scholarly journals The Failure Mechanism and Stability of the End Slope of Inclined Composite Coal Seam

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Haoran Li ◽  
Han Du ◽  
Runcai Bai ◽  
Guangwei Liu ◽  
Mingyuan Zhao ◽  
...  
Keyword(s):  
Coal Seam ◽  
Slope Angle ◽  
Mining Area ◽  
Open Pit ◽  
The West ◽  
Evolution Law ◽  
Weak Layer ◽  
Side Slope ◽  
Western Side ◽  
The Stability

In view of the inclined occurrence of coal seam in Heishan open-pit coal mine, in the longitudinal exploitation process of the first mining area, the height of the slope at the west end is increasing, and the occurrence of weak interlayer in the slope is in production. The failure mechanism and stability of the end slope of the inclined composite coal seam, which is typical of the West end slope of Heishan open-pit mine, are studied by means of field investigation, theoretical analysis, limit equilibrium analysis, and numerical simulation. The factors affecting the stability of the western side slope and the potential landslide mode are analyzed. The residual thrust method and simplified Bishop method were used to study the stability of two potential landslide modes on the western slope, and the landslide mode, final slope angle, and slope morphology were determined. FLAC3D was used to simulate the western end of the slope, reveal its landslide mechanism, and clarify the evolution law of the slope rock mass displacement. The results show that the landslide mode at the west end of the first mining area is the combined sliding mode of “cutting and bedding.” With the decrease of longitudinal mining depth, the final slope angle functions from 40° to 37°. The stress and strain are concentrated at the weak layer of the coal floor of the western side slope 13-2 and at the foot of the slope. Meanwhile, the failure also occurs inside the slope. The internal cracks connect through the weak layer of the coal floor and slide along the weak layer of the coal floor 13-2. The displacement evolution law of the slope monitoring point shows that the deformation of the slope is mainly horizontal displacement, the maximum displacement deformation is at the foot of the slope, and the degree of displacement deformation of the slope surface is obviously greater than that of the inside of the slope.

scholarly journals Study on shaping slope stability of dump in eastern grassland open-pit mine

2020 ◽  
Vol 194 ◽  
pp. 04043
Author(s):  
Guo Xiaoli ◽  
Yan Jiancheng ◽  
Li Xueliang ◽  
Wen Xin ◽  
Li Xingli
Keyword(s):  
Slope Stability ◽  
Slope Angle ◽  
Mining Area ◽  
Open Pit Mine ◽  
Open Pit ◽  
Open Pit Mining ◽  
Dump Slope ◽  
The Stability ◽  
Step Type ◽  
Mine Dump

The dumps in the open-pit mining area in the eastern grassland are prone to landslides due to the fragile ecological environment, so it is inevitable to reshape the dump slopes. In order to explore a more scientific method for slope shaping of open-pit mine dump, slope stability analysis were used to compare effect of three types of slope-type (wave-shaped, slope-shaped and step-shaped slope shaping method)in outside dumping site of Baori Hiller open-pit mine. The results show that the slope stability is negatively correlated with the slope angle, and the stability of different shaping slopes is realized as wave-shaped slope (F=2.711)> Slope-shaped slope(F=2.513)>Step-shaped slope(F=1.047), in which the wave type and slope type are all within the safe range, but the step type slope is unstable; in consideration of cost, stability and erosion resistance, it is better to set the slope angle of the dump to 15°.The wave-shaped shaping method of the natural dumping of the excavation field outside the Baori Hiller open-pit mine has the best effect and is worth promoting.

