Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie Number 01/2022

The activities of the Commission for Surface Protection at the State Mining Authority are regulated by an ordinance [10] and its composition by a decision [1] of the President of the State Mining Authority. The tasks of the commission include issuing opinions on the state of public safety related to mineral exploitation, and in particular on the evaluation of mining exploitation programs and issuing opinions on: mining and construction prophylaxis in mining areas, methods of mine liquidation and directions of development of post-mining areas along with evaluation of their suitability for development. In addition, the Committee initiates research on the impact of mining activities on the environment and buildings and gives its opinion on draft regulations, Polish Standards and instructions on the above issues. In the years 2012-2020, the Committee considered 24 motions, of which the most frequent were motions concerning mining operations near Bytom and Marklowice, in the protective pillar of Lubin, and those concerning the mining seismic intensity scale. A particular problem discussed at the commission's meeting was a letter on shortcomings in forecasting the impact of the planned exploitation by mining enterprises. The list of applications reviewed in 2012-2020 by the commission (Table 1) shows that their number is gradually decreasing, which is due to, among others, restructuring of the hard coal mining industry, which resulted in termination of exploitation under the center of Bytom and also Wirek district in Ruda Śląska.

During the expansion of the IInd line of the Warsaw underground, the only elements made with the use of mining technology were tunnel connectors. Connectors are short transverse corridors between tunnels serving one-way traffic, the basic function of which is to enable quick evacuation of passengers between tunnels in the event of hazard. Because according to the Ordinance of the Minister of Infrastructure [1] the mutual distance between the connectors should not be greater than 400 m, there were made 10 connectors: 4 in the western section of the line and 6 in the eastern-northern one. Variability of alluvial formations along the metro road did not allow for hollowing the connectors without application of special preventive measures. So, to strengthen the soil a jet injection was used. This method has successfully proven in providing cement-soil with sufficient compactness, that enabling the use of the traditional mining method and simple mining machines. A sufficient compactness of soil was proven with the use of traditional drilling methods. At the same time, being aware of the occurrence of small discontinuities in the reinforced layers, additional security measures were taken - control openings. In the event of discontinuity of cement-soil, the problem was removed by making a caulking injection with appropriate resins. The applied solutions proved to be fully effective, making it possible to perform tunnel connectors without problems.

Last years were the time of rapid development of drones technology. That’s why SSE Group has developed Matterhorn drone based system for open pit mines, which is described in the paper. Appropriate selection of drone fly parameters and alignments of software made possible to optimize the time of data collection and creation of photogrammetric model. Integration of data from photogrammetric analyse and evaluation of rock mass quality (based on information on drilling parameters) allows appropriate design of location and mass of blasting materials as well as number of blasting holes. The use of the system solutions allows also to assess output fragmentation based on 3D model created, in the context of shooting effects control. Integration of different available technologies (such as: drones, GNSS, explosives, drilling, computer designing, data collection and exchange) allows therefore to increase quality of drill and blast service. But first of all the use of Matterhorn system makes possible to improve occupational health and safety, because of shortening the time of workers presence in the open pit as well as elimination of people mistakes during drilling holes and shooting designing. Thanks to optimization of production processes it therefore allows to improve economic effects of open pit exploitation.