【摘要】 选用43次地震中获得的350条地震波,进行单自由度(SDOF)系统的非线性时程分析。运用统计回归方法,得到4类场地上SDOF系统强度折减系数与弹性周期和位移延性比的关系谱。将规则桥梁等效为SDOF系统,提出利用弹性反应谱和强度折减系数谱计算规则桥梁最大弹塑性地震反应的简化方法。等效SDOF系统的恢复力关系通过桥墩塑性铰截面的弯矩-曲率分析确定,并考虑了桥墩基础弹性变形的影响。运用给出的简化方法和非线性时程分析,对32 m铁路简支梁桥在罕遇地震下自振周期及墩顶最大位移进行计算,验证了该方法的有效性。该方法既可用于桥梁结构的抗震设计,也可用于抗震评估分析。更多还原

【Abstract】 Total 350 recorded earthquake waves in the past 43 earthquakes are used for nonlinear time history analysis of single-degree-of-freedom(SDOF) systems.The strength reduction factor spectra for 4 site conditions related to elastic period and displacement ductility ratio of SDOF systems are obtained using statistical and regression analysis.Regular bridges are transformed to equivalent SDOF systems.A simplified method for determining the maximum inelastic response of regular bridges directly by elastic response spectra analysis and strength reduction factor spectra is proposed.In the proposed method,the force-displacement relationship of the SDOF system is constructed using moment-curvature analysis of the plastic region section of bridge piers.The soil-foundation interaction is considered.The natural period and maximum pier top displacement of a 32 m simply-supported railway bridge subjected to rare earthquakes are calculated using the proposed simplified method and nonlinear time history analysis method,and results show that the proposed method is effective.The proposed method can be used for seismic design of new bridges as well as seismic assessment of existing bridges.更多还原