자유낙하식 수중 콘관입 시험기의 지반 관입깊이 추정

Abstract

A track type underwater construction robot was developed by Korea Institute of Ocean Science & Technology (KIOST). In order to operate underwater construction robot on the seabed, it is required to the characteristics of the seabed ground.By this reason, KIOST is developing the free fall cone penetrating tester(FFCPT). FFCPT is a bullet-shaped object with various sensors attached to the con-probe. It drops freely from the sea level to the sea floor and measures the movementand soil resistance and pore water pressure during the time that the object penetrates the seabed. The characteristics of the seabed should be measured with the same sampling as the acceleration because it should be expressed by the physical quantity varying with depth of penetration. The depth of penetration is calculated using the change in acceleration from the impact time whne the FFCPT hit the ground to the final arrest time by the penetrated ground. In lab test, penetration depth can be estimated under a 12% error level.