Effect of Offshore Earthquake Ground Motions and Temporal-Spatial Correlation on the Dynamic Response of Subsea Pipelines

摘要

In this study, artificial ground motions with temporal-spatial correlationare first synthesized based on a collected offshore recording fromKyoshin Network (K-NET). Second, a finite element model of 400-meter subsea pipeline is created, and the time-domain earthquakeanalyses are carried out under two patterns of seismic inputs. One is theuniform excitations without considering temporal-spatial variations,whereas the other is the non-uniform multi-point excitations withtemporal and spatial coherence functions. Comparisons of the transientdynamic response are therefore conducted. It is shown that the nonuniformexcitations tend to trigger a stronger dynamic amplificationeffect than uniform excitations do in the aspect of maximumacceleration and maximum displacement. Furthermore, the maximumprinciple stress is approximately 1.33 times under non-uniformexcitations as compared to that of the uniform excitations, which isconsistent with the trend of maximum relative displacement. Theimportance to account for the effect of temporal-spatial variations inthe seismic ground motions on the dynamic response of subsea seismicpipelines thereby is manifested in this study.