Coal Mine Accidents Research Articles

Modified Stochastic Petri Net-Based Modeling and Optimization of Emergency Rescue Processes during Coal Mine Accidents

The coal mine accidents seriously affect the safety and efficiency of mining for coal mining enterprises. The reliable emergency rescue (ER) processes are explored to minimize the loss of accidents. This paper introduces the stochastic Petri net (SPN) and Markov chain (MC) models based on the system structure flow to analyze the ER processes of coal mine accidents. In addition, a triangle fuzzy strategy is presented to optimize the SPN model. The “9·28” major water inrush accident in Shanxi Fenxi Zhengsheng Coal Company of China is adopted to evaluate the time performance and accident data of the ER process. The MC model-based steady-state probabilities of the system under various states are used to calculate the average delay time of this system. The triangular fuzzy strategy is used to analyze the change value of the total time in the ER system at the unit transition speed when the firing rate of each transition is changed, which finds the most time-consuming key activities in the ER process. The results show that SPN and MC can reflect the dynamic behaviors of ER process, which provides a reference for the rescue operations of other coal mine accidents. The triangular fuzzy strategy can quickly find out the key activities affecting the ER time, which greatly decreases the calculations generated by analyzing the total time of the system changed at the unit transition speed.

Development of Intelligent Wellhead Platform for Rescue Truck-mounted Drilling Rig

In view of the low efficiency of rescuing trapped people in coal mine accidents, the factors affecting rapid drilling are analyzed. Through the modular and intelligent technology of rescue vehicle drilling rig, a kind of intelligent wellhead platform drilling tool is developed. The wellhead platform has the functions of automatic levelling and automatic screwing and unloading of drilling tools, and realizes the efficient centering, clamping and automatic screwing and unloading functions of all kinds of diameter drilling tools. The automatic levelling of the intelligent wellhead platform adopts the closed-loop control strategy, the dynamic automatic levelling of the wellhead platform, and the automatic screwing and unloading device adopts program control, which realizes the automatic unloading of drilling tools with one button. The intelligent wellhead platform can be quickly assembled with the main engine, saving drilling auxiliary time, and is of great significance for underground rescue in coal mines.

Construction and analysis of a coal mine accident causation network based on text mining

It is important to systematically identify the contributing factors in coal mine accidents from a large-scale analysis of accident reports. However, previous scholars have mainly used human analysis methods to define accident-causing factors, leading to incomplete and biased cause checklists due to personal experience and knowledge. Furthermore, a data-driven method is needed to quantify the importance of each factor and clarify the mechanism of different types of accidents. Considering these, this study creatively combined text mining technology and a complex network to explore the coal mine accident-causing mechanism. Through the text mining of 307 accident reports, 52 main accident-causing factors were identified, and a coal mine accident causation network was constructed based on the strong association rules among factors. Second, eight core factors and their associated sets, as well as seven critical links for different accident types, were clarified through network centrality analysis and accident path analysis. This study shows that regulatory authority is the most influential level of accident causation, gas accidents are the most easily triggered accident type, a lack of effective mechanism for safety supervision→failure to arrange full-time safety inspectors to follow the shift→lack of serious and thorough on-site hidden danger investigations→inadequate anti-surge measures are the key links in gas accident causation. This study contributes new perspectives on identifying contributing factors and their complex interaction mechanisms from accident report data for practical applications in risk analysis and accident prevention.

Study on the role of the accident statistics in the design of coal mine safety signs

Accident statistics is an important basis in designing coal mine safety signs. In this paper, we study the process and feasibility for accident statistics as the design basis of the coal mine enterprise safety signs. This paper comes into a conclusion of unsafe actions which cause the accident can be divided into two categories: illegal action and error action. Illegal action could be subdivided into habitual illegal action and accident illegal action, while error action could be subdivided action into skills, decisionmaking and physiological perceptual action. In this paper, we specifically analyze five coal mine accident cases as examples, in order to conclude unsafe actions and unsafe states in every case. Specifically, unsafe acts are: bolt pretightening does not reach the designated position, sitting on the belt, no remote operating point column, maintenance without power cuts and operating under pressure. In addition, these unsafe acts lead to relative unsafe states, which are insufficient bolt pressure, point column instability, machine charging electricity and hydraulic pipe under pressure? Finally, these unsafe states become causations of accidents. Based on statistical analysis, we found out illegal actions of coal mine accident cases and specifically designed five safety signs, which are ‘bolt must be preloaded in place’, ‘be careful of the column’, ‘ban to sit on belts’, ‘forbidden pressing operation’ and ‘maintenance must be power outages’.

