Behavioral Analysis of Silt Protectors in Seawater Using the Mass-Spring Model

When sea tide and wave velocity change, the behavior of silt protectors underwater changes, and a hydraulic force exceeding the anchor wave force is applied. In this study, the movement mechanism of a silt protector has been analyzed using the mass-spring method. The initial position of the silt protector was in the Jindo area near Gwangpo Port (742-1, Gyupori, Chongdo-myeon, Jindo-gun, Jeonnam, Korea). The tension required to exceed the holding power of the anchor was 0.05 ㎧ at 318 sec., 0.15 ㎧ at 77 sec., 0.25 ㎧ at 43 sec., and 0.3 ㎧ at 37 sec.. As the anchor started to move from the sea floor and the tide speed increased to 0.01 ㎧, anchor movement start time shortened by an average of 11.2 sec.. Compared with when tide was the only affecting factor, the silt protector and anchor were found to have moved 19.7 % at 0.1 ㎧, 7.6 % at 0.15 ㎧, 5.8 % at 0.2 ㎧, 4.3 % at 0.25 ㎧ and 2.8 % at 0.3 ㎧, showing an increase. When wave effect was added to the tide, anchor movement started when the flow rate was slow 7.6 % of the time. With a high flow velocity, anchor movement started without any significant difference less than 4.3 % of the time. When tide speed exceeded 0.13 ㎧ and the direction of the waves matched, the silt protector was not able to perform due to collisions with surrounding sea structures. When installing a silt protector, the fluid flow situation and the silt protector situation must be carefully analyzed using the mass-spring method to apply the result found in this study.