A Model of Coal Mine Water Disaster Emergency Logistics Risk Assessment Based on AHP and BP Neural Network
基于AHP和BP神经网络的煤矿水害应急后勤风险评估模型
Future Communication, Computing, Control and Management, Lecture Notes in Electrical Engineering Volume 142, 2012, pp 535-542
Abstract: According to needs of rescue and relief work in coal mine water disaster, the article expounds the significance of coal mine water disaster emergency logistics risk assessment, analyses the characteristics of traditional risk assessment methods and the advantages of neural network method in the evaluation problems, and puts forward the idea that combining the analytic hierarchy process (AHP) with the BP neural network vertically. A set of coal mine water disaster emergency logistics risk assessment index system is designed, and a model for coal mine water disaster emergency logistics risk assessment based on AHP and BP neural network is set up. Besides, the article introduces the implementation process of the model, and verifies the feasibility of the model through demonstration analysis in the MATLAB software platform.
An Experimental Investigation of Permeability Measurement of Water Flow in Crushed Rocks
碎岩水流渗透性测量实验研究
Transport in Porous Media, September 2014
Abstract: Due to the high permeability of water flow in crushed rocks, flow catastrophes and water inrush accidents are apt to take place in the broken zones of aquifers in coal mining engineering. The pore, crack and fracture geometries needed for water transport are strongly influenced by grains diameter size and axial displacement conditions. In order to inspect and quantify the influence, we designed and manufactured a water flow apparatus that can be connected to the electro-hydraulic servo-controlled test system MTS815.02 which provides loading pressure in the experiment. Using the apparatus and MTS system, we tested crushed mudstone, limestone and sandstone specimens and obtained the relationship between permeability and variable grain diameter of a (2.5–5 mm), b (5–10 mm), c (10–15 mm), d (15–20 mm) and e (mixed sizes) under variable axial displacement (10, 15, 20, 25, 30, 35 and 40 mm). In particular, the permeability calculation based on collection of water flow velocity and pore pressure gradient difference has involved the influence of non-Darcy flow. The results show that (1) The porosity decreases with the increase of axial displacement and decrease of bigger particle size, respectively. Particle crushing during compaction is a main cause of size 0–2.5 mm appearing, some fine particles be washed away is a main cause of weight loss because of the effect of water seepage. (2) Water flow properties of crushed rocks are found to be strongly influenced by axial displacement and grain diameter size; in general, the permeability decreases with the increase of axial displacement and the decrease of grain diameter, respectively. (3) The fluctuations of permeability–axial displacement are especially intense for mudstone and sandstone than that for limestone. The permeability of crushed rocks is not only related to loading levels but also to grain diameters, style of arrangement. (4) To each grain diameter sizes, the permeability change of sandstone has a greater value than that of mudstone and limestone. The permeability of crushed mudstone shows much less than that of limestone and sandstone.
Evaluation and zoning of groundwater hazards in Pingshuo No. 1 underground coal mine, Shanxi Province, China
中国山西平朔一号地下煤矿水灾害评估与分区
Hydrogeology Journal, May 2014
Abstract: Coal mining safety has been compromised with water inrushes from aquifers either overlying or underlying the coal seams. Detailed studies of the associated hydrogeological conditions in China have led to different approaches to mitigate the water inrush risks from these two types of aquifers—the ‘three diagram method’ for overlying-aquifer water inrushes and the ‘vulnerability index method’ for underlying-aquifer water inrushes. The ‘three diagram method’ consists of: (1) aquifer water-abundance distribution charts derived from a geographic information system and analytic hierarchy process based water-abundance index model; (2) a fracture height map showing mining-induced fractures above the coal seam, established with stratified numerical simulations; and (3) a comprehensive partition map identifying the overlying-aquifer water inrush risk. The ‘vulnerability index method’ uses site-specific data to establish thematic maps for major factors that affect the underlying-aquifer water inrushes, whereas the weight of each control factor is determined by the analytic hierarchy process. The calculated vulnerability index is indicative of water inrush risks. The effectiveness of these methods is illustrated with a case study at the Pingshuo No. 1 underground coal mine, Shanxi Province, China.