PERSEPSI KARYAWAN TERHADAP SISTEM PELAPORAN KECELAKAAN KERJA DAN POTENSI BAHAYA DI PERTAMBANGAN BATUBARA PT. PUTRA KAJANG KALIMANTAN TIMUR

Work accidents in coal mining still occur frequently, so an accident reporting system is needed as an effort to prevent work accidents. This study aims to explain the perceptions of coal mining employees on the reporting system for work accidents and potential hazards. The research design was descriptive with a sample size of 55 people. Data collection was carried out using a questionnaire. Data were analyzed descriptively. As many as 67.3 % of employees have positive perceptions and 32.7 % of employees have negative perceptions of the work accident reporting system and potential hazards. There are 72.7% of employees consider it important to report accidents and potential hazards. It was found that 30.9 % of employees had experienced work accidents and only 5.4 % of them reported accidents. Employees consider a good accident reporting system, among others, digitally 84.6 % and manually 9.1 %. As many as 90.9 % of employees agree and 81.8 % of employees are willing to report accidents and potential hazards if the company implements a digital-based reporting system. There are still employees who have negative perceptions of the work accident reporting system and potential hazards in coal mining. Therefore, efforts are needed to increase employee perceptions from negative to positive perceptions of the work accident reporting system and potential hazards in coal mining companies.

From aggregate to part: Study on the change of coal mine safety records in China under the intervention of risk pre-control management system

Risk pre-control management is of great significance to the safe production of China's coal-mining industry, so it is necessary to clarify the role and existing problems of the current risk pre-control system in China's coal-mining enterprises. On the basis of expounding the background and mechanism of the risk pre-control system, this paper first evaluates the overall intervention effect of the system by constructing an interrupted regression model, and then analyzes the prevention effect of the system on coal mine accidents by category, finding out the urgent needs for improvement. The results suggest that the establishment of risk pre-control management system has no obvious effect on the improvement of coal mine safety records in the short term, but has a significant positive effect in the long run. Moreover, since the construction of the system, its intervention effect on roof accidents, transportation accidents, flood accidents and other accidents is tremendous, while the effect on gas accidents and electro-mechanical accidents is weak, and the control of fire accidents is the worst. Finally, from the system construction process and the nature of accidents, this paper puts forward the corresponding safety management suggestions and accidental prevention measures to further improve the quality of risk pre-control management in China.

Characteristics and trends of coal mine safety development

ABSTRACT During the “12th Five-Year Plan” period (2011–2015), the safety production situation of coal mines in Guizhou province was generally good. The main types of accidents are gas, flood and roof accidents. The average fatalities for each type of accident were 6.2, 6.8 and 1.2, respectively. During the “12th Five-Year Plan” period, 45 gas accidents occurred and 277 people died, accounting for 18.03% and 48.94% of the total accidents, respectively; 10 flood accidents caused 68 deaths, accounting for 4.1% and 12.01% of the total accidents, respectively; 106 roof accidents caused 129 deaths, accounting for 43.44% and 22.79% of the total accidents, respectively. The number of accidents and casualties is decreasing year by year. Compared with 2015 and 2010, the number of accidents and fatalities decreased by 213 and 324, decreased by 96.82% and 95.27%, respectively. The accident rate of state-owned coal mines was relatively high, and the rate of decline was higher than that of private coal mines. After 2012, the accident rate of production mines was lower than that of construction mines, and preventive measures were explained in terms of safety law enforcement, supervision and technology. The research results have certain reference significance for the government supervision departments to strengthen coal mine safety production, and help to take safety precautions to avoid coal mine accidents.

Correlation in Causality: A Progressive Study of Hierarchical Relations within Human and Organizational Factors in Coal Mine Accidents.

