The fabric which develops as a result of the processes used to prepare soil samples for testing has a significant influence on the observed mechanical behaviour of the soil. For fibre reinforced soil samples, the preparation process influences the whole soil–fibre structure including the distribution of fibre orientation which largely governs the effectiveness of the fibre inclusions. The soil/fibre fabric has been explored for three different types of fibre, with different cross-sections and different lengths. For these fibres, dissection of soil/fibre mixtures has demonstrated that the moist tamping fabrication technique led to preferred near-horizontal orientation of the fibres. A new fabrication procedure for fibre reinforced samples, using vibration of moist sand/fibre mixtures, has been investigated and its effects on the fibre orientations have been assessed. The sample layering associated with the moist tamping technique appears to have a limited effect on the fibre orientation distribution. Analytical expressions have been developed to describe the distribution of fibre orientation for both fabrication techniques and the three types of fibres. The results of drained triaxial compression and extension tests on reinforced specimens prepared using both procedures are presented and compared with simulations made using a constitutive model that is able to incorporate the experimentally determined distribution of fibre orientations.
|Translated title of the contribution||Assessment of laboratory sample preparation for fibre reinforced sands|
|Pages (from-to)||69 - 79|
|Journal||Geotextiles and Geomembranes|
|Publication status||Published - Oct 2012|