Contact Pressure Distribution in Geocell Reinforced Rural Roads

Abstract

About 60 and 95% of the road network comprised of rural roads in United States and India, respectively. Everyday rural roads are being constructed by the engineers all around the world to meet the traffic needs, for which, the traditional pavement design and construction practices require high-quality materials for fulfillment of construction standards. Quality materials are unavailable or short of supply in many parts of the world. Design engineers are often forced to seek alternatives using substandard materials, commercial construction aids, and innovative design practices to improve the structural support to the pavement structure when weak subgrades are encountered. In this research, results from a series of large-scale laboratory tests on a simulated rural road consisting of a reinforced and unreinforced dense base/sub-base layer overlying weak subgrade were considered. A series of large-scale laboratory testing were conducted on geocell reinforced rural road under traffic loading conditions. The base/sub-base and weak subgrades were prepared at 75 and 30% relative densities, respectively, by pluviation technic in a large steel tank. An equivalent single axle wheel load (ESAL) of 550 kPa was considered which was applied through a circular steel plate using dynamic hydraulic actuator of 100 kN capacity. Several earth pressure cells were placed at the interface of the dense base/sub-base and weak subgrade layers to measure the contact pressure transmitted on to the weak subgrade. Results indicated that the pressures exerted by the traffic loads can be reduced to about 60% by introducing geocell mattress in base/sub-base layers over weak subgrades.