Objectives - To examine the incidence, clinical state, personal risk factors, haematology and biochemistry of heat exhaustion cases occurring at a deep underground metalliferous mine. To describe the underground and surface thermal conditions associated with the occurrence of heat exhaustion cases.Methods - A one-year prospective case-series of acute heat exhaustion cases was undertaken at a deep underground metalliferous mine in tropical and Australia. A case-control study of body mass index (BMI) and maximal oxygen uptake (VO(subscript)2max) in heat exhaustion was also undertaken. A history was obtained using a structured questionnaire. Pulse rate, blood pressure, tympanic temperature and urine specific gravity were measured before treatment. Venous blood was analysed for haematological and biochemical parameters, during the acute presentation and after recovery. BMI and VO(subscript)2max were measured after recovery and in a group of controls. Psychrometric wet bulb temperature, dry bulb temperature and air velocity were measured at the underground sites where heat exhaustion had occurred. Air cooling power and psychrometric wet bulb globe temperatures were derived. Surface 24-hour mean wet bulb and dry bulb temperatures were recorded. Surface 24-hour mean wet bulb globe temperatures were derived.Results - 106 cases were studied in the case series. The incidence of heat exhaustion during the year was 43.0 cases per million man-hours. In February it was 147 cases per million man-hours. The incidence rate ratio for mines operating below 1200m compared to those operating above 1200m was 3.17. Mean estimated fluid intake was 0.64 litres/hour (SD 0.29, Range 0.08-1.50).The following were raised on acute presentation compared to recovery (P value, % of acute cases above the normal clinical range): neutrophils (P<0.001, 36%), anion gap (P<0.001, 63%), urea (P<0.001, ++ / 21%), creatinine (P<0.001, 30%), glucose (P<0.001, 15%), serum osmolality (P=0.030, 71%), creatine kinase (P=0.002, 45%), aspartate transaminase (P<0.001, 14%), lactate dehydrogenase (P<0.001, 9.5%), and ferritin (P<0.001, 26%). The following were depressed on acute presentation compared to recovery (P value, % of acute cases below the normal clinical range): eosinophils (P=0.003, 3 8%) and bicarbonate (P=0.0 11, 32%). Urea and creatinine were significantly raised in miners with heat cramps compared to miners without this symptom (P<0.001), while there was no significant difference in sodium concentration (P=0.384).Mean psychrometric wet bulb temperature was 29.0 degrees celsius (SD 2.2, Range 21.0-34.0). Mean dry bulb temperature was 37.4 degrees celsius (SD 2.4, Range 31.0-43.0). Mean air velocity was 0.54 m/s (SD 0.57, Range 0.00-4.00). Mean air cooling power was 148 W/m(subscript)2 (SD 49, Range 33-290). Mean psychrometric wet bulb globe temperature was 31.5 degrees celsius (SD 2.0, Range 25.2-35.3). Few cases (<5%) occurred at a psychrometric wet bulb temperature <25.0'C, dry bulb temperature <33.8'C, air velocity >1.56 m/s, air cooling power >248 W/m(subscript)2, or psychrometric wet bulb globe temperature <28.5 degrees Celsius.The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred compared to those days on which it did not occur (P<0.001). The relative risk of heat exhaustion on days when the surface 24-hour mean wet bulb globe temperature was in the range 26.0-28.0 degrees celsius was 4.82 (95% CI 2.12-10.96).65 cases of heat exhaustion and 119 controls were studied in the case-control study. Heat exhaustion cases had a significantly higher BMI than controls (P=0.006). The odds ratios increased with BMI. For a BMI of 32.00-36.99, compared to a BMI of less than 27.00 the odds ratio was 3.63 (95% ++ / confidence interval 1.42-9.36). V0(subscript)2max was not significantly lower in cases than controls. The odds ratios for heat exhaustion increased with decreasing VO(subscript)2max, but not significantly. The sample size provided 80% power of detecting an odds ratio of 2.5 or greater.Conclusion - Heat exhaustion in underground miners is associated with hypohydration, neutrophil leukocytosis, eosinopenia, metabolic acidosis, increased glucose and ferritin, and a mild rise in CK, AST and LD. Heat cramps are associated with hypohydration but not hyponatraemia. The incidence of heat exhaustion increases during summer and at depth. An increased fluid intake is required. Heat exhaustion would be unlikely to occur if ventilation and refrigeration achieved air cooling power >250W/m2 at all underground work sites. Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion. Deep underground miners should be advised to maintain a BMI of 24-27.

