Underground Workplace Research Articles

Evaluation of orderliness of underground workplace system based on occupational ergonomics: A case study in Guangzhou and Chengdu metro depots.

An underground workplace (UGW) is a complex system with multiple subsystems that interact with each other. However, the research on UGW from a systemic perspective has not received due attention. This study constructs an evaluation approach to the orderliness of UGW and systematically evaluates the UGW with Guangzhou and Chengdu metro depots as case studies. First, the evaluation index system is established based on occupational ergonomics. Second, the system entropy model is constructed based on information entropy. Third, a dissipative structure judgment model is built based on the Brusselator. Fourth, the orderliness evaluation model is constructed based on information entropy and synergetics. The UGW of the metro depot has not yet reached the dissipative structure and is in a medium-order state. But the system is in the trend of orderly development. The entropy increase caused by the physical environment and health status is the main obstacle for the system to move toward order. The equipment configuration is an essential source of system negative entropy. The coordination between equipment configuration, health status, and physical environment is low, and that of work effectiveness, equipment aging and failure, and organizational environment is high. Equipment configuration cannot fully cope with the harsh physical environment and meet the needs of underground workers. Safety security equipment has more room for improvement. Humanized support facilities can introduce more negative entropy to the system. Organizational intervention can reduce the negative impact of adverse factors on the system.

The Impacts of Workplace Environment on Coal Miners' Emotion and Cognition Depicted in a Mouse Model.

Most coal mine accidents are caused by the unsafe behavior of employees. Previous studies have shown that there is a significant connection among the working environment, the psychological state of employees, and unsafe behaviors. However, the internal biological mechanism has not been revealed. To explore the physiological and psychological alterations of coal mine workers and the underlying mechanisms that cause unsafe behaviors, the current study established a novel coal mine environment biological simulation (CEBS) model in mice. This model recreated the underground workplace environment facts in coal mines such as temperature, humidity, and noise, and mice were employed to receive these conditioning stresses according to the 8-h work. Animal behavior tests were performed to evaluate the evolution of the mental state including anxiety and depression, as well as the abilities of learning and memory during the 4-week environmental simulation. CEBS mice showed the adaptation process of anxiety from occurrence to stability in the process of environmental simulation, and also suffered from severe depression compared to the control mice. In addition, impaired spatial memory was also implicated in mice after 4-week CEBS. The behavior results of CEBS mice were consistent with the previous psychological investigation of coal workers. In summary, a novel mouse model was established in this study to depict the occurrence of negative emotions and impaired cognition in coal miners by simulating the underground workplace environment, which provided a basis for further exploring the biological mechanism of miners’ unsafe behavior.

Study on application of two risk assessment methods in coal dust occupational health risk assessment

Objective: To evaluate the applicability of quantitative grading method (GBZ/T 229.1-2010) and occupational hazard risk index method in coal dust occupational health risk assessment. Methods: Taking 4 coal mines as the research object of risk assessment and making occupational health field testing and investigation. Based on two risk assessment methods, we analysed the health risk levels of 20 occupations which were exposed to coal dust in workplaces. Results: Coal dust working post had different risk levels in 4 coal mines, the post of higher risk level were mainly concentrated in the underground workplace of coal mine, especially the post of coal mining and tunneling system. The two risk assessment results showed that the risk levels of coal-mining machine drivers and tunneling machine drivers were the highest. The risk levels of coal dust working post used by two risk assessment methods had no significant difference (P>0.05) and were highly correlated (r=0.821, P<0.001) . Evaluation results of two risk assessment methods were supported by the field investigation and literatures. Conclusion: The two risk assessment methods can be used in coal dust occupational health risk assessment.

Radon measurements and dose estimate of workers in a manganese ore mine

In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm−3. This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices – including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) – were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm−3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold.

