A Study on Application of Strategic Planning And Operations Research Techniques in Open Cast Mining

Mining happens to be the second oldest industry in the world considering the agriculture as the first and the foremost. That primitive society relied nearly on mined produce that is reflected aptly through nomenclature such as Stone Age, Copper Age, Bronze Age and Iron Age. These nomenclatures rightly capture the ethos of the time that shows increasing complexity of people’s society’s relationship with mining produce and use of metals. Our remote ancestors did practice mining on hard rock. Mining remained with their common occupation to earn livelihood and meet their needs. Since they had meager requirement of fuels; their major need of fuel was met mostly from dense forests on the earth. As the time passed, they required to meet ever increasing standards of living. As a result, demand of fuel was felt as extremely necessary for the existence of mankind and it kept on growing. In order to meet ever increasing demand, mining of coal took a shape in one way or the other.

Environmental and occupational characterisation of coals and dust from coal mining

Tesi en modalitat de compendi de publicacionsThe main objective of this PhD thesis is the study of coal mine dust patterns produced by different types of mining operations and different types of coal. In addition, the potential links between oxidative potential (OP) of coal dust and its geochemistry have been investigated in order to identify indicators of potential concern for human health. To these ends, extensive particle size, chemical, mineralogical and OP analyses were carried out on: i) deposited coal mine dust collected in from different areas in underground and open-pit coal mines; ii) a selection of powdered coal samples from in-seam channel profiles covering a wide and contrasting variety of coal geochemistry patterns. In both cases, the respirable fractions (<4 µm) were extracted and analysed to simulate actual suspended respirable coal dust (PM4). The novelty of these sampling and analytical programmes made it necessary to calibrate and validate new methodologies, and design and implement new protocols, in order to separate the respirable fractions of dust and obtain comprehensive particle size, geochemical and mineralogical characterisations. The results of this thesis are summarised in five scientific articles in high-impact journals. Article #1 introduces the subject and includes a review of major health-relevant coal dust geochemical patterns. Articles #2 to #4 show results from the sampling of deposited coal dust in a number of underground coal mines (China and Europe) and an open-pit coal mine (China), and describe the separation and characterisation of respirable fractions. The samples were collected from different zones of the coal mines in order to encompass the most relevant mining operations being undertaken. In addition, in Article #5, powdered coal seam samples, covering a wide range of geochemical patterns from China, were used to separate and characterise their respective respirable fractions. In Articles #3 to #5 the respirable coal dust samples were selected (according to size and geochemistry) in order to evaluate the relationships among OP markers (ascorbic acid, AA; glutathione, GSH; and dithiothreitol, DTT). This toxicological methodology was applied using cross-correlation and multilinear regression analyses on underground mine dust samples (Article #3), open-pit mine samples (Article #4) and powdered coal samples (Article #5). The approach was repeated including both respirable fractions from deposited coal mine dust and from powdered coal samples (Article #5). Suspended coal dust measurements were reported in Articles #2 to #4 (Europe and China), including online ambient measurement of PM2.5, PM10, BC and UFP (PM <2.5 µm, <10 µm, black carbon, and ultrafine particles, respectively) around several mining open-pit mine (Article #4). The results of this thesis demonstrate that coal dust particle size is a key parameter controlling coal dust resuspension. Coal dust levels, also provide evidence that respirable coal dust levels are markedly higher in the working front areas. Moreover, concentrations and geochemical patterns of coal dust are noticeably influenced by the mining operations carried out in a given mine area. Results for the evaluation of the impact geochemical patterns on the OP demonstrated that OPAA is mostly linked with inorganic species, whereas OPGSH and OPDTT are linked with organic species of coal. The main drivers were found to be Fe, pyrite, sulphate minerals and anatase for OPAA, as well as moisture content, Ca, Mg, Na and Ba, for OPGSH and OPDTT. Furthermore, the correlations of the contents of most of these components in dust or coal with the OPAA, OPGSH and OPDTT increase only in high-rank coal or high coal-rank mine dust (mostly bituminous in this study). Moreover, PM10 measurements reported in this study demonstrate the importance of the effectiveness of dust control measures implemented in underground and open-pit coal mines in order to reduce airborne dust concentrations.L’objectiu principal d’aquesta tesi doctoral és l’estudi dels patrons de la pols de carbó produïts pels diferents tipus d’operacions mineres i l’estudi dels principals patrons