Study and Practice on the Technology of Filling Mining in Xin Wen Mining Area

2011 ◽  
Vol 121-126 ◽  
pp. 2892-2896
Author(s):  
Ming Tao Gao ◽  
Ming Zhang ◽  
Ming Zhou
Keyword(s):  
Mining Area ◽  
Scientific Basis ◽  
Surface Subsidence ◽  
Open Pit ◽  
Coal Waste ◽  
Coordinated Development ◽  
Underground Disposal ◽  
Rock Movement ◽  
The Stability ◽  
Technology Processes

Because of mine production, the open-pit enission of coal gangue solid waste and surface subsidence are one of important causes to failure the mining area land and environment, so the key technology, processes and equipment of filling mining to replace coal have been developed, which convergences the existing system of mining technology, And the stability theory of the control of filling mining rock movement and the method of surface subsidence prediction have been established, which provides a scientific basis for equipment Selection and the design of subsidence control; the key technologies of filling mining to replace coal is successfully applicated, which significantly improves the recovery rate of coal resources in China and constructs the new coordinated development model that is combined by the underground disposal of coal waste, mining subsidence control and the “under three”safe coal mining, through the above, the target of green mining and the coordinated development of mining social, economic and environmental will be achieved.

Analysis of the Relative Position of the Slope and Underground Mining Area and its Influence Properties

2013 ◽  
Vol 634-638 ◽  
pp. 3277-3281 ◽  
Author(s):  
Shi Guo Sun ◽  
Hong Yang ◽  
Chun Sheng Li ◽  
Bao Lin Zhang ◽  
Jia Wang ◽  
...  
Keyword(s):  
Slope Stability ◽  
Underground Mining ◽  
Mining Area ◽  
Open Pit ◽  
Stability Factor ◽  
Mining Depth ◽  
Extracellular Region ◽  
Geological Conditions ◽  
Slope Rock ◽  
The Stability

The stability state of slope rock mass is relating to each other’s relative location during the transformation from open-pit to underground mining, it’s the most disadvantageous influence on the slope stability when the underground mining area is located in the toe of slope, and it’s the best influence as in the slope extracellular region. Slope stability factor changes with the geometric dimensions of underground mining increased, but not in direct proportion. Under the condition of constant geometric dimensions of mining area, the influence on slope stability is changing with the mining depth increased. Thus indicating that the influence on slope stability by underground mining has its spatial property, and to determine the specific influence value requires a combination of many factors, such as the relationship of relative spatial position, the geometric dimensions of mining area, engineering geological conditions and so on.

scholarly journals Evaluating the Effects of Dam Construction on the Morphological Changes of Downstream Meandering Rivers (Case Study: Karkheh River)

2017 ◽  
Vol 7 (2) ◽  
pp. 1515-1522
Author(s):  
A. Liaghat ◽  
A. Adib ◽  
H. R. Gafouri
Keyword(s):  
Morphological Changes ◽  
Slope Angle ◽  
Dam Construction ◽  
Lateral Migration ◽  
Average Width ◽  
River Bank ◽  
Before And After ◽  
Western Side ◽  
The Stability ◽  
River Migration

The establishment of stability in rivers is dependent on a variety of factors, and yet the established stability can be interrupted at any moment or time. One factor that can strongly disrupt the stability of rivers is the construction of dams. For this study, the identification and evaluation of morphological changes occurring to the Karkheh River, before and after the construction of the Karkheh Dam, along with determining the degree of changes to the width and length of the downstream meanders of the river, have been performed with the assistance of satellite images and by applying the CCHE2D hydrodynamic model. Results show that under natural circumstances the width of the riverbed increases downstream parallel to the decrease in the slope angle of the river. The average width of the river was reduced from 273 meters to 60 meters after dam construction. This 78% decrease in river width has made available 21 hectares of land across the river bank per kilometer length of the river. In the studied area, the average thalweg migration of the river is approximately 340 meters, while the minimum and maximum of river migration measured 53 and 768 meters, respectively. Evaluations reveal that nearly 56% of the migrations pertain to the western side of the river, while over 59% of these migrations take place outside the previous riverbed. By average, each year, the lateral migration rate of the river is 34 meters in the studied area which signifies the relevant instability of the region.

scholarly journals ANALISIS BENTUK GEOMETRI TERHADAP STABILITAS LERENG PADA TAMBANG TERBUKA DARI ASPEK GEOTEKNIK

2020 ◽  
Vol 3 (2) ◽  
pp. 166-176
Author(s):  
Lisa Fianti ◽  
Munirwansyah Munirwansyah ◽  
Halida Yunita
Keyword(s):  
Slope Stability ◽  
Soil Depth ◽  
Slope Angle ◽  
Geometric Shape ◽  
Open Pit ◽  
Open Pit Mining ◽  
Primary Data ◽  
Soil Parameters ◽  
Soil Parameter ◽  
The Stability

