Development of a Strain-Based Model to Predict Strength of Geosynthetic Fiber-reinforced Soil

Results from an experimental program to evaluate the behavior of fiber-reinforced soils under drained and undrained loading conditions are presented. The results indicate that mobilization of resistance in reinforcing fibers is heavily strain dependent, which necessitates that failure models include consideration of acceptable levels of strain for a particular application. Furthermore, analyses of the results suggest that the reinforcing fibers produce both hydrostatic (or mean) and deviatoric (or shear) stress changes that combine to produce the overall improvement observed for the fiber-reinforced soil composite. The hydrostatic contribution to stress was observed to produce consistent, but unusual pore pressure and volume change responses under undrained and drained loading conditions, respectively. A simple, "strain-based" model is also presented that accounts for both the hydrostatic and deviatoric contributions of the fibers as well as initial stresses induced in the fibers due to compaction, extrusion, and consolidation of the specimens.