"Safety is a value, not just a Priority" Geomechanically stable underground excavations require continuous assessment of rock mass behavior for maximizing safety. Optimizing pillar design is essential for preventing hazardous incidents and improving production in room-and-pillar mines. Maintaining regional and global stability is complicated for underground carbonate or stone deposits, where extensive fracture networks and groundwater flow become leading factors for generating unsteady ground conditions including karsts. A sudden encounter with karst cavities during mine advance may lead to safety issues, including ground collapse and outflow of unconsolidated sediments and groundwater. The presence of these eroded zones in pillars may cause their failure and poses a risk to the lives of miners apart from disrupting the pre-planned mining operations. A pervasive presence of joints and fractures plays a primary role in promoting structurally controlled failures in stone mines, which accelerates upon interaction with the karst cavities. The prevalent empirical and analytical approaches for pillar design ignore the geotechnical complexities such as the spatial density of discontinuities, karst voids, and deviation from the design during short-range mine planning. With the increasing market demand for limestone products, mining organizations, as well as enforcement agencies, are investing in research for increasing the efficiency of extracting valuable resources. While economical productivity is essential, preventing risks and ensuring the safety of miners remains the cardinal objective of mining operations. According to the Mine Safety and Health Administration (MSHA), since 2000, about 31% of occupational fatalities at all underground mines in the United States are caused due to ground collapse, which rises to 39% for underground stone mines. The objective of this study is to provide a reliable and methodological approach for pillar design in underground room-and-pillar hard rock mines for safe and efficient ore recovery. The numerical modeling techniques, implemented for a case study stone mine, could provide a pragmatic framework to assess the effect of karsts on rock mass behavior, and design future pillars detected with voids. The research uses data acquired from using remote sensing techniques, such as LiDAR and Ground-penetrating Radar surveys, to map the excavation characteristics. Discontinuum modeling was valuable for analyzing the pillar strength in the presence of discontinuities and cavities, as well as estimating a safe design standard. Discrete Fracture Networks, created using statistical information from discontinuity mapping, were employed to simulate the joints pervading the rock mass. This proposed research includes the calibration of rock mass properties to translate the effect of discontinuities to continuum models. Continuum modeling proved effective in analyzing regional stability along with characterizing the redistributed stress regime by imitating the excavation sequence. The results from pillar-scale and local-scale analyses are converged to optimize pillar design on a global scale and estimate the feasibility of secondary recovery in stone mines with a dominating discontinuity network and karst terrane. Stochastic analysis using finite volume modeling helped evaluate the performance of modified pillars to assist production while maintaining safety standards. The proposed research is valuable for improving future design parameters, excavation practices, and maintaining a balance between an approach towards increased safety while enhancing production. / Doctor of Philosophy / "The most valuable resource to come back out of a mine is a miner" – Anonymous. The United States accounted for 27% of the global limestone market share which was valued at US$58.5 billion in 2020 [148]. It is projected to reach a target of US$65.3 billion in 2027, growing even in midst of the COVID-19. As surface reserves deplete, much of the mineral demand gap is supplemented by mining underground deposits. Underground mines extract minerals from deep within the earth compared to surface mines. As a result, the miners experience a greater number of accidents in a constricted environment because of roof/tunnel collapse, fewer escape routes, ventilation, explosions, or inundation. According to the Mine Safety and Health Administration (MSHA), about 15% of all underground mine injuries in the US were caused by rockfalls since 1983. The majority of underground stone deposits are mined using the room-and-pillar mining method, which resembles a chessboard design where the light squares are mined, and the dark squares are left as rock pillars to support the tunnels. Limestone, a carbonate rock, contains a lot of fractures and joints (discontinuities). Erosion of rocks due to continuous water flow through the fractures leads to the formation of cavities known as karsts. Interaction of karsts with the prevalent fracture network increases rockfall risk during mining. The collapse of voids along with an inrush of filled rock-clay-water sludge can harm miners' lives, damage machinery, and stop further operations. Literature is scarce on topics that quantify the risk and disruption posed by these cavities in underground mines. Most rock classification systems cannot classify their effect because of the unpredictability and extensive analysis required. The objective of this research is to provide a reliable and methodological approach for designing pillars in underground hard rock mines for ensuring a safe working environment and efficient mineral recovery. This research starts with analyzing the strength of pillars, in which karst cavities were discovered while mining. The safety concerns often lead the miners to not excavate around the cavities and leave valuable resources unmined. Data from ground-penetrating radar and laser scanning surveys were used to characterize the voids and map the discontinuities. Discrete-element numerical modeling was used to simulate the pillars as an assembly of blocks jointed by the discontinuities. The simulation results help us understand the instability issues in the karst-ridden pillars and ways to improve upon the existing design. The findings were used to modulate the parameters for regional-scale models using finite volume modeling for less computationally intensive analyses and simulating rock as a continuum. The continuum models were highly effective in analyzing the instability issues due to the prevalent karstic network. This helps understand any alternative scenario that could have been implemented to optimize ore recovery while preventing risks. The results from the single pillar and regional analyses are combined to optimize pillar design on a global mine scale. This dissertation focuses on improving hazard mitigation in mines with unpredicted anomalies like karsts. Although this research is based on a specific mine site, it empowers the operators to explore the presented techniques to increase safety in all underground mines. The suggested methodology will help devise better strategies for handling instability issues without jeopardizing the mine operations. The primary motivation is to keep the underground miners safe from hazardous situations while fulfilling the secondary objective of maximizing mineral production.