composicionals de diferents tipus de carbó, cobrint un ampli rang geoquímic. A més, la relació entre el potencial oxidatiu (OP) i la geoquímica de la pols de carbó va ser investigada amb la finalitat d’identificar possibles indicadors o traçadors potencials que puguin perjudicar la salut humana. Amb aquesta finalitat, es van dur a terme anàlisis de mida de partícula, químics, mineralògics i d’OP per a: i) la pols de carbó recol·lectat en diferents zones i processos miners per a mines de carbó subterrànies i de cel obert, ii) una selecció de mostres de perfils de capes de carbó moltes, cobrint una àmplia i contrastada varietat de paràmetres geoquímics dels carbons explotats actualment a la Xina. En tots dos casos, les fraccions respirables (<4 µm) van ser separades i analitzades per simular la pols de carbó respirable en suspensió (PM4). La novetat d’aquests protocols de mostreig i anàlisi van requerir tasques de calibratge i validació d’aquestes noves metodologies, i dissenyar i implementar nous mètodes per separar les fraccions respirables de pols i obtenir caracteritzacions completes de mida de partícula, geoquímiques i mineralògiques. L’article #1 és introductori i conté una revisió dels patrons geoquímics de la pols de mineria del carbó més rellevants per la salut humana. De l’article #2 al #4 es mostren resultats per al mostreig de pols de carbó dipositat a nombroses mines de carbó subterrànies (Xina i Europa) i una mina de cel obert (Xina), i descriu la separació i caracterització de fraccions respirables. Les mostres es van recollir a diferents zones de les mines per tal de cobrir les operacions mineres més significatives. També, les mostres de carbó molt de l’article #5, comprenent un ampli rang de patrons geoquímics a la Xina, es van utilitzar per separar i caracteritzar detalladament les fraccions de pols respirable. Als Articles #3 a #5 van ser seleccionades mostres de pols respirable (d’acord amb la seva mida i els patrons geoquímics) per tal d’avaluar les relacions entre els marcadors OP (àcid ascòrbic, AA; glutatió, GSH; i dithiothreitol, DTT) amb els patrons fisicoquímics més rellevants, duent a terme una anàlisi de relació creuada i regressió multilineal per a les mostres de pols de mines subterrànies (Article #3), mostres de pols de la mina de cel obert (Article #4) i mostres de carbó molt (Article #5). Finalment, les anàlisis van ser repetides incloent totes les fraccions respirables de les mostres dipositades de pols de carbó i de les mostres de carbó molt (Article #5). A més de les mesures de pols de mina respirable extretes de pols sedimentada o de carbó molt, es van reportar mesures directes de pols de mina en suspensió dels Articles #2 a #4 (Europa i la Xina), incloent-hi mesures ambientals de PM2.5, PM10, BC i UFP (PM <2.5 µm, <10 µm, carboni negre, i partícules ultrafines, respectivament) al voltant de diverses operacions mineres a la mina de cel obert (Article #4). Els resultats d’aquesta tesi doctoral subratllen la importància de continuar investigant sobre les propietats i nivells de pols a la mineria del carbó en el context de la millora de les condicions laborals dels miners, especialment atès que, probablement, es mantindrà una producció de carbó molt elevada a països com la Xina durant les dècades vinents.El carbón ha sido un recurso muy valioso en nuestra sociedad durante siglos; sin embargo, sus beneficios como fuente de energía siempre han sido parcialmente contrarrestados por el daño ambiental causado por sus emisiones contaminantes. Aunque se han propuesto muchos acuerdos y políticas para reducir el uso de las energías fósiles, como el Acuerdo de París sobre el cambio climático que trata de reducir las emisiones de gases invernadero, el carbón se sigue consumiendo y produciendo actualmente a gran escala. Además, se pronostica que este escenario permanezca intacto durante las siguientes tres décadas. La exposición a elevados niveles de polvo de minería es considerada un factor de riesgo ocupacional muy importante para los mineros del carbón. Durante el paso del tiempo, las regulaciones mineras, los avances en la ingeniería minera y la mayor consciencia de la seguridad de los trabajadores del carbón ha fomentado mejoras en la protección ocupacional. A pesar de ello, la exposición ocupacional al polvo de carbón durante su minería y manipulación sigue siendo la principal causa de enfermedades pulmonares del polvo del carbón (CMDLD), como la neumoconiosis (CWP), la silicosis y la fibrosis masiva progresiva (PMF). Esto, en parte, probablemente se deba a la mejora en la eficiencia tecnológica de la maquinaria minera usada para trabajar el carbón, resultando en la emisión de partículas más finas y concentraciones más altas de polvo de carbón (al explotarse mayores cantidades de carbón), un efecto que ha estado relacionado con el incremento de CMDLD, afectando incluso a trabajadores más jóvenes. Sin embargo, a pesar de los cambios en los métodos mineros y sus emisiones de polvo, sigue existiendo una notable escasez de estudios paralelos sobre temas relevantes para la salud, relacionándolos con la inhalación de partículas en las minas de carbón modernas. El principal objetivo de esta tesis doctoral es el estudio de los patrones de polvo de carbón producidos por los diferentes tipos de operaciones mineras y el estudio de los principales