Rock mechanics

Rock mechanics is the discipline that studies the mechanical behaviour of a rock mass subjected to its physical environment force fields. Any excavation or loading of a rock mass will induce changes to the force fields and the rock mass response to these changes falls under this discipline.

Projects such as tunnels, caverns, underground garages, dams, hydroelectric power plants, road cuts or mining projects, either underground or open pit (mines and quarries), are typical examples of projects carried out by the department.

Basically, the approach consists of establishing representative geotechnical models of the rock mass from collected geomechanical data and studying the rock mass behaviour according to various constitutive models and failure criteria.

Ultimately, these studies aim implementing viable engineering solutions to ensure safe and stable workings in or on rock, whether they are temporary or permanent.

  • Safe execution of work and cost optimization;
  • No simple or complex structure involving rock can be designed or built safely without the assistance of a rock mechanics specialist. Rock falls or tunnel collapses are examples of hazards that can be mitigated with proper assistance;
  • An understanding of the rock mass behaviour helps with project cost optimization, whether it can be achieved by an optimized geometry, an optimal sequencing or an optimized structure.

  • Rock mechanics is a theoretical and applied science that uses several theories from strength of materials to probability and statistics;
  • A typical project includes a geomechanical data collection campaign (drilling, laboratory tests, in situ tests, mapping, etc.), a rock mass characterization study and ultimately stability studies which can combine analytical, empirical and numerical approaches;
  • During the construction phase of the project, the rock mechanics specialist will assist in the safe and successful achievement of the project by performing inspections, ensuring ground control, refining previous recommendations given the newly made available geomechanical information, etc.

  • Rock mechanics specialists are essentially geological engineers, civil engineering, mining engineering or geologist who have developed a specialty in the design of rock mass excavations;
  • At Groupe ABS, the rock mechanics team is made of geologists and engineers who have strong backgrounds and who have participated in the design and construction of major civil and mining projects around the world.

  • Rock mechanics services target a wide range of clients in all sectors;
  • Transport infrastructure (tunnels, underground stations and road section);
  • Municipal infrastructure (underground pipeline and surge tank);
  • Mining and natural resources;
  • Quarries;
  • Buildings (floors and underground garages);
  • Energy developments (dikes, dams and deep geological repository).

Services related to Rock Mechanics

  • Geomechanical data collection (drilling, laboratory tests, detailed structural description, packer, dilatometer, optical and acoustic televiewer, mapping)
  • Rock characterization studies
  • Stability studies of rock walls (tunnel, open pit, road section)
  • Consolidation/Support of rock walls
  • Geotechnical monitoring
  • Instrumental monitoring (inclinometer, extensometer, piezometer)

Rock mechanics is a complex discipline that is essential for any rock mass-involved project. It is equivalent to what structural engineering is to building construction, but instead of working with steel or concrete, the material the rock mechanics engineer work with is the rock mass.

Working with a rock mechanics engineer from the pre-feasibility phase allows optimizing the entire project as the engineer will study how to work with the material, i.e. the rock mass, for the benefit of the project. If the project is not optimized and the geometry is adverse, the amount of structural elements required to achieve stability will not be optimal.