Вестник МГТУ, 2021, Т. 24, № 2.

Вестник МГТУ. 2021. Т. 24, № 2. С. 214-227. DOI: https://doi.org/10.21443/1560-9278-2021-24-2-214-227 Carbonate rocks form a lens-shaped deposit of 1.7 km long, with a width of up to 0.5 km in the southwest wing of the anticlinal fold. Carbonate thickness is divided into three packs: the lower pack with a width of 200-300 m of layered white and gray calcite and calcite-dolomite marbles; an average part of up to 80 m pure white calcite marbles; a top pack with a width of up to 200 m of gray and dark gray dolomite and calcite- dolomite marbles. In some places marbles are in varying degrees skarnished and contain silicate minerals: tremolite, actinolite, serpentine, pyroxene, quartz, and mica. The coloration of marbles varies from dark gray and black due to the inclusions of the corner coallike matter to the snow-white, sometimes with bright green and yellow spots and stripes width from a few millimeters to 10-50 mm. The prevailing structure is thin- and fine-grained, the texture is layered, striped, sometimes spotted and flowing. The mineral composition of marbles is heterogeneous and complex. Composition of calcite marbles: calcite - 80-100 %, dolomite - up to 10 %, quartz - up to 1 %. Dolomite and calcite-dolomite marbles contain dolomite - 65-100 %, calcite - up to 35 %, quartz - up to 10 %, silicate minerals - up to 15 %. The field development system is completely correlated with the shape of the bodies of calcite marbles. If in the southern part of the deposit the extraction of marble was conducted in an open way, in the northern part, where the body bends sharply to the west, the development of the ore body was conducted underground. Both open quarry and the underground part of the deposit are currently places o f tourist interest. In recent years, the attendance of the Ruskeala Mountain Park has steadily increased, exceeding 300,000 people per year in 2019. At the same time, there are risks on the territory of the park associated with an unprofessional assessment of the threats arising from the extraction of minerals, since the quarry and underground workings were not rehabilitated in due time and were not transferred to a safe state. Materials and methods The activities for the maintenance and control of the behavior of underground workings in parks and museums, in which they are used as "exhibits", are significantly different from the same activities that are carried out in existing mines and open pits. First of all, this is due to the absence of various kinds of dynamic operations (explosions, drilling) that affect the rock massif, the presence of professional personnel who are prepared for mining operations in workings and the financial capabilities that are higher for a mining enterprise has in comparison with a museum. In this regard, the problem arises of ensuring supervision over the safe behavior o f the massif in conditions when professional mining engineers and similar professional specialists cannot be used in the museum business due to their insufficient workload by profession and, accordingly, the impossibility of compensating for their work according to their qualifications. The solution to this issue is the preparation o f special regulations for monitoring the sustainability of workings based on simplified methods, which are within the power of non-professional staff in a museum environment under the control of a professional outsourcing company. As such a regulation, it has been proposed to use a sequence of measures to ensure control over the safety o f mine workings, based on visual, optical (laser), photogrammetric (lidar) control over deformations of the roof and walls in underground workings, and deformations of the walls of the quarries. The aim of the work is to determine the periodicity of monitoring the stability of mine workings at different stages using various technical solutions. The study of hazardous areas has been carried out mainly by a visual method with the study of cracks in massif, extracted from polygonal models (not considered in this paper). The surveyed territories are recorded in photographs and presented in the form of polygonal models. The western side of the quarry (indicated by number 1 in Fig. 4) is a vertical cliff up to 30 meters high, part of which is hidden under water. Considering the instability o f this kind of walls and its collapse prism, traces of previous collapse, it can be assumed that it is in a state where its collapse can occur at any time. Therefore, photographs were taken along the western side for further processing o f materials by photogrammetry methods - to obtain models of the wall. The western side of the quarry being a vertical cliff is the most popular place visited by tourists while walking through the park and at the same time it is the most dangerous one. Figs. 5, 6, 7 show the conditions in which the rocks o f this area are situated. The east side is in a safe condition: the angle of inclination is 45-60 degrees and does not exceed the critical value. This ensures a steady and stable condition for most of the quarry east wall, where the risks of injury are eliminated by erecting fencing. Photogrammetry investigations were taken at intervals o f 1 year to assess deformities at the selected site. The results of comparing models of different years (Fig. 7) showed the nature o f the visual movement of the array towards the quarry. Brown color characterizes qualitative changes in the sides due to various deformations. 217