An experimental investigation of creep processes in a crushable sand

Experimental laboratory research was carried out on a crushable sand examining the relationship between the evolution of particle breakage and the time dependant behaviour of soil. Similar samples were tested using different loading rates and stress paths. Traditional creep tests were also conducted. Each sample was carefully sieved after testing to analyse the particle breakage, relating it to the load applied, the sample density, the stress path and the loading rate. The distribution of particle sizes due to the breakage in shear, isotropic and one-dimensional compression has been investigated. The volume change due to the creep and the strain-rate dependency of the sand were also evaluated and these phenomena have been related to varying amounts of breakage. The data show that the particle grading after testing depends on the stress path. They do not confirm that a "fractal distribution" always develops in compression. A strain-rate effect has been identified at very high rates of loading.