【摘要】 选取谱加速度为地震动强度参数,最大墩底弯矩为工程需求参数,对铅芯橡胶支座隔震简支梁桥与非隔震简支梁桥进行概率需求分析,定量计算研究铅芯橡胶支座对提高桥梁结构抗震性能作用。计算结果表明,隔震桥梁结构回归方程斜率均小于非隔震桥梁结构回归方程斜率,说明隔震结构对地震动强度改变的敏感性小于非隔震结构;场地危险性分析表明,同一场地桥梁结构体系遭遇某水平谱加速度的超越概率,隔震结构小于非隔震结构,应用隔震支座可降低桥梁结构对应的场地危险性;概率地震需求危险性分析表明,铅芯橡胶支座隔震桥梁结构发生墩底纵筋屈服年超越概率远小于非隔震结构概率。研究表明,概率地震需求分析方法可作为基于概率的定量分析方法用于不同结构体系的桥梁结构抗震性能评价。更多还原

【Abstract】 By choosing spectral acceleration as an intensity magnitude parameter and maximum bending moment at pier bottom as an engineering demand parameter,probabilistic seismic demand analyses for a seismically isolated simply supported beam bridge with lead rubber bearing(LRB) and a non-isolated beam bridge were presented here,the function of LRB was studied with a quantitative computation method.The results of probabilistic seismic demand analysis(PSDA) showed that the regression slope of the isolated bridge is smaller than that of the non-isolated bridge;it means the bridge installed with LRB is less sensitive to increase in ground motion intensity.The results of probabilistic seismic hazard analysis showed that the exceeding probability of the isolated bridge encountering a certain spectral acceleration is lower than that of the non-isolated bridge,so using LRB decreases the bridge’s hazard level.The results of probabilistic seismic demand hazard analysis indicated that LRB can greatly decrease the bridge’s annual exceeding probability when the pier bottom reches yield with the site condition and structure parameters here.It was shown that probabilistic seismic demand analysis,as a probability-based quantitative analysis method,can be adopted in evaluation of different aseismic design methods or aseismic devices.更多还原