The relationship between the microfabric and the engineering properties of weathered granite

The results and conclusions of a microfabric study of weathered granites are related to a review of the engineering properties of weathered granites. The changes in engineering properties of granites induced by weathering are attributed to microfracturing, opening of grain boundaries and development of an intragranular porosity. The shear strength of granite weathered to an engineering soil is considered in detail. A model is developed, involving the microfabric of the clay weathering-product and extent of decomposition, to explain the typically high angles of friction shown by such material. Deformability is also considered.