Mining Technologies Innovative Development

The present book covers the main challenges, important for future prospects of subsoils extraction as a public effective and profitable business, as well as technologically advanced industry. In the near future, the mining industry must overcome the problems of structural changes in raw materials demand and raise the productivity up to the level of high-tech industries to maintain the profits. This means the formation of a comprehensive and integral response to such challenges as the need for innovative modernization of mining equipment and an increase in its reliability, the widespread introduction of Industry 4.0 technologies in the activities of mining enterprises, the transition to "green mining" and the improvement of labor safety and avoidance of man-made accidents. The answer to these challenges is impossible without involving a wide range of scientific community in the publication of research results and exchange of views and ideas. To solve the problem, this book combines the works of researchers from the world's leading centers of mining science on the development of mining machines and mechanical systems, surface and underground geotechnology, mineral processing, digital systems in mining, mine ventilation and labor protection, and geo-ecology. A special place among them is given to post-mining technologies research

Advanced Theoretical and Computational Methods for Complex Materials and Structures

The broad use of composite materials and shell structural members with complex geometries in technologies related to various branches of engineering has gained increased attention from scientists and engineers for the development of even more refined approaches and investigation of their mechanical behavior. It is well known that composite materials are able to provide higher values of strength stiffness, and thermal properties, together with conferring reduced weight, which can affect the mechanical behavior of beams, plates, and shells, in terms of static response, vibrations, and buckling loads. At the same time, enhanced structures made of composite materials can feature internal length scales and non-local behaviors, with great sensitivity to different staking sequences, ply orientations, agglomeration of nanoparticles, volume fractions of constituents, and porosity levels, among others. In addition to fiber-reinforced composites and laminates, increased attention has been paid in literature to the study of innovative components such as functionally graded materials (FGMs), carbon nanotubes (CNTs), graphene nanoplatelets, and smart constituents. Some examples of smart applications involve large stroke smart actuators, piezoelectric sensors, shape memory alloys, magnetostrictive and electrostrictive materials, as well as auxetic components and angle-tow laminates. These constituents can be included in the lamination schemes of smart structures to control and monitor the vibrational behavior or the static deflection of several composites. The development of advanced theoretical and computational models for composite materials and structures is a subject of active research and this is explored here for different complex systems, including their static, dynamic, and buckling responses; fracture mechanics at different scales; the adhesion, cohesion, and delamination of materials and interfaces

Numerical analysis of Double-O-Tube shield tunnelling

Underground tunnels play an important role in the mass transportation systems in modern cities. The ground movements induced by tunnel excavation in short term and long term are of great concern due to their potentially irrecoverable impact on the surrounding buildings and services. The numerical modelling, in conjunction with well documented case studies to validate the modelling approach, is an efficient methodology for adequate and robust predictions of the ground response caused by tunnelling. The Double-O-Tube (DOT) shield tunnelling is a new technology developed since 1989, and has been applied in over 20 engineering cases in China and Japan. Due to its unique double tube cross-sectional shape, the DOT tunnel is expected to perform differently in mechanical terms compared to traditional twin tunnels. Therefore, a systematic study of its engineering behaviour, of the ground response and of tunnel lining is necessary. This research involves numerical simulations and investigation of DOT construction in soft clay and stiff clay conditions, represented by Shanghai clay and London clay respectively, using Imperial College Finite Element Program (ICFEP). In the first part of the thesis, the Shanghai clay and the whole ground profile are characterised referring to the laboratory data and field experimental evidence. A numerical model is developed in ICFEP for the case of DOT tunnel in the Shanghai Metro system, applying an extended Modified Cam Clay (MCC) model to represent the ground conditions and discretising the tunnel lining with elastic beam elements. The predicted short-term settlement troughs achieve good agreement with the field monitoring data, validating the reliability of the numerical model. Additional sensitivity studies investigate the conditions of the tunnel lining joints and the effects of the pressure exerted by grouting in the constructions process. The second part of the thesis focuses on the modelling of the reinforced concrete segments of tunnel lining using an advanced elasto-plastic concrete model. The model validation is performed with the simulation of loading tests on a single lining segment performed in the laboratory, demonstrating very close agreement between the predicted and measured segment deflections under applied load and an accurate onset of cracking in concrete. Such a concrete model is applied in the analysss of DOT tunnelling in Shanghai to investigate its merits against a simpler lining representation. Finally, the application of DOT tunnelling is explored in stiff clay ground conditions, utilising the Jubilee Line Extension and the Crossrail case studies in London clay, and applying an advanced kinematic surface hardening model for soil behaviour. The comparison of numerical predictions against field monitoring data demonstrates comparable magnitudes of ground movements mobilised by DOT tunnelling with respect to conventional twin tunnelling.Open Acces

