Materiały konferencyjne SEP 2020

Seismic Activity of the Rock Mass and Measurements of the Convergence Excavations Carried Out by the ARAMIS MSD Convergence System Module in Selected Regions at the Rudna Mine An important element of the underground copper mining is seismic activity, which reflects the existing state of rockburst hazard in the extracted mining panels. The level of this threat is il- lustrated by the example of the most seismically active Rudna Mine, that in year 2019 occurred 20941 seismic events with a total energy of 7.78E8J. During this period, 52 mining tremors oc- curred with energy  1,0E6J. One of the basic threats associated with mining exploitation is the rapid release of energy from the rock mass. Part of this energy is propagating in the form of elastic waves, cause rock mass vibration. This is a threat for mining excavations in the underground part of the mine and for objects on the surface. In the first case, tremors can be a source of a rockburst in mining exca- vation, and in the second, they can cause damage to objects on the surface. To observe the be- havior of the rock mass during ore extraction, a set of test methods and measurements of the rock mass pressure are used. These are mining, geomechanical and geophysical methods that are used either on an immediate or continuous basis. In Legnica Głogów Copper Basin (LGCB) mines, the scope of used observations, tests and measurements includes: • registration and analysis of rock mass seismic activity (mining seismology), • measurements of inducted seismoacoustic activity with a microprocessor-based MLT-3 cracker counter, • geotechnical measurements: measurements of excavation convergence, measurements of stratification of rock mass surrounding the excavation (stratification signaling devices, mining endoscopy), measurements of rock deformations in boreholes, leveling meas- urements of roof settlement, • visual-acoustic observations and tests of rock physical and mechanical properties. The paper discusses the current state of seismic activity at the Rudna Mine, present conclusions from the obtained convergence measurements with the ARAMIS MSD system. Convergence measurements in selected mining panels from the three-year period of their extraction are pre- sented as a method of recognizing rockburst hazard on the basis of on-line assessment.