【摘要】 桥梁结构尤其是桥墩在强震作用下的地震动损伤、滞回耗能及其分布,是基于性能抗震设计的重要基础。本文引入改进的Park-Ang双参数损伤评估模型,以某靠近活动断层的高速公路RC梁式桥等效单墩模型为对象,深入分析了加速度峰值(PGA)、频谱、持时等三个地震动要素对损伤、滞回耗能及其分布的影响规律。研究表明,损伤及累积滞回耗能沿桥墩竖向自下而上显著减小,随着PGA的增大,墩底及附近截面的损伤指标明显增大,损伤高度不断扩大,损伤参与系数分布基本稳定,墩底损伤一般占桥墩总损伤的30%～40%。累积滞回耗能所致损伤可达总损伤的20%～80%,不容忽略。地震动频谱特性影响显著,当地震波卓越周期与结构自振周期接近时,会导致各项指标的显著增加。持时对损伤分布比例没有明显影响,但强震持时对于截面损伤值存在累加效应。更多还原

【Abstract】 The distribution characteristics of seismic damage and hysteretic energy dissipation for bridge structures,especially,bridge piers under strong earthquake is an important basis of performance-based seismic design.Here,the improved two-parameter Park-Ang damage assessment model was introduced,and an equivalent pier model of a RC highway bridge near active fault was studied.The influence of peak ground acceleration(PGA),frequency spectrum and time duration on the distribution of seismic damage and hysteretic energy disspation was analyzed deaply.Studies showed that damage and cumulative hysteretic energy disspation declines significantly along the piers upwards;with increase in PGA,the damage of the cross section near the pier bottom enlarges apparently,and the damage height expands at the same time;the distribution of damage participation factor is stable,and the damage proportion for the bottom segment to the whole pier is 30%-40%;the seismic damage from cumulative hysteretic energy dissipation is 20%-80% of the total damage,it should not be ignored;the frequency spectrum characteristics of ground motion has significant influence,when its predominant period is close to the bridge’s self-vibration period,each index increases saliently;time duration has no significant impact on the distribution proportion of damage,but strong earthquake duration exerts cumulative effect on the damage value of each cross section.更多还原