Prospective tendencies of coal mining risk management

Purpose. The main purpose is to identify underground coal mining risks as well as approaches for their reasonable and efficient management taking into consideration internal production reserves in order to improve technological processes’ efficiency and operational efficiency. Methods. In order to achieve a target goal, the paper highlights and analyzes production processes involving the highest risk level. Methods of analogous risk characteristics, systematic approach towards developing a system of coal mining risk management as well as methods of distributed control have been applied to develop risk management innovative methods. Findings. The reasons stipulating coal mining risks based upon geologic, technologic, and economic aspects of mining practice as well as imperfection of human psychology, have been defined. Attention is drawn to the necessity to involve efficient counterweights relying upon additional bonuses for detecting violations, innovative trainings, and training of personnel to prevent safety inhibitions. A matrix structure has been demonstrated as the optimum structure for risk management, which should implement the idea of distributed control. Combination of effective operative information support with a system of open communication helps to develop conditions to change attitude of participants of underground coal mining towards risks to ensure safety. Originality. For the first time, the reasonability of combining matrix structure with distributed risk management has been demonstrated as well as substitution of unifactor discrete cumulative characteristic of explosion probability or methane ignition for analogous characteristic, dependent on several factors. Practical implications. Performance assessment throughout coal mines’ operations improves reliability and safety of production processes and mining practices as well as provides for proactive risk management.Мета. Виявлення ризиків підземного вуглевидобутку, а також підходів до їх раціонального та оперативного управління з урахуванням внутрішніх резервів виробництва для підвищення ефективності технологічних процесів і операцій. Методика. Для досягнення поставленої мети в роботі виділені та проаналізовані виробничі процеси, що володіють найбільш високим ступенем ризиків, а для розробки інноваційних шляхів управління ризиками використані методи аналогових характеристик ризику, системний підхід до створення системи керуванням ризиками вуглевидобутку, методи розподіленого управління. Результати. Надано характеристику причин, що визивають ризики вуглевидобутку, заснованих на геологічних, технологічних та економічних аспектах гірничого виробництва, а також викликаних недосконалістю людської психології. Акцентовано увагу на необхідності залучення ефективних противаг, заснованих на додатковому преміювання за виявлення порушень, на інноваційних тренінгах і навчанні персоналу для запобігання порушенню безпеки. Показано, що оптимальною структурою управління ризиками є матрична, яка повинна реалізувати принцип розподіленого управління. Поєднання ефективного оперативного інформаційного забезпечення з системою відкритої комунікації дозволяє створити умови для зміни ставлення учасників процесу підземного вуглевидобутку до ризиків для забезпечення безпеки. Наукова новизна. Вперше показана доцільність комбінування матричної структури і розподіленого управління ризиками, а також заміни однофакторної дискретної кумулятивної характеристики ймовірності вибуху або спалаху метану на аналогову, що залежить від декількох факторів. Практична значимість. Врахування результатів роботи при функціонуванні вугільних шахт підвищує надійність і безпеку виробничих процесів та операцій видобутку, а також забезпечує проактивне управління його ризиками.Цель. Выявление рисков подземной угледобычи, а также подходов к их рациональному и оперативному управлению с учетом внутренних резервов производства для повышения эффективности технологических процессов и операций. Методика. Для достижения поставленной цели в работе выделены и проанализированы производственные процессы, обладающие наиболее высокой степенью рисков, а для разработки инновационных путей управления рисками использованы методы аналоговых характеристик риска, системный подход к созданию системы управлением рисков угледобычи, методы распределенного управления. Результаты. Дана характеристика причин, вызывающих риски угледобычи, основанных на геологических, технологических и экономических аспектах горного производства, а также вызванных несовершенством человеческой психологии. Акцентировано внимание на необходимости задействования эффективных противовесов, основанных на дополнительном премировании за выявление нарушений, на инновационных тренингах и обучении персонала для предотвращения нарушения безопасности. Показано, что оптимальной структурой управления рисками является матричная, которая должна реализовать принцип распределенного управления. Сочетание эффективного оперативного информационного обеспечения с системой открытой коммуникации позволяет создать условия для изменения отношения участников процесса подземной угледобычи к рискам для обеспечения безопасности. Научная новизна. Впервые показана целесообразность комбинирования матричной структуры и распределенного управления рисками, а также замены однофакторной дискретной кумулятивной характеристики вероятности взрыва или вспышки метана на аналоговую, зависящую от нескольких факторов Практическая значимость. Учет результатов работы при функционировании угольных шахт повышает надежность и безопасность производственных процессов и операций добычи, а также обеспечивает проактивное управления ее рисками.The paper did not originate from any project and no funding was raised

Report fragment of a crosscut's support inspection

1. Fragment of a report presents the results of an underground roadway (crosscut) inspection. The crosscut has been driven at the depth of 950 m. 2. Two movies demonstrate the results of FLAC3D simulation of U-shape support yielding. The first video shows a normal yielding process. The second movie shows how the normal process of the reciprocal sliding has been disrupted by twisting of the profile

Results of FLAC3D simulation

Coordinates X, Y and Z of zones' centroids where hydro-fracturing occurred. There are six components of the strain increment in every zone. One cycle corresponds to 0.688 sec

Оперативне управління проектом в умовах параметричної і структурної невизначеності: визначення поняття і його часових параметрів

