• Journal of the Society of Naval Architects of Korea
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• v.45 no.4
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• pp.462-467
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• 2008

In this paper, we investigated the design method of mooring system in ultra deep sea and carried out the conceptual design for offshore West Africa oil field in ultra deep sea of 3000 meters. Recently, it was feasible to design and install the offshore floating structures in deep sea of up to 2000 meters. Due to the simplicity, two-point mooring design is fully utilized. Force-excursion curves are throughly examined to find out the feasibility of various combinations of mooring lines. Free length and pretension effects are discussed. It is found that composite materials including synthetic fiber rope may be good solution for ultra deep sea mooring design.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.54-63
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• 2018

In this study, the stability and economic feasibility of a MSE (Mechanically stability earth) wall with a pre-cast concrete pacing panel was investigated for a standard section of highway. Based on the design criteria, the MSE walls of the panel type were designed considering the load conditions of the highway, such as the dead load of the concrete pavement, traffic load, and impact load of the barrier. The length of the ribbed metal strip was arranged at 0.9H according to the height of the MSE walls. Because the length of the reinforcement was set to 0.9H according to the height of the MSE wall, the external stability governed by the shape of the reinforced soil was not affected by the height increase. The factor of safety (FOS) for the bearing capacity was decreased drastically due to the increase in self-weight according to the height of the MSE wall. As a result of examining the internal stability according to the cohesive gravity method, the FOS of pullout was increased and the FOS of fracture was decreased. As the height of the MSEW wall increases, the horizontal earth pressure acting as an active force and the vertical earth pressure acting as a resistance force are increased together, so that the FOS of the pullout is increased. Because the long-term allowable tensile force of the ribbed metal strip is constant, the FOS of the fracture is decreased by only an increase in the horizontal earth pressure according to the height. The panel type MSE wall was more economical than the block type at all heights. Compared to the concrete retaining wall, it has excellent economic efficiency at a height of 5.0 m or more.