scholarly journals Prevention of Water Inrushes in Deep Coal Mining over the Ordovician Aquifer: A Case Study in the Wutongzhuang Coal Mine of China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Huichao Yin ◽  
Bin Xu ◽  
Shangxian Yin ◽  
Wuzi Tian ◽  
Hui Yao ◽  
...  
Keyword(s):  
Coal Mining ◽  
Prevention And Control ◽  
Water Pressure ◽  
Water Inrush ◽  
Mining Area ◽  
Full Time ◽  
Time Space ◽  
And Control ◽  
Ternary Structure

Through field observation and theoretical study, we found that the Hanxing mining area has a typical ternary structure in coal mining under high water pressure of the aquifer. This ternary structure is the Ordovician limestone aquifer-aquiclude including thin limestones-coal seam. Although the aquiclude is considerably thick, there is still a great risk of water burst during mining under water pressure in the deep burial environment. Multidimensional characteristics of floor water inrush in deep mining are summarized in the paper, including water migration upwardly driven by the Ordovician confined water, the planar dispersion of the water inrush channel, the stepped increase of the water inrush intensity, the hysteretic effluent of the water inrush time and the exchange, and adsorption of the water quality. The water inrush mechanism is clarified that the permeability, dilatancy, fracturing, and ascending of the water from the Ordovician limestone aquifer form a planar and divergent flow through the transfer, storage, and transportation of thin limestone aquifers. The corresponding water inrush risk evaluation equation is also proposed. Based on the thickness of the aquiclude, the thickness of the failure zones, and the water inrush coefficient, the floor aquiclude is classified into five categories. While water inrush cannot be completely controlled by the traditional underground floor reinforcement with ultra-thick aquiclude or even zonal grouting, a comprehensive prevention and control concept of the four-dimensional floor water hazard in full time-space domain are proposed. A tridimensional prevention and control model of three-dimensional reticulated exploration, treatment, verification, and supplementation is presented. A full time domain technological quality control process of condition assessment, exploration, remediation, inspection, evaluation, monitoring, and reassurance is formed, and a water disaster prevention method with full time-space tridimensional network in deep coal mining is established. Case study in the Hanxing mining area demonstrates that the proposed methods are highly effective.

scholarly journals Controlling Mechanism of Rock Burst by CO2 Fracturing Blasting Based on Rock Burst System

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Tianwei Lan ◽  
Chaojun Fan ◽  
Jun Han ◽  
Hongwei Zhang ◽  
Jiawei Sun
Keyword(s):  
Coal Mining ◽  
Rock Burst ◽  
Coal Mine ◽  
Prevention And Control ◽  
Stress Measurement ◽  
Tectonic Stress ◽  
Microseismic Monitoring ◽  
Time Space ◽  
Controlling Mechanism ◽  
And Control

Rock burst induced by mining is one of the most serious dynamic disasters in the process of coal mining. The mechanism of a rock burst is similar to that of a natural earthquake. It is difficult to accurately predict the “time, space, and strength” of rock burst, but the possibility of rock burst can be predicted based on the results of microseismic monitoring. In this paper, the rock burst system under the tectonic stress field is established based on the practice of coal mining and the result of mine ground crustal stress measurement. According to the magnitude of microseismic monitoring, the amount of the energy and spatial position of the rock burst are determined. Based on the theory of explosion mechanics, aiming at the prevention and control of rock burst in the coal mine, the technique of liquid CO2 fracturing blasting is put forward. By the experiment of blasting mechanics, the blasting parameters are determined, and the controlling mechanism of rock burst of liquid CO2 fracturing blasting is revealed. The application of liquid CO2 fissure blasting technology in the prevention and control of rock burst in Jixian Coal Mine shows that CO2 fracturing blasting reduces the stress concentration of the rock burst system and transfers energy to the deeper part, and there is no open fire in the blasting. It is a new, safe, and efficient method to prevent and control rock burst, which can be applied widely.

scholarly journals Perspective Of Stakeholders On The Sustainability Of Tuberkulosis Program

2020 ◽  
Vol 9 (1) ◽  
pp. 224-240
Author(s):  
Indasah Indasah ◽  
Dedi Saifulah ◽  
Anita Restu Korbaffo
Keyword(s):  
Prevention And Control ◽  
Case Study Research ◽  
Qualitative Approach ◽  
Service Program ◽  
Tb Control ◽  
Descriptive Research ◽  
Tb Treatment ◽  
Complete Treatment ◽  
And Control

This research is a type of descriptive research using a qualitative approach design using a case study research design. Funding for the TB program in Pasuruan Regency was sourced from the APBD and also Health Operational Assistance sourced from the Special Allocation Fund decreased. The budget for TB prevention prevention programs is absorbed entirely But the performance of achieving the discovery targets is still not significant. Still not found the whole case, complete treatment has not been maximized, some even DO. TB control activities allocated for TB prevention and control services appear to be relatively small compared to the TB treatment budget. Based on all the challenges faced, a strategy was formulated to eliminate TB within the next 5 years by strengthening the leadership of a quality TB service program with a sustainable program across stakeholders

