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Artykuły w czasopismach na temat "Tunnels - Blast"
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Senthil, Kasilingam, Muskaan Sethi i Loizos Pelecanos. "A review on the performance of the underground tunnels against blast loading". Journal of Structural Engineering & Applied Mechanics 4, nr 1 (30.03.2021): 1–17. http://dx.doi.org/10.31462/jseam.2021.01001017.
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The tunneling system has become an important part of the present infrastructure system in all over the world. Therefore, it has become important to ensure the safety of the tunnels against any type of man-made blasting activities or other accidental blasting occurrence. In order to evaluate the performance of the tunnels against blast loading, a detailed review is carried out. Based on the review in the last couple of decades, the various parameters such as tunnel lining materials, tunnel shapes, tunnel lining thickness, tunnel burial depth, charge weight and standoff distance are high influences on the performance of underground tunnels against blast loading. It was observed that the tunnel roof and the tunnel wall center are most vulnerable to the blast loads. Also, it was found that more of the tunnel lining thickness results in lesser deformation at the tunnel roof and the tunnel wall center. The increase in the burial depth of the tunnel would reduce the extent of damage to the tunnel caused by effects of surface blast loading. The stiffness and strength of the ground media may be enhanced against the effects of blast loading by grouting measures. The studies revealed that the lining materials possessing blast waves absorbing properties can be best suited to be used in tunnel linings. Further, it was observed that more damage was caused to the tunnels due to the magnitude of the charge weight. An increase in the blast load causes a significant increase in the fracture area, residual stress and lateral displacement caused to the tunnel by the action of blast load. The standoff distance of the blast load from the tunnel also plays a significant role in the damage of the tunnel. More is the distance between the charge and the tunnel, lesser damage caused to the tunnels. In addition to that, the lining thickness was predicted and the trend was calibrated and fitted logarithmically with the available results. Based on the observation from the literature, it is concluded that the use of a single lining material in the tunnel against blast loading was studied predominantly in the couple of decades. Further, the performance of the tunnels in combination of different tunnel lining materials against blast loading was found limited. The influence of barriers to save the underground tunnels against blast loading was found limited.
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Zhang, Qingbin, Zongxian Zhang, Congshi Wu, Junsheng Yang i Zhenyu Wang. "Characteristics of Vibration Waves Measured in Concrete Lining of Excavated Tunnel during Blasting in Adjacent Tunnel". Coatings 12, nr 7 (5.07.2022): 954. http://dx.doi.org/10.3390/coatings12070954.
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The effect of a blasting vibration from an excavating tunnel on an adjacent excavated tunnel is of great importance for the stability and security of twin tunnels. Due to the relatively small distance between the tunnel face of the excavating tunnel and the concrete lining of the excavated tunnel, the impact of blasting could be significant and should be considered in a practical project. In order to control the blasting scales during the excavation of one tunnel and minimize the effect of blasting on the adjacent one, research based on field-blasting tests performed on twin tunnels is presented in this study. The particle velocities on the concrete lining of the excavating tunnel caused by blasting from the adjacent excavated tunnel were measured and analysed during six rounds of blasts. According to the measured vibration waves, it was clear that the peak particle velocity (PPV) from each blast was always induced by cut blasting, therefore, the maximum vibration due to each blast was mainly dependent on cut blasting. The measured maximum PPV for all the blasts was 15.55 cm/s, corresponding to a maximum tensile stress of 1.44 MPa observed on the concrete lining, which was smaller than the tensile strength of the concrete lining, in accordance with the one-dimensional elastic-wave theory. Moreover, the attenuation of the vibration waves varied in different regions, and they could be utilized to demonstrate the impact characteristics of the blasting; e.g., the particle velocities in the region along the excavating direction were 1.12 to 1.79 times larger than those in the region opposite to the excavating direction, and the difference increased with the increasing distance to the blasting source. The particle velocities on the side of the excavated tunnel close to the excavating tunnel were larger than those on the other side of the excavated tunnel. However, the particle velocities of the two aforementioned regions were similar when the distance between the measuring point and the blasting source was more than 6 m in the longitudinal direction of the tunnels. Furthermore, the measured vibration waves could be used to evaluate and improve the blast designs of tunnelling with the drill-and-blast method.
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Nawar, Mahmoud, Alaa Ata, Marwa Nabil i Sally Hassan. "Numerical analysis of underground tunnels subjected to surface blast loads". Frattura ed Integrità Strutturale 15, nr 55 (28.12.2020): 159–73. http://dx.doi.org/10.3221/igf-esis.55.12.
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The increased terrorist attacks on important public structures and utilities have raised the vital necessity for the investigation of performance of structures under blast loads to improve the design and enhance the behavior of structures subjected to such threats. In this study, 3-D finite element analysis is used to study the effect of surface explosions on the response of RC bored tunnels. The soil behavior is modelled using Drucker-Prager Cap model. Two types of soil are investigated, and the blast load is considered through various weights of TNT explosive charges at heights of 0.50 m and 1.0 m from ground surface. To study the effect of horizontal standoff distance, six different horizontal distances are considered. The results show that the soil type has a significance effect on tunnel response due to surface blasts. Also the weight and the location of charge have a great effect on the safety of the tunnel. Finally, a parametric study is established to define the borders of the restricted area around the tunnel location to be safe.