Este trabalho tem o objetivo de discutir conceitos, desafios e perspectivas relacionados à aplicação de tecnologias de automação e informação em minas subterrâneas. Exemplos de aplicação contextualizam técnicas e tecnologias atuais de lavra, suas tendências de evolução para o futuro e a interação com aspectos humanos, operacionais e gerenciais. Dados coletados, referentes a indicadores de produtividade e confiabilidade, são utilizados para um estudo sobre a utilização de um jumbo de perfuração computadorizado nas operações de desenvolvimento e produção de uma mina subterrânea no Brasil. Uma série de desafios devem ser considerados para que sistemas computadorizados embarcados em conjunto com infraestrutura de tecnologia da informação se tornem parte da estratégia operacional. Gestores devem efetivamente adaptar as organizações a novos padrões de segurança, eficiência operacional e gestão integrada da informação. A padronização de interfaces deve ser aceita como premissa básica para a integração de processos. / This study aims to discuss the concepts, challenges and perspectives related to automation and information technologies application in underground mines. Application examples contextualize current mining techniques and technology, future evolution and the interaction with human, operational and management aspects. Productivity and reliability data collected are used to study the utilization of a computerized drilling jumbo for development and production operations in an underground mine in Brazil. A series of challenges must be considered for onboard electronic systems combined with information technology infrastructure become part of the operational strategy. Leaders must effectively manage to adapt organizations to new standards. It is evident the value-added operation with all the benefits related to safety, operational efficiency and integrated information management. Interface standardization must be accepted as a basic premise for process integration.

This diploma thesis presents the results of the study of historical exploitation of gold in Vodňany, which were partly introduced in previous bachelor thesis. The core of the thesis is a list of locations that have been researched mainly through studying lidar pictures, field and heavy minerals prospecting, professional literature and geological maps. Based on the observation of common or different features of the individual areals, the thesis further solved questions related to the morphology of the areals, the probable occurrence of gold, the method of its mining, and, consequently, property and settlement links.