The Prevention and Control of Marine Pollution: A Progress Report

1972 ◽  
Vol 1 (1) ◽  
pp. 51-78 ◽  
Author(s):  
E. D. Brown
Keyword(s):  
Prevention And Control ◽  
Oil Pollution ◽  
Marine Pollution ◽  
Progress Report ◽  
Hazardous Substances ◽  
Current Debate ◽  
Full Time ◽  
Look Ahead ◽  
Overlapping Spheres ◽  
And Control

Whether one is concerned with the continuing availability of caviar or the state of the beach at Brighton, it is difficult to remain unaware of the almost obsessive attention which is being paid to pollution in general and to marine pollution in particular by a host of institutions, national and international. Not only because the problem is a very complex and many-sided one but also because it is a politically fashionable one, there are very few international institutions which have not felt the necessity to take part in the current debate. One result is that it is rapidly becoming a full-time occupation to collect, digest and assess the ever-increasing volume of documentation, much of which reffects the overlapping spheres of juisdiction of the institutions concerned. The purpose of this paper, therefore, is to present a comprehensive progress report on the work of these institutions, whether their concern be with the prevention and control of marine pollution or with compensation for the damage it causes. It is hoped that such a report will provide a useful framework of reference for a better understanding of the preparations for and results of the several international conferences which are scheduled to meet in the next few years. The paper falls into six main parts. Following an introductory section on the institutional framework within which work is proceeding, parts II-V deal with the substance of that work on the prevention of oil pollution; liability for oil pollution; radioactive pollution; and marine pollution by other hazardous substances. Finally, part VI is devoted to a summing up and look ahead.

scholarly journals A Mechanical Model of the Overlying Rock Masses in Undersea Coal Mining and a Stress-Seepage Coupling Numerical Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jie Fang ◽  
Lei Tian ◽  
Yanyan Cai ◽  
Zhiguo Cao ◽  
Jinhao Wen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Coal Mining ◽  
Water Inrush ◽  
Mining Area ◽  
Analysis Model ◽  
Fractured Zones ◽  
Working Face ◽  
Seam Mining ◽  
Overlying Strata

The water inrush of a working face is the main hidden danger to the safe mining of underwater coal seams. It is known that the development of water-flowing fractured zones in overlying strata is the basic path which causes water inrushes in working faces. In the engineering background of the underwater mining in the Longkou Mining Area, the analysis model and judgment method of crack propagation were created on the basis of the Mohr–Coulomb criterion. Fish language was used to couple the extension model into the FLAC3d software, in order to simulate the mining process of the underwater coal seam, as well as to analyze the initiation evolutionary characteristics and seepage laws of the fractured zones in the overlying strata during the advancing processes of the working face. The results showed that, during the coal seam mining process, the mining fractured zones which had been caused by the compression-shear and tension-shear were mainly concentrated in the overlying strata of the working face. Also, the open-off cut and mining working face were the key sections of the water inrush in the rock mass. The condition of the water disaster was the formation of a water inrush channel. The possible water inrush channels in underwater coal mining are mainly composed of water-flowing fractured zones which are formed during the excavation processes. The numerical simulation results were validated through the practical engineering of field observations on the height of water-flowing fractured zone, which displayed a favorable adaptability.

scholarly journals Hydrogeochemical Evolution and Control Mechanism of Underground Multiaquifer System in Coal Mine Area

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Qiding Ju ◽  
Yu Liu ◽  
Youbiao Hu ◽  
Yuquan Wang ◽  
Qimeng Liu ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Mine Water ◽  
Control Mechanism ◽  
Water Inrush ◽  
Pyrite Oxidation ◽  
Mining Area ◽  
Carbonate Dissolution ◽  
Mining Activities ◽  
Hydrogeochemical Evolution ◽  
And Control

Mining activities interfere into the natural groundwater chemical environment, which may lead to hydrogeochemical changes of aquifers and mine water inrush disasters. The study of hydrogeochemical evolution processes of underground aquifers is helpful to the prevention and control of mine water inrush. The results show that the study area is mainly impacted by four hydrogeochemical processes: dissolution, cation exchange, desulfurization and reduction, and pyrite oxidation. The Cenozoic aquifers are dominated by carbonate dissolution and desulfurization. The Permian aquifers are impacted mainly by cation exchange and sulfate dissolution, followed by pyrite oxidation. The Carboniferous aquifers are mainly impacted by dissolving sulfate, followed by pyrite oxidation and cation exchange. The hydrogeochemical evolution of the aquifers was controlled by mining activities and tectonic changes, and a certain regularity in space. For the Cenozoic aquifers, sulfate dissolution and cation exchange increase from west to east, and desulfurization weakens. For the Permian aquifers, cation exchange and sulfate dissolution are stronger near synclines and faults, pyrite oxidation is enhanced, and desulfurization decreases from the middle to the east of the mining area. For the Carboniferous aquifers, there is a higher dissolution of rock salt, pyrite oxidation, and cation exchange from west to east, and the desulfurization effect weakens.

