Ground engineering · 1989 · 41 citations · 0 references
EngineeringCivil EngineeringGeotechnical EngineeringPavement EngineeringSoil MechanicsHighway PavementsPavement ConstructionPavement DesignPavement GeotechnicsPavement MaterialsSoil ReinforcementBearing Capacity ReductionGranular Layer MechanicsPavement ReinforcementShear Strength Of Subgrade SoilsSoft Clay BehaviorSoft Soil ReinforcementStress Distribution In Pavement Layers
A new method is presented for the design of unreinforced and reinforced unpaved roads. The type of unpaved road considered consists of a layer of granular fill over a soft clay subgrade. In the reinforced case, the reinforcement (either polymer grid or a geotextile) is placed between the fill and the clay. The design is based on the concept that, as vertical loads are applied to a granular layer, horizontal stresses must also develop within that layer. These stresses are held in equilibrium by shear stresses at the surface of the subgrade, and in unreinforced roads these shear stresses have a detrimental effect on the bearing capacity. The new method moves away from a previous emphasis on membrane action to explain the function of reinforcement, and is therefore able to account for observed improvements due to reinforcement at small surface deflections. The new method is compared with the results of model tests. (TRRL)