Research On Burial Protection Index(BPI) Of Submarine Cables

At present,the submarine cable burying protection has become an essential protection measure for submarine cable burying engineering,that is,submarine cables are buried to a certain depth through trenching machines,which can effectively prevent the damage of anchor dropping and fishing,and reduce the corrosion of electrochemistry and biology on the outer protective layer of cable.But at present,there is no uniform standard for the buried depth of submarine cables,and most of them are based on operating experience or general definition.This paper studies the buried depth of the submarine cable in Zhoushan sea area based on the characteristics of sea bottom.First of all,this paper introduces the research of submarine cable protection at home and abroad,and discusses the engineering significance of submarine cable protection.Then,this paper studies the main forms of submarine cable damage,determines the two possible forms of damage caused by the anchoring operation to the submarine cable according to the damage of the anchorage to the submarine cable.We select typical ships and determine the specifications of ship anchors based on the situation of ships in Zhoushan sea area.Secondly,this paper analyzes the impact damage and drag damage of ship anchor.We analyze the impact probability,impact energy and penetration depth of the anchor in terms of the impact damage,and analyze the drag force and movement process of the anchor,and determine the penetration depth of the anchor in terms of drag damage.The penetration depth values of impact damage and drag damage are compared and analyzed to determine the impact damage for further study.Thirdly,the LS-DYNA simulation analysis is carried out on the process of anchor penetration into seabed sediment.In the pre-processing module,three different penetration speeds and four different anchor weights are set respectively.The penetration depth of anchor in seabed sediment under different working conditions is obtained by simulation calculation.Finally,this paper studies the influence of anchor weight and anchor dropping speed on the penetration depth of anchor.The final test data is compared with the simulation results and the recommended depth values of the existing specifications.The research and result of this paper provides reference and value for the submarine cable burying in Zhoushan sea area.