It has been revealed in numerous investigation reports that human and organizational factors (HOFs) are the fundamental causes of coal mine accidents. However, with various kinds of accident-causing factors in coal mines, the lack of systematic analysis of causality within specific HOFs could lead to defective accident precautions. Therefore, this study centered on the data-driven concept and selected 883 coal mine accident reports from 2011 to 2020 as the original data to discover the influencing paths of specific HOFs. First, 55 manifestations with the characteristics of the coal mine accidents were extracted by text segmentation. Second, according to their own attributes, all manifestations were mapped into the Human Factors Analysis and Classification System (HFACS), forming a modified HFACS-CM framework in China’s coal-mining industry with 5 categories, 19 subcategories and 42 unsafe factors. Finally, the Apriori association algorithm was applied to discover the causal association rules among external influences, organizational influences, unsafe supervision, preconditions for unsafe acts and direct unsafe acts layer by layer, exposing four clear accident-causing “trajectories” in HAFCS-CM. This study contributes to the establishment of a systematic causation model for analyzing the causes of coal mine accidents and helps form corresponding risk prevention measures directly and objectively.

Analysis on the Causes of Coal Mine Accidents and Research on Prevention Countermeasures

In order to explore coal mine accident prevention and control countermeasures, the coal mines in Jiangxi Province were taken as representatives to analyze the causes of coal mine accidents in Jiangxi Province from 2000 to 2013 and put forward targeted prevention and control countermeasures. It is of great significance to the prevention and control of similar coal mine accidents.

Safety Monitoring System in Coal Mine Using IoT

The key abstract is to use IoT to incorporate a coal mine safety monitoring system. The extraction of coal from the field is known as coal mining. Coal is used as a fuel in the steel and cement industry to extract iron from ore and to manufacture cement. Every parameter in the underground mining industry must be controlled on a regular basis, including methane gas, high temperatures, fire incidents, and so on. The level of safety in coal mines is still poor, resulting in fatalities. A coal mineshaft salvage action is profoundly perilous because of various elements. It is particularly risky for rescuers to enter a coal mineshaft burrow in a debacle without earlier attention to the climate on the grounds that ensuing blasts are probably going to happen at any second. It is along these lines basic to recognize unstable climate data like toxic gases and high temperatures, just as to direct a visual review of excavators caught in a fell passage through the imploded burrow. These information would aid rescuers in devising a strategy and equipping themselves to carry out the rescue operation defensively. This paper proposes a design for coal mines that will reduce the damage caused by a coal mine accident and allow for a more effective rescue operation.

Coal Mine Safety Monitoring and Alert System

The accidents in coal mines are increased day by day. There are numerous life losses of many skilled workers and laborers. There is no advent precaution measure to detect the alarming cause of the coal mine accidents and provide an alert system. Occupational accidents and occupational diseases are common in the mining. The most common causes of accidents in coal mining are firedamp and dust explosions, landslips, mine fires, and technical failures related to transport and mechanization. An analysis of occupational accidents in the consideration of social and economic factors reports that the real causes behind these accidents, which are said to happen inevitably due to technical deficiencies or failures. Thus an automated alarming coal mine accident detect ion system is employed to rescue and protect the workers from the hazards. This system incorporates the combined action of the temperature, pressure and gas sensor and IOT module to detect the temperature, pressure and atmosphere in the coal mine and log every data onto the cloud using data logging. Then these data are accepted by a admin controlled sever page through data acquisition. The data processing takes place at a server page and the alert is send to the device to glow the alarm and to the concerned officials and rescue stations for taking the prevention measures.

Experimental Study on Injuries to Animals Caused by a Gas Explosion in a Large Test Laneway

Gas explosion accidents in underground coal mines caused a significant number of casualties. By using a large laneway test system, the damage to Sprague-Dawley (SD) rats at locations at different distances from the source of ignition along the direction of propagation of an explosion was investigated after 100 m3 of the gas-air mixture was ignited and exploded. In this way, the data pertaining to explosion flames and explosion pressures at different propagation distances were obtained to investigate the propagation of explosion flames and explosion pressures along the laneway. Besides, the damage to SD rats at different propagation distances was statistically analyzed. Furthermore, the damage mechanism of explosion flames, explosion pressures, and hazardous gases on humans or animals was discussed. The results indicated that explosive blast injury induced by the gas explosion was the primary reason for the death of animals and SD rats at a distance equal to or greater than 80 m from the point of ignition under the effects of an explosive blast even though SD rats at a distance of 240 m were killed. During the explosion of 100 m3 of mixed gas, the explosion flames propagated 40 m from the point of ignition, and the SD rats in the cage located some 40 m from the point of ignition were subjected to combined damage involving being burned at high temperature and suffering the effects of the explosive blast. These findings provide a theoretical basis for emergency rescue and salvage after gas explosion accidents in underground coal mines.

