Mining exploitation techniques

Contact : hedi.sellami(-at-)mines paristech.fr

In this field, the Geosciences department benefits from a long experience that has enabled it to have an important expertise. The Engineering Geology and Geomechanics group is regularly working on issues relating to the optimization of exploitation techniques and the improvement of their security. Issues frequently addressed concern explosive, mechanical or hydraulic techniques of rock fragmentation, the stability of underground works or open cast slopes.

  •  Works stability

The study of underground works stability and of reinforcement techniques has been one of the key issues of the activity of the department from its very creation. The question is to develop laboratory test tools and numerical tools for the study and the construction of underground or open pit works in safe and economic conditions.

Laboratory works consist in the implementation of appropriate tests to study the behaviour of the ground under various stresses (mechanical, hydraulic, thermal, chemical stresses), the establishment of laws reflecting the rock behaviour at different spatial-temporal scales and criteria describing rock rupture and aging process.

The modelling of the behaviour of works and the development of numerical tools in the frame of continuous (finite elements) and discontinuous (block mechanics) approaches, coupled with various solicitation types, constitute the second major component of the activity of the department in this field.

  •  Mechanical rock cutting

The objective of studying the process of mechanical rock cutting is to understand the general aspects related to rock cutting, including harsh and/or very abrasive rocks, to identify requirements to be met while optimizing and/or designing cutting devices.

The technical and scientific field covered by mechanical cutting is rather broad : rock mechanics, the rupture theory and the materials science to study the interaction between a cutting device and the rock, mechanics when studying the efforts on the cutting head or the static and dynamic balance of the cutting system.

The aim of the team is to extend the use of mechanized cutting systems to harder and more abrasive rocks. This research issue is conducted in close collaboration with laboratories specialized in materials science, in particular the Materials Department of MINES ParisTech.

  •  Rock blasting

For about forty years, the department has been conducting researches to optimize rock blasting process, especially in the frame of underground works (mines and tunnels) or quarrying. The objective is to improve the performance of the blast, to optimize the grain size distribution resulting from the blast, while ensuring the safety of this operation. The Engineering Geology and Geomechanics group has an important expertise in the optimization of blasting models. The aim of its current research project is to better understand and simulate the interaction process between the explosive and the rock. One of the key points here is the development of behaviour laws concerning rocks submitted to quick stresses as those applied by the explosive. These works can be extended to the impact study of any type of blast on the stability of underground works.