scholarly journals STABILITY ASSESSMENT OF ADJACENT ROCK MASS IN THE DEVELOPMENT OF COALBED OUTLETS

2018 ◽  
pp. 51-59
Author(s):  
Olga G. Bessimbaeva ◽  
Elena N. Khmyrova ◽  
Farit K. Nizametdinov ◽  
Elena A. Oleinikova
Keyword(s):  
Rock Mass ◽  
Coal Seam ◽  
Active Phase ◽  
Geological Structure ◽  
Stability Assessment ◽  
South Side ◽  
Southern Side ◽  
The Stability ◽  
External Forces ◽  
Adjacent Rock

The problems of stability assessment of the quarry’s southern side during the development of the coal seam D6 are considered. To  assess the stability of the quarry’s southern side in the development  of coalbed outlets, modern research methods are applied: study of  the geological structure and analysis of the adjacent rock mass  state, the creation of an observation station and the production of observations, calculation of stability of adjacent rock mass of the  quarry’s south side and the research results analysis. Quarry’s south  side consists of clayey sediments up to 5 m, then siltstones and  mudstones up to 10-20 m and a coal seam with a capacity of up to  5 m. The substantiation of the calculated strength characteristics of  rocks composing the slopes of the quarry ledges, which determine the stress state of the slopes arising under the influence  of internal and external forces, is done. Instrumental observations of the laid station and the survey of cracks on the quarry’s side allowed  to determine the contours of the deformation zone and the  landslide prism size. A geomechanical model of adjacent rock mass  was created and the stability assessment was carried out for the  geological section along the line of the maximum development  depth. After additional loading on the quarry’s southern side slopes,  the safety factor of stability is nу = 1.69−173, which means active  phase termination of quarry’s side deformation and sustainable condition.

scholarly journals Stability Assessment of Deep Three-Soft Outburst Coal Seam Roof Based on Fuzzy Analytic Hierarchy Process

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qingling Meng ◽  
Yanling Wu ◽  
Minbo Zhang ◽  
Zichao Wang ◽  
Kejiang Lei
Keyword(s):  
Coal Seam ◽  
Analytic Hierarchy Process ◽  
Evaluation Method ◽  
Stability Assessment ◽  
Analytic Hierarchy ◽  
Soft Coal ◽  
Outburst Coal Seam ◽  
The Stability ◽  
Soft Coal Seam ◽  
Hierarchy Process

The stability of deep “three-soft” coal seam roof has always been a key issue in coal mining. There are a lot of factors affecting the stability of deep three-soft coal seam outburst roof. However, there is currently no definite method able to draw an accurate assessment conclusion on roof stability. In order to accurately determine the main influencing factors of the stability of deep three-soft coal seam outburst roof and reduce the loss of coal production, this paper performed three-soft coal seam risk identification on Lugou Mine based on the introduction of the fuzzy analytic hierarchy process theory. 23 main risk factors were identified. Then, it established a hierarchical structure model of coal seam roof stability in accordance with experts’ opinions. The analytic hierarchy process was used to calculate the weights of indicators at all levels. Next, the paper used the fuzzy comprehensive evaluation method and expert scoring to evaluate various risk factors in the indicator system, as well as the overall safety level. The results showed that the deep three-soft coal seam stability of Lugou Mine ranks the third hazard level. The main risk and harmful factors include safety awareness, safety monitoring system, roof weakness, ventilation system, fire-fighting system, and rock bolt quality. In response to the evaluation results, this paper formulated corresponding control measure in terms of ventilation risk, safety monitoring risks, construction personnel risks, and fire protection risk to reduce losses in the mining process, providing a new evaluation method for the stability assessment of deep outburst coal seam roof.

The Quantitative Evaluation of Coal Seam Stability Based on Component GIS

2012 ◽  
Vol 500 ◽  
pp. 168-174
Author(s):  
Long Quan Chen ◽  
Run Yuan Kuang
Keyword(s):  
Coal Seam ◽  
Quantitative Evaluation ◽  
Spatial Data ◽  
Theoretical Basis ◽  
Assessment System ◽  
Current Status ◽  
Stability Assessment ◽  
Stability Evaluation ◽  
Component Gis ◽  
The Stability

The stability of the mining is important for coal, and stability of the current status of coal was analyzed, selecting appropriate indicators that evaluate the importance of stability of the coal seam is so significant. Using GIS Spatial database to achieve a unified data management for spatial data and attributes, and analyze of coefficient of variation of coal thickness and correlation dimension of coal thickness, and use of these two indicators of a coal mine in the coal seam to analyze stability evaluation. Finally, developed stability assessment system of coal based on component-based GIS MapX. The results show that quantitative evaluation of the stability of the coal is reliable, can provide a theoretical basis for coal mining.

