Modelling of Non-linear Shear Displacement Behaviour of Soil–Geotextile Interface

Behaviour of reinforced soil structures depends on the material properties of soil and geosynthetics. Apart from individual properties of soil and reinforcement, the interaction between reinforcement and soil also plays important role in deciding the behaviour of reinforced soil structures. The modelling of the interface characteristics is a very important aspect in developing a correct numerical model for predicting the performance of reinforced soil structures. For simulating the interface behaviour a linearly elastic model with Mohr–Coulomb criterion is commonly used. Experimental observations made from direct shear tests usually show that the force–displacement relationship is non-linear till a peak is attained, beyond which softening behaviour is observed. In this paper a constitutive model appropriate for geosynthetic interfaces has been implemented in FLAC^3D and used to simulate the shear stress displacement behaviour of different sand–geotextile interfaces. In the present study, shear stress–displacement behaviour of interfaces of different types of sands and geotextiles (monofilament woven, multifilament woven and nonwoven) have been considered for simulation. The simulated curves using the FLAC^3D showed very good agreement with the experimental data over the complete stress-displacement ranges.