Progressive failure mechanical behaviour and response characteristics of sandstone under stress-seepage coupling

AbstractConventional triaxial loading tests with different confining pressures and stress-seepage coupling tests on sandstone with different confining pressures and seepage pressures were conducted. A permeability model considering strength and strain was established, which better characterized the progressive deformation mechanical behaviour of sandstone under stress-seepage coupling. The results showed the following. (i) The confining pressure not only affects the peak strength of sandstone but also affects the axial deformation under conventional triaxial loading conditions. (ii) Compared with the seepage pressure effect, the degree of the confining pressure effect on the strength of sandstone was weaker, but the degree of that on the axial, radial and volumetric deformations of sandstone was stronger under stress-seepage coupling. (iii) With increasing confining pressure, the axial strain of sandstone decreased, while the corresponding radial and volumetric strains showed progressively increasing evolution characteristics under identical seepage pressures and different confining pressures. With increasing seepage pressure, the axial strain continuously decreased, while the corresponding radial and volumetric strains showed the progressive evolution characteristic of first increasing and then decreasing under identical confining pressures and different seepage pressures. (iv) Compared with the confining pressure effect, the degree of the seepage pressure effect on the permeability progressive evolution law of sandstone was weaker under stress-seepage coupling. The research conclusions could enrich the theories for the prevention and control of water inrush accidents in coal mines.

Framing and blaming: Media coverage of coal mining accident coverups in China

Coverups and under-reporting of coal mining accidents are pervasive in China, but no research has studied how the media has portrayed these accident coverups or attributed responsibility. By extracting news articles from major Chinese news outlets, this study shows that the coverup cases receiving the most coverage were those with high casualties and the involvement of government officials and journalists, while other cases did not receive much media attention. The media also intimated pervasive collusion between the government and coalmines. More blame was attributed to local officials than to coalmine owners. Victims’ families were also accused of accepting higher compensation and being part of the coverup network. This study further explores the underlying motivations for the media's framing choices and their possible effects on society and policymaking. It maintains that the portrayal of pervasive government-coalmine collusion in coverage of accident coverups may have led to more similar incidents.

Preparation and performance analysis of bisamido-based cationic surfactant fracturing fluid for coal seam water injection

Coal seam water injection fracturing can achieve the gap formation of the coal seam and increase the porosity of the coal seam. The water injection fracturing fluid wetting the coal body can wet the coal body in advance, reducing the generation of coal dust during coal mining, as well as play a preventive role in many coal mine accidents and optimize the safety state of the coal mine. To further improve the water injection efficiency of the coal seam. In this paper, erucic acid, N,N-dimethyl-1,3-propanediamine and epichlorohydrin were used as raw materials to synthesize a bisamido cationic surfactant under acidic conditions, and mixed with a KCl solution to prepare a clean fracturing fluid that can be used in the water wetting of a coal seam. The functional groups and microstructure changes of the product are observed by FTIR and SEM. Related performance experiments show that the product has the advantages of good shear stability viscosity, low filtration loss, good gel breaking performance and strong wettability. The analysis of the cleanability shows that the gel breaking liquid has a low residue content and good compatibility. Therefore, the product is an ideal clean fracturing fluid for water injection fracturing of coal seam.

Surface-to-Underground Nuclear magnetic Resonance Detection of Aquifer

The water hazard is one of the major accidents in coal mines. The existing geophysical exploration methods do not meet the precise requirements for exploration accuracy. Nuclear magnetic resonance (NMR) is currently the only geophysical method that can directly detect groundwater. This paper firstly introduces the basic principles and working methods of surface-to-underground NMR, and then gave the NMR response of the uniform earth excited by a circular loop source, at last, the NMR responses of some aquifers at different depths were simulated by the numerical modeling. The response for the observation underground is higher than that on the surface, which shows that the surface-to-underground NMR can increase the detection depth.

