Analysis of membrane action in reinforced unpaved roads

Abstract

Polymer grid or geotextile reinforcement may be used to improve the performance of reinforced fill layers placed on soft ground. This paper is concerned with the mechanics and design of reinforced unpaved roads built over soft clay, which is a particular application of this reinforced soil technique. A discussion is given of the mechanics of reinforced unpaved roads for the case of a single application of a plane strain, monotonic load, and the design procedures that are currently available for this type of structure are reviewed. A new analytical design model is proposed. This new model is based on a membrane reinforcement mechanism and is appropriate for cases where large surface deformations are acceptable. Results obtained using this new model are shown to compare well with data obtained from previously published laboratory tests. The use of a finite element method to study this type of structure is described, and the results of finite element analysis are used to discuss the accuracy of the proposed analytical model. Key words : soil reinforcement, unpaved roads, membrane, finite elements, reinforcement mechanisms, foundations.