A Study on Recycled Plastic Pins as Micropile in Stabilization of Cohesive Slope

Stabilization of cohesive slope is very important on large-scale infrastructure projects as there is always an inherent tendency of slope failure causing threats to life and property. The aim of this research work is to utilize waste plastic for stabilization of earthen slope. For this, recycled plastic pins, made up with recycled plastics, sawdust and fly ash are used as micropile. Experiments were conducted in a model cohesive slope with slope angle 30º made inside a steel tank of dimension 1 m × 1 m × 1 m. Two different diameters (d) of micropiles, 22 mm and 30 mm are used in two lengths, 20d and 30d and at three different spacings 3d, 4.5d and 6d. Four number of micropiles are arranged in a row along the slope in an A-frame with inclinations 0º, 5º, 10º and 15º with vertical. The load-settlement behavior of micropile groups is studied under static axial vertical compressive load. The ultimate load carrying capacity of micropile group under specific settlement is determined from experimental observations. Plaxis-3D models are also developed to validate the experimental results. It is observed that the load carrying capacity of a micropile group increases with the increase in diameter, length, spacing and inclination of micropiles.