Read Journal 1865 – Vol 68 No 2 – Mechanical properties of tropical residual soils – recommended test procedures and evaluation

Current soil mechanical testing procedures and methods for deriving soil parameters are based on experience and research on soils transported from temperate climates. This research has resulted in well-accepted and well-understood soil mechanical principles and, combined with decades of experience, has led to numerous reliable correlation methods for deriving various soil mechanical parameters. However, there are vast areas of the world where the soils are formed by in-situ weathering, mostly in tropical regions, so the correlation methods and experience based on transported soils may not be applicable and should be used with great caution. Extensive research on tropical residual soils has been conducted by geologists and there is a good understanding of the genesis and processes leading to the unique parameters of these soils. Unfortunately, this knowledge is not as well known among geotechnical engineers. This paper is therefore addressed to the geotechnical engineer and attempts to provide unambiguous definitions to describe tropical residual soils. It also highlights the differences
between tropical and temperate soils, both in terms of the soil itself and the test results obtained using conventional, well-established test methods. Practical recommendations for the derivation of soil parameters are given.