Aceh Province is one of the coal producers, especially Sumber Batu Village in Meurebo District, West Aceh Regency. In the implementation of coal mining, it is necessary to pay attention to the slope stability of open-pit mining to identify and estimate the possibility of landslides. For this reason, the author conducted research in analyzing the geometric shape of the slope stability with the slope variance of modeling the reduction of the existing angle αeks - 10% to the depth of three layers of soil 11 meters. The 1st layer of soil is 1.5 meters, the second layer of soil is 2.5 meters, and the third layer of soil is 7 meters. Slope stability is strongly influenced by the geometric shape of the slope and the strength of soil parameters. To identify the stability of the slope against slope failure, computationally performed using the finite element method with Plaxis software as the reference for the value of FK 1.25, which is considered safe/stable, meaning that collapse rarely occurs. In this research, primary data is used in the form of direct observation in the field, namely taking soil samples to obtain soil data in the form of soil physical properties and soil mechanical properties into soil parameter data, which is tested in the soil laboratory. Secondary data used are map data, boring data, and Sondir data. Soil parameter data were processed using Plaxis software. The results of the slope stability analysis showed that by modeling the geometric shape of the slope (αeks - 10%) on the open slope of a coal mine with a soil depth of 11 meters, the FK value was 3.60. From the results of the FK scores, it shows that the slope of the slope is 3.60 1.25 above the reference value of safe/stable FK. The FK value is 0.2 greater than the FK existing geometry. The conclusion of this study is that geometric shapes play an important role in determining the stability of an open coal pit excavation slope. The smaller the slope angle, the greater the FK value obtained, or the more gentle the slope, the higher the safety value of a slope.

scholarly journals Research on the Influence of Weak Interlayer in Open-Pit Slope on Stability

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhong Shuheng ◽  
Miao Yinjun
Keyword(s):  
Sliding Mode ◽  
Limit Equilibrium ◽  
Open Pit ◽  
Weak Layer ◽  
Overall Stability ◽  
Weak Interlayer ◽  
Different Depths ◽  
Dip Angle ◽  
The Stability ◽  
Theoretical Results

The weak interlayer in the slope meets with water threatening the overall stability of the slope. Sequestration location of the weak layer has an impact on the stability of the slope. Based on this, taking the south-side slope of Fushun West Open-Pit Mine as the background, the limit equilibrium method was used to study the influence of different depths and dip angles of weak interlayers on the factor-of-safety and sliding mode of the slope. After analyzing the effect, a bottom friction experiment was conducted to verify the theoretical results. The research results show that, as the buried depth of the weak layer becomes larger and the dip angle becomes smaller, the safety factor of the slope increases. Dip angle and depth both affect the sliding mode of the slope. This can provide a reference for study of the influence mechanism of weak interlayer on slope stability in multi-weak-layer slopes.

Slope movement hazards of the mining-dumps in the Dorog Basin, Hungary

2021 ◽  
Author(s):  
Gáspár Albert ◽  
Dávid Gerzsenyi ◽  
Réka Pogácsás
Keyword(s):  
Machine Learning ◽  
Waste Treatment ◽  
Slope Angle ◽  
Mining Area ◽  
Mining Waste ◽  
Cement Industry ◽  
Machine Learning Classification ◽  
Geomorphological Mapping ◽  
The Stability ◽  
Natural Slopes

