Behaviour of the Undrained Shear Strength of Soft Clay Reinforced with Natural Fibre

The term soil reinforcement is conventional since decades ago for the stabilization of soft ground such as of clay and peat. Numerous research has arisen in the utilization of natural fibres as the reinforcement materials. Cost reduction, increment of sustainability awareness and eco-friendly environment are some of the advantages when using natural fibres to stabilize soft ground. A research study was carried out to evaluate the strength of the soft soil when unreinforced and reinforced using natural fibres. The findings on the experimental investigation of the study will be presented in this paper. Crushed coir fibres were used to reinforce an intermediate plasticity soft clay where both materials were collected locally in Brunei Darussalam. The crushed coir fibres were added at 0.5%, 1.0%, 1.5% and 2.0% to the dry weight of the sample. A series of an unconsolidated undrained Tri-axial test was conducted on the unreinforced and reinforced samples where the behaviour of the samples were observed and compared. The results indicated that inclusion of fibres affects the soil's undrained shear strength. It was observed that increasing the percentage inclusion increases the undrained shear strength of the soil, up to a certain amount. Further increment of fibres, however, does not show further improvement in the undrained shear strength.