## 2 Materials and Methods  
### Geological and Mining Conditions in the Area  
The copper deposit formed in the bed-like structure found within the panel XVII/1 in the copper mine Rudna comprises light-grey sandstones in the Rotliegend rock, and lower Zechstein copper-bearing shales and dolomites (Figure 1). Along the principal NW-SE direction coincident with the bed extension range, there is a sedimentation-type field of geological disturbances in the form of white sandstone roof elevation. In the vicinity of this disturbance, the thickness of the copper-bearing shale layer is decreasing and finally disappears. At the same time, the mineralisation profile across the layer is altered. On the slope of the bed elevation, sandstone layers with illite-anhydrite binders, up to 5 m in thickness, are found locally in the roof of sandy formations. The bed thickness in the south-west section varies from 4 to 8 m and then increases to 13 m in the northern part, subsequently going down to 6-7 m along the direction coinciding with that determined by the presence of old excavations in this area. The deposit lies at the depth of about 1050 m, dipping at 2-6\({}^{\circ}\) in the NE direction; however, in the elevation zone, the ascending vertical angle tends to vary considerably. In the roof strata where the shale is found, there is some dark-grey sandy striped dolomite with few anhydrite inclusions. In the shale-free section, the roof adjoins more compact grey-coloured limestone dolomite with anhydrite and gypsum inclusions. The total thickness of the carbonate-shale layer in the considered section varies from 72 to 96 m; it is overlain by a 160 m thick anhydrite layer. The floor comprises light-grey, fine-grained quartzite sandstone with an illite binder, 8-14 m in thickness, with the increasing depth gradually replaced by medium-grained red-coloured sandstone, about 300 m in thickness (Figure 1). Figure 1: A part of lithological profile in the vicinity of the ore deposit (XVII/1 site). Within the panel, there are discontinuities and dislocations in the form of major faults (70-90\({}^{\circ}\)) oriented in the NW-SE and NE-SW direction, with the downthrow of 0.1-4.4 m. There are also some vertical and inclined roof fractures, oriented mainly in the NE-SW (25-35\({}^{\circ}\)) and NW-SE (295-305\({}^{\circ}\)) direction. Geomechanical properties of the rock strata in the investigated area were determined through the geotechnical analyses of rock samples from several boreholes. The variability range of basic rock parameters in the face entry drivage and in the immediate roof and floor layers is shown in Table 1.  
Panel XVII/1 is located in the central part of the mined area in the Rudna mine. According to plans, the mining operations started at the boundary with the adjacent panel XVI/1, advancing on the strike. The face of panelling operations 550-850 m in length advanced along the cluster of galleries T-236/236a (on the right-hand side) and the abandoned excavations (on the left-hand side), in the direction of the descending gallery U5/8. Because of the varied thickness of the commercial deposit, three versions of room-and-pillar stoping methods were employed, designated as R-UO (to mine beds up to 7 m in thickness, with roof deflection), RG-6 (to mine beds up to 15 m in thickness, with rock filling) and RG-8/9 (to mine beds up to 15 m, with sand filling). Due to a locally elevated risk of roof caving, in Year 3 and Year 4, two face advance operations were employed: the main stoping over the distance of \(\sim\)700 m (advancing on the strike) and supplementary operations over the distance \(\sim\)480 m (advancing to the rise). The sketches below illustrate the state of mining operations within panel XVII/1 in the 3-year time interval: at the end of Year 3 (Figure 2) and the at end of Year 6 (Figure 3). The indicated time intervals are by no means arbitrarily chosen. Actually, they are associated with high-energy seismic events registered in December in Year 3 and in Year 6, leading to major rockbursts in mining excavations.