HEMS technique for heat-harm control and geo-thermal utilization in deep mines

With the increasing exploitation scope and intensity, the shallow resources would be exhausted in the future; and the deep mining will become an essential choice. In deep tunnel engineering, the heat-harm becomes one of the main barriers. Investigations on high temperature coal mine have been done in Northern China, with the constructing of three models of high temperature mines suffering heat-harm, at the Jiahe mine, Sanhejian mine and Zhangshuanglou mine. The domestic and abroad cooling technologies of the mine respectively are also summarized after comparatively analyzing the advantages and disadvantages of each technology. Finally, we find that the high temperature exchange machinery system (HEMS) technology that use mine discharge as the cold source, is excellent to heat-harm control in deep mines. Taking the Jiahe coal mine as an example, we systematically introduce this technology by disposing three main workstations. HEMS technology with its operations and functions in different exploitation levels are accomplished, including the extraction of refrigerating output, the transportation of chilled water by closed circulation line, the decompression of circulation lines and equipment by pressure transformation machine, and the heat exchange and cooling of workplace by heat exchange between wind stream and the chilled water. The exchanged heat source from the workplace is taken to ground heating by the circulating water which acts as a carrier. It shows that the HEMS-technology benefit in environment protection and emission reduction. Results of this project illustrate that it is efficient in heat-harm control with the temperature decrease of the workplace down to 26–29 °C, and being 4–6 °C lower than the original, and the relative humidity 5 %–15 % lower than before. It greatly improves the working environment of underground workplace suffering heat-harm of high temperature and high humidity. In addition, by the extracting of deep geothermal energy, ground fired boiler for heating has been replaced, reducing environmental pollution. This technology is worth generalization in deep mines and related fields.

Mine Dust Concentration Measurement Method Based on Model of Dust Concentration and Humidity

According to the coal mine underground work place humidity changes affect the measurement precision of dust concentration, improper spray cause coal with the water loss and wastes a lot of water resources, the paper put forward a correction factor of dust concentration based on the relative humidity, establish the relation model of concentration and humidity. The test results show that: the dust concentration correction factor and relationship model of concentration and humidity are effective and scientific, it has better practicability to solve the problem of underground coal mine.

Comparison of real-time and traditional monitoring methods for diesel particulate matter in underground metal mines: A meta-analysis

Objective To conduct a meta-analysis of published studies to determine if a real-time instrument can be used as a screening tool to estimate the concentrations of diesel particulate matter (DPM) in air within an underground mine workplace. The instrument chosen for review is the TSI DustTrak. The DustTrak was chosen because of the growing popularity, ease of use, and relative low cost as compared to other real-time instruments used in the underground mining industry. Determination of acceptability for DustTrak use would be based on comparison of instrument results to monitoring results from the currently accepted pump-filter air sampling methods for DPM. Methods After a comprehensive literature search, a total of two studies meeting requirements for a meta-analysis on performance of the DustTrak were identified and used for this analysis. Results Meta-analysis of the available DPM exposure monitoring data resulted in a Combined Pearson's Correlation Coefficient (CPCC) of 0.893 (p Conclusions The results from this meta-analysis are supportive of the DustTrak as an acceptable supplementary sampler (e.g., used to verify the adequacies of exposure controls) for providing acceptably accurate real-time concentration levels of DPM in air in an underground mining operation. Although the DustTrak correlates well with the NIOSH method, its monitoring results do consistently read higher than the NIOSH method.

Radon dose calculation methodology for underground workers in the Czech Republic

The project focused on classifying the level of irradiation from natural ionising radiation sources for workers in publicly accessible caves and in caves used for speleotherapy, with applicability to other underground workplace. A correct and accurate procedure (and calculation) is defined for determining the effective dose that workers are exposed to in caves, based on the results of integral measurements of radon volume activity and on the length of time spent by workers in the caves. A review was made of various approaches for evaluating lung irradiation found in the literature. Experimental measurements of cave atmosphere characteristics (continuous measurement of radon volume activity, continuous and integral measurements of radon decay products, interior climatic parameters and aerosol spectra) were the main sources for the methodology.

