scholarly journals Microseismic Response Characteristics Induced by Mining Activities: A Case Study

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xuesong Bai ◽  
Zhi Tang ◽  
Tao Zhao ◽  
Xiaoyang Cheng ◽  
Kai Chen
Keyword(s):  
Coal Mine ◽  
Energy Levels ◽  
Spectral Characteristics ◽  
Temporal Distribution ◽  
Release Mechanism ◽  
Level Energy ◽  
Mining Activities ◽  
Low Frequencies ◽  
Periodic Distribution ◽  
Working Face

For deep coal mines, geological disturbances or mining activities can cause damage to coal and rock masses, easily inducing dynamic disasters such as rock bursts or coal and gas outbursts, which seriously threaten the safety production of coal mine. In this paper, first, the Liyazhuang Coal Mine introduced the SOS MS (Sensor Observation Service Microseismic) monitoring system from the Polish Research Institute and verified the accuracy of its positioning. Then, to study the characteristics of MS signals induced by different mining activities, based on the field monitoring results, the waveform and frequency spectrum characteristics of MS signals at different energy levels induced by different mining activities are analyzed, and the energy levels of MS signals caused by different mining activities are classified. Studies have shown that there are large differences in the waveform and spectral characteristics of MS signals at different energy levels. High-level energy seismic signals are characterized by large amplitudes, low frequencies, relatively concentrated distribution, long vibration duration, and slow attenuation. In addition, the relationship between mining activities and MS events is also statistically analyzed based on the spatial and temporal distribution of MS events with the advancement of working face, and the results show that the increase of vibration frequency and energy can be precursor information for roof pressure. With the advance of the working face, the MS energy has the characteristic of periodic distribution, which is consistent with the periodic weighting revealed by the working resistance of the support. This study provides a reference for further revealing the energy release mechanism of rock burst.

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 Research on Deformation Mechanisms of a High Geostress Soft Rock Roadway and Double-Shell Grouting Technology

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Fengnian Wang ◽  
Shizhuang Chen ◽  
Pan Gao ◽  
Zhibiao Guo ◽  
Zhigang Tao
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Large Deformation ◽  
Coal Mine ◽  
Soft Rock ◽  
In Situ Stress ◽  
Deformation Monitoring ◽  
Deformation And Failure ◽  
Working Face ◽  
High Geostress

In this study, the deformation characteristics and mechanical properties of coal and rock mass in the S2N5 working face of the Xiaokang coal mine are analyzed to address the problem of large deformation of soft rocks with high in situ stress surrounding roadways. Through a newly developed grouting pipe, a double-shell grouting technology, consisting of low-pressure grouting and high-pressure split grouting, is proposed for the Xiaokang coal mine. In addition, the effect of grouting is evaluated by borehole peeping and deformation monitoring. The results show that the double-shell grouting technology can effectively improve the overall mechanical properties of the surrounding coal and rock mass, preventing the large deformation and failure of the roadway. This technology can be useful when analyzing and preventing large deformation of soft rock roadways.

scholarly journals DETECTING THE AREA DAMAGE DUE TO COAL MINING ACTIVITIES USING LANDSAT MULTITEMPORAL (Case Study: Kutai Kartanegara, East Kalimantan)

2018 ◽  
Vol 14 (2) ◽  
pp. 151
Author(s):  
NFn Suwarsono ◽  
Nanik Suryo Haryani ◽  
Indah Prasasti ◽  
Hana Listi Fitriana ◽  
M. Priyatna ◽  
...  
Keyword(s):  
Change Detection ◽  
Coal Mining ◽  
Coal Mine ◽  
Vegetation Index ◽  
Detection Method ◽  
Land Reclamation ◽  
Environmental Damage ◽  
Mining Activities ◽  
Landsat Data ◽  
East Kalimantan

Coal is one of the most mining commodities to date, especially to supply both national and international energy needs. Coal mining activities that are not well managed will have an impact on the occurrence of environmental damage. This research tried to utilize the multitemporal Landsat data to analyze the land damage caused by coal mining activities. The research took place at several coal mine sites in East Kalimantan Province. The method developed in this research is the method of change detection. The study tried to know the land damage caused by mining activities using NDVI (Normalized Difference Vegetation Index), NDSI (Normalized Difference Soil Index), NDWI (Normalized Difference Water Index) and GEMI (Global Environment Monitoring Index) parameter based change detection method. The results showed that coal mine area along with the damage that occurred in it can be detected from multitemporal Landsat data using NDSI value-based change detection method. The area damage due to coal mining activities  can be classified into high, moderate, and low classes based on the mean and standard deviation of NDSI changes (ΔNDSI). The results of this study are expected to be used to support government efforts and mining managers in post-mining land reclamation activities.

scholarly journals Characteristics of New Permanent Magnetic Eddy Current Drive System of the Scraper Conveyor

2021 ◽  
Author(s):  
shuang wang ◽  
Yongcun GUO ◽  
Deyong LI
Keyword(s):  
Eddy Current ◽  
Coal Mine ◽  
Mining Area ◽  
Current Drive ◽  
Drive System ◽  
Model Accuracy ◽  
Working Face ◽  
Scraper Conveyor ◽  
Mining Face ◽  
Motion Characteristics

