Some Studies on Prestressed Reinforced Granular Beds Overlying Weak Soil

Abstract

This paper mainly investigates, from a series of laboratory scale bearing capacity tests carried out on a model square footing, the improvement in bearing capacity and reduction in settlement of a geonet reinforced granular bed (RGB) overlying weak soil due to prestressing the reinforcement. The parameters are the strength of the underlying weak soil, thickness of the granular bed, and magnitude and direction of prestressing force. The settlements at the interface are also measured. The addition of prestress to geonet reinforcement results in significant improvement in the load carrying capacity and settlement response of the prestressed geonet RGB. Improvement in bearing capacity is found to be more with biaxial prestressing than with uniaxial prestressing. Experimental results are also used to validate a proposed numerical model. The BCR (bearing capacity ratio) values predicted from this model are found to be in good agreement with the experimentally obtained BCR values. Finite element analyses are also carried out using the programme PLAXIS, to study the effect of prestressing the reinforcement. Results obtained from finite element analyses are also found to be in good agreement with the experimental results.