近断层地震作用下悬跨海底管线响应分析

Analysis of Free Spanning Subsea Pipeline Under Effects of Near-fault Ground Motion

随着近几年近断层地震的频发,人们发现近断层地震在某些情况下更易引起严重的结构破坏。为了研究近断层地震中不同脉冲效应对悬跨海底管线的影响,选取了近断层的向前方向性效应和滑冲效应及远断层效应作为地震动输入,通过大型结构分析软件Ansys对不同悬跨海底管线进行非线性响应分析,比较了同一震级下不同悬跨长度管线的响应。结果表明,随着悬跨长度的增加,体系周期的增大,近断层效应对结构的影响更加显著,因此在管线抗震结构设计中应加以重视。

With the frequent occurrence of near-fault earthquakes in recent years, it is demonstrated that near-fault earth- quakes can cause more serious structural damages under certain circumstances. In order to study the effect of different pulses on free spanning subsea pipelines during near-fauh earthquakes, near-fault ground motions with forward directivity and fling-step effects and far-fault effects were selected as seismic inputs to analyze different nonlinear response of free spanning subsea pipelines by using the finite element software Ansys, and the responses of different span length pipelines under the same magnitude were compared. The results indicate that the system period increases with the span length and the influence of near-fault effects on the structure is more obvious, so more attention should be given to the seismic design of the pipelines.