Approche multi échelles du comportement mécanique des sables injectés

Abstract

Grouting creates an increase of the mechanical properties of sand: stiffness, cohesion and, to a less extent, friction angle. We developed a constitutive model adapted for cohesive-frictional materials from an homogenisation technique which allowed us to integrate constitutive relations at the grain levels to obtain constitutive equations for the equivalent continuous granular medium. The role played by the cement grout in the sand pores was introduced by means of an adhesive force between grains in contact. We present several examples of simulation which show that the model can reproduce with sufficient accuracy the mechanical improvement induced by the grout as well as the damage of the grout during loading.