STRENGTH ANALYSIS OF GEOTEXTILE REINFORCED SUBGRADE

Abstract

Geotextiles are an excellent solution for reinforcing subgrades in road projects, as they effectively address the common challenge of poor subgrade strength. In this comparative study, the strengths of subgrades reinforced with jute textile and polypropylene (PP) geotextile are investigated. The direct shear test (DST) and California bearing ratio (CBR) tests are conducted on both reinforced and non-reinforced soil samples. The positioning of geotextiles is crucial to the overall strength of the subgrade. The test results reveal that jute textile, a natural fibre, increases the shear strength of the soil samples. Conversely, the shear strength of the soil decreases when reinforced with polypropylene geotextile, a synthetic fiber. The study explores the placement depths of D/2, D/3, and D/4 from the top surface for the geotextile. For the CBR test, a single, double, and triple layer of geotextile is used to reinforce the soil samples. The double layer reinforcement at depths D/3 and D/4 demonstrates optimal strength. The focus of the study is on cohesionless pavement geomaterial reinforced with multi-layers of jute fibers. The research aims to evaluate the strength and stiffness capacity of the pavement geomaterial using the CBR test. The study optimizes the embedment depth of jute fiber at D/2, D/3, and D/4 in single, double, and triple layers based on CBR values. A novel concept of stiffness capacity, along with the penetration factor, is introduced to assess the strength of unreinforced and jute-reinforced geomaterial. The test results indicate that incorporating jute fibre in single, double, and triple layers increases the stiffness capacity of the soil at the optimum depth of D/4.The stiffness capacity varies from 0.378 to 0.682 at the maximum penetration factor, representing an 80.42% enhancement in the strength of pavement geomaterial. The findings of this study offer a cost effective solution for improving the strength of cohesionless soils in embankment, subgrade, and pavement construction technologies.