무인자동형 착저식 해양콘관입시험기의 개발

Abstract

In the design and construction of the coastal/offshore structures, it is very important to evaluate the geotechnical characteristics of marine soils, which support the structures. Although the offshore site investigation is much more difficult than onshore, safe and precise jobs have not been guaranteed because of the insufficiency of the test equipments especially for sites with deep water depth and high testing depth. Previously developed test equipments need to possess some massive structures to protect the successive conventional rods. The main objective of this study is to develop a new type of marine cone penetration testing (CPT) system, which can be utilized even for deep sea conditions and high depth (about 50m) of soil layer without any additional structural reinforcement device. The system is a seabed type and employs conventional cone, which shows more reliable results than a miniature cone. The most important parts of the marine CPT such as continuous rod system, cone penetration system with wheel drive, automatic cone rod assembly/disassembly system etc., were newly designed and manufactured. Some tests to verify the developed marine CPT system were performed at both onshore and offshore sites as well as mechanical tests in the laboratory. The test results show the consistent and promising performance of the new equipment, and thereafter the system would be applicable to various sites with practical/economical advantages