Abstract This study provides a new permanent magnetic eddy current drive system to solve the ener-gy-saving drive problem of the scraper conveyor working under bad conditions, including overload startup, severe abrasion and pollution. Considering the practical conveying conditions of the scraper chain on a fully mechanised coal mining face, this study creates a mathematical model for the new permanent magnetic eddy current drive system of the scraper conveyor based on its characteristics and indicates the motion characteristics of the scraper chain driven by two wheels. This study verifies the model accuracy with a pre-startup technology depending on the scraper conveyor on the No. 12318 working face of the 8th coal mine in the West No. 1 mining area of the Pansan Coal Mine of the Huainan Mining Group. According to the results, the motion acceleration of the scraper chain based on the new permanent magnetic eddy current drive is lower than that of the scraper chain with a hydraulic coupler under the same running condition and load during startup and acceleration and declines by approximately 14.7%. Consequently, this can decline the startup impact due to the serious abrasion and frequent overload of the scraper chain working under bad conditions.

The main projects and development status of noise forecasting and controlling on working face in coal mine

2010 ◽  
Vol 16 (2) ◽  
pp. 198-205 ◽  
Author(s):  
You-duo Peng ◽  
Ying-fu Guo ◽  
Li-tao Wu ◽  
Xin Li ◽  
Wei-hua Xie ◽  
...  
Keyword(s):  
Coal Mine ◽  
Development Status ◽  
Working Face

The Optimum Arrangement of Working Face Ventilation System for Coal Mine

2012 ◽  
Vol 482-484 ◽  
pp. 1691-1694
Author(s):  
Ning He ◽  
Qiu Ju Ma ◽  
Yu Zhu Shi
Keyword(s):  
Coal Mine ◽  
Ventilation System ◽  
Dynamics Simulation ◽  
Practical Significance ◽  
Gas Migration ◽  
Optimal Layout ◽  
High Concentration ◽  
Working Surface ◽  
Working Face ◽  
Optimum Arrangement

It was most effective and practical that using computational fluid dynamics simulation to analyze the distribution of flow field in gob for studying optimal layout scheme of the working face ventilation system. In this paper, numerical simulation was applied for studying the migration laws and high concentration of gas gathering area of N1201 working face in Tunliu Coal Mine; the gob of robbing working surface gas migration laws and high concentration of gas gathering area was obtained; the optimum arrangement of ventilation system for the working face was given. The conclusions had a certain theoretical value and practical significance for controlling the working face gas.

Electronic and structural features of uranium-doped graphene: DFT study

2021 ◽  
pp. 1-7
Author(s):  
Lina Majeed Haider Al-Haideri ◽  
Necla Cakmak
Keyword(s):  
Density Functional ◽  
Energy Levels ◽  
Electronic Conductivity ◽  
Structural Features ◽  
Level Energy ◽  
Size Dependent ◽  
The Density Functional Theory ◽  
Doped Graphene ◽  
Homo And Lumo ◽  
Model Size

Electronic and structural features of uranium-doped models of graphene (UG) were investigated in this work by employing the density functional theory (DFT) approach. Three sizes of models were investigated based on the numbers of surrounding layers around the central U-doped region including UG1, UG2, and UG3. In this regard, stabilized structures were obtained and their electronic molecular orbital features were evaluated, accordingly. The results indicated that the stabilized structures could be obtained, in which their electronic features are indeed size-dependent. The conductivity feature was expected at a higher level for the UG3 model whereas that of the UG1 model was at a lower level. Energy levels of the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO) were indeed the evidence of such achievement for electronic conductivity features. As a consequence, the model size of UG could determine its electronic feature providing it for specified applications.

Spectra of quarry blasts and microearthquakes recorded at local distances in Israel

1993 ◽  
Vol 83 (6) ◽  
pp. 1799-1812
Author(s):  
Yefim Gitterman ◽  
Torild van Eck
Keyword(s):  
Time Delays ◽  
Spectral Characteristics ◽  
Open Pit ◽  
Frequency Range ◽  
Simple Method ◽  
Low Frequencies ◽  
Event Identification ◽  
Routine Basis ◽  
Seismograph Network ◽  
Discrimination Method

Abstract In northern Israel, quarry blasts and microearthquakes occur in a region with complicated tectonics. Therefore correct event identification, preferably based on a simple method that can be applied on a routine basis, is essential for accurate and detailed seismotectonic studies. Spectral analysis of quarry blasts and microearthquakes recorded at local distances (5 < Δ < 2000 km) by stations of the Israel Seismograph Network revealed spectral characteristics in the frequency range less than 12.5 Hz that can be used routinely for event identification. Most quarry blasts in northern Israel are ripple-fired, open pit blasts, consequently we chose an event discrimination method based on the recognition of ripple-firing patterns in the signal. A simple model for ripple firing parameters, based on interference theory of linear systems and including random effects, predicts spectral minima at low frequencies identical for different seismic phases. We compared the spectra of complete seismogram signals of 52 events recorded by the ISN at different distances and azimuths, including both microearthquakes and quarry blasts in a selected region of northern Israel. Consistent spectral modulation was found in a band from about 2 to 8 Hz for 18 of 21 reliably identified, i.e., reported, quarry blasts with time delays of 20 to 40 msec. The spectral minima frequencies correspond to those predicted by the theory.

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