考虑多振型贡献和弹塑性位移谱的改进地震动强度参数  

An improved ground motion intensity measure considering multi-mode contributions and inelastic displacement spectrum

作　　者：黄青隆 罗永峰[1] 朱钊辰 相阳[1] HUANG Qinglong;LUO Yongfeng;ZHU Zhuochen;XIANG Yang(College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学土木工程学院

出　　处：《建筑结构学报》2020年第2期22-31,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51378379)

摘　　要：为减小增量动力分析中结构地震反应的离散程度,提出了改进的地震动强度参数。首先,基于等效模态荷载和模态组合系数,提出并定义模态强度参数。然后,采用推广的模态推覆方法,构造1阶振型的等效单自由度体系,采用非线性时程分析计算该体系的弹塑性位移谱谱值,用于修正1阶模态强度参数。最后,组合各阶模态强度参数,得到改进的地震动强度参数。对不同矢跨比的两个格构钢拱模型进行36条地震波的增量动力分析结果表明,改进参数可有效减小结构反应离散性。相比于其他常用地震动强度参数,该参数对各项需求指标拟合结果的判定系数均处于0.9678~0.9786范围内,拟合标准差均处于0.195~0.239范围内,具有更好的相关性、有效性。同时,该参数拟合斜率较高,具有较好实用性;其拟合残差通过了显著性检验,满足充分性的要求。In order to reduce the dispersion of structural responses in incremental dynamic analysis,an improved ground motion intensity measure is proposed.Firstly,modal intensity measure is defined based on equivalent modal load and modal combination factor.Secondly,a first-mode equivalent single degree of freedom system(ESDF)is established using extended modal pushover analysis.The inelastic displacement spectrum of the ESDF system is obtained from nonlinear response history analysis,according to which the first order modal intensity measure is modified.Thirdly,the improved ground motion intensity measure is then proposed by combining all the modal intensity measures.The results of 36 incremental dynamic analyses of two latticed arches with different rise-span ratio indicate that the proposed intensity measure can reduce the dispersion of structural responses.Compared with other common intensity measures,the coefficient of determination of each individual seismic demand on the proposed intensity measure is in the range from 0.9678 to 0.9786,and the fitting standard deviation of the proposed intensity measure is in the range from 0.195 to 0.239,which indicate stronger correlation and better efficiency.The proposed measure also shows adequate practicality due to its high fitting slope.Furthermore,its fitting residual errors pass the test of significance,which proves that the proposed intensity measure meets the requirements of sufficiency.

关 键 词：大跨度拱形结构 地震动强度参数 模态组合系数 弹塑性位移谱 模态强度参数 

分 类 号：TU391[建筑科学—结构工程] TU311.41