Required minimum reinforcement stiffness and strength in geosynthetic-reinforced soil (GRS) walls and abutments

Abstract

In current design methods for geosynthetic-reinforced soil (GRS) walls and abutments, there is a fundamental design assumption that the reinforcement strength and spacing play an equal role in the performance of a GRS wall/abutment, i.e., larger reinforcement spacing can be fully compensated by using proportionally stronger reinforcement and lead to the same performance. This has encouraged designers to use larger reinforcement spacing in conjunction with stronger reinforcement for reduction in construction time. Recent studies, however, has indicated that reinforcement spacing plays a much more significant role in the performance of a GRS wall/abutment than reinforcement strength. In this paper, an analytical model that is capable of reflecting more accurately the roles of reinforcement spacing and reinforcement strength is presented. Using available data from large-scale experiments, it is shown that the analytical model provides a much improved tool for predicting reinforcement forces at failure than the current design equation. Based on the analytical model, a protocol for determination of required minimum reinforcement stiffness and strength in design is presented.