Strength relationship in compacted lateritic soil liners and covers for waste containment

Abstract

The suitability of some selected lateritic soils as materials for land liners and covers were sought in the research together with a
relationship between Brazilian Tensile Strength (BTS) and Unconfined Compressive Strength (UCS) of the soils. Three different
lateritic soil samples that fall into the same Unified Soil Classification System (USCS), British Soil Classification System
(BSCS) and American Association of State Highway and Transportation Officials (AASHTO) classes were used in the research.
The moisture-density relationship of the samples was investigated at four compactive effort: Reduced British Standard Light
(RBSL), British Standard Light (BSL), West African Standard (WAS) and British Standard Heavy (BSH) and seven-point
moulding water content. The Unconfined Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) of the samples were
determined at each of these compactive effort and moulding water content. The UCS and BTS results obtained from laboratory
tests show values ˃ 200 kPa in most cases. This shows that the soils can be used as landfill liners and covers based on strength
criterion. The results of UCS and BTS were fitted to correlation analysis and regression analysis with BTS as dependent variable
and UCS as independent variable. Significant correlation coefficient (R ˃ 0.75) and coefficient of determination (R-squared =
0.629) were obtained respectively. A linear model was developed from these relationships to predict BTS from UCS.