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Mandal, Jagriti, i Manmohan Dass Goel. "Effect of Geo-Material on Dynamic Response of Tunnel Subjected to Surface Explosion". Geotechnics 2, nr 3 (11.08.2022): 635–48. http://dx.doi.org/10.3390/geotechnics2030031.
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Prime materials involved in a problem such as underground structures are concrete, reinforcement steel, and geo-material surrounding the tunnel. Among these three materials, concrete and steel are manufactured materials and their properties can be controlled up to a certain extent. However, geo-material is a naturally occurring material whose constitutive properties vary from region to region, making it highly unpredictable. Findings from one study cannot be applied to other geotechnical problems directly, especially in the case of tunnels subjected to surface explosions. The blast wave generated has to travel through the geo-material before it interacts with the tunnel. As the shock wave propagates radially, its characteristics are likely to be altered by the geo-material. Limited study has been carried out considering this problem. In the present study, the effect of various types of geo-material on the blast response of tunnels subjected to surface explosions is investigated. Finite element analysis has been carried out using LS-DYNA®, wherein the problem has been modeled using the multi-material arbitrary Lagrangian–Eulerian (MM-ALE) method. Materials with fluid behavior such as air, explosives, and soil are modeled using ALE formulation. Other materials including tunnel lining, reinforcement steel, and rock are modeled using Lagrangian formulation. Blast loading is simulated using the Jones–Wilkins–Lee (JWL) equation of state. Geo-materials considered for the comparative study are sandy loam, saturated clayey soil, sandstone, and granite. Vertical displacement measured at the crown of the tunnel is used to determine the response of the tunnel. Sandy loam soil, being a highly compressible soil, exhibits non-linear and fluid-like behavior under high-strain loading such as explosions. Tunnels undergo extreme deformation in the case of sandy loam soil and clayey soil compared to rock cases. Further, the effect of saturation in sandy loam on tunnel stability is studied. It is observed that with the increase in saturation of soil, more blast energy is transmitted to the structure, which results in higher deformation. Lastly, the effect of the weathering of rock on the tunnel’s response is investigated in the case of sandstone and granite. It was observed that weathering in rock led to more displacement of tunnel crown when compared to intact rock.
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Mandal, Jagriti, ManmohanDass Goel i AjayKumar Agarwal. "Effect of Horizontal Curve on the Response of Road Tunnels under Internal Explosion". Proceedings of the 12th Structural Engineering Convention, SEC 2022: Themes 1-2 1, nr 1 (19.12.2022): 1293–97. http://dx.doi.org/10.38208/acp.v1.653.
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Internal explosion in a tunnel is a complex loading phenomenon where the tunnel lining is subjected to not only direct impact of explosion but also loading due to multiple reflection of blast waves which could be of magnitude higher than that of incident blast wave. This kind of loading is complex in nature and difficult to predict using simple analysis tools. Further, it poses a serious threat to its structural integrity. Studies have been conducted in the past to understand the behaviour of tunnel under internal explosion. However, they have been focused on straight tunnels ignoring the convex and concave shapes introduced due to horizontal and vertical curves. Shape of the target surface has significant effect on the characteristics of blast wave. This study investigates the effect of horizontal curves on the damage behaviour of tunnel lining due to internal explosion. A series of numerical simulation are performed on box-shaped tunnel with varying curvature radius and the results are compared with that of straight tunnel adopting Multi-Material Arbitrary Lagrangian-Eulerian (MM-ALE) method using LS-DYNA®. Explosive and air are modeled using ALE formulation, whereas, tunnel and soil are modeled using Lagrangian formulation. Further, Jones-Wilkins-Lee equation of state is used to model the explosion. Damage to the tunnel lining is measured in terms of peak particle velocity (PPV) and von-Mises stress. It is observed that walls of curved tunnels undergo more PPV compared with straight tunnel wherein concave wall show the highest PPV. Propagation of blast wave along the tunnel length is significantly affected due to the introduction of curvature resulting in change in reflection patterns. This further leads to variation in stress contours on tunnel lining with higher concentration of stress in curved tunnels than in straight tunnel.
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Bai, Fengtao, Qi Guo, Kyle Root, Clay Naito i Spencer Quiel. "Blast Vulnerability Assessment of Road Tunnels with Reinforced Concrete Liners". Transportation Research Record: Journal of the Transportation Research Board 2672, nr 41 (28.09.2018): 156–64. http://dx.doi.org/10.1177/0361198118798458.