Photogrammetry and laser scanning are remote sensing technologies with the potential to monitor movements of rock masses and their support systems in underground mine environments. Displacements underground are traditionally measured through point measurement devices, such as extensometers. These are generally restricted to measuring one dimension, may change behavior with installation, may obstruct mining operations, and are restricted to monitoring the behavior of a small area. Photogrammetry and laser scanning offer the ability to monitor rock mass movements at millions of points in a local area, both accurately and quickly. An improved, or augmented, method for measuring displacements underground in a practical, cost-effective manner will lead to an improved understanding of rock mass behavior. Several experiments were performed that demonstrate the applicability of these remote sensing techniques to monitoring rock mass changes. An underground mining environment presents unique challenges to using these tools for monitoring rock movements, such as: poor lighting, dust, fog, and unfavorable geometries. It is important, therefore, to demonstrate that these tools which have applications in other industries, can also be adapted to the conditions of an underground mine. The study sites chosen include two different underground limestone mines, two different underground coal mines, and the Mine Roof Simulator (MRS) at the Pittsburgh Office of Mine Safety and Health Research. Both photogrammetry and laser scanning were tested at different limestone mines to detect scaling and spalling on ribs that occurred over several weeks. Both methods were successfully used to reconstruct three-dimensional models of the limestone ribs and detect areas of rock change between visits. By comparing the reconstructed point clouds, and the triangulated meshes created from them, volumes of rock change could be quantified. The laser scanned limestone mine showed a volume of 2.3 m3 and 2.6 m3 being displaced across two ribs between visits. The photogrammetry study involved seven different pillars and at least one rib face modeled on each, with volume changes of 0.29 to 4.03 m3 detected between visits. The rock displaced from the ribs could not be measured independently of the remote sensing, but a uniform absence of rock movement across large areas of the mine validates the accuracy of the point clouds. A similar test was performed using laser scanning in an underground coal mine, where the displacement was induced by removing material by hand from the ribs. Volume changes as small as 57 cm3, or slightly larger than a golf ball, and as large as 57,549 cm3, were detectable in this environment, despite the change in rib surface reflectance and mine geometry. In addition to the rib displacement, photogrammetry was selected as a tool for monitoring standing supports in underground coal mines. The additional regulatory restrictions of underground coal may preclude the use of laser scanning in these mines where deformation is most likely to occur. The camera used for photogrammetry is ATEX certified as explosion proof and is indicative of the specifications that could be expected in an MSHA approved camera. Three different experiments were performed with this camera, including a laboratory controlled standing support deformation at the MRS and an in-mine time-lapse experiment measuring the response of a wooden crib and steel support to abutment loading. The experiment reconstructing a standing support in the MRS showed a cumulative convergence of 30.93 cm through photogrammetry and 30.48 cm as measured by the system. The standing support monitoring in the underground coal mine environment showed a steel support cumulative convergence of 1.10 cm, a wooden crib cumulative convergence of 0.62 cm, and a measured cumulative convergence on the wooden crib of 0.62 cm. These techniques explored in this report are not intended to supplant, but rather supplement, existing measurement technologies. Both laser scanning and photogrammetry have physical and regulatory limitations in their application to measuring underground mine deformations, however, their ability to provide time-lapse three-dimensional measurements of entire mine sections is a strength difficult to emulate with traditional point measurement techniques. A fast, cost-effective, and practical application of remote sensing to monitoring mine displacements will improve awareness and understanding of rock mass behavior. / Ph. D.