Comparison Optimization Analysis of the Location of Power House under Complex Geological Structure

2006 ◽  
Vol 306-308 ◽  
pp. 1455-1460
Author(s):  
Jing Zeng ◽  
Qian Sheng ◽  
Qing Chun Zhou
Keyword(s):  
Rock Mass ◽  
Geological Structure ◽  
Surrounding Rock ◽  
Obvious Effect ◽  
Power House ◽  
Mass Comparison ◽  
Geological Conditions ◽  
Stability Of Surrounding Rock ◽  
Complex Geological Structure ◽  
The Stability

The power house of Yantan extended hydropower project, with complex geological conditions such as fault f211 below the power house and quartzite on top of it, is a huge underground cavern with large span and high wall. In order to evaluate the stability of the power house surrounded by such complex geological structure, the numerical simulation excavation of power house with different location schemes were studied by the elasto-plastic 2D FEM method. The deformation and evolutive process of the stress with the progress of excavation were analyzed. On the condition ensuring the whole stability of surrounding rock mass, comparison optimization analyses were conducted on the power house location scheme. The rational location scheme was demonstrated. The final analyses results show that: (1) The mechanical properties of quartzite and its relative location to the power house has no obvious influence to the stability of surrounding rock mass.(2) The f211 is the main bad geological structure which affect the stability of power house. (3) The case of moving 10m upward of power house is the most rational scheme for the whole stability of power house. (4) The Supporting measures, which would has an obvious effect in controlling the influence on the stability of surrounding rock mass by weak geological structure, are suggested at the out-crop of f211.

scholarly journals NUMERICAL SIMULATION OF THE STABILITY OF THE SIDES OF COAL MINES UNDER THE INFLUENCE OF DISTRIBUTED LOADS

2020 ◽  
Vol 12 (3) ◽  
pp. 428-435
Author(s):  
Dashzhan NARODKHAN ◽  
◽  
Tuiak ISABEK ◽  
Rustam KHODJAEV ◽  
Nurbol KHUANGAN ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Critical Distance ◽  
Mining Operations ◽  
Bead Surface ◽  
Negative Effect ◽  
Strip Mine ◽  
The Republic ◽  
The Stability ◽  
Adjacent Rock

The open method of solid minerals winning occupies a significant place in the total opening of the mining complex deposits of the Republic of Kazakhstan. In the energy band, a prominent role belongs to the Ekibastuz coal basin, where a number of large coal strip mine operates. The level of subsurface, equal parts of spoil bank of the external and internal stripping after a while lead to complex problems of ensuring the stability and safety of mining operations. The location of large external rock dumps on the bead surface has a negative effect on the stability of the latter. The purpose of the work was to establish the degree of the external rock dump influence located on the bead surface on the stability of adjacent rock mass of the coalmine depending on the distance of the dump to the upper edge of the side. There was numerical simulation of stress-strain state of adjacent rock mass under action of distributed load from rock dump carried out. It has been shown that studies of any point stability of the array from this type of load should be carried out on the basis of elasticity and the use of the finite element method theory implemented in packages of programs oriented specifically to scientific and engineering applications. There are the methodology and results of numerical modeling of quantitative assessments of various sections stability of the side loaded with an external rock dump with a height of 160m presented on the example of «Ekibastuz» coal mine. Based on a certain theory of rock strength and the criteria for their discontinuity, limit estimates of the critical distance of the external rock dump from the upper edge of the side were obtained, at which the latter may lose stability.

scholarly journals Stress and deformation analysis of gob-side pre-backfill driving procedure of longwall mining: a case study

2021 ◽  
Author(s):  
Rui Wu ◽  
Penghui Zhang ◽  
Pinnaduwa H. S. W. Kulatilake ◽  
Hao Luo ◽  
Qingyuan He
Keyword(s):  
Rock Mass ◽  
Stress Distribution ◽  
Coal Seam ◽  
Abutment Pressure ◽  
Longwall Mining ◽  
Vertical Stress ◽  
Floor Level ◽  
Working Face ◽  
Floor Heave ◽  
Stress And Deformation

AbstractAt present, non-pillar entry protection in longwall mining is mainly achieved through either the gob-side entry retaining (GER) procedure or the gob-side entry driving (GED) procedure. The GER procedure leads to difficulties in maintaining the roadway in mining both the previous and current panels. A narrow coal pillar about 5–7 m must be left in the GED procedure; therefore, it causes permanent loss of some coal. The gob-side pre-backfill driving (GPD) procedure effectively removes the wasting of coal resources that exists in the GED procedure and finds an alternative way to handle the roadway maintenance problem that exists in the GER procedure. The FLAC3D software was used to numerically investigate the stress and deformation distributions and failure of the rock mass surrounding the previous and current panel roadways during each stage of the GPD procedure which requires "twice excavation and mining". The results show that the stress distribution is slightly asymmetric around the previous panel roadway after the “primary excavation”. The stronger and stiffer backfill compared to the coal turned out to be the main bearing body of the previous panel roadway during the "primary mining". The highest vertical stresses of 32.6 and 23.1 MPa, compared to the in-situ stress of 10.5 MPa, appeared in the backfill wall and coal seam, respectively. After the "primary mining", the peak vertical stress under the coal seam at the floor level was slightly higher (18.1 MPa) than that under the backfill (17.8 MPa). After the "secondary excavation", the peak vertical stress under the coal seam at the floor level was slightly lower (18.7 MPa) than that under the backfill (19.8 MPa); the maximum floor heave and maximum roof sag of the current panel roadway were 252.9 and 322.1 mm, respectively. During the "secondary mining", the stress distribution in the rock mass surrounding the current panel roadway was mainly affected by the superposition of the front abutment pressure from the current panel and the side abutment pressure from the previous panel. The floor heave of the current panel roadway reached a maximum of 321.8 mm at 5 m ahead of the working face; the roof sag increased to 828.4 mm at the working face. The peak abutment pressure appeared alternately in the backfill and the coal seam during the whole procedure of "twice excavation and mining" of the GPD procedure. The backfill provided strong bearing capacity during all stages of the GPD procedure and exhibited reliable support for the roadway. The results provide scientific insight for engineering practice of the GPD procedure.

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