Geomechanics and mining research
The project is aimed at strengthening the international cooperation and personal development of scientists from the Institute of Geonics of the CAS. The project implementation will enhance cooperation with major research organizations and their scientists. The realization of individual mobility stays will significantly contribute to the professional development of project participants and improvement of their workplaces. In addition, higher publishing activity and engagement of the IGN in international projects is expected at the same time.
The aim of the project is to support the professional development of young researcher as well as experienced researchers who will gain new skills and contacts at prestigious international workplaces. The final goal is the strengthening of the science and research in the Czech Republic. The fellowship will also contribute to the subsequent transfer of the acquired experiences to other IGN researchers during the return phase of the project.
The expected outputs are the participation and paper presentation at international conferences and the development of cooperation with foreign scientific institutions. An internal condition of the international mobility project is the preparation of a publication at a particular foreign workplace which will be published in a foreign journal of high impact.
The following 6 activities will be carried out: 3 working stays abroad for junior researchers and 3 working stays abroad for senior researchers - with the subsequent return phase.
The basic objective of the project is the development and operation of infrastructure and research-scientific teams created in the framework of the project Institute of clean technologies for mining and utilization of raw materials for energy use on the premises of the applicant VSB – Technical University of Ostrava and the participant Institute of Geonics of the CAS. The project preserves the built-up system of research teams interconnected with the laboratory infrastructure and is divided into two research programs that are interconnected and supplement each other.
The scope of Research Program 1 Multiphase Rock Environment is to obtain the knowledge of physical, chemical, isotopic, structural and mechanical properties of environmental components using modern instrument equipment, which basically increases the level of knowledge and possibilities of its generalization for the given geological conditions by means of mathematical modelling. This information is the basic precondition for the design of environmentally friendly technologies for the exploitation of mineral resources and also for the further utilization of rock environment.
Research Program 2 Environmentally Friendly Technologies is based on the findings from Research Program 1 and deals with oriented research and application solutions in the area of mining of energy raw materials, use of byproducts for the introduction of wasteless technologies to the mining of mineral resources, creation of conditions for minimization of safety risks based on the knowledge of causal processes, and with methods of valuation and influencing of the rock environment in connection with large projects under preparation that are concerned with the use of geothermal energy, permanent deposition of nuclear waste and underground storage facilities for energy raw materials.
Main research objectives which are solved in the Institute of Geonics are as follows:
- Properties and behaviour of geomaterials depending on their inner structure, type of loading and physical conditions. The comprehensive knowledge of petrological, chemical-physical and mechanical properties of rock environment is the basic precondition for the effective, safe and environmentally friendly design of technologies for the mining, processing and use of mineral resources or the driving of mine workings and the building of demanding underground and geotechnical constructions. The objective is to acquire knowledge of the influence of composition and character of inner structure of rocks and rock mass on their strength-deformation and transport behaviour and to acquire reliable and relevant data that can be used directly as input into numerical models and data for their experimental verification and inverse analysis.
- Intensification of effects of high-velocity water jets in the course of disintegration. The objective of solving this activity is to intensify the effects of high-velocity water jets using the physical phenomenon originating at the impingement of a droplet on a solid surface, because during the collision of a liquid moving at a high velocity with a solid, a short-term transient phenomenon appears, which is accompanied by a marked increase in pressure at the point of liquid impingement on the surface and can cause serious damage both to the surface and to the inner structure of materials subjected to the action of the falling liquid. For this reason, the solving will focus on the study of possibilities of influencing the flow before the nozzle to generate a jet utilizing the above-mentioned physical phenomenon for material disintegration.
- Development of changes in induced stress and deformation fields in underground utilization of a rock mass. In underground exploitation of mineral deposits and building of underground construction works, as a result of these activities, changes in the stress states in the rock mass take place. In the case of exceeding of relevant limit parameters of structural units of the rock mass, changes in stress can induce brittle fracture damage, which induces seismic events in affected areas. In complicated natural and mining conditions, this process may be accompanied by a sudden release of energy accumulated in the rock mass and the origin of anomalous geomechanical phenomena with manifestations in underground cavities. Significant stress and strain changes in the rock mass may also show themselves on the surface, play a significant role in the process of design of mine workings driven in the rock mass and affect the transport properties of the rock mass. The research objective will be to acquire findings in this area and to apply them to mining activity and underground construction.
Within the project, the Institute of Geonics has acquired several unique devices for the investigation of rock environment and development of geo-technologies. They are analytic devices, software, but mainly a servo-hydraulic testing system with a triaxial cell for testing THM (thermo-hydro-mechanical) properties of rocks, equipment for water jet application, and X-ray CT (computer tomograph) for non-destructive research of plane and space inhomogeneity in materials and for crack detection.
A thorough evaluation of the stress and structural record in granitic environments is essential for evaluation of the long-term safety of deep nuclear waste repositories located in such environments. The international project “Large-Scale Monitoring” (LASMO) leaded by Nagra was aimed at determining a comprehensive way to describe stress changes in granitic rock caused by large-scale unloading/loading of the rock mass. The experimental phase of the project was being conducted at the underground laboratory of the Grimsel Test Site situated in the Swiss Alps. The measurements and the subsequent monitoring of strain changes, along with the analysis of stress-strain relations and special studies focusing on internal anisotropy of rock provide important characteristics of the overall stress evolution in the investigated region, influencing the stability of the rock mass. The above mentioned subproject LASMO belonged among SURAO supported activities within the LASMO international project. The Institute of Geonics CAS, the Czech Geological Survey and the Institute of Rock Structure and Mechanics CAS collaborated on this task.