Study of the volumetric behavior of a residual tropical clay

Abstract

This paper focuses on the volumetric behavior of residual tropical soils. Two residual tropical soils belonging to the same geological formation and located in the coastal sedimentary basin of Gabon are studied. These soils are known as pelitic soils. As the hydromechanical behavior of residual tropical soils is still relatively unknown, it is interesting to study the influence of suction on the volumetric behavior of these soils through shrinkage curves. The purpose of this study is twofold. First, to study the volume variations in the two studied residual tropical soils with suction changes. Secondly, to propose a modelling of soil-water retention curves (SWRCs) of these soils. For this purpose, shrinkage tests are carried out to study the volume variations of the studied soils. These tests are supported by determining a bilinear approximation model to enable the variation in suction during drying to be estimated. Tests to determine SWRCs at different initial dry densities are used to calibrate the bilinear approximation model between void ratio and suction. The modified Kovács model (MK model) has been adapted to model SWRCs of the studied soils.

Keywords:

• Residual tropical soils
• soil water retention curve
• air entry value
• shrinkage curve
• volumetric deformation

Acknowledgments

Special thanks to SETRAG (Company exploiting the Trans-Gabon Railway) and COMILOG (Ogooué Mining Company) for supporting this research project.

Data availability statement

Some or all data, models, or code generated or used during the study are available from the corresponding author by request.