超高层结构地震剪力系数限值研究

Research on seismic shear gravity ratio limit for super high-rise buildings higher than 500m

基于目前抗震设计规范中地震剪力系数限值的要求,针对目前国内高度较高(500m以上)的超高层建筑设计实际,介绍了地震剪力系数一般较难满足规范要求的情况,分析了超高层结构地震剪力系数的影响因素,指出结构周期、场地土特征周期是相对较为显著的影响因素,超高层结构阻尼比因变化幅度较小一般对地震剪力系数影响较小。分析了设计中提高地震剪力系数的方法。提出了地震剪力系数限值的一些建议,包括地震剪力系数限值与场地土类型相关、减小高度超高结构地震剪力系数限值等。

For super high-rise buildings higher than 500 meters, seismic shear gravity ratio is often hard to satisfy code requirement for most projects in China. Several influence factors of shear gravity ratio were analyzed. The structural periods, design characteristic period of ground motion influence much while damping ratio influence little for little varying for general super high-rise structures. Methods to increase shear gravity ratio were introduced. Some suggestions to modify shear gravity ratio limit were introduced, such as changing limit value according to different site, or decreasing the limit value for super high-rise structures higher than 500 meters.