|
| |
|
| |
|
|
Topical issues connected with necessity of improvement of mining hazards prevention
Drzewiecki, J. ; Kabiesz, J. ; Przeczek, A. ; Koníček, Petr
Many mine induced seismic events are monitored in Upper Silesian Coal Basin both in Czech and Polish parts. In some cases these seismic events are attendet by rock bursts. Many broadly-based researches are carried out by Czech and Polish science institutions to explain the rockburst genesis. For all that we consider rockburst as hardly predictable mining risks. The contribution focuses on rockburst control solution. The examples of the stress-strain monitoring methods used by both Polish and Czech researchers are described together with some useful rock burst prevention methods. The high level of knowledge of the determinative parameters of the rockbursts occurrence help to create effective rockburst model. Anyway the research collaboration in the area of rock burst study improve the degree of mining safety.
|
|
|
Evaluation of effectiveness of destress coal blasting fro stress release
Koníček, Petr ; Przeczek, A.
Destress blasting in the coal seam are important active rockbursts measures in conditions of Czech part of the Upper Silesian Coal Basin. Destress coal blasting involves regularly setting off carefully tailored blasts in the fractured coal immediately ahead of a mining face, so as to encourage slip on pre-existing fractures, in order not to allow the accumulation of high strain energy density in the rock mass. In some cases high stress in coal seams (or surrounded rocks) can be reduced. In cases that we demands high stress release we evaluates effect of stress release. Evaluation of stress release is carried out the same procedure without difference between destress blasting in rock and in the coal seam. Paper describes the first analysis of destress blasting in coal seams realised in period 2008 – 2010 (source of seismological databases, about 1200 data). The result of analysis shows of necessity of separate system of stress release evaluation by destress blasting in coal seams and rocks.
|
|
|
Verification of the possibility of utilization of rockbolt technology in the Nováky colliery conditions
Koníček, Petr ; Souček, Kamil ; Šňupárek, Richard ; Hrabovský, J.
Deformation of longwall gates are significant mining complication in conditions of mining of thickness brown coal seams. Difficult mining conditions are coped with standard way – reduced steel arch support spacing, wood polygon supports and timber poles etc. Presented contribution introduces the first step to application bolt technology for strengthening of current longwall gate support. In roadway No. 111 114-05 was installed dozen set of glass fibre reinforce plastic grouted rockbolts K60-25 by polyester resin Lokset in conditions of Nováky Colliery. Afterwards it was carried out pull tests of rockbolts, their assessment and it was defined recommendation for rockbolts using in conditions of Nováky Colliery
|
|
|
Rock mass quality rating for the intention to build an underground construction: Natural Gas Storage Rožná – Rodkov
Souček, Kamil ; Ptáček, Jiří ; Koníček, Petr ; Staš, Lubomír
Práce hodnotí kvalitu horninového masivu pro záměr vybudování podzemní stavby „Zásobník zemního plynu Rožná - Rodkov“ (ZPRR). Zpráva byla vypracována na základě prací provedených jak v laboratoři, tak in situ. Laboratorní práce měly za úkol především zhodnotit fyzikálně mechanické vlastnosti hornin v zájmové oblasti, práce in situ pak byly prováděny posouzenim kvality horninového masivu pomocí geotechnických (geomechanických) klasifikačních systémů, které hodnotí horninový masiv podle parametrů rozhodujících z pohledu výstavby podzemních staveb (např. vlastnosti puklinového systému, mechanické vlastnosti hornin, vliv podzemní vody, vzájemný vztah puklinového systému a směru ražení, napjatost horninového masivu vzhledem k pevnostem hornin apod.)
|
|
|
Verification of Recent-Stress-Strain in Czech part of Upper Silesian Coal basin
Ptáček, Jiří ; Grygar, R. ; Koníček, Petr ; Souček, Kamil ; Staš, Lubomír ; Waclawik, P.
A stresss strain model of Variscan structural tectonic pattern in the Czech part of Upper Silesian Coal Basin (USCB) based on paleostress analyse have been interpreted. It was compiled used many of tectonic measurements of planar and linear elements and their comparison with the knowledge of dynamic development of Variscan body in a larger framework of Moravo Silesian zone. It was took account the influence of Alpine deformation due to Carpathian nappe. There were more stress tensor gauging realised in the region above all using hydrofrac and treated overcoring methods during last ten years. It’s becoming apparent that for information of recent stress fields is usable the interpretation of focus mechanisms of energetic significant seismic events, which were observed here more than ten years. The aim of project is the verification of recent stress strain state in the easternmost region of Czech part of USCB.
|
|
| |
|
| |
|
| |
guest ::
