摘要
对部分悬跨海底管道在空间变化地震动作用下的反应进行了分析。建立了含有悬跨段的长距离埋设海底管道多点输入计算模型,据此推导了多点输入运动方程,采用了一种改进的多点地震动模拟方法生成了空间相关多点地震动时程并对海底管道进行了3维多点输入地震反应时程分析。比较了海底管道在不同地震输入模型(多点输入、行波输入、一致输入)作用下的地震响应。同时进一步分析了地震动空间变化特性、模型计算长度、悬跨段长度、管道外径、钢管壁厚、混凝土配重层厚度以及海床坡度对海底管道多点输入反应的影响。分析结果显示地震动的空间变化特性能显著增大海底管道的地震反应,其他因素也在不同程度上对海底管道多点输入地震反应产生影响。
The seismic response of the partly spanning submarine pipelines due to spatial variation of ground motions is presented.An improved method was adopted for simulating multiple-station ground motions.A three-dimensional(3D) finite element model of long-distance buried submarine pipeline with a middle free span was built and 3D multi-input time-history analysis was performed.Furthermore,seismic response of submarine pipelines was compared with different input method such as the multi-station input,traveling wave input and identical input.Some factors including pipe length,free span length,outside diameter of the pipe,wall thickness of the pipe,concrete coating thickness,and seabed slope were studied in the sensitivity analysis.The numerical results display that the spatial variation of ground motions can significantly increase the seismic response of submarine pipelines.Meanwhile,the other factors also influence on the response of the submarine pipelines under multiple-station earthquake ground motions to some extents.
引文
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