The effect of corrosion on the performance of rock support and reinforcement in Australian underground mines has not been widely researched and is generally not well understood. This is despite the number of safety concerns and operational difficulties created by corrosion in reducing the capacity and life expectancy of ground support. This thesis aims to investigate corrosion and relate how the environmental conditions in Australian underground hard rock mines impact on the service life of rock support and primarily rock reinforcement. Environmental characterisation of underground environments was completed at a number of mine sites located across Australia. This provided an improved understanding of the environmental conditions in Australian underground hard rock mines. Long-term testing on the impact of corrosion on the load bearing capacity of reinforcement and support under controlled experimental conditions was conducted in simulated underground environments. Rock reinforcement elements were examined in-situ by means of overcoring of the installed reinforcement and surrounding rock mass. Laboratory testing of the core determined changes in load transfer properties due to corrosion damage. These investigations provided an excellent understanding of the corrosion processes and mechanisms at work. Corrosion rates for a range of underground environments were established through the direct exposure and evaluation of metallic coupons in underground in-situ and simulated environments. / It was found that the study of corrosion is challenging due to the time required to gather meaningful data. In particular, the wide range of materials that comprise ground support systems means that it is impossible to examine all the possible combinations of variables and their potential influence on the observed levels of corrosion and measured corrosion rates. Despite these challenges, the systematic investigation has resulted in new corrosivity classifications for both groundwater and atmospheric driven corrosion processes for various reinforcement and support systems used in the Australian underground mining industry. Previous corrosivity classifications were not found applicable. Furthermore, these new corrosivity classifications are simpler than previous classifications and corrosion rates may be predicted from readily obtained measurements of ground water dissolved oxygen and atmospheric relative humidity. Different types of reinforcement and surface support systems have been rated with respect to their corrosion resistance and estimates have been made for the expected service life for various rates of corrosion.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-04T11:32:21Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_INALDO.pdf: 12292650 bytes, checksum: 47271b94bc4307fa96add30491036a09 (MD5) / Made available in DSpace on 2016-07-04T11:32:21Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_INALDO.pdf: 12292650 bytes, checksum: 47271b94bc4307fa96add30491036a09 (MD5) Previous issue date: 2015-08-04 / CAPEs / Este trabalho tem por objetivo simular numericamente via método dos elementos finitos a deformabilidade e estabilidade geomecânica de lavras subterrâneas em evaporitos, considerando cenários de galerias executadas pelo método de câmaras e pilares e de escavação para estocagem de gás natural. Os evaporitos são economicamente importantes por serem fontes de matéria-prima para a fabricação de diversos produtos. A silvita é o mineral mais explorado para a produção de potássio, pois a sua estrutura química de cloreto simples favorece o seu aproveitamento industrial. No Brasil, a produção de potássio é realizada pela CVRD (Companhia Vale do Rio Doce) na mina de Taquari-Vassouras, que está localizada em Sergipe. Foi utilizado o modelo constitutivo mecanismo duplo de deformação com ativação térmica. Para validação do modelo constitutivo foi comparado resultados de simulações com resultados de medições, reais, de convergência de deformação, de câmaras do Painel D1. Foi estudado a possibilidade de influxo de água no Painel I5 e apresentou-se uma modelagem de um pilar 3D. Foi simulado, ainda, queda de blocos laterais e uma câmara para estocagem de gás natural. Para reproduzir os efeitos do processo de formação de fraturas, apresenta-se a técnica de fragmentação, a qual usa os elementos de interface para reproduzi-las. Onde os elementos regulares têm comportamento assumidamente de fluência e o comportamento dos elementos da região de interface é regido por um modelo constitutivo inelástico capaz de simular os fenômenos envolvidos no processo de degradação do material até a formação da fratura, como o modelo de dano. Tanto o modelo de dano como o modelo mecanismo duplo de deformação, de fluência estacionária, encontram-se implementados no programa, in-house, de elementos finitos CODE_BRIGHT (COupled DEformation BRIne Gas and Heat Transport). As análises apresentaram resultados consistentes, possibilitando o conhecimento do comportamento de fluência das rochas salinas, e seus efeitos, como subsidência, influxo de água, formações de chocos. Além disso, as análises demonstraram a viabilidade da aplicação da técnica de fratura em projetos de Engenharia com a aplicação da metodologia proposta. / This study aims to simulate numerically via the finite element method the deformability and geomechanical stability of underground mines in evaporites considering scenarios galleries performed by the method of room and pillar and digging for natural gas storage. The evaporites are economically important because they are sources of raw material for the manufacture of several products. The sylvite is the most explored mineral for potash production because its chemical structure simple chloride favors its industrial use. In Brazil, potash production is carried out by CVRD (Company Vale do Rio Doce) in the Taquari- Vassouras mine, which is located in Sergipe. We used the constitutive model dual mechanism of deformation with thermal activation. To validate the constitutive model was compared simulation results with measurement results, real, deformation convergence of the cameras of Panel D1. It studied the possibility of water inflow in Panel I5 and presented himself a modeling a pillar 3D. Was simulated also down side blocks and a camera for storage of natural gas. To reproduce the effects of the training process fractures, shows the fragmentation technique, which uses the interface elements to play them. Where regular elements have openly creep behavior and the behavior of the interface elements region is governed by an inelastic constitutive model able to simulate the phenomena involved in the material degradation process until the formation of the fracture, as the damage model. Any damage model as the model dual mechanism of deformation, creep stationary, are implemented in software, in-house finite element CODE_BRIGHT (Gas and Brine Deformation Coupled Heat Transport). The analysis showed consistent results, enabling the knowledge of the creep behavior of the salt rock, and its effects, as subsidence, water inflow and falling blocks. Furthermore, the analysis demonstrated the feasibility of applying the fracture technique in engineering projects with the application of the proposed methodology.

