scholarly journals Borehole-Based Monitoring of Mining-Induced Movement in Ultrathick-and-Hard Sandstone Strata of the Luohe Formation

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1157
Author(s):  
Xiaozhen Wang ◽  
Weibing Zhu ◽  
Jianlin Xie ◽  
Hongkai Han ◽  
Jingmin Xu ◽  
...  
Keyword(s):  
Lower Boundary ◽  
Mining Area ◽  
Microseismic Monitoring ◽  
Mining Operations ◽  
Strata Movement ◽  
Mining Areas ◽  
Working Face ◽  
And Migration ◽  
Shallow Strata ◽  
Deep Strata

Water outbursts and rock bursts often occur during the mining of coal seams under water-rich sandstone strata with thicknesses exceeding 50 m, otherwise called ultrathick-and-hard strata (UTHS), which are common throughout the mining areas of northwestern China. It is important to understand the behaviors of their movement and the evolution of their internal fractures to inform the formulation of effective disaster prevention. Due to the presence of the Luohe Formation UTHS in the overburden of the Tingnan Coal Mine in the Binchang mining area and the powerful mining-induced pressure (MIP) events that occurred during the excavation of Panel #2, the internal strata movement of the overburden and the evolution of its fractures were monitored in situ by fiber optic and multipoint borehole extensometers (MPBX) during the excavation of Working Face #207. It was found that a large number of ring-shaped fractures were observed at 24.8–81 m above the lower boundary of the Luohe Formation—in areas above the goaf of Working Face #206—before Working Face #207 was mined. When Working Face #207 was mined, the fractures that were originally located in the deep strata of the Luohe Formation started to close and migrate towards shallow strata. Crack closure and migration were also observed during the monitoring of internal strata movement. Furthermore, the final displacements of Y1-1-1#, Y1-2-2#, and Y1-2-3# relative to the surface were 77, 248, and 134 mm, which were very small relative to the surface subsidence of 1380 mm. It was found that mining-induced perturbations caused the Luohe Formation UTHS to subside continuously and no risk of a large and sudden break would occur in the Luohe Formation UTHS during the mining of Working Face #207. The results of this study provide important data for the safety of mining operations at Working Face #207, which were validated by microseismic monitoring during the mining of it.

scholarly journals Study on the mechanism of water inrush in the arid western mining area

2019 ◽  
Vol 118 ◽  
pp. 03008
Author(s):  
Chao Zheng ◽  
Lan Yu ◽  
Jiangyi He ◽  
Fengfeng Yang ◽  
Jufeng Zhang
Keyword(s):  
Large Scale ◽  
Water Pressure ◽  
Water Inrush ◽  
Hydrodynamic Pressure ◽  
Mining Area ◽  
Mining Areas ◽  
Isolation Layer ◽  
Working Face ◽  
Combined Action ◽  
Tension Fracture

The analysis found that the coal mining process in the western mining area has the mining loss and disaster effect of the water-rich aquifer of the coal seam roof, which is mainly manifested by the overburden water in the roof. On this basis, the formation and development of the separation water of the roof is proposed, and the mechanism of the water inrush from the layer is revealed. It is found that there is hydrostatic pressure and hydrodynamic pressure in the separated water, under the combined action of bed separation water pressure, the mining-induced fracture and water-isolation layer tension fracture are connected, which causes water inrushing in the coal working face of the mine, and provides a theoretical guarantee for the large-scale development of coal resources in western mining areas.

scholarly journals WORKABLE MONITORING SYSTEM BASED ON SPACEBORNE SAR IMAGES FOR MINING AREAS - STINGS DEVELOPMENT PROJECT

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1951-1957
Author(s):  
C. H. Yang ◽  
A. Müterthies ◽  
U. Soergel
Keyword(s):  
Monitoring System ◽  
Surface Deformation ◽  
Warning System ◽  
Mining Area ◽  
Development Project ◽  
Night Vision ◽  
Mining Operations ◽  
Spatiotemporal Resolution ◽  
Sar Images ◽  
Mining Areas