In many parts of Australia the climate is such that people are working long hours in the heat. Consequences of excessive environmental heat stress range from reduction in safety due to impairment of concentration, to heat illness, which in extreme cases can be fatal. A critical factor in tolerance of workers to environmental heat stress is their level of hydration. Maximising productivity without compromising the health and safety of the work force requires quantification of the degree of stress posed by the thermal environment. For this purpose a number of heat stress indices have been developed. A recently introduced index is the Thermal Work Limit (TWL), which has been widely adopted and implemented in the underground mining industry in Australia. The field use of TWL and protocols in the mining industry with resultant reduction in heat illness and lost production is a practical endorsement of the index, and its validity under controlled conditions has been confirmed by a preliminary study. The further work needed to complete this validation forms part of this thesis. TWL was found to reliably predict the limiting workload in the controlled environment, reinforcing the validity of the algorithm and its application in the workplace. To date TWL has largely been used in the underground environment, however as the algorithm is equally applicable to the above ground environment where radiant heat forms a significant component of the thermal load, field studies were carried out at mining installations in the Pilbara region of Western Australia to evaluate this application of the index. The current industry standard index of heat stress is the Wet bulb Globe Temperature (WBGT). / The shortcomings of this index are widely acknowledged and in practice it is frequently ignored as it is seen to be unnecessarily conservative in many situations. The sensitivity of TWL to the cooling effect of air movement implied that TWL would be more relevant than WBGT as a predictor of the impact of environmental heat stress in outdoor work environments and this was supported by the results. On the strength of this, recommended management protocols linked to TWL similar to those already in place in many underground workplaces, were developed for the management of thermal risk in outdoor work environments. Maintaining adequate hydration is the single most important strategy to counteract the effects of thermal stress. No heat stress index can protect workers from the combined effects of dehydration and thermal stress. To document the hydration status of the outdoor workforce in the Pilbara, the hydration level of groups of workers was assessed from the specific gravity of their urine. To further evaluate whether the fluid replacement behaviour of the workers is adequate to replace fluids lost in sweat, a fluid balance study was carried out to quantify average fluid intakes and sweat fluid losses. The majority of workers were found to be inadequately hydrated at the start of the shift and their fluid intakes were in general well below the requirements to replace sweat losses - let alone improve hydration. Recommendations for fluid intakes based on documented rates of sweat loss are included in the thesis. Based on the findings of this study workable management strategies have been recommended to minimise the risk to outdoor workers in thermally stressful environments.

Mine safety is of paramount concern to the mining industry. The generation of a Geographic Information Systems (GIS) which can administrate relevant spatial data and metadata of underground mining safety efficiently is a very vital issue in this sense. In an effort to achieve a balance of safety and productivity, GIS can contribute to the creation of a safe working environment in underground (U/G) mining. Such a system should serve to a continuous risk analysis and be designed for applications in case of emergency. Concept for safety should require three fundamental components, namely (i) constructive safety / (ii) surveillance and maintenance / and (iii) emergency. The implementation has to be carried out in a Web-Based Geographic Information System. The process comprises first the safety concept as the application domain model and then a conceptual model was generated in terms of Entity- Relationship Diagrams. After the implementation of the logical model a user interface was developed and GIS was tested. Finally, one should deal with the question if it is possible to extend the method of resolution used to a national GIS infrastructure.

The use of backfill in underground mining is increasing due to need for systematic backfilling of mine openings and workings to avoid surface damage, increase safety and contribution to sustainable mining. This study is to investigate backfill materials and new methods suited for systematic selection and application of backfill in underground mines. Laboratory tests were carried out on physical, chemical and mechanical properties of different backfill materials and mixtures thereof. Special attention was paid to materials generated as by-products and other cheaply available materials e.g. fly ash and FGD-gypsum from power plants, natural and synthetic anhydrite. The different material mixtures investigated can be used as a technically and economically viable backfill for underground mines. In summary, the systematic selection of backfill materials from by-products, mine waste and tailings from the mineral processing of mining industry and other industries were suited as a backfill material for test field in China coal fires and recommended for underground potash mines in Thailand.

Este trabalho tem o objetivo de discutir conceitos, desafios e perspectivas relacionados à aplicação de tecnologias de automação e informação em minas subterrâneas. Exemplos de aplicação contextualizam técnicas e tecnologias atuais de lavra, suas tendências de evolução para o futuro e a interação com aspectos humanos, operacionais e gerenciais. Dados coletados, referentes a indicadores de produtividade e confiabilidade, são utilizados para um estudo sobre a utilização de um jumbo de perfuração computadorizado nas operações de desenvolvimento e produção de uma mina subterrânea no Brasil. Uma série de desafios devem ser considerados para que sistemas computadorizados embarcados em conjunto com infraestrutura de tecnologia da informação se tornem parte da estratégia operacional. Gestores devem efetivamente adaptar as organizações a novos padrões de segurança, eficiência operacional e gestão integrada da informação. A padronização de interfaces deve ser aceita como premissa básica para a integração de processos. / This study aims to discuss the concepts, challenges and perspectives related to automation and information technologies application in underground mines. Application examples contextualize current mining techniques and technology, future evolution and the interaction with human, operational and management aspects. Productivity and reliability data collected are used to study the utilization of a computerized drilling jumbo for development and production operations in an underground mine in Brazil. A series of challenges must be considered for onboard electronic systems combined with information technology infrastructure become part of the operational strategy. Leaders must effectively manage to adapt organizations to new standards. It is evident the value-added operation with all the benefits related to safety, operational efficiency and integrated information management. Interface standardization must be accepted as a basic premise for process integration.