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Tunnels are a critical component of our transportation infrastructure, and unexpected damage to a tunnel can significantly and adversely impact the functionality of a transportation network. Tunnel systems are vulnerable to potential threats of intentional and accidental blast events because of their relatively unrestricted public access. These events can lead to spalling and breach of the tunnel liner which, depending on the surrounding media, can result in local damage and progressive collapse of the tunnel. Current approaches for evaluating blast-induced damage to a tunnel liner either require significant computational effort or oversimplification such that accurate spatial distributions of damage cannot be obtained. This study presents an effective approach to predict and map the damage to a reinforced concrete liner of a roadway tunnel from various explosive threat sizes and tunnel geometries. A literature review of existing studies is conducted, and potential scenarios of blast events are examined with varying charge position and size. Rectangular, horseshoe, and circular tunnel geometries, each with the same traffic throughput, are evaluated. An efficient analytical approach to determine the spatial distribution of blast-induced spall and breach damage is presented and shows good agreement with numerical models analyzed in LS-DYNA. The proposed approach is then used to examine the relationship between increasing blast hazard intensity and the extent of spall and breach damage. Inflection points in this relationship can be used to identify hazard levels at which a progressive collapse evaluation would be warranted.
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Liu, Zichao, Jun Wu, Qinyi Chen, Shutao Li, Qiushi Yan i Haitao Yu. "Analysis on the Vulnerability of a Tunnel Entrance under Internal Explosion". Sensors 22, nr 24 (12.12.2022): 9727. http://dx.doi.org/10.3390/s22249727.
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Tunnels play an essential role in the transportation network. Tunnel entrances are usually buried at a shallow depth. In the event of an internal explosion, the blast pressure will cause severe damage or even collapse of the tunnel entrance, paralyzing the traffic system. Therefore, an accurate assessment of the damage level of tunnel entrances under internal blast loading can provide effective assistance for the anti-blast design of tunnels, post-disaster emergency response, and economic damage assessment. In this paper, four tunnel entrance specimens were designed and fabricated with a scale ratio of 1/5.5, and a series of field blast tests were carried out to examine the damage pattern of the tunnel entrances under internal explosion. Subsequently, static loading tests were conducted to obtain the maximum bearing capacity of the intact specimen and residual bearing capacities of the post-blast specimens. After that, an explicit non-linear analysis was carried out and a numerical finite element (FE) model of the tunnel entrance under internal blast loading was established by adopting the arbitrary Lagrangian–Eulerian (ALE) method and validated based on the data obtained from the field blast and static loading tests. A probabilistic vulnerability analysis of a typical tunnel entrance subjected to stochastic internal explosions (assuming various charge weights and detonation points) was then carried out with the validated FE model. For the purpose of damage assessment, the residual bearing capacity of the tunnel entrance was taken as the damage criterion. The vulnerability curves corresponding to various damage levels were further developed based on the stochastic data from the probabilistic vulnerability analysis. When the charge weight was 200 kg, the tunnel entrance exhibited slight or moderate damage, while the tunnel entrance suffered severe or even complete damage as the charge weight increased to 1000 kg. However, the tunnel entrance’s probability of complete damage was less than 10% when the TNT charge weight did not exceed 1000 kg.
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Shin, Jinwon, Seungki Pang i Dong-Keon Kim. "Effects of Entrance Shape and Blast Pocket on Internal Overpressure Mitigation for Protective Tunnels Exposed to External Detonation on the Ground". Applied Sciences 13, nr 3 (30.01.2023): 1759. http://dx.doi.org/10.3390/app13031759.
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This study presents a numerical analysis to reduce the overpressure inside protective tunnels for external detonations. A three-dimensional computational fluid dynamics model of a tunnel subjected to detonation for a hemispherical charge with a charge weight of 555 kg and a standoff distance of 7.6 m was established, based on a mesh sensitivity study to obtain an optimal element size, stability analysis of overpressure, and validation study to evaluate the accuracy of the numerical results based on Unified Facilities Criteria (UFC) 3-340-02. A parametric analysis was performed using the validated numerical model to investigate the effects of the entrance shape and blast pockets on the reduction in the maximum overpressure. The maximum overpressures were effectively reduced as the slope angle of the tunnel entrance decreased and the length of the blast pocket divided by the tunnel width decreased. An optimized shape of the tunnel was proposed based on the numerical results, where the peak overpressures were reduced by a maximum of 64.5%. This study aims to protect facilities, personnel, and equipment and further reduce construction costs by lowering the overpressure rating of blast valves in protective tunnels.
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Langdon, Geneive, Gerald Nurick, Neil Du Plessis i Ian Rossiter. "Using Perforated Plates as a Blast Wave Shielding Technique for Application to Tunnels". Applied Mechanics and Materials 82 (lipiec 2011): 467–72. http://dx.doi.org/10.4028/www.scientific.net/amm.82.467.
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Tunnels are vulnerable to devastating explosions, due to the concentration of explosive energy that would be many times greater than in an unconfined blast. One way to mitigate the damage resulting from an explosion is to disrupt the blast wave as it propagates along a tunnel. This paper presents the results of an investigation into the performance of perforated plates as a blast wave mitigation method in tunnel-like structures. Plastic explosive was detonated at the open end of a small-scale rigid steel tube and the blast wave propagated down the tube towards a thin, steel target plate. Increasing the separation distance between the perforated plate and target plate decreased the target plate deformation and increased the impulse at which tearing initiated. Large plastic displacement of the perforated plates was observed. Ansys Autodyn was used to model the experiments and provide additional insight into the blast wave propagation.
