundancy,and thus a wide range of vertical collapse occurs which finally results in laterally progressive story-by-story collapse. Through the investigation of collapsed ruins,the damaged state of ＂strong beam weak column ＂ for the specimen is in accordance with the earthquake damage investigation results. In the end,the living space for people to survive is discussed,and the suggestions to resist this typical collapse are also recommended.

关 键 词：RC框架结构 振动台试验 倒塌全过程 侧向增量倒塌 竖向连续倒塌 生存空间 

分 类 号：TU375.4[建筑科学—结构工程] TU317.1