Evaluation model of coal mine emergency rescue resource allocation based on weight optimization TOPSIS method

In order to solve the problems of unreasonable allocation and low efficiency of emergency rescue resources in coal mine accidents, it is necessary to establish a coal mine emergency rescue resource allocation model by using comprehensive weight-approximation ideal solution (TOPSIS method).This paper takes rock burst in a coal mine as an example by extending this designed emergency rescue plan. Firstly, calculated the weight of the evaluation index affecting the emergency rescue is selected by AHP method and entropy weight method respectively. Then weight optimization is inspired by comprehensive weight method. Finally, the optimal scheme is selected by TOPSIS method, and the model is verified by AHP method approaching ideal solution and entropy weight method approaching ideal solution. The results shows that: (1) There are two influencing factors have great effect on the evaluation of coal mine emergency rescue model, which are rescue time and advance of rescue channel; (2) The optimal scheme is program 5 through comprehensive weight approaching ideal solution, which is consistent with the actual situation of the project, indicating that the model has high reliability.

Molecular model construction of Danhou lignite and study on adsorption of CH4 by oxygen functional groups.

In view of the frequent occurrence of gas accidents in coal mines, the mechanism of oxygen-containing functional groups (OCFGs) in Danhou lignite adsorbing gas was studied by experiment and simulation. Elemental analysis, X-ray photoelectron spectroscopy (XPS), solid-state 13C nuclear magnetic resonance spectroscopy (13C-NMR), and adsorption experiment of CH4 were applied to establish the macromolecular model of Danhou lignite. Then, molecular mechanics (MM) and molecular dynamics (MD) were utilized to optimize the coal macromolecular model, and the density of coal was determined via adding periodic boundary conditions. The mechanism of gas adsorption by OCFGs was studied by grand canonical Monte Carlo (GCMC) and density functional theory (DFT). The results showed that the aromatic structures mostly exist in the form of pyrenes; the structure of aliphatic carbons are mostly methylene and methine groups; the alkanes are mostly long chains; oxygen atoms are mainly in the form of hydroxyl groups and ether groups; nitrogen atoms are mainly in the form of pyridines; and the density of Danhou lignite is 1.25 g/cm3. The isotherm adsorption curve and Langmuir adsorption curve have a good fit, a single coal molecule reaches saturation after absorbing four CH4 molecules, and the error between experiment and simulation is small. The results of DFT calculation showed that the adsorption of CH4 by OCFGs is affected by the adsorption positions and adsorption directions. Due to CH4 molecules are affected by different electrostatic forces, the adsorption capacities of OCFGs are different, and the order is carbonyl groups > ether bonds > hydroxyl groups > carboxyl groups. The results can be used for reference in the prevention and control of coal and gas outburst.

Predictive Model for Concentration Distribution of Explosive Dispersal.

At present, concentration of explosive dispersal is very difficult and uncertain to measure. Numerical experimentation can avoid this deficiency. Data of particles during dispersal are readily available, including velocity, displacement, and mass. However, there is minimal research on the concentration of explosive dispersal. Existing models used for the calculation of particle concentration neglect measuring the initial condition of particles and cannot, therefore, accurately describe the whole particle dispersion process. Moreover, existing concentration models do not take into account the continuous decrease in the size of particles caused by stripping and evaporation effects during flight, resulting in inaccurate descriptions of the concentration distribution. Consequently, this work derives a model to predict the concentration distribution of liquid and granular material dispersal, considering the two questions above. Concentration can be calculated based on the condensed-phase distribution and gas-phase distribution of the fuel cloud at different times by the model. This model was validated using experimental data on the mean concentration of dispersal and was well fitted. Therefore, it can be used as a tool to predict the dispersal of liquid and granular material, an explosion suppressant in coal mine accidents, and an aerosol fire extinguishant in remote forest fire extinguishers. Moreover, being able to predict the concentration of large-scale dispersal can significantly improve the accuracy and efficiency of secondary detonation.

Analysis and measurement of multifactor risk in underground coal mine accidents based on coupling theory

Coal mine accidents are not only caused by a single factor risk, but also by the coupling between multifactor risks. Therefore, exploring the mechanism of multifactor risk and measuring the coupling risk is particularly important for controlling coal mine accidents. This paper explores the definition, classification, coupling process and decoupling principle of multifactor risk in underground coal mine accidents. A multifactor risk measurement model based on coupling theory is proposed to measure the magnitude of the risk coupling effect using data of 375 major accidents from 2001 to 2016. The results indicate that the risk caused by the coupling of human-environment-management is the greatest in the three-factor risk coupling of coal mine, and the risk coupling of human and management factors produces greatest risk in two-factor risk coupling. The risk value of coal mine accident increases with the increase of coupling factors. The decoupling idea can be used to weaken the coupling effect among the factors found in coal mining enterprises.