We studied a prompt project management which is often used under conditions of uncertainty.  The aim of the paper was to determine the quantitative limits in the time scale for the prompt decision making that is close to the optimal. These time limits were investigated through the examination of the artificial intelligence activity using artificial neural networks which were trained by a genetic algorithm. We found that the average limit of the time Tc that the networks spent to find the decision that is close to the optimal is 12±4% of the time period To that needs to rich the optimal decision. Deviation of the decisions from the optimum did not surpass 20% which corresponds to the Pareto principle. This finding disclosed the essential time reserves that might be utilized during the prompt project management under time shortage pressing. Finally, we concluded that the profit from cutting of the time for the prompt decision making exceeds the losses caused by the deviation of decisions from the optimal ones if 0.2To ≤ Tc < To.Показано, что в условиях параметрической и структурной неопределенности целесообразным является оперативное управление проектом. Определен критерий оперативного управления проектом и установлены его временные параметры.Показано, що в умовах параметричної і структурної невизначеності доцільним є оперативне управління проектом. Визначено критерій оперативного управління проектом і встановлено його часові параметри

SP&AIC

Data deposition for the paper ‘Project schedule expediting under structural and parametric uncertainty’ by Nazimko V. and Zakharova L. File 2021.xlsx contains: List ‘initial data’ – min, mode, max duration of the tasks taken from Tolentino Rena, R.A. (2009). Project management: A simulation-based optimization method for dynamic time-cost tradeoff decisions (M.S. thesis) Rochester, NY: Rochester Institute of Technology List ‘Critical Paths’ – critical paths and their frequencies (probabilitiwes) received by SP and AIC run List ‘Task criticality’ – tasks criticality received by SP and AIC run List ‘Results’ – results of the run of SP and AIC. These results are dublicated in the file ‘result_realdstr.dat’ as output file of SP and AIC running

Video of a twisted yeildable bolt driving into a rock hole

This video shows the process of 23-degree twisted rock bolt (TYB) driving into a hole with 25 mm diameter. TYBs were made of low-alloy steel of 09G2C grade having yield strength 325 MPa, tensile strength 470 MPa, elongation 21% and impact toughness 59 Дж/см3. Uniaxial tensile strength of the rock was 42.3±3.6 MPa and elasticity module 14 GPa. TYB cylindrical rode had diameter 20 mm. The rod had two feathers 3 mm high. The feathers cut the 0.5 grooves. A pneumatic hammer was used to drive the bolt. The hummer had a ring piston, inner channel and a clamp. The bolt was inserted into the channel and fixed with the clamp. The rod bolt was marked with a chalk every 10 cm.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Synchronization of the yield as a way to increase bearing capacity of frame supports

Results of testing of a yield frame support having synchronized clutches. Testing of the frames in situ and in a laboratory showed that opposite clutches yield by turn, one after another that is compliant with thermodynamics of irreversible processes. Such behavior causes blocking of the clutches, longitudinal twist of frame profile, its plastic deformation, breaking of the clutch components, asymmetrical yield of the clutches, buckling and shifting of the frames, what reduces their bearing capacity. Synchronization of the opposite clutches yielding is a key solution to provide stable operation of the frame saving and maintaining their bearing capacity. Synchronization of the opposite clutches was provided using a flexible link, for example, steel rope joining opposite clutches. New frame design proved to be much more efficient than a traditional prototype frame equipped with independent clutches. SC always demonstrated practically the same yield and synchronous paths of pliancy. Yield of SC occurred by smaller portions, average value of which was 1.962±2.29 mm, whereas corresponding elementary yield of IC extended to 6.641±6.7 mm, what increased probability of clutches blocking and destroying. Possibility of the IC jamming increases additionally because standard deviation of IC yield exceeds 100%, whereas standard deviation of SC yield in four tests was 0.43% only. Average resistance of the frame equipped with SC was 1.23 times more in comparison with IC prototype. Irreversible work of the SC resistance was 1.73 times more than corresponding work of IC. In addition, SC facilitate stable operation of the frame because variance of its resistance is 20% versus 67% for the frame having IC, and variance of the work is 10% for SC versus 50% for IC. The most important advantage is that weak but specific action of a frame equipped with SC induces strong interactions among blocking rock fragments, which produce self-supporting effect that increases stability of underground roadway

Monitoring of multipoint borehole extensometers and results of physical modelling

Data concerning monitoring the rock bolt heads are in file roof_subsidence.xls (roof subsidence) and Schem&vol-measur2001.xls (distance between the heads of adjacent rock bolts)Subdirectory Fisical_model contains the data concerning the physical modeling. File Physical_model_fotos.docx presents photos of the all model states, which were selected to digitize the marks positions and then incremental displacements of the marks, namely the difference of the positions between serial (sequential) states. File affin_transform_01.xlsx contains data described affine transformation of the photos. Files *.srf present fields of the incremental displacement of the marks between successive state of the model.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

SP&AIC

Data deposition for the paper ‘Project schedule expediting under structural and parametric uncertainty’ by Nazimko V. and Zakharova L. File 2021.xlsx contains: List ‘initial data’ – min, mode, max duration of the tasks taken from Tolentino Rena, R.A. (2009). Project management: A simulation-based optimization method for dynamic time-cost tradeoff decisions (M.S. thesis) Rochester, NY: Rochester Institute of Technology List ‘Critical Paths’ – critical paths and their frequencies (probabilitiwes) received by SP and AIC run List ‘Task criticality’ – tasks criticality received by SP and AIC run List ‘Results’ – results of the run of SP and AIC. These results are dublicated in the file ‘result_realdstr.dat’ as output file of SP and AIC running