|
The water storage capacity of a carboniferous rock mass and its impact on the flooding process of mi |
|
|
|
|
The water storage capacity of a carboniferous rock mass and its impact on the flooding process of mine workings in the Upper Silesian Coal Basin Author: P. Bukowski
The water storage capacity of a rock mass as one of the factors flooding process affecting mines has not been thoroughly examined in the past. The value of the water storage capacity of rock mass has been obtained through field investigations and calculations, including the water capacity of the rock masses in the vicinity of mine workings and similar rock masses łocated beyond the mine workings themselves, but able to drain into the mined area. In this paper, the so-called "additional" water capacity of rock masses in the external part of the drainage zone has been defined and a method for its quantification is presented. It allows to calculate the water storage capacity of a rock mass and the total void volume of the reservoirs. The water storage capacity of the Carboniferous rock mass in the Upper Silesian Coal Basin (USCB) has been estimatcd by using prognostic calculations and the results of field observations. It was estimated with respect to the complex geological and tectonic conditions and, in particular, to the hydro-geological and mining conditions, including the geo-mechanical properties of the rocks surrounding mine workings. It has been found that the overall percentage proportion of each void volume- componenfs capacity in relation to the specific, empirically determined real volume of the reservoir can be proportionally responsible for its formation time and how the process develops. For capacities related to the water storage capacity of a rock mass, this proportion can be from 35% to 75%. Considering the wide usc of the parameters in mines, the author also suggests using the so-called "rock-mass water-storage capacity index ? d sub rm in the calculations. This index can correct the total void volumes of the reservoirs in mine workings by introducing values of the water storage capacity of the rock mass and their local zones of drainage. The values of index d sub rm for the reservoirs investigated can vary from 0.95 to 4.78. Knowing the principles of its determination, it may be used not only for the predietion of the flooding process in mine workings, but also for the predietion of the drainage process in flooded mine workings.
|
2009