基于弹塑性谱位移的钢筋混凝土框架概率地震需求分析  

Probabilistic seismic demand analysis of reinforced concrete frames based on inelastic spectra displacement

作　　者：徐超[1] 耿飞[1] 温增平[1] XU Chao;GENG Fei;WEN Zengping(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]中国地震局地球物理研究所,北京100081

出　　处：《振动与冲击》2018年第16期162-171,184,共11页Journal of Vibration and Shock

基　　金：国家自然基金(51378477;51408561);国家科技支撑计划(2015BAK18B01);中国地震局地球物理研究所基本科研业务专项(DQJB17C04;DQJB15C05)

摘　　要：地震动参数的选择是影响概率地震需求分析中输入地震动的选择和调整以及分析结果可靠性的重要因素。开展概率地震需求分析时,常采用的地震动参数主要有峰值加速度和对应于结构基本周期的加速度反应谱值。但是,一方面,结构响应与地震动峰值加速度的相关性较差。另一方面,对应于结构基本周期的加速度反应谱值不能体现结构基本周期之外的地震动频率成分对结构地震反应的影响。以弹塑性谱位移作为地震动参数开展RC框架结构的概率地震需求分析研究。基于模态Pushover分析提出了弹塑性谱位移的计算方法;借助云图法和改进的增量动力法开展典型框架结构的概率地震需求分析,基于回归拟合及残差分析研究了弹塑性谱位移的充分有效性,并与弹性谱位移进行了比较。研究表明:弹塑性谱位移能够反映大于结构基本周期的地震动频率成分对结构弹塑性地震反应的影响,改善了弹性谱位移仅反映单一地震动频率成分对结构反应影响的不足,可以较合理地揭示由于结构软化导致自振周期延长后地震动的破坏作用。Ground motion intensity measurement is an important factor affecting the input ground motions selection and the reliability of probabilistic seismic demand analysis results.Peak ground acceleration and acceleration spectrum values corresponding to the fundamental period of a structure are commonly used measures of ground motion intensity.But using peak ground acceleration leads to a large dispersion of structural responses,and an acceleration spectrum value corresponding to a structure’s fundamental period cannot reflect the impact of multiple ground motion frequency components on structural response.In this study,inelastic spectral displacement was used as an alternative intensity measurement to characterize the ground motion damage potential,and inelastic spectral displacement-based probabilistic seismic demand analysis was performed.The inelastic spectral displacement calculation method was presented based on modal pushover analysis.Probability seismic demand analyses of typical RC frames were performed by means of cloud analysis and advanced incremental dynamic analysis.The sufficiency and efficiency of inelastic spectral displacement were investigated by means of regression and residual analyses and compared with elastic spectral displacement.The study shows that inelastic spectral displacement characterizes the impact of frequency components with periods larger than the fundamental period on inelastic structural response,improving the deficiency of elastic spectra displacement.The damage potential of ground motion on structures with fundamental period prolonging caused by structural softening can be caught by inelastic spectral displacement.

关 键 词：概率地震需求分析 地震动强度参数 弹塑性谱位移 非线性动力时程分析 

分 类 号：TU375.4[建筑科学—结构工程] P319.5[天文地球—固体地球物理学]