Interface friction properties of EPS geofoam blocks from direct shear tests

摘要

The dry friction properties at the interface between EPS geofoam blocks were investigated by means of an advanced direct shear (DS) apparatus. A pair of EPS blocks having densities equal to 20 or 30 kg/m~3 were used in respective DS tests performed at different constant normal stresses and at different constant driving velocities (i.e., different lateral displacement rates). It was found that the interface friction properties depend on the normal stress, the EPS density and the driving velocity in a specific way that is different from the classical trends usually observed with solid-solid interfaces: i.e., the pre-peak lateral displacement and post-peak strain-softening are noticeable, while the friction coefficient increases with an increase in the normal stress and with a decrease in both the density and the driving velocity.