Dynamics of a taut mooring line accounting for the embedded anchor chains

Xiong, Lingzhi; Yang, Jie; Zhao, Wenhua

doi:10.1016/j.oceaneng.2016.05.011

Cited by 43 publications

(4 citation statements)

References 20 publications

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“…Problems with mooring safety in sea locks connecting inland canals and the open sea [1,2] are usually related to structural overload and damage to bollards directly caused by the mooring force or deterioration of the material properties of metal indirectly caused by corrosion related to environmental factors such as seawater intrusion [3][4][5][6][7][8]. Mooring systems are of vital importance for offshore floating facilities [9][10][11][12], and bollards are a key part of mooring systems at the sea lock, which are anchor points for mooring lines used to secure a vessel or ship [13]. They can generally be classified as fixed bollards and floating bollards (FBs) [14].…”

Section: Introductionmentioning

confidence: 99%

Dynamic Inversion Model of the Mooring Force on a Floating Bollard of a Sea Lock

Xiang

Shu³

et al. 2023

JMSE

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Sea locks that connect inland canals and rivers to the open sea are crucial links that ensure the efficient navigation of ships. Floating bollards (FBs) are significant components of sea locks, and they are affected by factors such as large ships, speed of entry, and irregular mooring lines coupled with corrosion by chloride salts from seawater intrusion from the environment. These factors aggravate damage to metal structures, which seriously threatens the safety of FBs. Overloading of FBs by mooring forces caused by the illegal use of FBs for the braking of large ships that enter locks at excessive speed is the main cause of structural damage and overload failure for FBs. Controlling the dynamic mooring force acting on the FB is an important prerequisite to ensure the safe passage of a ship through a lock. It is impossible to perform real-time monitoring of the magnitude and direction of the mooring force on an FB by installing load-measuring equipment on the mooring line. Therefore, in this study, the structure of an FB in a sea lock project was taken as an example, and the mathematical relationships between the strain in the load-sensitive area of the FB and the mooring force and the mooring angle were quantified. A dynamic inversion model of the ship mooring force on an FB was proposed. This model used real-time feedback from the strain signal in the load-sensitive region of the FB structure to obtain information about the mooring force. The accuracy of the model was verified by conducting tests with a physical model of the topside structure of the FB and comparing the predicted results with the test data. The research results can lay a theoretical foundation for real-time monitoring of the structural response of an FB under the action of mooring forces and promote the development of intelligent methods for the operation and maintenance of a sea lock, which have important scientific significance and engineering value.

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Section: Introductionmentioning

confidence: 99%

Dynamic Inversion Model of the Mooring Force on a Floating Bollard of a Sea Lock

Xiang

Shu³

et al. 2023

JMSE

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“…Seabed trenches near the moor lines and pipelines have an ignorable influence on these structures [16]. In some semi-taut mooring systems, the upper floaters drive the mooring line to repeatedly penetrate the soil, which remolds and degrades the surficial seabed soil [17][18][19]. Then, the soil particles are eroded by the seabed flow/turbulence, which leads to seabed trenches near the mooring chain touchdown area, as shown in Figure 1 [20].…”

Section: Introductionmentioning

confidence: 99%

A Framework for Mooring and Anchor Design in Sand Considering Seabed Trenches Based on Floater Hydrodynamics

Rui

Long

et al. 2023

Sustainability

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Seabed trenches reduce anchor capacity. However, the adverse influence is not considered in the current design, and no guideline is found in engineering practice. This paper presents a framework for mooring and anchor design in sand considering seabed trenches based on floater hydrodynamics. First, a hydrodynamic calculation of the studied floater coupled with the mooring system was conducted. Then, the potential trench profile was assessed using a mooring line–seabed dynamic model. Third, after assessing the suction anchor performance based on its installation and capacity, a refined anchor, caisson–plate gravity anchor (CPGA), was proposed, and the capacity mechanisms were analyzed. It was found that the tensions of mooring lines l1 and l2 resist maximum loads under a 45° load condition. Due to the sand’s high strength, a trench is difficult to form in this mooring type. The suction anchor is not suitable as an anchor for the carbonate sand, considering its installation and capacity. The analyses indicate that the increase in soil stress and soil mobilized range in front of the caisson promotes the capacity of CPGA. This paper provides a framework/example to design moorings and anchors considering potential trenches and provides a solution to the anchor design in carbonate sand.

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“…Guo et al 2016 employed a two-dimensional quasi-static model to predict the response of mooring lines comprising multiple types of mooring lines or chains. Xiong et al 2016 investigated the influence of embedded chains on the response of mooring line considering the interaction of soil and chains.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Analysis of Embedded Chains in Mooring Line for Fish Cage System

Hou

Dong

et al. 2018

Polish Maritime Research

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Investigation of the embedded chains in soil starts to play an important role in understanding the structural performance of mooring system, when the embedded anchors will be employed to sustain large loads with the gradually growth of installation depth of offshore aquaculture farm. The aim of this study is to investigate the dynamic response of mooring line considering the influence of embedded chains in clay soil for net cage system. Lumped-mass method is used to establish the numerical model for evaluating the performance of mooring line with embedded chains. To validate the numerical model, comparisons of numerical results with the analytical formulas and the experimental data are conducted. A good agreement of the profile and the tension response is obtained. Then, the effect of embedded chains on the static and dynamic response of mooring line is evaluated, and the dynamic behavior of mooring system considering embedded chains for net cage system is investigated. The results indicate that the soil resistance on embedded chains should be included to predict the mooring line development and the load on the embedded anchors in the numerical simulations. An appropriate safety factor should be included if employing the simplified model Case C at the initial design phase. And the effect of embedded chains on the holding capacity of embedded anchors in single-point mooring system for single net cage cannot be negligible during the design and operation phases. Consequently, it is profound to take into account the interaction of embedded chains and soil for accurately predicting the reliability of mooring system for fish cage.

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Dynamics of a taut mooring line accounting for the embedded anchor chains

Cited by 43 publications

References 20 publications

Dynamic Inversion Model of the Mooring Force on a Floating Bollard of a Sea Lock

Dynamic Inversion Model of the Mooring Force on a Floating Bollard of a Sea Lock

A Framework for Mooring and Anchor Design in Sand Considering Seabed Trenches Based on Floater Hydrodynamics

Dynamic Analysis of Embedded Chains in Mooring Line for Fish Cage System

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