<p><strong>Abstract.</strong> Nowadays monitoring of mining areas, e.g., regarding dam stability, has become increasingly important with rising awareness of safety and environmental protection. An appropriate monitoring scheme is necessitated to legally activate, reactivate, or terminate mining operations. Usually such monitoring relies on in situ surveys, which are unrealistic to cover an extensive mining area. Alternatively, remote sensing based on spaceborne data offers efficient and cost-effective solutions for regular surveillance of large areas. Spaceborne SAR sensors provide images captured rapidly over vast areas at fine spatiotemporal resolution. These sensors are characterized by weather independent and day-and-night vision, which guarantees intensive image series without cloud occlusion. Using multi-temporal SAR images, advanced DInSAR such as PSI and SBAS is a mature technique to evaluate surface deformation at best millimetre level. This technique has been commercialized as a standard service in many Geoinformation companies. Nevertheless, experts from other fields like mining engineers often doubt the information about movement derived from DInSAR. Our duty in industry is to solve these doubts and tailor our techniques for various applications. With the support of STINGS project, we have developed an initial prototype of our monitoring system. The final goal is to launch an interactive GIS-based platform as an early warning system to the public. In this paper, we demonstrate our initial test result using Sentinel-1 images at a mining site in Chile. We also propose the strategies to solve the problems in real applications and discuss how to improve the overall quality.</p>

scholarly journals Features of new sites designing on quarry fields of the existing open pit mines of Kuzbass

2020 ◽  
Vol 174 ◽  
pp. 01003
Author(s):  
Eugene Plotnikov ◽  
Valery Kolesnikov ◽  
Zuzana Šimková ◽  
Nuray Demirel
Keyword(s):  
Mining Area ◽  
Production Costs ◽  
Underground Mines ◽  
Open Pit ◽  
Open Pit Mining ◽  
Residential Areas ◽  
Mining Operations ◽  
Surface Mine ◽  
Open Pit Mines ◽  
Mining Areas

At a number of large open pit mines in Kuzbass, coal production costs have increased due to the deepening of mining operations. In order to reduce them, separate sections of coal mining at the upper horizons are operating or are being designed for mining at low current stripping ratio. For the same purpose, open-pit mining areas at the fields of existing quarries are operated and designed. Examples of such existing and projected areas are: the “Complex Synclinal” area at the Krasnobrodsky surface mine; the “Prirezka” area at the Chernigovsky surface mine; a number open-pit areas at the underground mines; etc. The main factors complicating the involvement in the development of new sites are: the presence of residential areas, industrial buildings and structures near the boundaries of the mining area; power supply lines, transport communications, which limits or excludes the production of mass explosions in the preparation of overburden for excavation; limited size or lack of areas for external dumps at a short distance from the site (in some cases, it is possible to close the mined-out space of the worked-out quarry field). When designing the development of areas characterized by such conditions, it is necessary to consider the application of new technical and technological solutions.

scholarly journals Effect of Assumed Boundary Conditions in Numerical Model of Road Pavement-Mining Subsoil System on Criterial Values Used in Design Using Mechanistic Methods

2021 ◽  
Vol 1203 (3) ◽  
pp. 032021
Author(s):  
Beata Parkasiewicz ◽  
Marta Kadela
Keyword(s):  
Boundary Conditions ◽  
Design Process ◽  
Underground Mining ◽  
Ground Surface ◽  
Mining Area ◽  
Mining Operations ◽  
Wheel Load ◽  
The Road ◽  
Mining Areas ◽  
Road Pavement

Abstract Underground mining brings benefits in the form of the extracted mineral. The negative effects of mining exploration are deformations of the rock mass, which also cause deformations on the ground surface. There are continuous deformations, discontinuous deformations and mining-induced tremors. Recommendations regarding the protection of the structure of cubature building against the negative effect of mining operations are discussed in detail, for example, in the recommendation published by the Building Research Institute (ITB) in Warsaw. In the case of road structures, the situation is different. Firstly, there are no general rules that would provide clear guidelines for the procedure for designing road pavement in mining areas, similarly to cubature buildings. Secondly, in the computer programs used for the individual design of road pavement, it is not possible to assign additional actions, including mining impact. Therefore, in order to analyze the behavior of the pavement-mining subsoil system, an advanced numerical analyze should be carried out. In this case, the subsoil thickness, the boundary conditions and the constitutive relationships of the materials of the road pavement layers and subsoil should be determined. This paper presents an attempt to select kinematic boundary conditions for the FEM model of the road pavement-mining subsoil system, analogically to the model of the building-mining subsoil system. The paper is aimed at assessment of the influence of kinematic boundary conditions selection on the criterial values that are taken into account during the design process of road pavement using mechanistic methods. For this purpose, three cases were considered: (i) horizontal mining strain (εdesign ), (ii) curvature of surface (Kdesign ), (iii) combined impact of these actions. In these cases, each time vehicle wheel load was assumed. Based on the analyzes, the computational horizontal strain of the mining area εcomp is decisive when assessing the criterial values taken into account in the design process of road pavement structures.

scholarly journals Research on dynamic prediction model of surface subsidence in mining areas with thick unconsolidated layers