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Li, Ao, Dingli Zhang, Qian Fang, Jiwei Luo, Liqiang Cao i Zhenyu Sun. "Safety Distance of Shotcrete Subjected to Blasting Vibration in Large-Span High-Speed Railway Tunnels". Shock and Vibration 2019 (14.10.2019): 1–14. http://dx.doi.org/10.1155/2019/2429713.
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The drill and blast method is widely used in constructing tunnels in rock. Unfortunately, blasting vibration can damage newly performed shotcrete layers which are major support structures to stabilize surrounding structures. Therefore, investigation of the influence of blasting on shotcrete and determining reasonable distance between blasting work face and shotcrete position is of great importance. In this paper, a large-span tunnel excavated by drill and blast method acting as a high-speed railway station has been investigated. Blast vibration in the tunnel was recorded using microseismic monitoring technique. Empirical prediction equations for peak particle velocity (PPV) were obtained through regression analysis based on the obtained monitoring data. The attenuation law of tensile stress imposed on shotcrete layer due to blasting and bond strength of shotcrete-rock interface was also investigated. Minimum safety distance between shotcrete and blasting positions was calculated based on bond failure criterion. Evolution law considering different factors including blasting charge, rock mass class, and setting time of shotcrete was also obtained, which could be applied to determine blast charge shotcrete arrangements for tunnel constructions in future. The obtained results showed that the safety of shotcrete could be ensured and shotcrete falling off the rock could be prevented under current blast constructions.
Rozprawy doktorskie na temat "Tunnels - Blast"
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Adderley, Geoffrey. "The effect of tunnel blast design on vibration". Thesis, University of Essex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506087.
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Koneshwaran, Sivalingam. "Blast response and sensitivity analysis of segmental tunnel". Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/78619/1/Sivalingam_Koneshwaran_Thesis.pdf.
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This research treated the response of underground transportation tunnels to surface blast loads using advanced computer simulation techniques. The influences of important parameters, such as tunnel material, geometrical configuration of segments and surrounding soil were investigated. The findings of this research offer significant new information on the blast performance of underground tunnels and will contribute towards future civil engineering applications.
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Ewusi, Solomon. "Misfires identification in tunnel blasts". Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/12023.
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Due to economic gain the use of explosives for rock breaking has been the preferred choice in the mining industry for extracting minerals and the construction industries for driving tunnels and underground excavations. Although misfires are not an expected outcome in any form of blasting operations, however, due to the confined nature of underground blast the likelihood of blasthole misfires occurring is increased compared to that of a surface blast. Past research on the use of explosives for rock breaking have been concerned with issues about improving the effective use of explosive energy neglecting such effect as safety hazards and increased operational cost resulting from blasthole misfires. This research project investigate misfires in tunnel blasts with the aim of developing method(s) of minimising it occurrence during the blast design and identify blasthole misfires should they occur. Through a series of test blasts carried out at the Holman’s Test Mine operated by the Camborne School of Mines, three identification techniques based on blast emission data were developed namely; Electro-Magnetic Pulse (EMP Signature), Light (Optical Signature) and seismic (Vibration Signature). The study therefore concluded that whilst no one single method developed could effectively identify blasthole misfires in tunnel blasts, the vibration signature approach is the most pragmatic method for misfire identification in tunnel blasts as measurements are remotely undertaken. Moreover, blast vibration is well understood and part of almost all tunnel blasting operation. The blast vibration measurements and analyses undertaken during the course of this research resulted in the identification of potential blasthole misfires and aided in the safe retrieval of unexploded detonators and explosives cartridges. As a result of the research project several misfires were identified immediately after full face tunnel blasts at the Holmans’ Test Mine and appropriate measures taken to handle the misfires.
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Mitelman, Amichai. "Numerical analysis of the effects of external blasts on tunnels". Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/53803.
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This thesis presents the application of the finite-discrete element method for simulation of the impact of external blast loads on tunnels in rock. An extensive database of field tests of underground explosions above tunnels is used for calibrating and validating the proposed numerical method. The numerical results are shown to be in good agreement with published data for large-scale physical experiments. 1D and 2D model results are compared to analytical spalling equations and to the field test findings. It was found that only the 2D models are suitable for support design. The influence of rock strength on tunnel durability to withstand blast loads is investigated. It was found that higher rock strength will increase the tunnel resistance to the load on one hand, but decrease attenuation on the other hand. Thus, under certain conditions, results for weak and strong rock masses are similar. Finally, a discussion on tunnel support design to withstand blasting is presented. A distinction between heavy spalling and light rockfall is made based on an estimation of the ratio of peak stress of the arriving wave to the rock tensile strength. Accordingly, different design approaches are suggested: for heavy spalling a low impedance isolating layer between the tunnel liner and surrounding rock is recommended. For light rockfall, a simplified static FEM analysis procedure is presented.Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate
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Qiu, Bo. "Numerical study on vibration isolation by wave barrier and protection of existing tunnel under explosions". Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0011/document.
