Performance Evaluation of Geocell Reinforced Unpaved Roads

This paper describes the utility of geocell, a three-dimensional product of geosynthetic family to reinforce the weak subgrade for the unpaved roads. The unpaved roads are majorly used as construction roads, access roads, and maintenance gallery of any infra-projects. Overnight rainfall or repetitive loading can cause severe damages on this type of construction roads especially which are resting on very weak subgrade. As geocell can effectively provide lateral confinement to infill material to increase the modulus and bearing capacity of the subgrade, compared to other alternatives like chemical stabilization or replacing the weak soil with stronger one, the geocell-based unpaved roads can be economic and cheap alternative. A major bridge project in between Assam and Meghalaya on the River Brahmaputra has been identified as the project of implementation. The trial section of 150 m has been identified to implement the geocell in single and two layers to reinforce the subgrade soil. The available riverbed sand has been used as the infill material of the geocell pockets. Field plate load tests have been performed to check the pressure-settlement behavior of the reinforced and unreinforced sections. Use of two layers of geocell has significantly increased the strength and stiffness of the unpaved roads. The test showed that the geocell reinforcement reduced the permanent deformation and increased the percentage of elastic deformation of the granular subgrade. The constructed unpaved roads already sustained one monsoon without any significant damage.