Geological-geotechnical correlation of a deltaic subsoil profile and characterization of its uppermost soft marine clay deposit with reference to infrastructure development in the Saigon-Dong Nai delta, Vietnam

The Saigon-Dong Nai (SG-DN) delta is adjoining the Mekong delta at the Southwest. Although it is smaller comparing to the latter, which is the third largest delta in the world, this delta is significant for the growth of Vietnam as it hosts Ho Chi Minh City, the biggest economic and industrial center of the country, where infrastructure has been developed extensively in the last few decades. A good understanding of the near-surface geosystem underlying the SG-DN delta is undoubtedly very needed. In this study, a correlation between the Quarternary formations and geotechnical soil layers was investigated for the first time. A computer-aided subsurface database was constructed based on data from geological and geotechnical boreholes to the depths of 350 and 140 m, respectively. Twelve geotechnical soil units were identified that could be correlated with five geological cycles of alternative trangression and regression, numbered I to V. In addition, an integrated geological-geotechnical characterization of the Middle-Upper Holocene formation, a very soft, soft to marine clay of high compressibility, was carried out for four selected inland and coastal sites. Notably, correlation relationships between geotechnical parameters, analyses of soil disturbance, and intrinsic compression behavior of soil samples were conducted. The results of this research are expected to be useful not only for geotechnical analyses but also for studies of land subsidence and its effects on infrastructure in the context of the global sea level rise.