管土作用下的钢悬链线立管动力响应及其疲劳分析

摘要

钢悬链线立管的疲劳分析得到越来越多的重视，尤其是其与海床土体相互作用引起的疲劳。本文根据 Aubeny提出的管土作用模型以及 Bridge提出的土体吸力模型，采用有限元方法，在考虑其与海床土体相互作用的基础上，分析了钢悬链线立管在不同载况作用下的动力响应及疲劳损伤。分析发现，钢悬链线立管上触地点和悬挂点处的疲劳损伤更为显著；洋流载荷对立管疲劳损伤的影响随着水深的增加而减弱；土体吸力的存在，会增大触地段尤其是触地点附近的疲劳损伤；立管触地点附近的疲劳损伤与土体刚度呈正相关。%Recently, more and more attention has been paid on the fatigue analysis of the steel caternary riser (SCR), especially the issue of the pipe-soil interaction. According to the pipe-soil interaction model proposed by Aubeny and the soil suction model proposed by Bridge, the dynamic responses analysis of a SCR under the sea load and other different conditions, are performed and discussed in this paper. The results were used as input data in fatigue analysis of the SCR. Compared with other points of the SCR, the touchdown point and the hanging point bear more drastic fatigue damage; the effect of sea flow on the riser fatigue damage decreases with the increase of water depth; the existence of soil suction will lead to a larger fatigue damage in the touchdown point and the region nearby; the higher the soil stiffness is, the larger the fatigue damage of the SCR in touchdown zone will be.