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Les vibrations du sol induites par les activités humaines telles que, les activités industrielles, la circulation des camions et voitures, les explosions dues aux constructions ou l’exploitation de la déconstruction, atteignent souvent la limite de gêne pour les usagers et parfois la limite de nocivité. Dans les régions urbaines à forte densité et pour les bâtiments abritant des équipements sensibles, les vibrations du sol doivent être strictement contrôlées. Jusqu'à présent, de nombreuses méthodes de réduction de vibration ont été proposées, dont l'une est l'installation d'une barrière d'ondes entre les sources et les structures à protéger. Au cours des dernières décennies, l'efficacité de l'isolation des vibrations à l’aide de barrière d'ondes a été étudiée. Toutefois, il y a peu de travaux consacrés à l’influence mutuelle des paramètres du système sol-barrière sur l'efficacité de l'isolation de la barrière d'ondes, et l'optimisation de la barrière d'onde est également rare. D'autre part, l'influence des vibrations du sol, générées par les explosions durant la construction d’un nouveau tunnel, sur un tunnel avoisinant, interpelle en raison des dommages qui peuvent être produits. Jusqu'à présent, il existe peu de mesures d'atténuation globale proposées par les chercheurs et les ingénieurs concernant la réduction de vibrations dans les tunnels lors des explosions. Pour répondre à ces insuffisances, cette thèse porte sur l'étude de l'influence des différents paramètres du système sol-barrière et qualifie l'efficacité de l'isolation de la barrière d'ondes. Les paramètres clés sont identifiés, leur rôle respectif quantifié. Plus important encore, une méthode de conception d'optimisation est mise au point, dans le but de proposer la barrière qui est capable de réduire au minimum la vibration du sol en site protégé. Enfin, le comportement dynamique du tunnel existant sous les sollicitations des explosions proches est examiné. Les paramètres qui influent considérablement sur la réponse du tunnel sont mis en évidence. Deux mesures d'atténuation pratiques, concernant l'installation d'une couche de protection le long de la paroi du tunnel d’une part et des explosions à retardement (plutôt que des explosions instantanées) d’autre part, sont présentées en détails. Les recherches menées dans le cadre de cette thèse sont en mesure de fournir des éléments pour la conception optimisée de la barrière d'ondes afin de réduire les vibrations du sol en site protégé et pour la conception de mesures d'atténuation concrètes afin de protéger un tunnel existant par des explosions à proximitéGround vibration induced by human activity such as industrial activities, car or truck traffic, or pilling and blasting in construction or deconstruction operation, generally reaches the troublesome limit for men and occasionally attains the harmful limit. In the densely populated urban regions and buildings housing sensitive equipments, ground vibration has to be strictly controlled. Up to now, many vibration reduction methods have been proposed, one of which is the installation of wave barrier between the dynamic sources and the protected structures. Over the past decades, the vibration isolation effectiveness of wave barrier has been extensively studied. However, to the best of the writer’s knowledge, there is little study about the mutual influence of the parameters of soil-barrier system on the barrier screening efficiency, and the optimization design for wave barrier is rare as well. On the other hand, the influence of ground vibration generated by explosions on the nearby existing tunnel has attracted more and more attention due to the recent damage or even failure of tunnels. Up to now, there are few mitigation measures comprehensively proposed by researchers and engineers for the tunnel vibration reduction during explosions. To overcome those drawbacks, this dissertation focuses on the investigation of the influence of various parameters of soil-barrier system on the barrier isolation efficiency. Key parameters are identified. More importantly, an optimization design method is developed, aiming to find out the desirable barrier that is able to minimize the ground vibration in protected site. Besides, the dynamic behavior of existing tunnel under nearby explosions is examined. Parameters that significantly affect the response of tunnel are pointed out. Furthermore, two practical mitigation measures: the installation of a protective layer along the tunnel lining and time-delayed explosions (rather than instantaneous explosions), are presented with details. The research in this dissertation is able to provide a good reference for the optimization design of wave barrier in reducing ground vibration in protected site and for the design of practical mitigation measures to protect existing tunnel from nearby explosions
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Nováková, Zuzana. "Podzemní garáže v Brně". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225514.
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The thesis focuses on the design of the underground garage in the centre of Brno under the Petrov hill. The main target of the thesis is to design spatial arrangement of the underground space and its feasibility study. In the following parts the design of the structural solution and its check calculation is carried out.
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Fekete, Stephanie. "GEOTECHNICAL APPLICATIONS OF LIDAR FOR GEOMECHANICAL CHARACTERIZATION IN DRILL AND BLAST TUNNELS AND REPRESENTATIVE 3-DIMENSIONAL DISCONTINUUM MODELLING". Thesis, 2010. http://hdl.handle.net/1974/6072.
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Contractors and tunnelling engineers consistently seek to identify techniques and equipment to improve the efficiency and lower the cost of tunnelling projects. Based on the recent successes of rock slope characterization with laser scanning techniques, the author proposes 3D laser scanning (LiDAR) as a new tool for geotechnical assessment in drill and blast tunnels.
