基于数值模拟的村镇典型砌体结构地震抗倒塌性能分析

Analysis on seismic collapse resistance performance of typical rural masonry structures based on numerical simulation

基于有限元软件MSC.MARC,开发了可用于模拟村镇砌体结构倒塌全过程的精细化有限元数值模型.基于数值模拟对我国广大村镇区域不同抗震构造措施的典型自建砌体结构进行了地震倒塌分析,并研究了构造柱、楼板形式、预制楼板支承长度等因素对结构抗倒塌性能的影响.结果表明:主要存在由砌体墙面内受力破坏导致的整体倒塌和由预制楼板坠落导致的局部倒塌2种模式;构造柱是形成整体倒塌机制、提高砌体结构抗倒塌性能的关键措施;预制楼板降低了各片墙体的协调性,使结构整体性和抗倒塌能力下降;预制楼板的支承长度小于100 mm时,会引发局部倒塌;无任何抗震构造措施的砌体结构在中震作用下就可能发生局部倒塌,抗倒塌能力较差.

Based on the finite element software MSC.MARC,a refined finite element model was developed for simulating the collapse process of rural masonry structures.Based on numerical simulation,the seismic collapse analysis of typical self-built masonry structures with different seismic structural measures in rural area was carried out.The effects of the structural columns,the slab form and the supporting length of the precast slab on the structural seismic collapse resistance were studied.The results show that there are two main collapse modes,including the overall collapse caused by the failure of the masonry wall and the local collapse caused by the fall of precast slab.The structural column is a key measure to form an integral collapse mechanism and improve the collapse resistance of masonry structures.Precast slabs reduce the coordination of each piece of the wall,thus lowering the structural integrity and collapse resistance.When the support length of precast slabs is less than 100 mm,local collapse occurs.Masonry structure without any seismic structural measures may collapse locally under moderate earthquake,and the collapse resistance capacity is poor.