Evaluation of Mechanical Behaviour of Sandstone and Andesibasalt Rockfill Materials Using Triaxial & Direct Shear Tests

The mechanical behaviour of rockfill materials and aggregates depends not only on particle size and compaction, but also on their strength and lithological properties. In this research two types of large triaxial and direct shear tests are performed on rockfill materials. This Paper compares the stress-strain behaviour of sandstone and andesibasalt materials in triaxial compression tests (300600mm) and direct shear tests (300300mm). The study evaluates Two kinds of aggregates with different lithological properties and the result reveald that how the same particle sizes aggregates behaved differently due to different lithology and test procedures. This research showed that shear strength of hard and strong rockfill mass (andesibasalt) is more and the deformability is less, compared to weak rockfill materials (sandstone), and this variation increases with increasing confining stress and surcharge