砖砌体结构房屋砖墙竖向轴压比限值研究

Research on the limit values of vertical axial compression ratios of brick walls in masonry structures

一般认为地震在地表面引起的破坏主要是S波的水平震动,较少考虑地震竖向力的作用。汶川地震震害资料表明,仅考虑水平地震作用不能全面反映震害特征。以汶川地震竖向地震加速度记录和国内外已取得的大量地震动记录为依据,给出了不同设防烈度、不同设计地震分组下竖向地震加速度与水平地震加速度之间的关系。采用冲量法得出不同设防烈度下砌体结构的竖向地震作用,分析了竖向地震力的分布规律以及对砌体结构的影响。为避免砖砌体结构房屋在竖向地震作用下局部楼层被压溃,提出了砖砌体结构轴压比限值建议。

h is generally considered that damage to buildings is caused by horizontal vibration of ＂S＂ wave and men seldom consider the effect of the earthquake vertical force. Based on the acceleration records got from the Wen- chuan Earthquake as well as domestic and abroad earthquakes happened in the recent ten years, the relationships between vertical earthquake acceleration and horizontal earthquake acceleration under different seismic fortification intensities and classifications of design earthquake are built. According to the relationships, the values of vertical earthquake force under different seismic design intensities are got by adopting the impulse method. And the analysis of vertical seismic force distribution as well as its impact on the masonry structure is studied. In order to prevent the collapse of buildings and the local compression damage to a certain floor, the concept of axial compression ratio of masonry structure is put forward, and the ultimate axial compression ratio of the masonry wall is given, which pro- vides a theoretical basis for improving the design level of masonry structures to resist the earthquake.