Liquefaction Behaviour of Reinforced Soils

Abstract

Soil is a non-homogenous material essential for any construction project because the foundation is to be rested on the soil. The initial studies were primarily based on static load carrying capacities, and advanced models and equations were developed. On the other hand, dynamic soil behaviour plays its part when the soil is subjected to dynamic loading conditions or earthquakes. Using composite material has given rise to a new and improved foundation and infill soil formations known as reinforced soils. Such soils have an enhanced strength property and resistance to any failures. Liquefaction is the phenomenon which is generally seen in cohesionless soils under cyclic load conditions. Liquefaction of substructure soil is a severe soil failure which results in various other failures. The phenomenon causes the soil to lose its shear strength and behave like a fluid. Thus, the soil becomes insufficient to withhold its strength, causing a significant failure of the foundation system; as a result, the superstructure fails catastrophically. Triaxial Test is one of the finest experiment set-ups used to study the mechanical behaviour of the soil under various loading conditions. It provides us access to drainage control, confining pressure control and rate of loading control, which can mimic the actual in-situ soil conditions. Using the provided controls and modern electronic sensors, we can accurately predict and analyse the soil behaviour and estimate properties required to calculate values like bearing capacity, liquefaction susceptibility, Shear Modulus, etc. This report deals with the liquefaction behaviour of fibre-reinforced soil analysed by laboratory experiments on cyclic triaxial testing equipment as well as numerical modelling of the triaxial test and analysis of the effect of different loading conditions on the test sample with and without reinforcement. Validating any numerical model using an analytical or experimental approach is crucial to study the model’s accuracy. This report also draws parallels between Numerical Modelling and Laboratory Experiments to study the reinforced sand and the effect of fibre content on the liquefaction behaviour during cyclic loading conditions.