The Development and Application of In-situ Testing Technology in Marine Geotechnical Engineering Surveys

In recent years, the global exploration and development of marine resources have prompted a surge in geotechnical engineering projects and experiments in oceanic settings. This expansion has necessitated enhanced in-situ testing technologies in marine environments. Traditional methods such as the Cone Penetration Test (CPT) and Piezocone Penetration Test (CPTU) often fail to ensure the reliability of data acquired in ultra-soft soil. Consequently, the Full-Flow Penetration Test has gained prominence in marine geotechnical engineering, offering improved data accuracy. This paper synthesizes findings from a wide array of global literature on in-situ testing technology, delineating the evolution of this technology and concentrating on the latest advancements in marine detection equipment. It provides an in-depth theoretical analysis of the probe penetration process and explores the application of in-situ testing technology in various domains, including soil classification, estimation of undrained shear strength, and sensitivity among others. Summary findings indicate that the increasing human engagement with oceanic exploration and utilization necessitates the development of testing equipment adept at navigating the complexities of seabed environments. The Full-Flow Penetration Test offers significant advantages over the Cone Penetration Test (CPT) and Piezocone Penetration Test (CPTU) when assessing soft and ultra-soft soils. It enables the estimation of undrained shear strength through laboratory-based cyclic testing, which facilitates soil remolding and obviates the necessity for in-situ testing to ascertain seabed soil properties. Nonetheless, the research into Full-Flow Penetration Test instruments is nascent, with scant comprehensive analysis on how strain rate and strain softening impact the penetration resistance coefficient. This area necessitates further empirical validation. Given the escalating global focus on marine resources and the imperative for marine surveys in resource exploitation, the Full-Flow Penetration Test methodology promises extensive utility in forthcoming developments.