论文部分内容阅读
为了研究地震动参数与大跨度刚构桥梁结构损伤的相关性,选取了国内外355条地震动记录,并从现有文献中选择了29个具有代表性的地震动参数来做相关性分析。以一座典型的高墩大跨连续刚构桥为工程背景,采用OpenSees作为动力分析平台,建立能够考虑材料刚度退化的非线性有限元分析模型,通过回归分析,建立各地震动参数独立的概率性地震需求模型,得到地震动强度与桥梁结构最大响应(墩底单元曲率以及墩顶和支座的位移)和桥梁损伤之间的相关性,并且对不同地震动强度指标进行分析和比较。结果表明:不同地震动强度指标与桥梁响应和损伤的相关性差别很大,其中峰值速度(PGV)、持续最大速度(SMV)、反应谱速度峰值、Housner强度与结构响应有很高的相关性,1s周期对应的谱参数、峰值速度(PGV)、Arias强度以及Housner强度与结构损伤有很高的相关性;而峰值加速度PGA、峰值加速度与峰值速度的比值、位移均方根值以及卓越周期与桥梁结构最大响应和结构损伤的相关性较差;对于周期较长的大跨度刚构桥,推荐使用PGV等具有较好相关性的地震动强度指标进行地震易损性分析和地震风险评估。
In order to study the correlation between ground motion parameters and structural damage of long-span rigid frame bridges, 355 earthquake records at home and abroad were selected and 29 representative ground motion parameters were selected from the existing literature for correlation analysis. Taking a typical high-pier long-span continuous rigid frame bridge as engineering background, OpenSees is used as the dynamic analysis platform to establish a nonlinear finite element model which can consider the material stiffness degradation. By means of regression analysis, a set of independent probabilistic earthquakes Demand model, the correlation between ground motion intensity and the maximum response of bridge structure (the curvature of pier bottom unit, the displacement of pier top and abutment) and the damage of bridge are obtained, and the indexes of different ground motions are analyzed and compared. The results show that the correlation between different ground motion strength indexes and bridge response and damage is quite different. The peak velocity (PGV), continuous maximum velocity (SMV), peak response spectrum velocity and Housner intensity have a high correlation with structural response The spectral parameters, peak velocity (PGV), Arias intensity and Housner intensity corresponding to 1s cycle have a high correlation with structural damage. However, the peak acceleration PGA, the ratio of peak acceleration to peak velocity, the root mean square value of displacement and the excellent period And the correlation between the maximum response of bridge structure and structural damage is poor. For long-span long-span rigid frame bridges, it is recommended to use seismic intensity indexes such as PGV that have good correlation to analyze seismic vulnerability and seismic risk assessment.