Volume II: Mining Innovation

Contemporary exploitation of natural raw materials by borehole, opencast, underground, seabed, and anthropogenic deposits is closely related to, among others, geomechanics, automation, computer science, and numerical methods. More and more often, individual fields of science coexist and complement each other, contributing to lowering exploitation costs, increasing production, and reduction of the time needed to prepare and exploit the deposit. The continuous development of national economies is related to the increasing demand for energy, metal, rock, and chemical resources. Very often, exploitation is carried out in complex geological and mining conditions, which are accompanied by natural hazards such as rock bursts, methane, coal dust explosion, spontaneous combustion, water, gas, and temperature. In order to conduct a safe and economically justified operation, modern construction materials are being used more and more often in mining to support excavations, both under static and dynamic loads. The individual production stages are supported by specialized computer programs for cutting the deposit as well as for modeling the behavior of the rock mass after excavation in it. Currently, the automation and monitoring of the mining works play a very important role, which will significantly contribute to the improvement of safety conditions. In this Special Issue of Energies, we focus on innovative laboratory, numerical, and industrial research that has a positive impact on the development of safety and exploitation in mining

Behaviour of segmental tunnel lining under static and dynamic loads

The aim of the research thesis is to provide a three-dimensional numerical model suitable to interpret the static and dynamic behaviour of a kind of segmental tunnel lining in soft soil. The static performance of the structure is investigated during the tunnel construction, involving the main tunnelling loads, obtaining the evolution of the state of stress and strain in the lining. The dynamic performance of segmental lining has been investigated both under uniform and not uniform seismic loads. In the case of uniform seismic load, pseudo static and full dynamic approaches have been compared, while non-linear coupled analysis have been used to investigate the post-earthquake lining condition. A study of the seismic vulnerability of such structures has been conducted based on fragility curves for different levels of damage. A procedure for the forecast method of risk assessment has been proposed for the case of segmental tunnel lining assuming as critical damage parameter the longitudinal joints rotation. Furthermore, a study of feasibility of Earthquake Early Warning System, EEWS, based on thresholds has been conducted through a probabilistic and a real-time approach for such tunnel structure. The coupling effect of multi-directional seismic motion both in transversal and longitudinal direction of the tunnel has also taken into account in the evaluation of dynamic tunnel behaviour. A comparison between the effect of synchronous and not synchronous seismic motion along the tunnel axis has been done in terms of dynamic increment of the components of forces in the lining

Synthetic Aperture Radar für Monitoring in städtischen Gebieten und im Bergbau

Considering it is hazardous to the environment and people, monitoring land movements at urban area become more and more significant. On the other hand, studying of land movements in non-urban area is also important. Synthetic aperture radar using interferometric technique, which is known as InSAR, is capable of providing a quite denser measurement over large areas. More specifically, Interferometric SAR (InSAR), Differential InSAR (DInSAR), Persistent Scatterers InSAR (PSI) techniques are developing to meet people¡¯s requirements of detecting land movements. Due to the different features of urban and non-urban area, the application of InSAR for land movements monitoring may come cross different challenges. D¨¹sseldorf was used as the urban test site by processing 20 TerraSAR-X images using PSI. Levelling results provided by the State Capital of D¨¹sseldorf validated the PSInSAR result, when two time series showed similar progress with very few discrepancies. Xishan mining region was chosen as the non-urban test site in this project, because of clear advantages. Such as well served mining schedule and literature and rapid movements with big phase gradients. In the experiments carried out in Xishan mine, InSAR fulfilled the aim of mining parameters derivation. GPS surveying was collated for the coordinates of corner reflectors, which can validate and improve the accuracy of geocoding (better than 5 m).Die Überwachung von Setzungen in städtischen Gebieten wird immer wichtiger, da es sich um eine potenzielle Bedrohung für die Umwelt und den Menschen handelt. Die Untersuchung von Landsenkungen in nicht-städtischen Bereichen sind ebenfalls sehr wichtig. Mit interferometrischen Auswertungen von Synthetic Aperture Radar Messungen (InSAR) ist man in der Lage große Bereiche hochauflösend zu beobachten. SAR Systeme können während des Tages, der Nacht und unter allen Wetterbedingungen arbeiten. Heutzutage gibt es zunehmendes Interesse an der Anwendung von SAR für das Monitoring von Veränderungen der Erdoberfläche. Hierzu wurden speziell die Techniken des Interferometrischen SAR (InSAR), Differential InSAR (DInSAR) und Persistent Scatterers InSAR (PSI) entwickelt. Aufgrund der unterschiedlichen Merkmale von urbanen und nichturbanen Gebieten, kann die Anwendung von InSAR für das Monitoring von Bewegungen unterschiedliche Herausforderungen stellen. Die Stadt Düsseldorf wurde als Testfeld für die Verarbeitung von 20 TerraSAR-X Bilder mit PSI ausgewählt. Die Ergebnisse aus dem Nivellement der Landeshauptstadt Düsseldorf wurden für die Validierung der PSInSAR Ergebnisse genutzt. Zwei Zeitreihen zeigen einen ähnlichen Verlauf mit sehr geringen Abweichungen. Die Bergbauregion Xishan wurde als nichturbanes Testgebiete in diesem Projekt ausgewählt, weil es die Möglichkeit bietet an Informationen über den Bergbau, die Zeitpläne und Literatur zu kommen und es dort schnelle Oberflächenbewegungen mit großen Phasengradienten gibt. Die durchgeführten Experimente im Xishan Gebiet zeigen, dass man mit der InSAR Auswertung auch Bergbauparameter ableiten kann. Für die Koordinatenbestimmung der Corner Reflektoren wurden GPS Messungen durchgeführt, die auch zur Verbesserung der Satellitenbasislinien dienen und die Genauigkeit der Geokodierung (kleiner 5 m) verbessern