patrones de distintos tipos de carbón cubriendo un amplio rango geoquímico. Además, se ha investigado la relación entre el potencial oxidativo (OP) y la geoquímica del polvo de carbón con el propósito de identificar posibles indicadores potenciales que puedan perjudicar la salud humana. Con estos fines, se llevaron a cabo análisis de tamaño de partícula, químicos, mineralógicos y de OP para: i) el polvo de carbón recolectado en diferentes zonas y procesos mineros para minas de carbón subterráneas y de cielo abierto, ii) una selección de muestras de perfiles de capas de carbón molidas cubriendo una amplia y contrastada variedad de parámetros geoquímicos de carbones explotados en China. En ambos casos, las fracciones respirables (<4 μm) fueron extraídas y analizadas para simular el polvo de carbón respirable en suspensión (PM4). La novedad de estos protocolos de muestreo y análisis hizo necesario calibrar y validar las nuevas metodologías, y diseñar e implementar nuevos métodos, con el fin de separar las fracciones respirables de polvo y obtener caracterizaciones completas de tamaño de partícula, geoquímicas y mineralógicas. Los resultados de esta tesis doctoral se incluyen en cinco artículos científicos publicados en revistas de alto impacto. El Artículo #1 es introductorio y contiene una revisión de los patrones geoquímicos más relevantes en la salud humana. En los Artículos #2 a #4 se muestran resultados para el muestreo de polvo de carbón depositado en numerosas minas de carbón subterráneas (China y Europa) y una mina de cielo abierto (China), asimismo se describe la separación y caracterización de fracciones respirables. Las muestras fueron recogidas en diferentes zonas de las minas de carbón con el fin de cubrir las operaciones mineras más significativas realizadas en ellas. Además, las muestras de carbón pulverizado del Artículo #5, que comprenden un amplio rango de patrones geoquímicos en China, fueron utilizadas para separar y caracterizar detalladamente sus fracciones respirables. En los Artículos #3 a #5, se seleccionaron muestras de polvo de mina y carbón molido (de acuerdo con su tamaño y los patrones geoquímicos) para evaluar las relaciones entre los marcadores OP (ácido ascórbico, AA; glutatión, GSH; y ditiotreitol, DTT) con los patrones fisicoquímicos más relevantes, llevando a cabo un análisis de relación cruzada y regresión multilineal para las muestras de polvo de minas subterráneas (Artículo #3), muestras de polvo de la mina de cielo abierto (Artículo #4) y muestras de carbón pulverizado (Artículo #5). Por último, se repitieron los análisis incluyendo todas las muestras de las fracciones respirables de las muestras depositadas de polvo de carbón y de las muestras de carbón pulverizado (Artículo #5). Además de las medidas de polvo de carbón respirable extraídas de polvo sedimentado o carbón pulverizado, se llevaron a cabo medidas directas de medidas in-situ y en continuo de polvo de mina en suspensión en los Artículos #2 a #4 (Europa y China), incluyendo medidas en aire ambiente de niveles de PM2.5, PM10, BC y UFP (PM <2.5 μm, <10 μm, carbono negro, y partículas ultrafinas, respectivamente) en torno a varias operaciones mineras en la mina de cielo abierto (Artículo #4). Los resultados de esta tesis doctoral demuestran que el tamaño de partícula del polvo de mina es un parámetro clave para el control de su suspensión. Los resultados también muestran que el tamaño de partícula del polvo depende de los contenidos de humedad y ceniza del mismo, que están negativa y positivamente correlacionados, respectivamente, con el porcentaje de las partículas finas en el polvo sedimentado/depositado. Basándose en la observación de los niveles de polvo de mina de carbón, los resultados evidencian que los niveles de fracción respirable son marcadamente superiores a las áreas del frente de trabajo de la capa de carbón. Desde allí, el polvo decrece considerablemente, aunque las fracciones finas sean fácilmente transportadas a otras partes de la mina, donde también reciben contribuciones de otras fuentes de emisión, como por ejemplo de la minería y manipulación de los estériles, transporte del carbón, sales del drenaje ácido de minas, desgaste de la maquinaria y erosión de galerías gunitadas. Estas contribuciones modifican notablemente el tamaño del polvo de mina y su composición, en comparación con el polvo proveniente del frente de trabajo donde se explota directamente la capa de carbón. Los resultados muestran, pues, que los niveles y patrones geoquímicos del polvo de mina de carbón están notablemente influenciados por las operaciones mineras llevadas a cabo en cada zona específica de la mina. La manipulación y el trabajo del carbón generan un polvo relativamente grueso, con proporciones variables de contenido mineral y matriz orgánica; mientras que la manipulación y el trabajo de los materiales de los estériles producen polvo fino y con alto contenido en ceniza, enriquecido en minerales como arcilla, cuarzo y calcita; los accesos a las galerías están caracterizados por bajos contenidos en polvo, pero con mayor proporción en material respirable, que contienen especies minerales enriquecidas en Ca, y también componentes potencialmente peligrosos (especies sulfatadas ácidas, Fe, As, Sb, entre otros) derivados de las sales de las aguas freáticas infiltradas, que