• Earthquakes and Structures
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• v.16 no.4
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• pp.455-468
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• 2019

The behavior of pile-deck connections of pile-supported marginal wharfs subjected to earthquake loading is of key importance to ensure a good performance of this type of structures. Two precast-pretensioned pile-deck connections used in the construction of pile-supported marginal wharfs were tested under cyclic loading. The first is a connection with simple reinforcement details and light steel ratio developed for use where moderate pile-deck rotation demands are expected in the wharf. The second is specifically developed to sustain the large rotation, shear force and bending moment demands, as required for the shortest piles in a marginal wharf. Data obtained from the test program is used in the paper to calibrate an equivalent plastic hinge length that can be incorporated into nonlinear analysis models of these structures when prestressed pile-deck connections with duct embedded dowels are used.

• Journal of Navigation and Port Research
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• v.30 no.8 s.114
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• pp.617-622
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• 2006

Gamcheon Harbor was developed to cope with increased freight demand of Busan port and supplement function of the north port. Because container wharf is opened to 1997 as well as general wharf, present maximum 50,000DWT class containerships have been incoming and outgoing. However, In Gamcheon port, small size ships such as fishing boats, miscellaneous boats account for 50 percent of the traffic and a public marine products wholesale market that is building on the north wharf will open in 2008. Therefore, it needs to grasp future year traffic volume before establishing operation plan for port management. Also, analysis on crossing situation risk is required because the breakwater entrance in Gamcheon Harbor is narrow and the crossed passing of ship is ever-present at breakwater front. Thus the traffic volume in the future was presumed and quantitative analysis was achieved on crossing situation though simulations with the traffic volume.

• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.57-71
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• 2021

The pile-supported wharf is the port structure in which the upper deck is supported by piles or columns. By installing batter piles in this structure, horizontal load such as earthquake loads can be partially delivered as axial forces. The codes suggests using the response spectrum analysis as a preliminary design method for seismic design of pile-supported wharf, and suggests modeling the piles using virtual fixed points or soil spring methods for this analysis. Recently, several studies have been conducted on pile-supported wharves composed of vertical piles to derive a modeling method that appropriately simulates the dynamic response of structures during response spectrum analysis. However, studies related to the response spectrum analysis of pile-supported wharves with batter piles are insufficient so far. Therefore, this study performed the dynamic centrifuge model test and response spectrum analysis to evaluate the seismic performance according to the modeling method of pile-supported wharves with batter piles. As a result of test and analysis, it is confirmed that modeling using the Terzaghi (1955) constant of horizontal subgrade reaction (n_h) most appropriately simulates the actual response in the case of the pile-supported wharf with batter piles.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09a
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• pp.25-27
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• 2008

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.79.2-79.2
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• 2009

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2008.09b
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• pp.25-27
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• 2008

• Journal of the Korean Institute of Navigation
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• v.12 no.2
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• pp.23-32
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• 1988

This paper offers a method of magnetic compass adjustment for the vessel alongside the wharf using newly designed magnetic north former, which makes the same magnetic field-change as the turning vessel does. The characteristics of the magnetic north former was examined by observing the deviation curves of the magnetic compass installed on the compass deviascop at laboratory. The magnetic north former consists of A and B arms which hold the permanent bar magnets at the both ends of each arm. The arm is to rotae in the horizontal plane about the vertical axis fixed at the center boss of the magnetic compass and it is to compensate the horizontal plane about the vertical axis fixed at the center boss of the magnetic compass and it is to compensate the horizontal component of the earth's field. The B arm makes the artificial magnetic north around the magnetic compass for every ship's heading. The results of investigation are summarized as follows ; 1. The observation and correction of magnetic compass deviation can be done without swinging the ship, of the effect of D coefficient is negligible. 2. The residual deviation curve of the magnetic compass depends on the accuracy of deduced value of ship's multplier($\lambda$). 3. The errors due to the inaccuracy of deduced value of ship's multiplier change in the same way as the B and C coefficient do.

• Journal of Ocean Engineering and Technology
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• v.22 no.1
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• pp.46-52
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• 2008

Lately Gun-Jang Harbor has undergone a drastic change in hydraulic characteristics due to newly added harbor protection measures, like a wharf and breakwater. The wharf and breakwater, with a training dike, were constructed to keep enough depth far navigation. They make the plan view of Gun-Jang Harbor semi closed and very elongated, which makes it very vulnerable to seiche. Hence it is an urgent task to unveil the hydraulic characteristics, like seiche, for the optimal operation of the new harbor system. In this study, we numerically analyze the seiche characteristics of Gun-Jang Harbor over the $10-4{\sim}10-3$ Hz frequency range, considering that wind waves due to seasonal winds are the most prevailing during winter in the West sea. As a wave driver, we use Mild Slope Eqs. and numerically integrate these using FEM based on Galerkin weak formulation. It turns out that the 1st, 2nd, 3rd and 4th eigen models are over 0.0009 Hz, 0.0013 Hz, 0.0017 Hz and 0.002 Hz.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.139-145
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• 2017

Recently, gusts, typhoon and tsunamis have been occurring more frequently around the world. In such an emergency situation, a moored vessel can be used to predict and analyze other vessel behavior, but if the mooring system is destroyed, marine casualties can occur. Therefore, it is necessary to determine quantitatively whether a vessel should be kept in the harbour or evacuate. In this study, moored ship safety in an exclusive wharf according to swell effects on motion and mooring load have been investigated using numerical simulations. The maximum tension exerted on mooring lines exceeded the Safety Working Load for intervals 12 and 15 seconds. The maximum bollard force also exceeded 35 tons (allowable force) in all evaluation cases. The surge motion criteria result for safe working conditions exceeded 3 meters more than the wave period 12 seconds with a wind speed of 25 knots. As a result, a risk rating matrix (risk category- very high risk, high risk and moderate risk) was developed with reference to major external forces such as wind force, wave height and wave periods to provide criteria for determining the control of capabilities of mooring systems to prevent accidents.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.04a
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• pp.229-236
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• 1998

Port structures are one of the important infrastructure of the nation. To ensure safety and extend lifetime of the existing port structures, it is necessary to develop proper maintenance program. In this study, port inspection manual for pier type structure are developed. The flow of inspection program is designed and defect type for each component of wharf is classified. Also systematic method of rating and evaluation is developed together with conceptual design of port maintenance data base system.