LAUSR

The stress–dilatancy relationship could be employed as the foundation to develop a constitutive model for polypropylene fiber-reinforced (PFR) soils. In this study, a number of triaxial compression tests were carried out to investigate the effect of uniform distributed fiber reinforcements on the stress dilatancy relationship of Nanjing sand. A new parameter representing the increase in the effective confining stress $$\sigma _{\rm FR}$$ was introduced to describe the stress–dilatancy of PFR sand, and a new stress–dilatancy relationship was proposed for PFR sand based on Rowe’s stress–dilatancy equation for granular materials. Moreover, the stress–dilatancy relationships in the conventional triaxial compression, extension and plane stain conditions were discussed in this paper. The stress–dilatancy relationship is validated against a series of triaxial tests on Nanjing sand and Hostun RF sand mixed with discrete polypropylene fibers. It is shown that the predicted results are in a good agreement with the experimental results.