se ven afectadas por el drenaje ácido de minas. El análisis de las fracciones respirables de las muestras de polvo mostró que la mayor parte de las ratios de concentración de las especies y elementos estudiados en ese polvo respirable versus el polvo depositado original fue menor o similar a 1.0. En cambio, ratios para minerales de la arcilla y algunos metales (Se, Mo, Pb, Zn, Sn, As, Cu, Sb, Ni, Co y Cr) alcanzó valores >1.0, indicando su enriquecimiento en su fracción respirable debido a su modo de ocurrencia más fino. Estos enriquecimientos pueden indicar la presencia de polvo proveniente de otras fuentes distintas a las emisiones de polvo de carbón del frente de trabajo, como el drenaje ácido de la mina y emisiones del desgaste de la maquinaria. Ello se ve corroborado por el hecho de que varios de estos elementos también tienen concentraciones más elevadas en PM10, comparados con el polvo respirable depositado. Así pues, aunque los niveles de PM son marcadamente inferiores lejos del frente de trabajo de la capa de carbón, su enriquecimiento en determinados metales y sales evidencian la importancia de monitorizar el polvo de minería en diferentes áreas de la mina, y no tan solo en el frente de trabajo de la capa. Los resultados de OP total (OPTOT) presentados aquí, junto con los de un artículo publicado en 2021 de polvo de mina de carbón en minas turcas, son pioneros en investigar las conexiones de los patrones geoquímicos del polvo de mina y OP. En esta tesis doctoral, los valores de OPTOT obtenidos para el polvo de carbón son marcadamente inferiores a los de otros estudios de PM publicados provenientes de los sistemas de metro urbano, PM en aire ambiente de áreas con altas emisiones de quema de biomasa doméstica y de calles urbanas transitadas. Se dedujo que las especies inorgánicas del polvo de carbón están más relacionadas con OPAA, mientras que las especies orgánicas lo están con OPGSH y OPDTT. Las especies y/o elementos que controlaron el OPAA fueron Fe, pirita, minerales sulfatados y anatasa, mientras que para los indicadores OPGSH y OPDTT fueron los contenidos en humedad (reflejando el contenido en materia orgánica carbonosa), Ca, Mg, Na y Ba. Además, las correlaciones de las concentraciones de la mayor parte de estos componentes en polvo de mina o carbón pulverizado con OPAA, OPGSH y OPDTT incrementaron cuando fueron evaluados sólo los carbones o polvo de carbón de alto rango (bituminosos en este estudio). Los resultados de la evaluación de las características geoquímicas de los carbones explotados en China que controlan el OP del polvo potencialmente generado durante su extracción y manipulación (Artículo #5) demuestran que los contenidos en pirita, ceniza, anatasa, cuarzo, S, Ti y varios metales traza, como Mn, Mo y U, gobiernan la OPAA. Por otra parte, al igual que lo deducido para el polvo de mina, es el contenido en la materia orgánica carbonosa el que gobierna los niveles de OPGSH y OPDTT de las muestras de carbón molido. Estos resultados son similares a los obtenidos en el polvo de mina de carbón respirable, indicando que la extracción de la fracción respirable de las muestras de capas de carbón pulverizado para su posterior análisis geoquímico y de OP se pueden utilizar como indicador del OP del polvo de mina de carbón, atendiendo a las limitaciones indicadas anteriormente, de las posibles fuentes de polvo adicionales a la del frente de trabajo en la capa. Los resultados de los indicadores de OP concuerdan con los de estudios y modelos previos que proporcionan evidencias de asociaciones de determinados elementos y especies en polvo de minería con la generación de especies reactivas del oxígeno (ROS). Especialmente en lo referente a las marcadas correlaciones entre Fe y pirita con OPAA, que demuestran la relevancia de los contenidos de Fe y pirita en polvo de mina y de carbón inhalables con el estrés oxidativo, incluyendo la posibilidad de provocar enfermedades pulmonares y el desarrollo de CWP. Las mediciones de PM10 realizadas en este estudio demuestran la importancia de aplicar medidas efectivas para el control del polvo de minería en las minas de carbón subterráneas y de cielo abierto para reducir su concentración. Especialmente relevantes son los altos niveles de polvo fino medidos en áreas donde los estériles son manipulados sin medidas de control, en la mina de cielo abierto. También, las mediciones in-situ y online de BC y UFP mostraron niveles de exposición moderados, obteniéndose niveles de exposición en cielo abierto comparables a los típicamente registrados en entornos de tráfico urbano intenso. Obviamente este no era el caso para los niveles de PM, siendo estos muy superiores en la mina. La baja dispersión atmosférica en el fondo de la mina de cielo abierto, en comparación con las áreas más elevadas, combinado con la alta maquinaria usada, y el denso tráfico de la zona, proporciona elevados niveles de contaminantes, en especial UFP y PM. Los resultados de esta tesis doctoral subrayan la importancia de seguir investigando sobre las propiedades y niveles de polvo en la minería del carbón en el contexto de la mejora de las condiciones laborales de los mineros; en especial debido a que probablemente se mantenga una producción de carbón muy elevada, en países como China, durante las próximas décadas.Postprint (published version