Study of Production Drifts Stability and Assessment of Reinforcement Requirements at LKAB Konsuln Test-Mine Levels 436 and 486 Using Geologic Structures Data, and Modelling Software - Dips and Unwedge:  a Part of dp1 Project (Mine Layout and Technology) of the Sustainable Underground Mining (Sum) Project Oludare Joseph Olufe Global population has been on exponential increase over the past half century. The population explosion is driving massive urbanization and infrastructure developments across the globe, which result in huge demand for metals, especially steel. The trend is forecasted to continue to rise steeply in for the next two decades. This is putting enormous strain on metals mining, especially because new surface economic deposits are rare to come by. Therefore, mining is steadily going deeper in many of the mining destinations across the world.     Mining at great depths present unique challenges, particularly regarding stability of excavations at depths. Rock falls, rock burst, excavation collapse are common occurrences associated with deep mining. In regions with high seismicity potentials the frequency and consequences could be very high. Over the past decade ground instability has become a significant challenge confronting mining at LKAB deep mines. There had been incidents that resulted in long term closure of sections of the mines, with resultant adverse economic impacts. More undesirable is loss of live of personnel.     The study was conducted at the Konsuln test mine levels 436 and 486, aimed to investigate the impacts of geologic structures on excavations instability at depths, at the Kiruna iron ore mines, on one hand.  And on the other hand, evaluate the influence of geologic structures on ground reinforcements at the mine. Structural data were collected and analysed using Dips program to define orientation of major structures. The results were used for wedge analysis and excavations stability modelling using Unwedge program. Important rock mechanical parameters were defined based on data provided, and others based on literatures. A design factor of safety of 1.5 was used.     Results from the study established that structures have significant impact on excavations instability at the Konsuln mine. 100% of the production drifts studied has minimum of four wedges formed in its perimeters. Out of this approximately 37% has factor of safety lower than 1.5. Evaluation of reinforcements (shotcrete and rock bolts) implemented in the mine found that approximately 15% of the total wedges formed in the production drifts has factor of safety less that 1.5 after both shotcrete and rock bolt reinforcements had been implement. Also, approximately 5% of the total wedges has apex height longer the rock bolt length.     It was therefore concluded that structurally induced instability is a major contributor to excavations instability at the Kiruna mine. The study approach presented a new methodology to understand and provide robust solution to ground instability problem at the mine.

The use of backfill in underground mining is increasing due to need for systematic backfilling of mine openings and workings to avoid surface damage, increase safety and contribution to sustainable mining. This study is to investigate backfill materials and new methods suited for systematic selection and application of backfill in underground mines. Laboratory tests were carried out on physical, chemical and mechanical properties of different backfill materials and mixtures thereof. Special attention was paid to materials generated as by-products and other cheaply available materials e.g. fly ash and FGD-gypsum from power plants, natural and synthetic anhydrite. The different material mixtures investigated can be used as a technically and economically viable backfill for underground mines. In summary, the systematic selection of backfill materials from by-products, mine waste and tailings from the mineral processing of mining industry and other industries were suited as a backfill material for test field in China coal fires and recommended for underground potash mines in Thailand.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Mining activities around the world are undergoing constant change and modernization owing to technological and scientific advancements. Consequently, there are frequent proposals to streamline and enhance processes in mining operations. This study deals with ore transportation in mechanized mining units and aims to optimize fleet management using the Lean Six Sigma methodology to obtain a model in this specific process. The proposed method was implemented using a Lean Six Sigma instrument known as DMAIC (Define, Measure, Analyze, Improve, and Control). The case study was applied to an underground mine located in the Huancavelica region, Peru. The simulation showed that 24% of the time in the ore transport cycle is un-productive time and the improvement potential time represents 53% of the transportation process time.