This project aims to develop a simulator for generating realistic data from vehicles operating in underground mines, encompassing positional data and sensor values of the velocity and angle. The project addresses the challenge of analyzing the Hybrid Positioning algorithm within Mobilaris Onboard, a navigation system for underground mines. The absence of the 100% ground truth for vehicle positions in the post-analysis of sensor log files necessitates the creation of this simulator. The project's mission includes generating vehicle paths and corresponding sensor readings, focusing on realism. Additional considerations include introducing realistic noise and integrating the simulator's output with visualization tools. Furthermore, the project aims to develop a tool for comparing simulated sensor values with actual sensor data, facilitating algorithm refinement and development. The project also incorporates time series analysis to interpret the sensor data generated by the simulator. This approach is crucial for understanding patterns and trends in the vehicle's positional and velocity data over time, providing valuable insights for refining the navigation algorithm.

Examination of seismic records during the time interval of the Sago Mine disaster in 2006 revealed a small amplitude signal possibly associated with an event in the mine. Although the epicenter of the signature was located in the vicinity where the explosion occurred, it could not be unequivocally attributed to the explosion. More needs to be understood about the seismicity from mine explosions in order to properly interpret critical seismic information. A seismic monitoring system located at NIOSH's Lake Lynn Experimental Mine has monitored nineteen experimental methane and dust based explosions. The objective of the study was to analyze seismic signatures generated by the methane and dust explosions to begin understanding their characteristics at different distances away from the source. The seismic signatures from these different events were analyzed using standard waveform analysis procedures in order to estimate the moment magnitude and radiated seismic energy. The procedures used to analyze the data were conducted using self-produced programs not available with existing commercial software. The signatures of the explosions were found to be extremely complex due a combination of mine geometry and experimental design, both of which could not be controlled for the purposes of the study. Geophones located approximately 600 m (1970 ft) and over from the source collected limited data because of the attenuation of the seismic waves generated by the methane explosion. A combination of the methods used to characterize the seismic signatures allowed for differentiation between experimental designs and the size of the explosion. The factors having the largest impact on the signatures were the mine geometry, size of the methane explosion, construction of the mine seal and location of the mine seal. A relationship was derived to correlate the radiated seismic energy to the size of the explosion. Recommendations were made, based upon the limitations of this study, on methods for better collection of seismic data in the future. / Ph. D.

The use of sulfur hexafluoride (SF6) as a tracer gas for analyzing underground mine ventilation systems has been practiced for over 30 years. As a result, the methods used to release, sample, and analyze SF6 are well accepted. Although improvements are still being made to enhance the analysis of this tracer, the overall technique remains largely the same. However, as the complexity and size of underground mine ventilation networks increase, coupled with steadily rising SF6 background levels, the ability of a single gas to function as a convenient, rapid means of analysis diminishes. The utilization of multiple tracer gases can mitigate these problems by allowing for a more comprehensive evaluation using multi-zone techniques. A well-documented alternative in HVAC studies to SF6 as a tracer are perfluorocarbon tracers (PFT). Many PFTs exist as volatile liquids at room temperature and pressure. This characteristic prevents a PFT from being released using the same technique as SF6. This paper introduces a passive release method for PMCH. Details about the development of the permeation plug release vessel (PPRV) from creating a GC calibration curve for vapor PMCH to the final field evaluation are presented. The following study successfully developed a mine-scale PPRV. The PPRV is designed to passively deploy PMCH vapor at linear. An equation was derived in this study that allows the prediction of the release rate as a function of temperature and plug thickness. Details regarding the development of the PPRV from preliminary laboratory studies to final field evaluations are provided. / Ph. D.

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