An Analytical Method for Positioning Drag Anchors in Seabed Soils  

作　　者：张炜 刘海笑 李新仲 李清平 曹静 

机构地区：[1]General Research Institute,China National Offshore Oil Corporation [2]School of Civil Engineering,Tianjin University

出　　处：《China Ocean Engineering》2015年第1期49-64,共16页中国海洋工程（英文版）

基　　金：financially supported by the National Basic Research Program of China(973 Program,Grant No.2009CB219507);the National Natural Science Foundation of China(Grant Nos.50639030 and 50979070);the National Science and Technology Major Project of China(Grant Nos.2011ZX05056-002 and 2011ZX05026-004)

摘　　要：Positioning drag anchors in seabed soils are strongly influenced not only by the properties of the anchor and soil, but also by the characteristics of the installation line. The investigation on the previous prediction methods related to anchor positioning demonstrates that the prediction of the anchor position during dragging has inevitably introduced some key and unsubstantiated hypotheses and the applicability of these methods is limited. In the present study, the interactional system between the drag anchor and installation line is firstly introduced for the analysis of anchor positioning. Based on the two mechanical models for embedded lines and drag anchors, the positioning equations for drag anchors have been derived both for cohesive and noncohesive soils. Since the drag angle at the shackle is the most important parameter in the positioning equations, a novel analytical method that can predict both the variation and the exact value of the drag angle at the shackle is proposed. The analytical method for positioning drag anchors which combines the interactional system between the drag anchor and the installation line has provided a reasonable theoretic approach to investigate the anchor behaviors in soils. By comparing with the model flume experiments, the sensitivity, effectiveness and veracity of the positioning method are well verified.Positioning drag anchors in seabed soils are strongly influenced not only by the properties of the anchor and soil, but also by the characteristics of the installation line. The investigation on the previous prediction methods related to anchor positioning demonstrates that the prediction of the anchor position during dragging has inevitably introduced some key and unsubstantiated hypotheses and the applicability of these methods is limited. In the present study, the interactional system between the drag anchor and installation line is firstly introduced for the analysis of anchor positioning. Based on the two mechanical models for embedded lines and drag anchors, the positioning equations for drag anchors have been derived both for cohesive and noncohesive soils. Since the drag angle at the shackle is the most important parameter in the positioning equations, a novel analytical method that can predict both the variation and the exact value of the drag angle at the shackle is proposed. The analytical method for positioning drag anchors which combines the interactional system between the drag anchor and the installation line has provided a reasonable theoretic approach to investigate the anchor behaviors in soils. By comparing with the model flume experiments, the sensitivity, effectiveness and veracity of the positioning method are well verified.

关 键 词：drag anchor anehorpositioning mechanical model drag line embedded line drag angle TRAJECTORY 

分 类 号：P754[天文地球—海洋科学]