• Title/Summary/Keyword: Ship and bridge collision

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A Study on Avoiding Collision between a Ship and Bridge and Minimizing Damages if Unavoidable (선박과 교량의 충돌예방과 충돌시 손상의 감소방법에 관한 연구)

  • Yoon, Byoung-Won;Yun, Jeom-Dong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.376-382
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    • 2007
  • A Collapse of bridge by ship's collision to the bridge post may lead a great calamity. This paper investigates on avoiding collision between a ship and bridge by improvement of environmental factors, submitting a counter plan of reducing collision effect by triangular type of collision protecting bar and ship maneuvering skills. Putting up collision protecting bar fences of triangular type around the bridge posts would decrease the collision impact force by 75 percent.

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Collision Fragility Analysis of Offshore Bridge by Ship (선박에 의한 해상교량의 충돌취약도 해석)

  • Cho, Byung-Il;Kim, Dong-Hyawn;Oh, Young-Min
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.4
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    • pp.224-229
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    • 2010
  • Collision fragility analysis of offshore bridge by ship was performed. Collision velocity and angle were chosen as random variables then collision of 18,000DWT and 30,000DWT ships with bridge was analyzed. Displacement response surface of bridge by ship collision was estimated by varying ship velocity from 2 m/s to 7 m/s. Using the result of reliability analysis, fragility curves of collision was established and risk of offshore bridge to collision velocity as median and log-standard deviation was presented.

Peak Impact Force of Ship Bridge Collision Based on Neural Network Model (신경망 모델을 이용한 선박-교각 최대 충돌력 추정 연구)

  • Wang, Jian;Noh, Jackyou
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.1
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    • pp.175-183
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    • 2022
  • The collision between a ship and bridge across a waterway may result in extremely serious consequences that may endanger the safety of life and property. Therefore, factors affecting ship bridge collision must be investigated, and the impact force should be discussed based on various collision conditions. In this study, a finite element model of ship bridge collision is established, and the peak impact force of a ship bridge collision based on 50 operating conditions combined with three input parameters, i.e., ship loading condition, ship speed, and ship bridge collision angle, is calculated via numerical simulation. Using neural network models trained with the numerical simulation results, the prediction model of the peak impact force of ship bridge collision involving an extremely short calculation time on the order of milliseconds is established. The neural network models used in this study are the basic backpropagation neural network model and Elman neural network model, which can manage temporal information. The accuracy of the neural network models is verified using 10 test samples based on the operating conditions. Results of a verification test show that the Elman neural network model performs better than the backpropagation neural network model, with a mean relative error of 4.566% and relative errors of less than 5% in 8 among 10 test cases. The trained neural network can yield a reliable ship bridge collision force instantaneously only when the required parameters are specified and a nonlinear finite element solution process is not required. The proposed model can be used to predict whether a catastrophic collision will occur during ship navigation, and thus hence the safety of crew operating the ship.

A Study on Construction of Collision Reproducing Simulator and Application to Analysis of Marine Casualty

  • Sohn, Kyoung-ho;Bae, Jun-young
    • Journal of Navigation and Port Research
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    • v.28 no.2
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    • pp.113-119
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    • 2004
  • Ships' collision accident has often occurred in congested waterways or in harbour areas. To examine the cause of collision accident may be necessary to prevention against another similar one. We discuss the construction of ship-manoeuvring-simulator system used for reproducing ships' collision phenomenon The system consists of one simulator bridge for own ship and two control consoles for own ship and target ship. Own ship and target ship are linked each other, and are simultaneously manoeuvred in simulator bridge or at control console respectively. And a simulator experiment for reproducing ships' collision phenomenon and for examining the cause of accident is carried out. Through the present case study, we find out that the constructed simulator system is very useful for reproducing ships' collision phenomenon and for examining the cause of accident.

Design Strength of Bridges against Ship Collision according to Vessel Traffic (선박통행량에 따른 교량의 선박충돌 설계강도)

  • Lee Seong-Lo;Lee Byung-Hwa;Kang Sung-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.663-666
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    • 2004
  • An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. AF is computed for each bridge component and vessel classification. The summation of AFs computed over all of the vessel classification intervals for a specific component should equal the annual frequency of collapse of the component. The designer should use judgment in developing a distribution of the vessel frequency data based on discrete groupings or categories of vessel size by DWT. In the present study the effect of vessel classification on the annual frequency of collapse in the ship collision risk assessment is investigated by illustrative numerical examples based on the vessel frequency data of the domestic harbor. The DWT interval for larger vessels has more effect on the ship collision risk. Therefore the expert judgement in determining the larger DWT interval is required because the design impact lateral resistances of bridge components depend on the ship collision risk.

