汚濁防止膜係留アンカーの把駐特性について

抄録

Field verification of the holding power of mooring anchors was conducted on a seabed composed of soft mud located in Tokyo Bay, Japan. The observed holding power of the anchors was compared with the estimates based on the current design. The holding power depends strongly on the properties of the seabed deposit, the type of anchor and the duration of service. The coefficient of holding power, which is defined as the ratio of the maximum holding power to the submerged weight of the anchor, was introduced to examine the effects of the loading rate and angle of the mooring wire of the anchors. Because of the action of the overturning moment, the effect of a loading rate was negligible for concrete block anchors with a loading angle of 45 degree or less. The coefficient of holding power was 0.6 or less for the above case. The holding power for suction anchors increased with the suction inside anchor. There was a weak correlation between the holding power and the loading rate for soft mud.