The grant project is focused on problems of formation of subsidence troughs depending upon the character of rock mass and the extent of mining by using the method of longwall working along the strike with controlled caving. The urgency of the subject comes from the needs of practice and efforts to apply a simple principle of observation to the assessment of condition of failure of a firm roof influenced by underlying workings, which is periodical measurement of height of surface of undermined mass. To specify the failure of rock mass behind the advancing face, other procedures can be used, e.g. dynamometric measurements in the worked-out space; however, these are too expensive. This fact leads to the necessity to use commonly made measurements that are part of mining impact observation for the assessment of condition of failure of the firm roof. A possibility of using the periodical height measurement for this purpose was already shown in the dissertation of the applicant. The dissertation was processed in the framework of one locality. For practical use, it is necessary to carry out the assessment on the basis of sufficient number of localities so that achieved results draw a general conclusion. The grant project will be thus orientated towards the processing of results from selected areas with the aim to propose practical uses for the assessment of prediction condition of failure of undermined firm roof. (en)
- vyhodnotit průběh porušování pevného nadloží dobývaných slojí na základě časoprostorového hodnocení poklesů povrchu vzhledem k dobývání a charakteru nadložních hornin - zobecnit závislost mezi rozsahem odrubané plochy a charakterem nadloží hodnocených případů