It has been demonstrated that practical deployment of a phase-based LiDAR system at the face of an active tunnel heading is possible with a simple tripod setup. With data collection requiring only 5 minutes at the tunnel face, it was shown that this technique could be integrated into geotechnical evaluation without interruption of the excavation cycle. Following the successful scanning at two active tunnelling projects and two completed unlined tunnels, the research explored the applications of the data. With detailed geometric data of the heading as it advanced, the author identified applications of interest to the contractor/on-site engineer as well as the geotechnical engineer or geologist responsible for rockmass characterization. Operational applications included the extraction of information about tunnel geometry and installed support, while geomechanical information provided important elements of rockmass characterization. Building on the success of retrieving joint network information, the research investigated the potential for LiDAR-derived structural databases to be the basis for highly-representative 3D discrete element models. These representative models were found to be useful for back-analysis or as predictive tools for future tunnel design.
The primary implications of the thesis are that a) LiDAR data collection at the face of a drill and blast tunnel operation is practical and potentially has great value, b) data extraction is possible for a wide range of applications, and c) that discontinuum stability analysis becomes a much more powerful tool with the integration of LiDAR data. The cumulative result of the work presented is a proposed workflow for integrating LiDAR into tunneling operations.Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2010-09-22 19:38:49.401
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CHIEN, M. C., i 簡敏忠. "Effects of dynamic soil properties on underground tunnel during blast loading". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/96473170594940432763.
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碩士國立臺北科技大學
土木與防災技術研究所
90
The effect of explosion in the ground above the MRT bored tunnel passing through the Sungshan Airport was simulated and studied in this paper . Stress waves generated by an explosion are of dynamic nature, which causes the surrounding soils to experience rapid loading and unloading cycles usually within several milliseconds. It is extremely difficult to simulate the behavior of the soil under such condition before we have a thorough understanding of the dynamic behavior of the soils. The finite difference method using FLAC program was used in this paper to assess the dynamic soil-structure (tunnel lining) interaction behavior and to evaluate the significance of each soil parameter. A series of parametric study was performed. Explosion characteristic parameters such as bomb penetration depths, explosion crater diameters, and instantaneous stress increase were derived from US Army Technical Manual TM 5-855-1. The explosion generates 3-D effects on the tunnel; nevertheless, a more conservative 2-D analysis was performed by simulating a 3-D condition with a modified 2-D condition.
Części książek na temat "Tunnels - Blast"
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Osinov, Vladimir A., i Stylianos Chrisopoulos. "Two Neighbouring Tunnels in Saturated Soil Under Blast Loading". W Recent Developments of Soil Mechanics and Geotechnics in Theory and Practice, 281–96. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-28516-6_15.
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Maheshwari, Priti, Sunny Murmu i Harsh Kumar Verma. "Modeling of Blast Induced Damage Distance for Underground Tunnels". W Lecture Notes in Civil Engineering, 617–26. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6466-0_57.
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Tiwari, Rohit, Tanusree Chakraborty i Vasant Matsagar. "Dynamic Analysis of Curved Tunnels Subjected to Internal Blast Loading". W Advances in Structural Engineering, 405–15. New Delhi: Springer India, 2014. http://dx.doi.org/10.1007/978-81-322-2190-6_35.
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Han, Yuzhen, Xiuren Yang i Jingfeng Ni. "Influence of Foam Liner on Tunnels Subjected to Internal Blast Loading". W Green, Smart and Connected Transportation Systems, 1373–78. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-0644-4_103.
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Senthil, K., S. Rupali i L. Pelecanos. "Prediction of damage intensity of reinforced concrete tunnels and soil against blast loading". W Geotechnical Aspects of Underground Construction in Soft Ground. 2nd Edition, 291–99. Wyd. 2. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003355595-37.
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Maidl, Bernhard, Markus Thewes i Ulrich Maidl. "Drill and Blast Tunnelling". W Handbook of Tunnel Engineering, 189–284. D-69451 Weinheim, Germany: Wiley-VCH Verlag GmbH, 2014. http://dx.doi.org/10.1002/9783433603499.ch5.
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Glascoe, L., i T. Antoun. "Application of High Performance Computing to Rapid Assessment of Tunnel Vulnerability to Explosive Blast and Mitigation Strategies". W Blast Mitigation, 21–53. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-7267-4_2.
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Zaid, Mohammad, i Irfan Ahmad Shah. "Blast-Resistant Stability Analysis of Triple Tunnel". W Lecture Notes in Civil Engineering, 35–42. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6969-6_4.
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Mandal, Jagriti, M. D. Goel i Ajay Kumar Agarwal. "Numerical Modeling of Tunnel Subjected to Surface Blast Loading". W Lecture Notes in Civil Engineering, 543–54. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-8138-0_41.
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Phulari, V. S., i M. D. Goel. "Dynamic Response of Tunnel Under Blast Loading and Its Blast Mitigation Using CFRP as Protective Barrier". W Lecture Notes in Civil Engineering, 555–62. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-8138-0_42.
