3D geological modelling and geotechnical characteristics of Phnom Penh subsoils in Cambodia

• The work presents a 3D geological model using GMS software.
• The analysis results employ over 1,200 boring log data.
• The engineering properties of the Phnom Penh subsoils are summarised.
• This paper could be considered as the first research document on Phnom Penh subsoils.

Subsoil characterisation is an important task in both geotechnical and geological engineering. In recent years, a number of subsurface investigations have increased as a result of infrastructure construction in Phnom Penh City in Cambodia. Although there had been investigations on the geotechnical characteristics of the subsoils, understanding soil characteristics and 3D modelling of geological structures of Phnom Penh subsoils have not yet been tackled. This research aims to conduct a 3D geological modelling by means of commercial software called Groundwater Modelling System (GMS), as well as provide an insight into the geotechnical properties of Phnom Penh subsoils. Over 1,200 soil boring log data were employed to build the 3D soil stratigraphic system in Phnom Penh City. The engineering properties of the Phnom Penh subsoils such as physical properties (i.e., grain size distribution and Atterberg limits) and engineering properties (i.e., compressibility, undrained shear strength and internal friction angle) have been highlighted in this paper. Finally, the analysis results of geotechnical data can be used to construct some useful empirical correlations such as the relationship of the undrained shear strength to the SPT-N value.