Towards Long-Term Monitoring of the Structural Health of Deep Rock Tunnels with Remote Sensing Techniques

Due to the substantial need to continuously ensure safe excavations and sustainable operation of deep engineering structures, structural health monitoring based on remote sensing techniques has become a prominent research topic in this field. Indeed, throughout their lifetime, deep tunnels are usually exposed to many complex situations which inevitably affect their structural health. Therefore, appropriate and effective monitoring systems are required to provide real-time information that can be used as a true basis for efficient and timely decision-making. Since sensors are at the heart of any monitoring system, their selection and conception for deep rock tunnels necessitates special attention. This work identifies and describes relevant structural health problems of deep rock tunnels and the applicability of sensors employed in monitoring systems, based on in-depth searches performed on pertinent research. The outcomes and challenges of monitoring are discussed as well. Results show that over time, deep rock tunnels suffer several typical structural diseases namely degradation of the excavation damaged areas, corrosion of rock bolts and cable bolts, cracks, fractures and strains in secondary lining, groundwater leaks in secondary lining, convergence deformation and damage provoked by the triggering of fires. Various types of remote sensors are deployed to monitor such diseases. For deep rock tunnels, it is suggested to adopt comprehensive monitoring systems with adaptive and robust sensors for their reliable and long-lasting performance