Pełny tekst źródłaStreszczenia konferencji na temat "Tunnels - Blast"
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Alostaz, Yousef. "Blast Vulnerability of Underground Tunnels". W Geotechnical and Structural Engineering Congress 2016. Reston, VA: American Society of Civil Engineers, 2016. http://dx.doi.org/10.1061/9780784479742.004.
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Geng, Jihui, i Kelly Thomas. "Blast Attenuation in Tunnels or Pipes With Turns". W ASME 2019 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/pvp2019-93751.
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Abstract Shock wave attenuation in a straight tunnel (or pipe) can be evaluated using existing methodologies. Shock attenuation is enhanced when there are right-angle turns along the length of the tunnel over which the shock is transmitted. A repeated set of such turns is generally defined as a blast trap. Little guidance is available in the open literature regarding the blast attenuation enhancement due to a right-angle turn or a blast trap in a tunnel. This paper presents guidance for shock wave attenuation as a function of the number of right-angle turns and blast wave parameters (i.e., peak pressure and duration). Characteristic parameters are utilized in order to define shock wave properties and tunnel dimensions. The shock attenuation due to up to four consecutive right-angle turns is evaluated. The purpose of this work is to provide a database of the shock attenuation within a tunnel due to multiple right-angle turns for use in designing tunnel structural components and evaluating the response of such components to postulated transmitted shock loads.
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Wu, P. K. K., J. Chin, R. Tsui i C. Ng. "Evaluation of Digital Rock Mass Discontinuity Mapping Techniques for Applications in Tunnels". W The HKIE Geotechnical Division 42nd Annual Seminar. AIJR Publisher, 2022. http://dx.doi.org/10.21467/proceedings.133.38.
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High-quality coloured 3D point clouds can now be readily generated by digital surveying techniques such as structure from motion (SfM) photogrammetry and terrestrial laser scanning (TLS). Point clouds allow discontinuities to be mapped digitally on rock slopes and this has been widely studied in Hong Kong. In comparison, few similar applications have been reported in tunnels in Hong Kong. To extend the application of this technology for tunnel excavation, we carried out three site trials in two drill-and-blast hard rock tunnels in Hong Kong. Both SfM photogrammetry and TLS were used to generate point clouds for the exposed rock tunnel surfaces. The generated point clouds were then tested for semi-automatic extraction of rock mass discontinuities using DRM2.0, Aurecon’s in-house developed software. This paper provides detail accounts of data acquisition, data processing, present the findings on the performance of semi-automatic identification of discontinuities, and the comparison between SfM and TLS techniques. The paper also discusses the challenges in digital mapping inside tunnels and provide useful suggestions on conducting laser scanning and photogrammetry in tunnels.
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Marjanishvili, S., i Mikheil Chikhradze. "Wireless System for the Detection and Mitigation of Explosions in Tunnels". W IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.0087.
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<p>Physical security challenges from explosions are amplified in confined spaces. The air-blast shock waves reflect and propagate throughout the confined space. This paper describes the process of designing, constructing, and validating a wireless system for identification of explosions in real time. Protection of critical infrastructure requires the creation of a reliable system which provides quick and accurate identification of the hazards and subsequent transmission of the alarm signal to response and rescue services. The proposed wireless system consists of transmitter and receiver modules spaced throughout the tunnel. The transmitter module contains sensors and a microprocessor equipped with blast identification software. The receiver module produces an alarm signal and activation signal for the operation of protecting devices. The experimental validation has been carried out at the underground experimental base of G. Tsulukidze Mining Institute, Tbilisi, Georgia. The results of the testing validated the main characteristics of the system, notably:</p><p>No false signals were generated during the series of 20 experiments</p><p>After a blast event, the duration for analyzing the potential threat is 2.4 msec and the duration for activating the protection device is 11 msec</p><p>The reliable transmission distance is 150 m (492 ft) in a straight tunnel and 50 m (164 ft) in a tunnel with a 90° bend.</p>
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Hoseini, Zia. "Energy Evolution and Blast Response of Segmented Circular Tunnels; Considering Depth and Different Soils". W 5th International Conference on Civil Engineering, Architecture and Urban Planning Elites. Acavent, 2018. http://dx.doi.org/10.33422/5th-caue.2018.02.36.
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Myers, Carl W., i James M. Mahar. "Underground Siting of Small Modular Reactors in Bedrock: Rationale, Concepts, and Applications". W ASME 2011 Small Modular Reactors Symposium. ASMEDC, 2011. http://dx.doi.org/10.1115/smr2011-6652.
