가속도와 선단저항의 관계를 통한 FFCPT 정상관입 판정 방법에 관한 연구

Abstract

Recently, as research on various equipment has been conducted through the marine IoT (Internet of Things), there is an increasing demand for unmanned and advanced missions such as the restoration of underwater cities and ports. Accordingly, a lot of research on seabed ground survey equipment is being conducted. Existing subsea ground investigations include the subsea anchoring method CPT (Cone Penetration Test) and SPT (Standard Penetration Test). However, this equipment is large, heavy, and expensive to operate and manufacture. To solve this problem, FFCPT (Free-Fall CPT) has been developed. However, due to the nature of the water, there was a lack of methods to confirm whether normal penetration had occurred. In order to solve this problem, this paper proposes a method for determining normal penetration using the correlation between acceleration and tip resistance. In order to verify the proposed method, an open sea area test was conducted, and it was confirmed that the proposed method has effectiveness by comparing normal and abnormal penetration situations.