암석의 기계굴착 성능 예측을 위한 유전자발현프로그래밍과 입자군집최적화에 기초한 혼합형 진화 계산 알고리즘

학위논문(박사) -- 서울대학교대학원 : 공과대학 에너지시스템공학부, 2022. 8. Seokwon Jeon.암반 기계 굴착 기술의 발전으로 기존의 발파 공법이 아닌 기계 굴착을 사용하여 지하 공간을 건설하는 사례가 증가하고 있다. 기계식 암석 굴착 분야에는 다양한 변수 간의 관계에 대한 상당한 수의 결정론적 해법이 있지만, 많은 경우 변수 간의 결정적 관계를 설정하는 것은 극히 어렵다. 그 결과 많은 연구자들이 회귀 분석을 사용하여 이러한 관계를 설명하려고 한다. 암석 파쇄 현상의 복잡하고 비선형적인 특성으로 인해 기존의 함수 피팅 기법에서 요구하는 통계 데이터에 부합하는 비선형 함수의 형태를 합리적으로 결정하기가 쉽지 않다. 따라서 본 연구에서는 기계 굴착 분야의 문제점을 해결하기 위해 유전자 발현 프로그래밍(GEP)과 입자 군집 최적화 (PSO)의 조합을 데이터 분석에 사용하였다. GEP 및 PSO는 진화적 계산 기술이며 GEP-PSO 알고리즘을 통해 데이터 세트에 맞는 비선형 함수의 형식과 상수를 자동으로 찾을 수 있다. 본 연구에서는 임팩트 해머에 대한 성능 예측 모델, 픽커터에 필요한 비에너지 예측 모델, 픽커터에 작용하는 절삭력, 수직력, 횡방향력 예측 모델을 개발하기 위해 알고리즘을 사용하였다. 모든 경우에 GEP-PSO 알고리즘을 사용하여 생성된 결과는 다중 선형 회귀에 의해 생성된 결과와 비교하여 상당히 높은 예측 정확도를 생성함을 확인하였다. 가능한 경우 GEP-PSO 알고리즘에 의해 생성된 결과와 다른 연구자가 개발한 예측 모델을 비교하여 현재 연구 과정에서 개발된 모델의 장점을 보여 줄 것으로 보인다. 높은 수준의 정확도 외에도 GEP-PSO 알고리즘을 사용하여 개발된 모델은 기존 예측 모델의 단점을 상당 부분 극복할 수 있다. 개발된 모델은 얻기 쉬운 입력 매개변수를 거의 요구하지 않으면서 더 많은 신뢰성 및 정확도를 제공하거나 기존 예측 모델에서 무시되었던 중요한 입력 매개변수를 포함하므로 더 유리하다고 볼 수 있다.With the advances in mechanical excavation technology, increasing number of underground spaces are built using mechanical excavation rather than the conventional drilling and blasting method. In the field of mechanical rock excavation, there are a fair number of deterministic solutions for the relations between different variables. However, in many cases, establishing such a relation is extremely difficult. As a result, many researchers try to explain those relations using regression analysis. Due to the complex and non-linear nature of rock cutting phenomenon, it is not easy to reasonably determine the form of the non-linear functions that fit to the statistical data as it is required by the conventional non-linear function fitting techniques. As a result, a combination of Gene Expression Programming (GEP) and Particle Swarm Optimization (PSO) was used for data analysis in this study in order to solve problems in the field of mechanical excavation. GEP and PSO are evolutionary computation techniques and the GEP-PSO algorithm is capable of automatically finding the form and constants of a non-linear function that fits on a data set. The algorithm was used in order to develop a performance prediction model for impact hammer, a prediction model for specific energy required by point attack picks, and models for prediction of cutting, normal, and side force acting on a point attack pick. In all cases, the results generated using the GEP-PSO algorithm produced significantly high prediction accuracy in comparison to those generated by multiple linear regression. When possible, comparisons were made between the results generated by the GEP-PSO algorithm and the prediction models developed by other researchers to show the advantages of the models developed over the course of the present study. In addition to high level of accuracy, the models developed using GEP-PSO algorithm could overcome shortcomings of the existing prediction models to a fair extent. The developed models are more advantageous as they provide more reliability/accuracy while requiring few easy-to-obtain input parameters, and/or they include the significant input parameters that have been neglected by the existing prediction models.1. Introduction 1 2. Literature Review 10 2.1 Impact hammer performance prediction 10 2.1.1 Existing performance prediction models 11 2.1.2 Performance prediction model 13 2.2 Specific energy prediction 14 2.2.1 Parameters with a significant impact on specific energy 16 2.2.2 Specific energy prediction model 22 2.3 Forces acting on a point attack pick 22 2.3.1 Existing force prediction models 23 2.3.2 Parameters with a significant impact on forces 29 2.3.3 Forces prediction models 30 3. Statistical Data 31 3.1 Impact hammer performance 31 3.1.1 Levent-Hisarustu tunnel 31 3.1.2 Uskudar-Cekmekoy tunnel 33 3.2 Specific energy required by point attack picks 37 3.3 Forces applied on point attack picks 41 4. Data Analysis Method 43 4.1 Gene Expression Programming (GEP) 45 4.1.1 Genetic Operators 47 4.1.2 The Basic Flowchart of GEP algorithm 55 4.2 Particle Swarm Optimization (PSO) 56 4.3 GEP-PSO algorithm 58 5. Results and Discussion 64 5.1 The suggested impact hammer performance prediction model 65 5.2 The model suggested for prediction of specific energy required by point attack picks 75 5.3 The suggested models for prediction of forces acting on a point attack pick 88 6. Conclusions 97 6.1 Performance prediction model for impact hammer 97 6.2 Prediction model for specific energy required by point attack picks 99 6.3 Models for prediction of cutting, normal, and side force acting on a point attack pick 100 References 102 초 록 116 Appendix A 118 Acknowledgment 138박