scholarly journals Hydrological Characteristics of Ordovician Karst Top in a Deep Region and Evaluation of Its Threat to Coal Mining: A Case Study for the Weibei Coalfield in Shaanxi Province, China

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Tao Li ◽  
Jiarui Zhang ◽  
Ying Gao ◽  
Xinqi Cao ◽  
Hongyang Liu ◽  
...  
Keyword(s):  
Coal Mining ◽  
North China ◽  
Water Pressure ◽  
Water Inrush ◽  
Drainage Water ◽  
Shaanxi Province ◽  
Water Drainage ◽  
Mining Areas ◽  
Hydrogeological Characteristics ◽  
In Situ Experiments

Widely distributed in North China, Ordovician karst is characterized by having high thickness, nonuniform aquosity, and significant water pressure-bearing properties. Deep mining in North China is threatened by associated water hazards; hence, research on the hydrogeological characteristics of deep Ordovician karst is needed. In this study, the Weibei coalfield in Shaanxi Province, China, was selected as the study area, especially mines in the Hancheng and Chenghe mining areas. In situ experiments, including water pumping, water drainage, water injecting and water pressure, and laboratory experiments, were conducted to study the hydrogeological characteristics of the Ordovician karst top in the study area. A comprehensive analysis was conducted on controlling factors for the development of the Ordovician karst top in the study area, and a method for evaluating the water inrush risk in coal mining areas based on karst hydrogeological characteristics was proposed. The research results indicated that the Ordovician karst top in the study area was characterized by heterogeneity, vertical zonation, and partially filled properties, which were mainly controlled by two factors: sedimentation and tectonism. The hydrogeological conditions of the Ordovician karst could be divided into three types: nonfilled and nonsignificant tectonism, filled and nonsignificant tectonism, and significant tectonism. Among them, the filled and nonsignificant tectonism type Ordovician karst top type had a filling thickness of 20 m. Based on karst hydrogeological characteristics, the methods were proposed to evaluate the water inrush risk in the coal mining floor. The practical tests verified the methods.

scholarly journals Optimization of Impervious Surface Space Layout for Prevention of Urban Rainstorm Waterlogging: A Case Study of Guangzhou, China

2019 ◽  
Vol 16 (19) ◽  
pp. 3613 ◽  
Author(s):  
Yu ◽  
Zhao ◽  
Fu
Keyword(s):  
Urban Renewal ◽  
Surface Runoff ◽  
Prevention And Control ◽  
Urban Runoff ◽  
Impervious Surface ◽  
Impervious Surfaces ◽  
Space Layout ◽  
And Control ◽  
Runoff Plots

With the rapid expansion of impervious surfaces, urban waterlogging has become a typical “urban disease” in China, seriously hindering the sustainable development of cities. Therefore, reducing the impact of impervious surfaces on surface runoff is an effective approach to alleviate urban waterlogging. Presently, the development mode of many cities in China has shifted from an increase in urban scale to the improvement of urban quality through urban renewal, which is the current and future development path for most cities. Optimizing the design of impervious surfaces in urban renewal planning to reduce its impact on surface runoff is an important way to prevent and control urban waterlogging. The aim of this research is to construct an optimization model of impervious surface space layout under the framework of a geographic simulation technology-integrated ant colony optimization (ACO) and Soil Conservation Service curve number (SCS-CN) model (ACO-SCS) in a case study of Guangzhou in China. Urban runoff plots in the study area are divided according to the area of the urban planning unit. With the goal of minimizing the runoff coefficient, the optimal space layout of the impervious surfaces is obtained, which provides a technical method and reference for urban waterlogging prevention and control through urban renewal planning. The results reveal that the optimization of impervious surface space layout through ACO-SCS achieves a satisfactory effect with an average optimization rate of 9.52%, and a maximum optimization rate of 33.16%. The research also shows that the initial impervious surface layout is the key influencing factor in ACO-SCS. In the urban renewal planning stage, the space layout of the impervious surfaces with a high–low–high density discontinuous connection can be constructed by transforming medium-density impervious surfaces into low-density impervious surfaces to achieve the flat and long-type agglomeration of the low-density and high-density impervious surfaces, which can effectively reduce the influence of urban development on surface runoff. There is spatial heterogeneity of the optimal results in different urban runoff plots. Therefore, the policy of urban renewal planning for urban waterlogging prevention and control should be different. The optimized results of impervious surface space layout provide useful reference information for urban renewal planning.

Sign in / Sign up

Export Citation Format

Share Document