不同地震作用方向下混凝土核心筒基于增量动力分析的抗震性能评估

摘要

The effect of aseismic performance of core walls on damage of a hybrid structure under a strong earthquake is very important.It is worth studying deeply seismic response of a core wall under double-direction or multidirection earthquakes action by choosing appropriate earthquake inputs.The dynamic time history analysis of a core wall was performed.By comparison,it was shown that the structural internal force under oblique directional seismic action is much stronger than that under unidirectional earthquake action and the design results based on unidirectional earthquake input may be unsafe.The aseismic performance of a core wall based on the single-input IDA method was analyzed under an earthquake action in the direction of 45° about the vertical axis.The results indicated that an oblique directional earthquake action has a certain effect on the IDA curves of a core wall; however,the displacement indexes corresponding to different performance levels are close to those under the vertical directional single earthquake action.%强震作用下,核心筒对混合结构发生破坏乃至倒塌有着重要影响.选择合适的地震输入,进行核心筒在双向或多向地震作用下的地震反应分析是值得深入研究的.采用动力时程分析方法,通过不同方向地震作用与单向地震作用下混凝土核心筒的地震效应对比可知,在进行结构设计时,大震作用下,斜向地震作用下的内力要明显偏大,仅考虑单向输入的水平加速度的设计结果会偏于不安全.并通过输入与Y轴45°斜向地震记录基于单条地震记录的增量动力分析方法(IDA方法)对核心筒进行抗震性能评估.结果表明,斜向地震输入对核心筒IDA曲线有一定影响,但各性能点对应的量化位移指标与Y向单条地震输入时相差不大.