Determining the angle of friction between commonly used construction materials and ground materials as applicable to the local situation

Abstract

Segmental gravity retaining walls consist of dry-stacked elements against a soil embanking which resist overturning and sliding forces by the virtue of their own weight. Sliding resistance will be solely dependant on the frictional coefficient of the materials used. Given the heterogeneous nature of construction materials and a lack of knowledge regarding the local materials, assumptions based specimens from other countries are used which can lead to an inefficient and unsafe design. The aims of this dissertation are: to find the frictional coefficients of dry-stacked local construction materials, verify rules of thumb for sizing retaining walls and validate empirical methods of calculating frictional coefficients to avoid laboratory testing for the local scenario. This study presents an analysis of a retaining wall varying in different heights, materials and loading scenarios, calculating the resulting safety factor for overturning failure. Pressures were then adopted for testing purposes to research the frictional coefficients of local construction materials. This proved that the rule of thumb that 'the wall width should be one-third the height of the retaining wall for walls without surcharge loading' is insufficient for certain situations and empirical techniques are not valid for the local scenario.