Researchers in Perm have developed an effective method to protect mining excavations from collapse.

During the extraction of minerals underground, voids are created during the excavation process. These spaces must be filled with a special mixture to prevent negative consequences associated with the emission of harmful gases and soil subsidence above the excavations, which can lead to emergency situations and loss of life. While the mixture hardens, the areas are enclosed with isolation barriers; however, these barriers are difficult to manufacture and install, and they cannot be reused. Researchers from Perm Polytechnic University propose replacing them with a new type of barrier, which could reduce both time and costs.

2024-11-30 10:01:04https://naked-science.ru/article/column/sposob-zashhity-gornyh

The article was published in the journal "Labor Safety in Industry." The operation of mining enterprises has a negative impact associated with environmentally hazardous emissions, subsidence, and the collapse of mined-out areas. One way to mitigate these consequences is through hydraulic backfill – the process of filling mined-out spaces in mines to stabilize unstable rock formations. This involves using mixtures whose composition is tailored to the specifics of extracting a particular type of material and the characteristics of the terrain. Within the technological process, it gradually solidifies layer by layer, forming a solid structure that replaces the mined rock and can effectively withstand pressure from the overlying layers.

“One of the most interesting stages of our research implementation is the creation of an algorithm that allows for the automatic modification of the structure's geometry: the positioning, quantity of beams, thickness of insulation material, the nature of the interaction between the framework and insulation, and so on. The script we developed accelerates the process of multifactorial analysis,” says Yuri Nosov, a graduate student and senior lecturer in the Department of "Computational Mathematics, Mechanics, and Biomechanics" at PNIPU.

“The voids left in the rock mass after the cessation of mining are gradually enclosed using insulation partitions and filled with backfill mixture. Currently, assembling these partitions is a labor-intensive process associated with creating a complex structure that can only be used once. One way to reduce resource costs is to manufacture and integrate a lightweight modular partition into the backfilling technology, allowing for its repeated use,” adds Laysan Sahabutdinova, a senior lecturer in the Department of "Computational Mathematics, Mechanics, and Biomechanics" at PNIPU and a candidate of technical sciences.

Scientists from Perm Polytechnic have proposed using the design of a mine ventilation partition as a basis and have explored the possibility of expanding its functionality for hydraulic backfill. This method had not been previously considered. The structure consists of a base, a frame, and insulation panels. To test the effectiveness of the solution, the polytechnic team developed a numerical analog of the partition and a simulation model of the technological process. High accuracy was achieved by taking into account all factors: material, feed rate, curing time, and more.

“The maximum reaction of the structure occurs at its supports, which necessitates the introduction of additional elements into the load-bearing frame. The numerical analog allows for analyzing the impact of changes in the geometry of the partition on its deformation, and based on the obtained data, engineering decisions can be made to introduce adjustments,” explains Alexander Nikolaev, a professor in the Department of "Mining Electromechanics" at PNIPU and a doctor of technical sciences.

“During complete filling of the mined-out area, the maximum stress intensity at the supports reaches 750 MPa, while the strength limit of steel, which is closest to the partition material, is 610 MPa. This means that the structure will not withstand such a load level, and a 12 mm thick wall will fail at the final stage. The situation can be remedied by securing the top of the partition and installing an additional horizontal beam in the central part. Then the proposed method can be fully utilized in hydraulic backfill,” comments Anna Kamenskikh, deputy director for educational activities at the Advanced Engineering School and a candidate of technical sciences.

Scientists from Perm Polytechnic have developed a method that will enhance industrial safety levels in mining operations during the backfilling of mined-out spaces. The creation of a new type of partition simplifies the technological process through quick assembly, disassembly, and repeated use.