Substantiating the optimal type of mine working fastening based on mathematical modeling of the stress condition of underground structures

Purpose. The research purpose is to substantiate a rational technology for mining steep-dipping ore bodies based on a complex of geomechanical studies in combined mining of deposits. Methods. Analysis of existing constructive methods for calculating the optimal mining system parameters when mining under-open-pit ore reserves in the zone of influence of surface mining operations, taking into account the natural stress-strain state of the rock mass. Numerical modeling is used to study the geomechanical processes occurring in the mass during the mining of under-open-pit reserves of steep-dipping ore bodies in order to substantiate the mining system with ore shrinkage. The geotechnical mapping of mine workings is conducted directly in the face to determine the mass rating. Findings. The calculation of the optimal parameters for the stope chamber, inter-chamber and inter-level pillars based on a complex of geomechanical studies has shown that the more intense horizontal stresses act in the bottom of the blocks and in the inter-block pillars, in which a large number of board gates have been driven. Originality. For the first time, using high-precision programs and given the nonuniform distribution of horizontal and vertical stresses acting in the mass for the Abyz Mine conditions, it has been revealed that when mining an individual block, the maximum horizontal stresses around the mined-out space reach 10-15 MPa; when mining a group of blocks – 20-25 MPa. Practical implications. The research results can be used in planning and mining with shrinkage of steep-dipping ore bodies during mining of under-open-pit reserves.

Section: Figure 6 Calculation Scheme For the Methods Of Successive Cy...mentioning

confidence: 99%

Geomechanical substantiation of the parameters for the mining system with ore shrinkage in the combined mining of steep-dipping ore bodies

Issabek¹,

Orynbek²,

Kozhogulov³

et al. 2022

“…Numerical modelling of the rock mass stress-strain state and the calculation of the load-bearing capacity of the support types used at the 10 th Anniversary of Kazakhstan's Independence mine have been performed with the help of the RS2 software [8]. This program, based on the Finite Element Method in a two-dimensional formulation, makes it possible to take into account a significant number of factors influencing the mass state.…”

Section: Methodsmentioning

confidence: 99%

Research into technology of fastening the mine workings in the conditions of unstable masses

Matayev¹,

Abdiev²,

Kydrashov³

et al. 2021

Self Cite

Purpose.Determination of the rock stability along the strike of the mass, where the drift mining of the horizon -480 m is conducted, considering the possibility of using the improved types of supports in the conditions of the 10th Anniversary of Kazakhstan’s Independence mine at the Khromtau field with the substantiation of using the effective type of fastening that increases technical and technological, operational and economic indicators of the mine. Methods. Numerical modelling of the stress-strain state of the rock mass applied at the mine have been performed using the RS2 software in a two-dimensional formulation. The rock mass state, as well as the physical-mechanical properties of mine rocks are determined according to building codes and regulations (SNiP II-94-80), depending on the category of the rock stability. Findings. It has been revealed that the combined supports from rock bolts and shotcrete are the most rational type of fastening in the studied mine. The efficiency and prospects of using the combined supports have been determined, which ensure a decrease in their material consumption and cost while increasing the reliability of mine workings and the labor productivity of miners. The use of combined support allows to increase the economy of materials for support by 1.7 times, as well as to increase the drifting rate by 1.6 times in comparison with the metal support. Originality.The paper proposes a new approach to substantiation of an effective fastening method by comparing the costs when driving horizontal underground mine workings in the mining-and-geological conditions of the 10th Anniversary of Kazakhstan’s Independence mine. Practical implications.The research results can be used when planning mining operations, in particular, stable fastening methods at the 10th Anniversary of Kazakhstan’s Independence mine of the Khromtay deposit, as well as other mining enterprises with similar mining-and-geological conditions.

“…To determine the influence of various factors on the displacement process development of the border mass rock layers around the preparatory working, it is possible to use a numerical experiment in a computer program for modeling displacements [49]- [51].…”

Section: Figure 2 the Nature Of The Development Of Horizontal Stress ...mentioning

confidence: 99%

Ensuring a safe geomechanical state of the rock mass surrounding the mine workings in the Karaganda coal basin, Kazakhstan

ZHOLMAGAMBETOV¹,

Khalikova²,

Demin³

et al. 2023

Purpose. The research purpose is to determine the instability zones in the host rocks and the dynamics of propagation of active fracturing zones to ensure the stability of the rock mass surrounding the mine workings. Methods. The research uses a set of analytical and experimental studies to determine the dynamics of the deformation process development in the coal-rock mass surrounding the mine workings. Mathematical modeling of the stress-strain state of the rock mass surrounding the active extraction workings is performed using the numerical method of finite elements in modern AN-SYS, Mergel and KMS-III software products. Findings. The influence has been studied of the mine working section shape and the coal seam dip angle on the value of the maximum stresses that arise in the rock mass when the mine working is fastened with the roof-bolt support. The instability zones in the host rocks and the dynamics of propagation of active fracturing zones have been determined both ahead of the front of the conducted mine working and on its sides for rocks of different strength. Originality. For the conditions of the Karaganda coal basin, the dependence of a change in the development of conventional inelastic deformation zones (CIDZ) on the host rock strength has been revealed. The influence of the coal seam dip angle on the dynamics of stratifications around preparatory working has also been substantiated. In addition, new data have been obtained on the influence of the roof rock strength on the stratification of the rock mass surrounding the mine working. Practical implications. By determining instability zones in the host rocks and the dynamics of propagation of active fracturing zones, it is possible to control geomechanical processes in the border rock mass of a mine working and influence it in order to prevent the occurrence of negative rock pressure manifestations. The data obtained are the basis for the development of recommendations on the use of roof-bolting technology for fastening extraction workings to ensure their stability and reduce the cost of their operation.