New development in theory and practice in mine water control in China
中国矿井水害防治理论与实践之新发展
Carbonates and Evaporites, June 2014, Volume 29, Issue 2, pp 141-145
Introduction: Mine water inrush events often occur during coal mine construction and production in China and account for a large proportion of the nation’s coal mine disasters and accidents. Figure 1 shows the number of water-related hazards and casualties in coal mines of China between 2000 and 2011. Over the 12 years, 1,089 water incidents have occurred with a total loss of 4,329 lives.
As the mining depths and mining intensity continue to increase, the encountered hydrogeological conditions will become more complicated. The Chinese mining engineers and hydrogeologists have been working hard to liberate approximately 27 % of their proved coal reserves that are currently threatened with water inrushes. In battling against the water hazards, they have overcome four major challenges and developed their solutions.
Seawater inrush assessment based on hydrochemical analysis enhanced by hierarchy clustering in an undersea goldmine pit, China
基于层次聚类水文化学分析的中国一海底金矿海水涌入评估
Environmental Earth Sciences, June 2014, Volume 71, Issue 12, pp 4977-4987
Abstract: Seawater inrush is deadly to undersea mine and it is very important to accurately assess the connectivity between seawater and the mine pit. With Xinli gold mine area as a case study, following the analysis of geological setting, a detailed hydrogeological survey and sampling were conducted and conservative ions test of mine water samples was carried out in the laboratory. Furthermore, the physical significances of ion concentration and ion ratios, such as Cl−, γSO4 2−/γCl− and γNa+/γCl−, were checked. The test data analysis, enhanced by the physical significance check and hierarchy clustering analysis, was used to assess the overlying seawater inrush into the mine pit. It was determined that the undersea rock masses in the Xinli mine area bear high-mineralization brine water. The ore-controlling fault gouge and a thin layer of clay in Quaternary block the seepage of overlying seawater into the undersea mine pit to a great extent. The mine water from surrounding rock of the northeast gopher drift is closer to seawater in hydrogeochemical features, which indicates that the connectivity between the northeast of footwall of the ore-controlling fault and seawater is relatively good and should be closely monitored in future production. The mine water from the southwest gopher drift and crosscuts is similar to the brine (salty) water in chemical features, drains the net reserves of brine (salty) water in bedrock fissures and will impose few impacts on production in the near future. This approach is feasible and cost-effective.
Impact of Effective Stress and Matrix Deformation on the Coal Fracture Permeability
有效应力与煤基变形对煤裂缝渗透性的影响
Transport in Porous Media, May 2014, Volume 103, Issue 1, pp 99-115
Abstract: The permeability of coal is an important parameter in mine methane control and coal bed methane exploitation because it determines the practicability of methane extraction. We developed a new coal permeability model under tri-axial stress conditions. In our model, the coal matrix is compressible and Biot’s coefficient, which is considered to be 1 in existing models, varies between 0 and 1. Only a portion of the matrix deformation, which is represented by the effective coal matrix deformation factor \(f_\mathrm{m}\) , contributes to fracture deformation. The factor \(f_\mathrm{m}\) is a parameter of the coal structure and is a constant between 0 and 1 for a specific coal. Laboratory tests indicate that the Sulcis coal sample has an \(f_\mathrm{m}\) value of 0.1794 for \(\hbox {N}_{2}\) and \(\hbox {CO}_{2}\) . The proposed permeability model was evaluated using published data for the Sulcis coal sample and is compared to three popular permeability models. The proposed model agrees well with the observed permeability changes and can predict the permeability of coal better than the other models. The sensitivity of the new model to changes in the physical, mechanical and adsorption deformation parameters of the coal was investigated. Biot’s coefficient and the bulk modulus mainly affect the effective stress term in the proposed model. The sorption deformation parameters and the factor \(f_\mathrm{m}\) affect the coal matrix deformation term.
Characteristic of water chemistry and hydrodynamics of deep karst and its influence on deep coal mining
深部喀斯特水文化学与流体动力学特征以及其对深部煤开采的影响
Arabian Journal of Geosciences, April 2014, Volume 7, Issue 4, pp 1261-1275
Abstract: The mining depth of main coal mines could reach around 600 m in eastern North China, and extends to the dept with speed of around 12 m/a. As the basement of eastern North China-type coal mine, the Ordovician karst aquifer is the main water source that influences the carboniferous coal seam mining. As the deep karst water has large buried depth and high water pressure (8–12 MPa), with10–30 m space between high pressure aquifer and coal seam, the geological area of deep coal occurrence is often forbidden for mining. Environmental damage, to a greater or lesser degree, is caused by coal mining. On the basis of analyzing the hydrogeological conditions of mining areas, this paper introduces the hydrogeological survey work of ultra-high confined karst water deep in the coal seam floor within researched region for preventing and controlling water disaster of the mine. After researching into the hydrogeological investigation data in the researched region, we explored the hydrodynamic and water chemical characteristics of deep karst water by using pumping test, dynamic observation, and dewatering test. Finally, this study suggests that the hydraulic pressure of deep mining could be mined, on the circumstances that reasonable and effective of water prevention measures are taken based on a detailed survey on water abundance of deep karst.
