scholarly journals Research on the Evolution Characteristics of Rock Mass Response from Open-Pit to Underground Mining

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jiabo Geng ◽  
Qihang Li ◽  
Xiaoshuang Li ◽  
Tao Zhou ◽  
Zhifang Liu ◽  
...  
Keyword(s):  
Underground Mining ◽  
Vertical Direction ◽  
Mining Area ◽  
Open Pit ◽  
Measuring Point ◽  
Deformation And Failure ◽  
Ore Body ◽  
Evolution Characteristics ◽  
The Impact ◽  
Overlying Strata

This study is based on the engineering background of pit no. 2 in Jinning Phosphate Mine, China. In order to systematically analyze the movement, deformation, and failure laws of surrounding rocks in underground stopes. The room and pillar method is used to excavate and stop the ore bodies in the mining area. Combined with the similar physical model experiments and discrete element MatDEM numerical simulations, it reveals the deformation and failure laws and evolution characteristics of the surrounding rock of the stope in the process of converting from open-pit to underground mining. The results show the following: (1) Along the inclination of the ore body, the farther the horizontal and vertical displacements are from the underground stope, the less the impact of mining stress. On the other hand, along the inclined vertical direction of the ore body, the farther the measuring point is from the stope, the smaller the range of mining influence will be. (2) In the process of ore body recovery, the rupture of the overlying strata of the stope has an obvious layered structure, with collapse zones, fissure penetrating zones, and microfracture loosen zones appearing from the bottom to top. In addition, the movement and destruction of the overlying strata of the entire stope is an “elliptical arch.” Therefore, the results of similar simulation experiments and numerical simulation are basically consistent.

Change Properties of Water Conductivity Height in Coal Roof Induced by Mining in Extra Thick Coal Seams under Influence of Complex Fissures Zone

2012 ◽  
Vol 446-449 ◽  
pp. 59-63
Author(s):  
Shi Guo Sun ◽  
Guo Hong Li ◽  
Jing Xin Wang ◽  
Hong Ying Zhao ◽  
Shao Jie Feng
Keyword(s):  
Underground Mining ◽  
Water Inrush ◽  
Technical Problem ◽  
Mining Area ◽  
Water Conductivity ◽  
Deformation And Failure ◽  
Mining Areas ◽  
Mining Safety ◽  
Strata Deformation ◽  
Overlying Strata

It’s a technical problem of underground mining safety to determine the water conductivity height in coal roof induced by mining under the condition of fully mechanized caving. With a number of mining engineering cases, we studied complex fault zone overlying rock mass damage characteristics under the compound effect of many mining area. The results show that overlying strata deformation and failure is the results of accumulation in mining of each mining area. Therefore, whether the overlying strata water inrush in mining process will happen or not, needs to take account of water in overlying strata in old mining area. Based on the change characteristics of water conductivity height induced by mining in seven mining areas, we built regression forecasting model, and achieved the prediction of water conductivity height induced by mining in lower coal seam, so as to provide a basis for decision-making for the safety of follow-up exploration.

scholarly journals Two-Dimensional Modeling of the Influence of Underground Mining Direction on Slope Stability in Coordinated Open-Pit and Underground Mining

2021 ◽  
Author(s):  
Bowen Liu ◽  
Zhenwei Wang ◽  
Xinpin Ding ◽  
Zhitao Wang ◽  
Bin Li
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Underground Mining ◽  
Mining Area ◽  
Two Dimensions ◽  
Open Pit ◽  
Engineering Practice ◽  
Inverse Slope ◽  
Coal Wall ◽  
Mining Face

Abstract Under a background of coordinated open-pit and underground mining engineering practice in the Pingshuo mining area, a combination of numerical simulations and similar-model experiments was used to study the influence of the underground mining direction on slope deformation in two dimensions. The results show that the disturbance caused by inverse-slope mining is more obvious than that caused by along-slope mining. Underground mining presents an asymmetric influence on the open-pit slope; the slope rock mass on the open-off cut side is disturbed more than that on the coal-wall side. Compared with the slope in front of the advancing direction of the underground mining face, the degree of rock-mass damage and stress concentration of the slope of the open-off cut side are more serious. As such, in coordinated open-pit and underground mining practice, an along-slope mining direction is recommended to reduce adverse effects on slope stability and improve the recovery rate of coal resources.

scholarly journals Slope ranking and geohazards correlation analysis for combined open-underground mining area

2018 ◽  
Author(s):  
Zhang Jin
Keyword(s):  
Correlation Analysis ◽  
Water Conservation ◽  
Laser Scanning ◽  
Underground Mining ◽  
Mining Area ◽  
Open Pit ◽  
Ground Subsidence ◽  
Data Sets ◽  
Mining Areas ◽  
Factor Data