Reconciling longwall gob gas reservoirs and venthole production performances using multiple rate drawdown well test analysis

Abstract Longwall mining is an underground mining method during which a mechanical shearer progressively mines a large block of coal, called a panel, in an extensive area. During this operation the roof of the coal seam is supported only temporarily with hydraulic supports that protect the workers and the equipment on the coal face. As the coal is extracted, the supports automatically advance and the roof strata cave behind the supports. Caving results in fracturing and relaxation of the overlying strata, which is called “gob.” Due its highly fractured nature, gob contains many flow paths for gas migration. Thus, if the overlying strata contain gassy sandstones or sandstone channels, gas shales or thinner coal seams which are not suitable for mining, then the mining-induced changes can cause unexpected or uncontrolled gas migration into the underground workplace. Vertical gob gas ventholes (GGV) are drilled into each longwall panel to capture the methane within the overlying fractured strata before it enters the work environment. Thus, it is important, first to understand the properties of the gas reservoir created by mining disturbances and, second, to optimize the well parameters and placement accordingly. In this paper, the production rate-pressure behaviors of six GGVs drilled over three adjacent panels were analyzed by using conventional multi-rate drawdown analysis techniques. The analyses were performed for infinite acting and pseudo-steady state flow models, which may be applicable during panel mining (DM) and after mining (AM) production periods of GGVs. These phases were analyzed separately since the reservoir properties, due to dynamic subsidence, boundary conditions and gas capacity of the gob reservoir may change between these two stages. The results suggest that conventional well test analysis techniques can be applicable to highly complex gob reservoirs and GGVs to determine parameters such as skin, permeability, radius of investigation, flow efficiency and damage ratio. The insights obtained from well test analyses can be used for a better understanding of the gob and for designing more effective gob gas venthole systems.

Acute changes in sputum IL-10 following underground exposure to diesel exhaust

Introduction. Although exposure to diesel exhaust has been linked with adverse health effects, little is known about the acute effects of exposure in the underground workplace. Methods. Cross-shift spirometry and sputum induction were completed on twelve subjects associated with comminuted rock removal (mucking) operations in an underground copper mine using diesel powered and pneumatic equipment on separate days, and sputum collected on a baseline non-exposure day as well. Results. For diesel operations, elemental carbon exposure averaged 538 ± 512 μg/m3 during the 1–2 hour operations. Sputum interleukin-10 decreased with diesel exhaust using one ELISA assay (3.69 v. 2.32 pg/ml, p = 0.015), but increased when measured with a different ELISA kit (0.18 v. 0.59 pg/ml, p = 0.019), consistent with an overall decline in IL-10 protein concentration but an increase in the biologically active form. Sputum interleukin-6 decreased with exposure to diesel exhaust, although this change lost statistical significance when restricted to non-smokers. There were no significant changes in spirometry, interleukins 1β, 4, and 8, tumor necrosis factor alpha or 8-hydroxy-2′-deoxyguanosine. Conclusion. High levels of diesel exhaust can result in rapid changes in sputum IL-10, suggesting possible protein modification.

Reservoir simulation-based modeling for characterizing longwall methane emissions and gob gas venthole production

Abstract Longwall mining alters the fluid-flow-related reservoir properties of the rocks overlying and underlying an extracted panel due to fracturing and relaxation of the strata. These mining-related disturbances create new pressure depletion zones and new flow paths for gas migration and may cause unexpected or uncontrolled migration of gas into the underground workplace. One common technique to control methane emissions in longwall mines is to drill vertical gob gas ventholes into each longwall panel to capture the methane within the overlying fractured strata before it enters the work environment. Thus, it is important to optimize the well parameters, e.g., the borehole diameter, and the length and position of the slotted casing interval relative to the fractured gas-bearing zones. This paper presents the development and results of a comprehensive, “dynamic,” three-dimensional reservoir model of a typical multi-panel Pittsburgh coalbed longwall mine. The alteration of permeability fields in and above the panels as a result of the mining-induced disturbances has been estimated from mechanical modeling of the overlying rock mass. Model calibration was performed through history matching the gas production from gob gas ventholes in the study area. Results presented in this paper include a simulation of gas flow patterns from the gas-bearing zones in the overlying strata to the mine environment, as well as the influence of completion practices on optimizing gas production from gob gas ventholes.