2021 ◽  
pp. 014459872098164
Author(s):  
Shenshen Chi ◽  
Lei Wang ◽  
Xuexiang Yu ◽  
Weicai Lv ◽  
Xinjian Fang
Keyword(s):  
Prediction Model ◽  
Mining Area ◽  
Influence Coefficient ◽  
Exponential Form ◽  
Dynamic Prediction ◽  
Mining Areas ◽  
Subsidence Basin ◽  
Subsidence Prediction ◽  
Working Face ◽  
Surface Dynamic

In order to improve the accuracy of the surface dynamic prediction model in mining areas with thick unconsolidated layers and improve Knothe time function, the influence coefficient was firstly changed into the coefficient in exponential form, and the influence coefficient of unconsolidated layer was added. Then, a subsidence basin prediction model for mining under thick unconsolidated layers was established. Next, the model was combined with the improved Knothe function, thus constructing a new mining subsidence prediction model. The new subsidence prediction model was applied in 1414 (1) working face in Huainan mining area. The results showed that the integrated model could better reflect the subsidence process, and the prediction values and the measured values agreed well.

scholarly journals Ground Fracture Development and Surface Fracture Evolution in N00 Method Shallowly Buried Thick Coal Seam Mining in an Arid Windy and Sandy Area: A Case Study of the Ningtiaota Mine (China)

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7712
Author(s):  
Yaokun Fu ◽  
Jianxuan Shang ◽  
Zhenqi Hu ◽  
Pengyu Li ◽  
Kun Yang ◽  
...  
Keyword(s):  
Surface Deformation ◽  
Mining Area ◽  
Ground Subsidence ◽  
Deformation Pattern ◽  
Self Healing ◽  
Thick Coal Seam ◽  
Mining Areas ◽  
Working Face ◽  
Fracture Development ◽  
Seam Mining

An observatory was established at the Ningtiaota Mine (China) in order to investigate the surface deformation pattern of N00 method workings mining in shallow buried thick coal seams in a windy-sand area. The observatory allows one to measure the coupling between the periodic changes of parameters related to ground subsidence and ground cracks with workings advancement. The data monitored in the field indicate that when the adjacent mining workings are mined below the ground, a sinkhole basin with a larger impact area will be formed. New ground fractures are formed above the mining area to connect with the fractures above the mining face. As a consequence a new pattern of “O” circle distribution beyond the working face is formed, which develops rapidly during the working face recovery. In addition, the dynamic fractures in coal mining are characterized by the phenomenon of self-healing. Our findings will help to protect the surface environment of the mine area during shallow buried high-intensity mining activities in the Lime Tower coal mine, and are also an important guideline in other windy beach mining areas.

scholarly journals Monitoring Mining Activities Using Sentinel-1A InSAR Coherence in Open-Pit Coal Mines

2021 ◽  
Vol 13 (21) ◽  
pp. 4485
Author(s):  
Lili Wang ◽  
Liao Yang ◽  
Weisheng Wang ◽  
Baili Chen ◽  
Xiaolin Sun
Keyword(s):  
Time Series ◽  
Coal Mines ◽  
Mining Area ◽  
Open Pit ◽  
Mining Activities ◽  
Mining Operations ◽  
Open Pit Mines ◽  
Bare Rock ◽  
Mining Areas ◽  
Illegal Mining

Long-term continuous monitoring of the mining activities in open-pit coal mines is conducive to planning and management of the mining operations. Additionally, this faciliatates assessment on their environmental impact and supervises illegal mining behaviors. Interferometric Synthetic Aperture Radar (InSAR) technology can be effectively applied in the monitoring of open-pit mines where vegetation is sparse and land cover is dominated by bare rock. The main objective of this study is to monitor the mining activities of four open-pit coal mines in the Wucaiwan mining area in China from 2018 to 2020, namely No. 1, No. 2 (containing two mining areas), and No. 3. We use the normalized differential activity index (NDAI) based on the coherence coefficient as an indicator of the mine activity due to its robustness to temporal and spatial decorrelation. After analyzing and removing the decorrelation caused by rain and snow weather, 70 NDAI images in 12-day intervals are obtained from Sentinel-1A InSAR coherence images. Then, the annually-averaged NDAI images are applied to an RGB composite technique (red for 2018, green for 2019, blue for 2020) to express the interannual variation of the mining activities. Points of interest are then selected for NDAI time series analysis. The RGB composite results indicated that No. 1 and 3 open-pit coal mines were continuously mined during the three years; whereas, the two mining areas of No. 2 were mainly active in 2018. The 12-day NDAI time-series graphs of No. 2 open-pit coal mine also indicate that the coal piles located in the coal transferring area of the first mining area were not completely removed until April 2019. It is also seen that the second mining area was decommissioned in November 2018 and became rehabilitated in July 2019. Results were validated using the Sentinel-2A images and related background information confirming the efficiency of the proposed approach for monitoring the mining activity in open-pit mines.