Applications of Advanced Computational Modelling for Principal Underground Mining Hazards Management and Control

Underground coal mining is facing increased threats from the hazards of spontaneous combustion and heating of coal, abnormal mine gas emissions, and harmful dust concentrations in underground workings, due to increased production outputs and extraction depth of cover. To control and mitigate these engineering problems, there is a need to gain critical knowledge of spontaneous heating in the longwall (LW) goaf, gas migration patterns onto the LW face, and ventilation dynamics and dust dispersion in complex underground environments. Advanced Computational Fluid Dynamics (CFD) modelling can be used to simulate various scenarios portraying these hazards that may occur in underground LWs and provide much-needed knowledge and fundamental science that can be used to develop robust and effective control and mitigation strategies against these hazards. A comprehensive literature review has been conducted to understand these principal mining hazards (PMH), with a particular emphasis on the applications of CFD modelling in the prevention management and control of those PMH arising during coal extraction process. The insufficiencies and gaps in research on spontaneous combustion in active LW goaf, gas migration onto the LW face, and dust dispersion and transport in the development heading were identified. In addition, several field studies were carried out in underground coal mines in Australia to gain a better understanding of these mining issues and collate essential data for the CFD modelling studies. In recent years, goaf heating and spontaneous combustion incidents have been reported in several Australian underground coal mines during normal production cycles. The onset of these heating incidents was dictated by many operational and environmental parameters. Based on the site-specific conditions of an underground coal mine, where the coal seam gas is of approximately 80% carbon dioxide (CO2) and 20% methane (CH4) with a gas emission rate of 2000 l/s, CFD models were developed and validated with field gas monitoring data collected from the Tube Bundle System. The CFD models incorporated a user defined function (UDF) of gas emission and permeability variations in a three-dimensional (3D) space of computational domain representing the LW panels and goaf areas. Simulation results indicated that better goaf inertisation could be achieved when nitrogen (N2) was injected via cut-throughs (C/T) at about 250 m behind the LW face on the maingate (MG) side and surface boreholes at 100 m and 700 m on the tailgate (TG) side, with a total injection rate greater than 1750 l/s. The oxygen concentration on the MG and TG side dropped below 5% at distances of 120 m and 75 m behind the LW face, with a confined oxidation zone area of 35375 m2, which was approximately one-third of the oxidation zone area without inert gas injection. The impact of geological variations (i.e., coal seam orientations and goaf gas composition) on spontaneous combustion prevention and management was further studied using CFD models. The influence of ventilation design and operational parameters (e.g., tightness of the goaf seals) on spontaneous combustion control was also investigated by additional CFD models based on field data. During LW sealing-off, the ventilation flow dynamics change within the goaf, which considerably increases the risk of spontaneous combustion and gas explosion. To prevent these hazards, CFD models were developed and calibrated with field gas monitoring data to simulate a range of operational scenarios of different ventilation arrangements. The modelling studies indicated that at least six gas sensors should be employed and positioned appropriately to ensure effective goaf atmosphere monitoring for risk management during the LW sealing-off process. Extensive CFD-DPM (Discrete phase model) coupling modelling studies were conducted to investigate dust-related issues in LW gateroad development panels. Based on site-specific conditions, a CFD model incorporating a Continuous Miner (CM), Shuttle Car (SC) and exhausting ventilation tube was established and validated with onsite dust monitoring data. Three scenarios of CM cutting at the middle, floor and roof positions were considered and simulated. In all cases, the simulation results indicated that high levels of dust exposure would occur to left-hand-side (LHS) operators and consequently they should be equipped with high-quality personal protective equipment and stay behind the ventilation duct inlet during coal cutting process, while miners standing at the right-hands-side (RHS) of the CM for roof and/or rib bolting and machine operation should stay immediately behind the bolting rig where dust concentration was relatively low. The studies conducted in this thesis provided new insights into the current goaf inertisation practices to effectively manage and control spontaneous heating in LW goaf by considering geological variations and mining design. Furthermore, the CFD modelling study of gas flow dynamics during the panel sealing-off process provides new knowledge of ventilation and goaf gas dynamics, which is critical to the positioning of gas monitoring sensors to reliably measure goaf atmosphere changes, thus minimizing spontaneous heating and gas explosion risks with much-improved mine safety. The research work also shed light on the dust and ventilation behaviour in gateroad development panels, and provided several recommendations for operators’ locations and dust mitigation strategies to improve the health and safety of miners. The research outcomes from this study contribute to the improvement of current practices and guidance for PMH management and control in underground mines and tunnelling projects