Miners, Engineers, and the Transformation of Work in the Western Mining Industry, 1880–1930

Miners, Engineers, and the Transformation of Work in the Western Mining Industry, 1880-1930 LOGAN HOVIS AND JEREMY MOUAT In September 1913 a mine manager wrote to the Engineering and MiningJournal, explaining that “we want to begin a small library for our underground foremen and shift bosses. What books would the Journal recommend?” The editor responded with a list of eight books, beginning with Herbert Hoover’s Principles ofMining. Both letter and books illustrate the changing basis of legitimacy in North America’s mining industry. Technical treatises by engineers were be­ coming a privileged source of knowledge, eclipsing the authority of the “practical man.” The new emphasis on the expertise of univer­ sity-trained engineers reflected the transformation of the mining in­ dustry, a process that devalued the traditional work practices of the skilled miner.1 When the mine manager wrote to the Engineering and MiningJour­ nalin 1913, the western mining industry was in the midst of a period of dramatic growth and change. Mining in western North America had begun in spectacular fashion with the gold rush to the Pacific Coast. At first, individuals and small groups employed rudimentary tools and simple technology to recover placer gold from water Mr. Hovis is employed by the U.S. National Park Service in Alaska, where he concentrates on the history, technology, and archaeology oflode and placer mining. His other areas of interest and research include trapping and trappers, transporta­ tion, and construction techniquesgermane to subarctic climates. Dr. Mouat teaches history at Athabasca University in Alberta, Canada. His research interests chiefly concern natural resource development in western Canada. The authors thank the editor and referees of Technology and Culture for comments and suggestions that helped them clarify their argument, and Bob McDonald of the University of British Columbia, a fine historian who taught them much. 'The letter appears in “Questions and Answers: A Small Mine-Library,” Engi­ neeringandMiningjournal,i)§ (September 20,1913): 558. Hoover’s bookwas a compi­ lation of his lectures at Stanford and the Columbia School of Mines (see Herbert C. Hoover, Principles ofMining [NewYork, 1909], p. iii, and the comments in George H. Nash, The Life of Herbert Hoover: The Engineer, 1874-1914 [New York, 1983], pp. 478-79).© 1996 by the Society for the History of Technology. All rights reserved. 0040-165X/96/3703-0002$01.00 429 430 Logan Hovis andJeremy Mouat courses. The richest sections were soon depleted, however, and min­ ers had to devise means of turning a profit from more extensive but much lower-grade mineral deposits. Techniques such as hydraulicking and dredging applied economies ofscale and mechanization to placer mining. Important as these changes were, by 1880 the pro­ duction of gold and other metals from underground mines far ex­ ceeded that from placer mining. The extraction of underground ore deposits—hard-rock min­ ing—was a far more complex affair than the placer operations typi­ cal of the rush era. The capital needed to develop the underground workplace, as well as the ancillary treatment plants above ground, meant that companies replaced the informal business arrangements of the industry’s first years. The actual work of mining also became much more complex. Naturally, mining still relied on the recovery of a mineral or minerals, but successful operations also depended upon the skill and knowledge of the underground workforce. And western mining remained an uncertain enterprise. In many cases it was a speculative gamble that on occasion returned windfall profits; most in the industry could recite tales of boom towns and bonanza wealth, bankruptcies and mine closures. In the following pages we argue that a crucial transition occurred in the half century from 1880 to 1930, a transformation intended to end the volatility that had characterized western mining and to render it a rational business like any other. By 1930 the technical training of the professional engineer—rather than the talents of the ingenious mechanic and the skilled miner—had become the essen­ tial element in successful mining operations. This shift was not straightforward, and our description touches on the consequences of the depletion of high-grade ore deposits, increasingly competitive market conditions, and the progressive and widespread adoption of new processes for ore...

Humanising the underground workplace: Environmental problems and design solutions : Wise, J.A., and Wise, B.K. In: Human Factors in Organisational Design and Management, Proceedings of the First Symposium held in Honolulu, Hawaii, 21–24 August 1984, Edited by H.W. Hendrick and O. Brown. North-Holland, Amsterdam, 1984, pp 125–135

Humanising the underground workplace: Environmental problems and design solutions : Wise, J.A., and Wise, B.K. In: Human Factors in Organisational Design and Management, Proceedings of the First Symposium held in Honolulu, Hawaii, 21–24 August 1984, Edited by H.W. Hendrick and O. Brown. North-Holland, Amsterdam, 1984, pp 125–135