The design of a mining slope must contemplate a geotechnical, structural, conceptual and hydrogeological model, said Esteban Hormazábal, vice president for Latin America of the International Society of Rock Mechanics (ISRM).
Within the framework of the international congress of mining slopes, Slope Stability, Hormazábal participated with the exhibition “Design and evaluation of mining slopes in rock at berm bank level”, in the Mining Thursday organized by the Institute of Mining Engineers of Peru (IIMP), Hormazábal also pointed out that it is key that the analysis and design of the berm bank configuration in rocks (whether on roads or open pits) have a standardized procedure, defining a methodological basis. While, for the survey and recording of geotechnical information in the field, it is advisable to work with the existing instabilities to estimate parameters of shear resistance of the structures.
He also indicated that it is recommended that the methodology for the calibration of the probabilistic analysis of the berm bank design should contain a kinematic analysis, reconciliation of real berm widths and the calibration of the synthetic slope.
“Today there are many technological tools for bank scanning that allow a large amount of information to be taken over a fairly large area. Now that information can be interpreted, even determining the slope of the slopes,” he said.
The mining engineer warned that although using technology in the design of mining slopes automates and improves the process, professionals in the field of geotechnics should not lose the ability to analyze and interpret.
“With technological advances, we have lost a little of the ability to analyze and interpret. We have collected a lot of information, but we have to capture it, try to define a geotechnical model that has the greatest number of parameters and allows us to make a more reliable design,” he said before the IIMP auditorium.
Hydrogeological model
Hormazábal added that in addition to generating a geotechnical and structural model, measurements are needed to build a significant network of hard data to feed the conceptual hydrogeological model. This model, he said, is used to predict groundwater behavior and manage any risks and impacts on the mining operation.
“When we face adverse hydrogeological conditions, we face two problems: first, the amount of water affecting the operation (the mine), and second, the pore pressure acting on the rock mass. That’s why it’s key to have a well-defined model to characterize them in terms of permeability, porosity, storage coefficient, etc., to determine the flow rate the pit will experience and whether this condition would affect the stability of the slopes,” he commented.
Probabilistic Analysis
The Mining engineer added that probabilistic analysis is also important, allowing for the determination of the stability and dimensions of potentially critical blocks, so its calibration and verification in the field is crucial.
“Probabilistic analysis has not been sufficiently exploited. I’ve seen some projects that use 3D models, but that requires supercomputers and a large amount of time running each 3D model, varying a parameter to obtain a result. This will continue to develop; there is much room to try to more accurately determine rock constitutive models. There is also room to try to represent weak rock masses that do not conform to what the industry generally uses” he concluded.
Slope Stability 2026 is organized by the Large Open Pit Project (LOP) and supported in Peru by the Peruvian Society of Geoengineering and the Institute of Mining Engineers of Peru (IIMP).