Geohazards in mining areas are mainly ground subsidence, slope landslides and ground cracks, surface cover degradation and environmental ecological pattern destruction. The classification and rank of terrain slope and the feature area extraction of the slope are the important content for the correlation analysis with the geohazards. The slope classification and rank index system for soil and water conservation, land use and man-made ground disasters was analyzed. According to the characteristics of open pit and underground associated mining area, we comprehensively analyzed the spatial correlation between different ground disaster and terrain features and landform types, and propose a new slope ranking index, dividing slope zones and forming slope classification map. Especially slope area of 35-45 degrees and more than 45 degrees was extracted, and the relationship between regional geohazards and slope zone was analyzed. The application of terrestrial laser scanning technology to establish open-pit high precision digital elevation model, extraction of slope, slope type, gully density characteristic factor, topography factor data sets are established, and correlation analysis, to enhance disaster information content.

scholarly journals Determination of the Ultimate Underground Mining Depth considering the Effect of Granular Rock and the Range of Surface Caving

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Rongxing He ◽  
Jing Zhang ◽  
Yang Liu ◽  
Delin Song ◽  
Fengyu Ren
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Mechanical Model ◽  
Surface Deformation ◽  
Underground Mining ◽  
Mining Area ◽  
Open Pit ◽  
Open Pit Mining ◽  
Mining Depth

Continuous mining of metal deposits leads the overlying strata to move, deform, and collapse, which is particularly obvious when open-pit mining and underground mining are adjacent. Once the mining depth of the adjacent open-pit lags severely behind the underground, the ultimate underground mining depth needs to be studied before the surface deformation extends to the open-pit mining area. The numerical simulation and the mechanical model are applied to research the ultimate underground mining depth of the southeast mining area in the Gongchangling Iron mine. In the numerical simulation, the effect of granular rock is considered and the granular rock in the collapse pit is simplified as the degraded rock mass. The ultimate underground mining depth can be obtained by the values of the indicators of surface movement and deformation. In the mechanical model, the modified mechanical model for the progressive hanging wall caving is established based on Hoke’s conclusion, which considers the lateral pressure of the granular rock. Using the limiting equilibrium analysis, the relationship of the ultimate underground mining depth and the range of surface caving can be derived. The results show that the ultimate underground mining depth obtained by the numerical simulation is greater than the theoretical calculation of the modified mechanical model. The reason for this difference may be related to the assumption of the granular rock in the numerical simulation, which increases the resistance of granular rock to the deformation of rock mass. Therefore, the ultimate underground mining depth obtained by the theoretical calculation is suggested. Meanwhile, the surface displacement monitoring is implemented to verify the reasonability of the ultimate underground mining depth. Monitoring results show that the indicators of surface deformation are below the critical value of dangerous movement when the underground is mined to the ultimate mining depth. The practice proves that the determination of the ultimate underground mining depth in this work can ensure the safety of the open-pit and underground synergetic mining.

scholarly journals Spatiotemporal Variation Characteristics of Groundwater Quality in A Semi-Arid Steppe Area in Northwest China

2021 ◽  
Vol 20 (4) ◽  
Author(s):  
Quansheng Li ◽  
Kai Zhang ◽  
Yingming Yang ◽  
Shan Chong ◽  
Wenfeng Du ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Coal Mine ◽  
Ph Value ◽  
Groundwater Resources ◽  
Vertical Direction ◽  
Mining Area ◽  
Open Pit ◽  
Temporal And Spatial Distribution ◽  
Pastoral Area ◽  
Semi Arid

In this paper, the open-pit coal mine in semi-arid grassland was taken as the research object. The water samples of the open-pit coal mine and its surrounding areas were collected and the hydrochemical parameters were detected. The temporal and spatial distribution characteristics of the parameters such as pH, electrical conductivity, and dissolved oxygen in the groundwater were studied. The results showed that the groundwater in the study area was alkaline and brackish water. Climate factors might have a certain impact on the pH, conductivity, and dissolved oxygen of groundwater. The pH value of groundwater in the mining area was higher than that in the surrounding pastoral area, while the conductivity value of the mining area was between the pastoral area in the west and the Xilin river area in the east. The parameters of pH, conductivity and total dissolved solids of the four monitoring wells around the mining area showed a slow change or stable phenomenon in the vertical direction with the increase of groundwater depth. This study is of great significance to understand the characteristics of groundwater chemistry in mining areas and the rational development and utilization of groundwater resources.