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Estimation of Ship Collision Energy with Bridge (교량의 선박충돌 에너지 산정)

  • Lee Seong-Lo;Kang Sung-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.416-419
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    • 2004
  • The kinetic energy during ship collision with bridge piers is released as the permanent deformations of structure and friction between the impact surfaces. So the ship collision energy is estimated from the equations of motions for ship-pier collisions which include the influence of the surrounding water, different impact angles and impact locations. The normal impact energy and tangent impact energy at a collision location and angle can be transformed into the normal impact force and friction force acting on the structure. Also the kinetic energy after collisions is calculated from the linear and angular impulse of ship collisions. The collision energy absorption system such as the protective structures for bridges is designed by evaluating the damage portions of ship and structure during the ship-structure collisions varying from the soft impact to hard impact and then the estimation of it will be suited for the design of protective measures.

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Ship Collision Risk of Suspension Bridge and Design Vessel Load (현수교의 선박충돌 위험 및 설계박하중)

  • Lee, Seong Lo;Bae, Yong Gwi
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.11-19
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    • 2006
  • In this study ship collision risk analysis is performed to determine the design vessel for collision impact analysis of suspension bridge. Method II in AASHTO LRFD bridge design specifications which is a more complicated probability based analysis procedure is used to select the design vessel for collision impact. From the assessment of ship collision risk for each bridge pier exposed to ship collision, the design impact lateral strength of bridge pier is determined. The analysis procedure is an iterative process in which a trial impact resistance is selected for a bridge component and a computed annual frequency of collapse(AF) is compared to the acceptance criterion, and revisions to the analysis variables are made as necessary to achieve compliance. The acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. This AF allocation method is compared to the pylon concentration allocation method to obtain safety and economy in results. This method seems to be more reasonable than the pylon concentration allocation method because AF allocation by weights takes the design parameter characteristics quantitatively into consideration although the pylon concentration allocation method brings more economical results when the overestimated design collision strength of piers compared to the strength of pylon is moderately modified. The design vessel for each pier corresponding with the design impact lateral strength obtained from the ship collision risk assessment is then selected. The design impact lateral strength can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics. Therefore more researches on the allocation model of AF and the selection of design vessel are required.

Design Strength of Bridge Piers against Ship Collision (교각의 선박충돌 설계강도)

  • Lee Seong-Lo;Bae Yong-Gwi
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.659-662
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    • 2004
  • An analysis of the AF is performed for each bridge pier exposed to ship collision. From this analysis, the impact lateral resistance can be determined for each pier. The bridge pier impact resistance is selected using a probability-based analysis procedure in which the predicted AF, from the ship collision risk assessment is compared to an acceptance criterion. In this study, the acceptance criterion is allocated to each pier using allocation weights based on the previous predictions. To determine the design impact lateral resistance of bridge components such pylon and pier, the numerical analysis is performed iteratively with the analysis variable of impact resistance ratio of pylon to pier. The design impact lateral resistance can vary greatly among the components of the same bridge, depending upon the waterway geometry, available water depth, bridge geometry, and vessel traffic characteristics.

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Ground Improvement under Ship Collision Protection of Myodo-Gangyang Suspension Bridge Concerning of Sedimental Condition in Gyangyang Bay (광양만 퇴적이력을 고려한 묘도-광양간 현수교 충돌방지공 하부 지반보강)

  • Chang, Yong-Chai;Yoon, Tae-Seob;Kim, Kyung-Taek
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.660-671
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    • 2008
  • The suspension bridge between Myodo and Gwangyang is located in the main navigation channel to Gwangyang Harbor. So, there is need for the collision protection against large vessels. As ship collision protection, artificial island with concrete block quay wall is planned. The risk analysis and non-linear numerical analysis are introduced to consider the ship collision effects. In the Gwangyang bay area, there are some different sedimental conditions in clayey stratums. For a desirable design, we classify into four zones and 2 layers in each zone, and then determine suitable soil properties considering these zones. As a ground improvement under artificial island, DCM and SCP methods are Planned.

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Design Vessel Selection of Maritime Bridges using Collision Risk Allocation Model (충돌위험분배모델을 이용한 해상교량의 설계선박 선정)

  • Lee, Seong-Lo;Lee, Byung Hwa;Bae, Yong-Gwi;Shin, Ho-Sang
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.3
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    • pp.123-134
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    • 2006
  • In this study ship collision risk analysis is performed to determine the design vessel for collision impact analysis of the maritime bridge. Method II which is a probability based analysis procedure is used to select the design vessel for collision impact from the risk analysis results. The analysis procedure, an iterative process in which a computed annual frequency of collapse(AF) is compared to the acceptance criterion, includes allocation method of acceptance criterion of annual frequency of bridge component collapse. The AF allocation by weights seems to be more reasonable than the pylon concentration allocation method because this AF allocation takes the design parameter characteristics quantitatively into consideration although the pylon concentration allocation method brings more economical results when the overestimated design collision strength of piers compared to the strength of pylon is moderately modified. From the assessment of ship collision risk for each bridge pier exposed to ship collision, a representative design vessel for all bridge components is selected. The design vessel size varies much from each other in the same bridge structure depending upon the vessel traffic characteristics.