Interface Shear Strength Behaviour of Marginal Soils with Geotextiles and Geogrids

Geosynthetic materials are increasingly used to reinforce the soil from past several years. Mostly cohesionless soil such as sands are used as backfill material in the reinforced-soil structures. However, the availability of natural sand is reducing continuously, and that created certain environmental and economical issues. The use of marginal soils can provide an easy and economical solution to this problem. Hence, the aim of the current study is to evaluate the interface shear behaviour of various marginal soils with different types of geosynthetics. The interface shear tests were carried out in a large-scale direct shear apparatus on five marginal soils with varying plasticity index and four different geosynthetics. The interface shear behaviour was analysed through the response of shear stress-horizontal displacement, vertical displacement-horizontal displacement, failure envelopes, and coefficient of interaction. Significant variation was found on the interface shear strength parameters of the same soil with different geosynthetics due to the contribution of different interfacing mechanism.