Groundwater outbursts from faults above a confined aquifer in the coal mining
煤开采中承压含水层之上断层的地下水突出
Natural Hazards, April 2014, Volume 71, Issue 3, pp 1861-1872
Abstract: Groundwater outburst has an impartible relationship with geological structures such as water-conducting faults, which are widely distributed in north China. In order to study the seepage property and mechanism of water outburst from the faults above a confined aquifer in the coal mining, the simulation model of ground water inrush for fault was designed. The water outburst parameters, such as water inflow, permeability, seepage velocity, porosity and other variables under different material combination and water pressures, were obtained; the research results indicate as follows: (1) The changes of the water inflow can be divided into three stages, i.e., the water inflow slowly increases at the early stage, rapidly increases at the middle stage and keeps unchanged at the late stage. (2) The seepage process can be represented by the seepage combination types, which are composed of pore flow, fissure flow and pipe flow, and the seepage changes not only with time but also with different conditions. (3) Mining would lead to the reactivation of faults and further enhance the permeability of fault zone potentially. The tiny granules in fault would be eroded and moved to exterior as the time under the high water pressure and lead to the change of porosity parameters. In this case, the seepage velocity would increase ceaselessly, and then the seepage would convert into pipe flow and finally lead to water inrush accidents.
Mining geohazards—land subsidence caused by the dewatering of opencast coal mines: The case study of the Amyntaio coal mine, Florina, Greece
露天煤矿排水引起的采矿地质灾害 – 地面沉陷：希腊Florina Amyntaio煤矿实例研究
Natural Hazards, January 2014, Volume 70, Issue 1, pp 675-691
Abstract: Mining activities impact the nearby environment, causing the so-called mining hazards. The land subsidence phenomena caused by the dewatering of the mines are listed among the mining-induced catastrophic geohazards slowly affecting extensive areas around the opencasts. These large-scale geo-hazards are related to both hydrogeological and geotechnical factors, and they cause irreversible damages. The research presented aims to clarify all the components of the phenomenon and to establish the proper modelling procedure for the study of its mechanism. The site under investigation is the area extending at the west—northwest of the Amyntaio opencast coal mine at Florina Prefecture, Northern Greece. The overexploitation of the aquifers for the protection of the slopes turned the opencast to a large-diameter well, draining the surrounding area. The extensive land subsidence phenomena extend 3–4 km around the mine causing severe damages in two villages. The established results can be used for monitoring and predicting the impact of the particular mining hazard on the natural and human environment, without precluding further exploitation and mining of the energy resources
Mitigation Measures Against Future Natural Disasters
未来减灾策略
Engineering for Earthquake Disaster Mitigation, Springer Series in Geomechanics and Geoengineering 2014, pp 275-322
Abstract: Reasons for the worldwide increase in the number of natural disasters, such as earthquakes, tsunamis, rainfalls and floods, are discussed, and the basic concept for mitigation of large-scale disasters is introduced. Earthquakes and tsunamis are predicted to occur in the near future in Japan, and the probable damage caused by such earthquakes is addressed. The strategies and organization of the Japanese government for disaster mitigation are introduced. Also introduced are recommendations to the Japanese government by the Science Council of Japan, for the creation of a safer country against increasing natural hazards and societal vulnerability, and for international cooperation in the mitigation of natural disasters.
Cloud technologies in mining geoinformation science
云技术在矿业地理信息学科中的应用
Journal of Mining Science, January 2014, Volume 50, Issue 1, pp 142-154
Abstract: The article discusses a new approach to implementation of a geoinformation environment for the mining geoinformation science problem solution using cloud technologies. In focus are the types of the cloud service as applied to the distributed geomonitoring networking for the wider range problem handling in mining. The authors describe specific structures of software support of the offered approach and exemplify problem solution in various spheres of mining geoinformation science.
