The challenge faced by some mines in the Andean mountain range is the lack of available space for waste dumps, given the steepness of the typical mountainous topography. Because of this, there is an even more urgent need to design dumps hundreds of meters high, in some cases reaching unprecedented heights. In these cases, detailed knowledge of the geomechanical behavior of the waste material becomes essential.
The Geotechnical Group of SRK Chile, has engaged in the work of characterising coarse waste material, which includes planning for large-scale sampling, scaling and testing of the materials using a large triaxial cell and odometer equipment.
The triaxial equipment used for this work belongs to the University of Chile in Santiago and allows for testing specimens 2m high and 1m in diameter, under controlled stress conditions, and confining pressures up to 2.5 MPa. The odometer equipment allows testing under applied stresses of up to 15 MPa.
During recent years, the SRK team has been investigating the shear strength, deformation characteristics and particle breakage of different materials under high stresses.
The study has shown the importance of considering the decrease of the angle of internal friction with the increase of normal effective pressure in designing very high dumps of granular materials.
