浮桟橋を用いた係留システムによる港内船舶の津波被害低減効果に関する基礎的研究

Abstract

Tsunami consecutively brings about several types of disasters, which is described as “disaster chain.” In the case that vessels are moored to the quay, the breaking of the mooring line possibly causes drift or collision with other vessels. There is also a case that a mooring tether of the vessel moored to the floating pier is not broken in the damage of tsunami, which was confirmed at Shiogama port in Miyagi when the East Japan Great Earthquake occurred on March 11, 2011. In this paper, the objectives are to clarify the effect of reducing mooring tether force in case of that vessel is moored to floating pier by using MPS method and also the advantages of floating pier for mooring quay. In addition, in this paper the authors are discussed the following items on the basis of Shiogama port: 1) Results of field investigation at Shiogama port in Miyagi, and accurate to reproducibility simulation of MPS method. 2) Response characteristics due to the difference in the Wave height in tsunami. 3) Response characteristics in various incidence angles. From the research results, the authors clarify following things: 1) Mooring vessel with floating pier has an advantage over mooring with quay. 2) It was possible to confirm the effect of reducing the mooring line tension, especially in the case where the incident angle of the tsunami is close to 90 degrees. 3) Reproducibility simulation on basis of the Shiogama port confirmed that the MPS method is suitable to the response of a moored floating body.