<p>The Dorog Basin was a mining area in northern central Hungary for more than two centuries. Tunnel mining and quarrying of Eocene coal was the main industrial activity in the basin from the mid-19<sup>th</sup> century until the late 1990s. Extensive quarrying of the Cretaceous marl and Triassic limestone for the cement industry is also present in the area, along with pits of sand and fire clay and travertine quarries. Though the waste treatment is controlled by law and strict directives, the morphology and the material characteristics of the waste heaps are often enough to increase the chance of slope failures. As the mining waste heaps and tailings are often adjacent to residential and agricultural areas, they are considered as hazard sources. The combined use of remote sensing and machine learning methods can help to evaluate the stability of the waste heaps and select the sites where further hazard assessment is needed on the field.</p><p>The slopes of the area were sorted into six stability categories (scarps, transitional slopes, debris, low-lying accumulation areas, hilltops, stabile slopes) with random forest machine learning classification. The sample areas for the analysis were selected based on geomorphological mapping in the area and the re-evaluation of the recorded landslides from the landslide inventory. The classifier (Rstudio) analysed one lithological and two to six morphometric predictor variables. We tested several sets of different variables and selected the best performing set, which included the slope angle, profile curvature, TWI, mean upslope area, and the normalized height morphometric indices.</p><p>After the classification, the distribution of the stability categories was computed for three different areas: the mining waste heaps, the remediated quarries, and the natural slopes. The mining waste sites and the quarries were delineated using the national mining waste inventory, satellite images and topographic maps. Then a likelihood ratio analysis was done to calculate the relative frequencies of the stability categories in the different area types. It was expected that the stability category representing the slope debris at rest will be the most frequent in the waste heap areas. The statistical analysis reinforced this hypothesis by resulting a 54% larger likelihood compared to the natural slopes. It was also revealed that the most dangerous category, the scarps, are less likely on the waste heaps than on the natural slopes, which is a reassuring result. However, the transitional types (slopes that are still in movement) are more likely by 25% on the waste heaps. Even this slightly increased likelihood makes the local villages more prone to hazardous events, so an increased concern is also justified.</p><p>From the part of G.A. financial support was provided from the NRDI Fund of Hungary, Thematic Excellence Programme no. TKP2020-NKA-06 (National Challenges Subprogramme) funding scheme. D. G.: The study was supported by the ÚNKP-19-3 New National Excellence Program of the Ministry for Innovation and Technology, Hungary.</p>

Quantitative analysis of parameters' influence on the stability of coal roadway clamped by upper and lower soft rock with extra thickness

2014 ◽  
Vol 05 (02) ◽  
pp. 1350023
Author(s):  
Zenghui Zhao ◽  
Weiming Wang ◽  
Jixing Yan
Keyword(s):  
Quantitative Analysis ◽  
Coal Seam ◽  
Significant Influence ◽  
Evaluation Method ◽  
Soft Rock ◽  
Mining Area ◽  
Remarkable Effect ◽  
Coal Roadway ◽  
The Stability ◽  
Rock Strata

In this paper, a physical model of coal roadway which is clamped by upper and lower soft rock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area. Then, a series of orthogonal numerical experiments were carried out by selecting the strength and stiffness parameters of soft rock and coal seam as well as the in situ stress of soft rock strata as experimental factors and roadway displacements (convergence displacements of sides, displacement of roof to floor) as experimental indexes. By constructing the F statistics with different inspection levels, evaluation method for influence of the experimental factors on stability indexes were defined. Thus, influence degrees of specified parameters on the stability of roadway were divided into five classes as follows: highly significant influence, significant influence, relatively significant influence, little significant influence, and no influence respectively which realize the quantitative analysis of the influence degrees of experimental factors. The finite element calculation results showed that main failure mode of coal roadway that usually showed as tension failure of coal seam in roof and deformation factors of coal seam had the most remarkable effect on roadway displacements. The conclusions provide theoretical basis for further analysis of the mechanism of "roof burst" in roadway maintenance.

scholarly journals Evolution Law of Gas Discharge of Carbon Monoxide in Mining Extra-Thick Coal Seam of Datong Mining Area

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhanyuan Ma ◽  
Feng Du
Keyword(s):  
Carbon Monoxide ◽  
Coal Seam ◽  
Seepage Flow ◽  
Mining Area ◽  
Gas Discharge ◽  
Maximum Magnitude ◽  
Thick Coal Seam ◽  
Evolution Law ◽  
Key Stratum ◽  
Working Face

