砖房抗震墙基准面积率分析

Analysis of characteristic ratio of seismic wall of brick masonry buildings

砌体结构砖房抗震墙基准面积率是多层砖房进行抗震鉴定的重要参数,是确定房屋抗震减灾对策的依据。为了评价砖房抗震墙基准面积率取值的合理性,分析了砖房抗震墙基准面积率取值的影响因素及存在的不足,提出了砖墙构造柱率指标。结合抗震评估指标及判别准则,从地震震害的角度,对砖房抗震墙基准面积率的取值进行考察,提出了考虑砖墙的构造柱率指标和楼板类型不同的砖房抗震墙基准面积率的计算模型,为研究砖房抗震墙基准面积率提供了一条新途径。结合算例,比较了基于地震震害得到的砖房抗震墙基准面积率计算模型取值与现行抗震鉴定标准规定值间的差异,结果表明:预制楼盖且墙体内构造柱含量较少时,两者的基准面积率相接近;同等抗震能力下,楼层墙体内构造柱面积含量的增加可降低地震作用下砖房抗震墙基准面积率的取值。

The characteristic ratio of seismic wall is an important parameter for seismic evaluation of multi-story masonry structures,which determines the results of earthquake disaster prevention and treatment measures. Firstly,in order to obtain a reasonable assessment of the characteristic ratio of seismic wall,some affecting factors and defects of the characteristic ratio of seismic wall of masonry buildings were analyzed. Secondly,an index of the ratio of constructional column area to wall area of masonry buildings was put forward. Meanwhile,the characteristic ratio of seismic wall of masonry buildings was studied at the earthquake field investigation point of view according to existing seismic evaluation theory and its judgment standards,and a new calculated model was put forward by taking into account the difference of the ratio of constructional column areas to wall areas and floor-slab type,which provides a new way to study the characteristic ratio of seismic wall. Finally,a comparison of characteristic ratio of seismic wall of masonry buildings between the new model and the existing seismic appraisal standard was studied with some examples.Results show that,the characteristic ratio is close when floor slab is precast and the number of constructional column is low. With the same seismic capacity,the increase of the number of constructional column in brick walls will reduce the value of characteristic ratio of seismic wall of masonry buildings.