Numerical Studies on Rutting Criteria of Geotextile Reinforced Flexible Pavement

Flexible type of pavement is the most common type of pavement in India. During the last few years excessive damages are observed in flexible pavements throughout the country mostly due to various factors such as subgrade conditions, traffic loading, environmental conditions, aging. All these factors cause an equally wide variety of distress in the form of fatigue, rutting, differential settlement, and reflective cracks in pavements. In order to reduce the rutting in the pavements and to increase the service life in poor subgrade soil new techniques of construction are adopted. The use of geosynthetics is widely used to stabilize poor subgrade soils. In this study the benefits of using coir geotextile in reducing rutting in pavements are analyzed using a finite element software PLAXIS 3D. Coir geotextile placed at the interface between the subgrade and subbase layer shows the maximum value of 18% in reducing settlement of flexible pavement. Also, the geosynthetic reinforcement potential for reducing the rutting and surface deflection is much more pronounced when using it in subgrade subbase interface as maximum surface deflection of 17% is obtained at this position. From the numerical modeling, the best placement location for the coir geotextile is at the subgrade subbase considering the surface deflection in pavements. It was found that pavement reinforced with coir geotextile has reduced rutting when compared to other pavement sections.