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 To control the cracks, two metal screws are embedded in rock on both sides (two bolts with a hexagonal head are placed in the rock) and two side faces of the head are oriented on both bolts parallel to each other. After that, the procedure for taking the distance readings between these metal screws will consist of using any (preferably of high accuracy) laser rangefinder, one end (heel) which will be mounted on the side of the head o f one metal screw and will measure the distance to the side face of the head of another metal screw, thus fixing the expansion of the crack or if necessary - the ensembles of cracks, as it is shown in Fig. 16. Fig. 16. Measuring the distance between two metal screws set to control crack expansion parameters Рис. 16. Измерение расстояния между двумя металлическими винтами (реперами), установленными для контроля параметров расширения трещин 3. Annual full control can be carried out using photogrammetric survey once a year and is a cheap solution to control the shape of workings with the emphasizing of "mobile" zones prone to collapse. For the same purposes, it is possible to use lidar surveying with the same periodicity, which will be a more expensive solution. This method makes it possible to predict the appearance of areas that are in unstable conditions, as well as to evaluate the geotechnical parameters o f the massif taking into account its fracturing. For Ruskeala Mining Park, polygonal models of the walls of quarries and underground workings are documented and prepared. They allow use this method to control changes occurring in the massif surrounding the mine workings after a certain time. Conclusion The work on the selection o f optimal solutions for monitoring the safety of mining objects operated as museum territories and exhibits has been permitted the author to offer a simple and effective method for monitoring hazardous phenomena: break downs, collapses, destruction of stone objects. This approach makes it possible to prevent threats arising during the stay o f tourists at these territories in the most effective way. Routine measures to prevent hazardous situations in mining museums include three stages of preparation: 1. Photogrammetric and engineering-geological survey of mining infrastructure facilities with the emphasizing of "suspicious" places by an outsourcing company at intervals of one year or more. 2. Installation of special reference points at the "dangerous" allocated places in order to monitor periodically their "mobility" (at intervals from 1-2 days to several weeks) with laser rangefinders. For Ruskeala Mining Park, the periodicity of 3-4 weeks has been established. When hazards arise, solutions to eliminate them are applied based on cooperation with an outsourcing organization. 3. In addition to the indicated instrumental observations, it is necessary to organize daily visual monitoring o f controlling areas in the territory where both tourists and museum personnel can occur. Compliance with such regulations at mining facilities used as museum objects will significantly reduce the threats to the stability of the mountain space even by the efforts of the company itself without using unjustified increased costs for this procedure. 225