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.

Environmental Impact Assessment Related by Energy Sector in Rovinari Mining Area

Mining Revue ◽  
2021 ◽  
Vol 27 (2) ◽  
pp. 59-75
Author(s):  
Crina-Adriana Gurică ◽  
Mircea Georgescu
Keyword(s):  
Environmental Impact ◽  
Impact Assessment ◽  
Environmental Impact Assessment ◽  
Thermal Power ◽  
Mining Area ◽  
Energy Sector ◽  
Open Pit ◽  
Open Pit Mining ◽  
Negative Effects ◽  
The Impact

Abstract In this article an impact assessment is carried out, generated by activities in the energy sector related to Rovinari mining area. Energy-related activities in this area are carried out by open pit mining activities in the context of Tismana, Roșia, Pinoasa, Peşteana and Rovinari locations and Rovinari thermal power plant. Some information that has formed the input for the author’s approach has been provided by SC. Complexul Energetic Oltenia SA (CEO) and S.C. Institute of Scientific Research, Technological Engineering and Mine Designs on Lignite S.A. Craiova (ICSITPML) which has been processed, analysed and used for the presented environmental impact assessment. Two methods from specialized studies have been used for the impact assessment, namely: the Matrix Method for Rapid Impact Assessment (MERI) and the Method for Integrated Quantitative Impact and Risk Assessment of Environmental Pollution (EIRM). Based on the analysis carried out, it can be concluded that the activity in this sector does not lead to significant negative effects strictly associated with it.

scholarly journals Mapping Annual Land Disturbance and Reclamation in a Surface Coal Mining Region Using Google Earth Engine and the LandTrendr Algorithm: A Case Study of the Shengli Coalfield in Inner Mongolia, China

2020 ◽  
Vol 12 (10) ◽  
pp. 1612 ◽  
Author(s):  
Wu Xiao ◽  
Xinyu Deng ◽  
Tingting He ◽  
Wenqi Chen
Keyword(s):  
Inner Mongolia ◽  
Land Reclamation ◽  
Underground Mining ◽  
Surface Mining ◽  
Mining Area ◽  
Google Earth ◽  
Open Pit ◽  
Open Pit Mining ◽  
Landsat Images ◽  
Google Earth Engine

The development and utilization of mining resources are basic requirements for social and economic development. Both open-pit mining and underground mining have impacts on land, ecology, and the environment. Of these, open-pit mining is considered to have the greatest impact due to the drastic changes wrought on the original landform and the disturbance to vegetation. As awareness of environmental protection has grown, land reclamation has been included in the mining process. In this study, we used the Shengli Coalfield in the eastern steppe region of Inner Mongolia to demonstrate a mining and reclamation monitoring process. We combined the Google Earth Engine platform with time series Landsat images and the LandTrendr algorithm to identify and monitor mining disturbances to grassland and land reclamation in open-pit mining areas of the coalfield between 2003 and 2019. Pixel-based trajectories were used to reconstruct the temporal evolution of vegetation, and sequential Landsat archive data were used to achieve accurate measures of disturbances to vegetation. The results show that: (1) the proposed method can be used to determine the years in which vegetation disturbance and recovery occurred with accuracies of 86.53% and 78.57%, respectively; (2) mining in the Shengli mining area resulted in the conversion of 89.98 km2 of land from grassland, water, etc., to barren earth, and only 23.54 km2 was reclaimed, for a reclamation rate of 26.16%; and (3) the method proposed in this paper can achieve fast, efficient identification of surface mining land disturbances and reclamation, and has the potential to be applied to other similar areas.

Stability Effect to Railway Tunnel of Underground Mining Using ABAQUS

2011 ◽  
Vol 361-363 ◽  
pp. 236-240
Author(s):  
Li Wei Yuan ◽  
Long Zhe Jin
Keyword(s):  
Numerical Simulation ◽  
Decision Making ◽  
Underground Mining ◽  
Vertical Direction ◽  
Theory Analysis ◽  
Railway Tunnel ◽  
Simulation Research ◽  
Strata Movement ◽  
Ore Body ◽  
Stability Effect

The paper used the software ABAQUS to the numerical simulation research of the strata movement process during the underground mining according to the actual characteristics of certain mine. Through the research and theory analysis of numerical simulation, the numerical value of deformation in horizontal and vertical direction of the strata movement at the railway tunnel is included. It showed that the exploitation of No.2 ore body would not affect the safety of railway tunnel nearly the mine, which provide decision-making basis for the railway departments and mining enterprises, reduce the waste of resources.

Sign in / Sign up

Export Citation Format

Share Document