Geotechnical Aspects of Revitalisation of Post-Mining Areas - An Example of the Adaptation of Katowice Hard Coal Mine for the New Silesian Museum / Geotechniczne aspekty rewitalizacji terenów pogórniczych - przykład adaptacji KWK „KATOWICE” na nowe muzeum śląskie

2013 ◽  
Vol 58 (2) ◽  
pp. 361-374
Author(s):  
Marek Cała ◽  
Anna Ostręga
Keyword(s):  
Coal Mine ◽  
Mining Area ◽  
Hard Coal ◽  
Historic Buildings ◽  
Mining Operations ◽  
Mining Areas ◽  
Protection Technology ◽  
Hard Coal Mining ◽  
History Of ◽  
Cultural Functions

The article presents the history of the Katowice Hard Coal Mine and the concept of revitalisation taking into consideration the historical development of the mine which today is closed. The concept accepted for realisation assumes adaptation of the post-mining area with its historical infrastructure for cultural functions, and namely for the construction of the New Silesian Museum. Basing the concept on the idea of minimum interference into the existing spatial layout of the former mine has had the result that the museum areas and garages have been designed under the surface of the area adjacent to the historic facilities of the mine. In relation therewith, it was necessary to carry out the works aimed at reinforcing foundations of the historic buildings and protecting the geotechnical pit slopes. The article presents the technological solutions applied to protect the historic buildings, the lift tower, and the excavations for new facilities of the Silesian Museum. Attention was drawn to the instability of the subsoil and of the rock mass due to previous mining operations conducted in the area, the need to adapt the protection technology to the existing conditions as well as the need of constant monitoring of geotechnical works underway.> It is emphasised that the presented investment is part of an ongoing process aimed at preserving the industrial part of the material cultural heritage of Upper Silesia, for centuries connected with hard coal mining and as such it stands a chance to become a showcase not only for Katowice but for the entire region of Silesia.

Prediction of rockbursts in a typical island working face of a coal mine through microseismic monitoring technology

2021 ◽  
Vol 113 ◽  
pp. 103972
Author(s):  
Chao Zhang ◽  
Gaohan Jin ◽  
Chao Liu ◽  
Shugang Li ◽  
Junhua Xue ◽  
...  
Keyword(s):  
Coal Mine ◽  
Microseismic Monitoring ◽  
Monitoring Technology ◽  
Working Face

scholarly journals Multifunctional Activities of Gold Nanoparticles Biosynthesized Using Bacteria Isolated from Mining Areas

2021 ◽  
Vol 11 (8) ◽  
pp. 3670
Author(s):  
Chih-Yu Chen ◽  
Yung-Chu Chang ◽  
Teh-Hua Tsai ◽  
Man-Hai Liu ◽  
Ying-Chien Chung
Keyword(s):  
Gold Nanoparticles ◽  
Mining Area ◽  
Synthesis Process ◽  
Average Particle ◽  
Bifidobacterium Lactis ◽  
E Coli ◽  
Mining Areas ◽  
Skin Cells ◽  
Study Results ◽  
Antityrosinase Activity

Research on gold nanoparticles (AuNPs) has often focused on their physical, chemical, and crystalline characteristics. Commercial AuNPs have been applied in the diverse fields of biomedicine, catalysis, photovoltaics, and sensing. In this study, we explored the various activities of AuNPs to widen their applicability. This paper presents a simple and rapid synthesis process of AuNPs with bacteria isolated from a gold mining area. We also investigated the optimization of reaction parameters for AuNP synthesis. The study results revealed that among the isolated strains, Bifidobacterium lactis and Escherichia coli demonstrated the highest capabilities of AuNP synthesis. The optimal pH values for AuNP synthesis by B. lactis (BLAuNPs) and E. coli (ECAuNPs) were 5.0 for 72 h of incubation and 8.0 for 24 h of incubation. The average particle sizes of ECAuNPs and BLAuNPs were 4.2 and 5.6 nm, respectively. Furthermore, these biogenic AuNPs were found to be stable with no aggregation after 3 months of storage. BLAuNPs and ECAuNPs exhibited high levels of antimicrobial, antioxidant, photocatalytic, and antityrosinase activity. Moreover, they were noncytotoxic to skin cells even at 100% melanin inhibitory concentrations. Considering the demonstrated multifunctional activities of AuNPs, BLAuNPs and ECAuNPs have promising potential for commercialization.

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