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Small modular reactors (SMRs) sited 100 to 300 meters deep in underground chambers constructed in bedrock having favorable geotechnical properties could be both cost effective and provide superior levels of safety and physical security. The bedrock adjacent to and enclosing the reactor chamber would become the functional equivalent of a conventional containment structure, but one with increased margins of safety for design-basis accidents, reduced risks for beyond-design-basis accidents, and a high level of inherent physical protection against external threats. In addition, seismic safety could be enhanced at lower cost because seismic waves are generally attenuated with depth in bedrock. Nominal steel and concrete around the reactor would be required as would sealing of tunnels and other penetrations into the reactor chamber. Nonetheless, the net result in capital cost savings could potentially more than offset the cost of underground excavation. For a hypothetical granitic bedrock site with SMRs at a nominal depth of 100 meters, preliminary excavation cost estimates for single- and four-unit installations constructed by drill-and-blast range from around $90 million to $45 million per reactor, respectively, and for a twelve-unit installation constructed by tunnel boring machine from $25 to $15 million per reactor. Specialized applications for bedrock-sited SMRs include collocation at underground hydropower stations, test and demonstration facility for prototype SMR designs, and deployments in regions at risk of terrorist or military attack.
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John, Endicott L., Franklin K. L. To i Andrew K. W. Seto. "A Review of Conventional and Innovative Permanent Support Systems for Rock Cavern Development in Hong Kong". W The HKIE Geotechnical Division 42nd Annual Seminar. AIJR Publisher, 2022. http://dx.doi.org/10.21467/proceedings.133.44.
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In recent years, the HKSAR government departments have been playing a leading role to study the feasibility of rock cavern development in Hong Kong. These studies include the relocation of existing surface sewage treatment works, service reservoirs, refuse transfer stations, archive centre and laboratory to rock caverns. After completion of the relocation, the previously occupied surface land can be released for other developments beneficial to the communities. Conventional permanent support systems comprise the cast-in-situ concrete lining with sheet waterproofing membrane. These have been applied in most of the highway and railway tunnels in Hong Kong. However, it involves the use of bulky steel shutter, heavy rebar fixing and an extra set of redundant temporary supports, which leads to very expensive and time-consuming construction. With the advance development in construction technologies, permanent rock reinforcements with sprayed waterproofing membrane could be a cost-effective engineering solution. With the integration of temporary and permanent supports, the tight daily drill-and-blast cycle and timely permanent support installation is greatly enhanced. This paper provides a general review of different conventional and innovative permanent support systems for rock cavern development with the purpose of achieving more efficient design and construction. It also discusses the application according to the unique requirements for various cavern facilities.
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van der Linden, Septimus, i Axel von Rappard. "Gas Turbine Development: More Than 50 Years Ago". W ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68966.
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With the celebration of the 50th Anniversary of Turbo Expo and 125 years of ASME, it would be appropriate to once again review a paper read at the meeting in London, UK, of The Institution of Mechanical Engineers (founded 1847) on the 24th of February, 1939. This Paper was titled, “The Combustion Gas Turbine, it’s History Development and Prospects” by Adolf Meyer [1]. At the time, the first Industrial Gas Turbine generating set of 4000kW was on order by the City of Neuchatel [2], and cycle improvements for future units were already being proposed, as well as new fields of applications, such as Locomotives, Ship Propulsion, Wind Tunnels, Blast Furnace Plants, as well as Combined Gas Turbine and Steam Plants. In the section “Glimpse into the Future,” the field in which much progress was expected was the improvement in compressor efficiency and increased turbine inlet temperatures. Raising the overall efficiency of compressor and turbine to 92% and the inlet temperature to 2200 F, thermal efficiencies of 50% at the shaft coupling were envisioned, with units capable of delivering 65MW. These were the topics for three generations of engineers in several disciplines. This promising technology success would not have been possible without the coordinated leadership of far sighted managers of different OEM’s, and the tremendous courage for the introduction by the end-users.
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Drummond, Robert, Claudia Sun, Andrew Valkenburg, Aaron Freidenberg i Jakob C. Bruhl. "Computer Predictions of Tunnel Response to Blast". W Structures Congress 2019. Reston, VA: American Society of Civil Engineers, 2019. http://dx.doi.org/10.1061/9780784482247.004.
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Leung, Simon, i Elton M. Y. Ko. "Active Site Supervision to Enhance Drilling & Blasting". W The HKIE Geotechnical Division 42nd Annual Seminar. AIJR Publisher, 2022. http://dx.doi.org/10.21467/proceedings.133.18.
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In Hong Kong, the steep hilly terrain is a significant constraint on surface development but provides good opportunities for underground rock caverns. The systematic use of rock caverns will be the long-termed options to increase the land supply, and drill-and-blast is still the most commonly adopted excavation method in underground. However, the technology adopted in site supervision of drill-and-blast excavation has no significant advancement along the time-tunnel of development in Hong Kong. The checking on the as-built blast holes is not comprehensive enough as only the layout on the blast face and the depth of only reachable blast holes can be checked. The alignment of blast holes behind the blast face is unknown, which is however important. In addition, no qualitative and quantitative review on the geological condition ahead of the blast face can be carried out continuously while drilling.
Raporty organizacyjne na temat "Tunnels - Blast"
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Glenn, L. A., i S. Neuscamman. Computer Simulation of Blast Waves in a Tunnel with Sudden Decrease in Cross Section. Office of Scientific and Technical Information (OSTI), sierpień 2011. http://dx.doi.org/10.2172/1113470.
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