Improving Energy Efficiency through Data-Driven Modeling, Simulation and Optimization

In October 2014, the EU leaders agreed upon three key targets for the year 2030: a reduction by at least 40% in greenhouse gas emissions, savings of at least 27% for renewable energy, and improvements by at least 27% in energy efficiency. The increase in computational power combined with advanced modeling and simulation tools makes it possible to derive new technological solutions that can enhance the energy efficiency of systems and that can reduce the ecological footprint. This book compiles 10 novel research works from a Special Issue that was focused on data-driven approaches, machine learning, or artificial intelligence for the modeling, simulation, and optimization of energy systems

An approach to the assessment of the agricultural impacts of coal mining

Contentions that expansion of the British coal mining industry into predominantly rural areas may pose serious threats to agriculture and food production are reviewed in the light of the available evidence. It is considered that, whilst the severity of impacts and rate of future development may have been overstated, the conflicts are sufficiently significant to warrant close examination. Further, land use planners are responding for the first time to mining proposals affecting entire coalfields, thus making it essential to establish the correct principles of development from the outset. It is noted that past assessments of agricultural impacts have failed to reflect their diverse and pervasive nature, thus necessitating the identification of more appropriate methods of forecasting. In the light of current weaknesses in practice, it is argued that a formal system of impact assessment may prove necessary. Those characteristics of mining operations and associated end-uses which are likely to affect agriculture are analysed, as are those aspects of the farm enterprise most vulnerable to disruption. These various characteristics are then used as a basis for the assessment of mining-agriculture impacts. A review of the strategic nature of impacts arising from mining programmes is considered desirable, and limited proposals are made regarding assessment at this scale. More detailed consideration is given to an appraisal framework for individual mining proposals, and this is tested in relation to part of the 'Vale of Belvoirl coalfield. It is concluded that, although further methodological refinements and field investigations are necessary, the early implementation of an impact assessment procedure is nevertheless justified

Towards Long-Term Monitoring of the Structural Health of Deep Rock Tunnels with Remote Sensing Techniques

Due to the substantial need to continuously ensure safe excavations and sustainable operation of deep engineering structures, structural health monitoring based on remote sensing techniques has become a prominent research topic in this field. Indeed, throughout their lifetime, deep tunnels are usually exposed to many complex situations which inevitably affect their structural health. Therefore, appropriate and effective monitoring systems are required to provide real-time information that can be used as a true basis for efficient and timely decision-making. Since sensors are at the heart of any monitoring system, their selection and conception for deep rock tunnels necessitates special attention. This work identifies and describes relevant structural health problems of deep rock tunnels and the applicability of sensors employed in monitoring systems, based on in-depth searches performed on pertinent research. The outcomes and challenges of monitoring are discussed as well. Results show that over time, deep rock tunnels suffer several typical structural diseases namely degradation of the excavation damaged areas, corrosion of rock bolts and cable bolts, cracks, fractures and strains in secondary lining, groundwater leaks in secondary lining, convergence deformation and damage provoked by the triggering of fires. Various types of remote sensors are deployed to monitor such diseases. For deep rock tunnels, it is suggested to adopt comprehensive monitoring systems with adaptive and robust sensors for their reliable and long-lasting performance

Seismic prediction and imaging of geological structures ahead of a tunnel using surface waves

To improve the performance and safety of tunnel constructions, we introduce a new seismic prediction method utilizing tunnel surface waves to detect relevant geological structures ahead of the tunnel face. On the basis of both synthetic and field data, we investigate the propagation characteristics of such surface waves propagating along the tunnel wall. We further introduce a simple but robust automatic prediction scheme that can estimate the distance to a reflector ahead of the tunnel