基于中美抗震设计规范的双向水平地震效应组合方法的有效性评估  

Evaluation of combination rules account for orthogonal seismic effects based on Chinese and American seismic design codes

作　　者：王健泽 戴靠山 WANG Jianze;DAI Kaoshan(Department of Civil Engineering,Sichuan University,Chengdu 610065,China;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China)

机构地区：[1]四川大学土木工程系,成都610065 [2]中国地震局工程力学研究所地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《世界地震工程》2022年第1期1-10,共10页World Earthquake Engineering

基　　金：国家自然科学基金(U1710111&51878426);中国地震局工程力学研究所基本科研业务费专项资助项目(2021D16)。

摘　　要：在地震来临时,一般假设建筑结构同时受到两个正交水平方向分量与一个竖向分量的地震动作用。双向水平地震效应组合方法用于估计两个正交水平分量地震动同时作用时结构的内力效应。本文主要对我国与美国抗震设计规范中规定使用的平方和开平方根(SRSS)方法与百分比组合方法的有效性进行了评估。首先,对比了我国与美国规范在考虑双向水平地震效应时的适用情况及相关规定上的异同。以一4层中心支撑-框架结构为工程案例,考虑两国规范在适用情况上的规定,设置了三个结构布置方案。对三个结构布置方案建立有限元模型,选取22组地震动,开展了动力时程分析。提出了针对SRSS方法与百分比组合方法的评估指标,基于时程分析结果,发展了双向水平地震效应组合的概率性评估方法。评估结果表明:SRSS方法与百分比组合方法用于平面扭转不规则结构的设计较为保守。在简化组合规则的适用条件上,美国规范对平面扭转不规则结构不进行考虑有一定的合理性。建议我国规范对中心支撑-框架结构中含双向受压柱的设计要求考虑双向水平地震效应组合。The ground motions subjected to buildings are usually simplified as two horizontal orthogonal components and one vertical component.The combination rules account for orthogonal seismic effects are used to estimate the force demands of structural components under simultaneously application of two horizontal ground motions.In this study,the effectiveness of SRSS and percentage rules prescribed by Chinese and American seismic design codes are assessed,respectively.The stipulations in Chinese and American design codes regarding the conditions that trigger the use of combination rules are compared.A 4-story concentrically braced frame building is adopted for assessment of the combination rules.According to the different trigger conditions specified in design codes,three design schemes of the building are considered.The numerical models of the three schemes are developed.A set of 22 pair ground motions is adopted and response-time analyses are performed.The assessment indicators and probalisitic-based assessment procedure for SRSS and percentage rules are proposed.The results show that,SRSS leads to a more conservative design for torsional buildings than percentage rules.It is reasonable that torsional irregular structures are not considered as a trigger condition in American codes.The Chinese design code is suggested to provide requirements on using combination rules for column that shared by orthogonally configured concentrically braced frames.

关 键 词：双向水平地震效应 SRSS 百分比组合规则 中心支撑-框架结构 扭转不规则 

分 类 号：TU271.1[建筑科学—建筑设计及理论]