【摘要】 近断层地震动最显著的特点是由方向性效应和滑冲效应引起的脉冲型地面运动。通过建立单自由度体系瞬时输入能计算模型,输入速度脉冲地震记录进行了弹塑性时程分析,计算出地震动对结构的瞬时输入能量,研究了具有速度脉冲型地震动这种荷载形式的瞬时输入能特性及与结构最大位移反应的关系。研究结果表明,对于12次强地震动中109条具有速度脉冲的地震记录,输入结构的最大瞬时输入能总处于速度脉冲发生位置,说明速度脉冲波形对地震动最大瞬时输入能具有决定作用,并由最大瞬时输入能量与结构最大位移反应的对应关系,验证了近断层地震动对结构的破坏作用与速度脉冲有关。此外,与无速度脉冲地震动相比,具有速度脉冲会增大长周期结构的瞬时输入能,并且输入结构的最大瞬时输入能随地面峰值速度(PGV)和峰值加速度(PGA)的比值增大而增大。更多还原

【Abstract】 It is believed that a pulse action is the main characteristic of near-fault ground motions.An instantaneous input energy model for a single-degree-of-freedom system is established and near-fault seismic records are input for elastoplastic time history analysis and instantaneous input energy of each earthquake is computed.It is found that maximum instantaneous input energy to structure coincides with velocity pulse in time history record and is proved to be determined by velocity pulse.Structure failure related to velocity pulse is verified.Furthermore,instantaneous input energy to long periods structure inflicted by velocity pulse ground motions is greater than no velocity pulse ground motions and is proportional to ratio of the peak ground velocity and the peak ground acceleration.更多还原