In order to reveal the evolution law of gas discharge of carbon monoxide in mining an extra-thick coal seam of the Datong mining area by the numerical simulation and field monitoring test, the 8202 working face and 8309 working face in the Tongxin coal mine are chosen as the test sites. The results show that the seepage flow of carbon monoxide gas reaches 1.854 × 10 − 8   m 3 / s in the #1 fracture after the #3 key stratum in the far field breaks in the 8202 working face, the seepage flow of carbon monoxide gas reaches 1.307 × 10 − 7   m 3 / s in the #2 fracture, the seepage flow of carbon monoxide gas reaches 4.276 × 10 − 7   m 3 / s in the #3 fracture, the seepage flow of carbon monoxide gas reaches 4.192 × 10 − 7   m 3 / s in the #4 fracture, and the seepage flow of carbon monoxide gas reaches 1.623 × 10 − 7   m 3 / s in the #5 fracture. The initial caving of the #3 key stratum in the far field occurs and collapses to the gob, when the working face in the #3-5 coal seam advances to 180 m, and the voussoir beam forms in the #3 key stratum. Besides, a shower shape was formed by the seepage flow of carbon monoxide gas, and the maximum flow in the working face reaches 4.562 × 10 − 4   m 3 / s . When the 8309 working face advances from 521.2 m to 556.4 m, the air pressure at the working face gradually rises and reaches the maximum magnitude and then begins to decrease; when the working face advances to 556.4 m, the air pressure at the working face reaches the maximum magnitude of 91.35 kPa. The gas discharge disaster of carbon monoxide in mining the extra-thick coal seam of the Datong mining area is effectively controlled by the dynamic balance multipoint control technology. The research results can be treated as an important theoretical basis for the prevention and treatment for carbon monoxide discharge disaster in mining the extra-thick coal seam of the Datong mining area.

scholarly journals Evaluation on water bursting risk of working faces near collapse column during the mining process

2020 ◽  
Vol 198 ◽  
pp. 02003
Author(s):  
Yang Xue ◽  
Huang Jingwu ◽  
Wang Hua ◽  
Liang Maoliang ◽  
Li Wei ◽  
...  
Keyword(s):  
Coal Seam ◽  
Fracture Zone ◽  
Economic Loss ◽  
Mining Area ◽  
Mining District ◽  
Maximum Height ◽  
The West ◽  
Working Face ◽  
Collapse Column ◽  
Water Bursting

Collapse column water bursting occurs from time to time in the coal mining process of North China Type Coalfield in China, which causes great economic loss and personal injury. Therefore, great attention must be paid to the harm of collapse column. 1301 working face and 1306 working face in the west wing of No.1 Mining District of Zhangji Coal Mine in Shanxian County are close to No.2 collapse column. Water bursting risk evaluation must be carried out before mining two working faces to ensure safety production. On the basis of fully analyzing the geological and hydrogeological conditions of the 3up coal seam in the west wing of No.1 Mining Area, the "Three Zones(caving zone, water conducted fracture zone and sagging zone) Theory of Coal Seam Roof", "Strata Movement Theory" and "Water Bursting Coefficient Theory" were used respectively to calculate and evaluate the water bursting risk of No.2 collapse column during the course of mining the 1301 working face and 1306 working face. The results show that: firstly, in the process of mining the 1301 working face, the maximum height of the water conducted fracture zone at the closest position of 1301 working face to No.2 collapse column would be 60.20 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.066~0.072 MPa/m, and the water bursting risk of the No.2 collapse column would be smaller; secondly, in the process of mining the 1306 working face, the maximum height of the water conducted fracture zone at the closest position of 1306 working face to No.2 collapse column would be 60.91 m, the water bursting coefficient on the boundary of water conducted fracture zone would be 0.057~0.089 MPa/m, and the water burst risk of the No.2 collapse column would be small. By August 31, 2020, the 1301 working face had been safely mined more than 200 meters long(exceeding over 120 m of the closest position in 1301 working face to No.2 collapse column), and the water bursting did not happen in the working face. This paper can provide a reference for the water prevention and control of similar collapse columns in coal mines.

Sign in / Sign up

Export Citation Format

Share Document