高烈度地区框架-核心筒结构中美抗震设计方法对比

Comparison of Chinese and American seismic design methods for frame-core wall structures in high seismic zone

按照中美相关抗震设计规范分别对位于中国8度抗震设防区和美国典型高烈度区域(旧金山地区)的两栋层高与结构相似的钢筋混凝土框架-核心筒高层建筑结构进行了设计。介绍了抗震设计过程中根据中美相关抗震规范确定的地震作用参数与材料强度,比较了两国混凝土结构尤其是剪力墙结构抗震构造措施的异同。建立了两结构的空间弹性分析模型,采用振型分解反应谱法计算了两结构的弹性地震响应,比较了两结构自振周期、基底剪力、层剪力、结构层间变形、构件尺寸、配筋以及连梁受剪承载力等。计算结果表明:按照两国设计规范分别设计的结构,其设计地震作用水平相当;根据美国规范设计的结构连梁受剪承载力与中国规范设计方案相比偏低,约为中国规范设计方案的0.63~0.95倍;中美两国规范设计的剪力墙约束边缘构件的范围与配筋差异较大,中国规范设计方案剪力墙约束边缘构件内纵筋和箍筋集中在端部固定范围内,美国规范设计的箍筋约束范围大,对应端部固定范围的配筋比中国规范配筋量小。

Two reinforced concrete frame-core wall structures with similar story height and configuration,one located in 8 intensity precautionary zone in China and the other on typical high seismic zone in America( San Francisco) were designed conforming to Chinese and American seismic design codes,respectively. How to determine earthquake ground motion parameters and material strengths according to Chinese and American seismic design codes was introduced,and the differences of detailing requirements of concrete structures especially shear wall structures were compared. Linear seismic responses of two structures were calculated by modal response spectrum method,and the structural periods,base shear force,story shear force,inter-story drift ratio,component dimensions and amount of reinforcement,shear resisting capacity of coupling beams were compared. The predicted results indicate that: the design seismic base shear forces of two structures are close to each other; for the structure designed in conformity with American seismic design guidelines,the shear resisting capacity of coupling beams is 0. 63 ~ 0. 95 times corresponding those with the Chinese seismic design codes; for the structure designed based on Chinese code,the longitudinal and transverse reinforcement of shear wall boundary element concentrate in the edge specified area,for the structure designed based on American code,transverse reinforcement of boundary element confines more area,and longitudinal reinforcement distributes over all the confined area,but the amount of longitudinal reinforcement is less than that of the structure designed based on Chinese code for the same edged area.