Effect of Geotextile Reinforcement on the Stability of an Embankment Constructed over Soft Marine Clay

Abstract

Embankment construction over soft marine clay presents significant geotechnical challenges because of the low undrained shear strength and high compressibility of the foundation soil. In such conditions, adequate stability during construction is essential to prevent excessive lateral deformation and potential slope failure. This study evaluates the contribution of basal geotextile reinforcement to the stability of an embankment constructed over soft marine clay at a development site in Kuala Langat, Selangor, Malaysia. The assessment was based on site investigation data obtained from five boreholes and the corresponding soil parameters established for the stability analysis. The investigated ground profile consists predominantly of very soft to soft marine clay, underlain by sand and suitable fill material. The embankment configuration comprises approximately 1.5 m of platform fill and a 2.0 m surcharge, with high-strength GML-20 geotextile installed beneath the embankment fill. Slope stability analyses were performed using the Limit Equilibrium Method with Bishop’s modified method to determine the critical factor of safety for the temporary unreinforced condition, temporary reinforced condition, and permanent condition. The GML-20 geotextile has an ultimate tensile capacity of 200 kN/m and was considered to provide tensile resistance against lateral deformation of the soft foundation soil. The calculated factor of safety increased from 1.113 for the temporary unreinforced condition to 1.230 when geotextile reinforcement was incorporated, representing an improvement in the calculated stability of the embankment. The permanent condition produced a factor of safety of 1.415. The results indicate that basal geotextile reinforcement can provide a measurable increase in embankment stability during construction over weak marine clay. The findings also demonstrate the importance of considering reinforcement capacity, soil–geotextile interaction, embankment geometry, and construction sequence when assessing reinforced embankments on soft ground.