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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Effet de projection de pellettes bioxycarbonées sur la qualité de revêtements élaborés par la projection thermique / Effect of dry ice blasting on the quality of coatings produced by thermal spraying

Dong, Shujuan 11 December 2013 (has links)
La technologie de projection plasma atmosphérique (APS) est largement utilisée pour des applications industrielles. Les revêtements élaborés par APS présentent généralement certains défauts. Les travaux effectués dans cette étude ont consisté à étudier et à développer un nouveau moyen pour assurer à la fois un refroidissement efficace au cours de procédé de projection APS et une adaptation des conditions superficielles en vue d’élaborer des revêtements de haute qualité. Ce moyen consiste à la projection de glace carbonique (glace sèche ou dioxyde de carbone solide) en association avec la projection plasma. Des simulations numériques ont été réalisées, qui ont permis de constater que les dimensions de la buse de projection de glace carbonique, la pression du gaz propulsif, et les propriétés des pellets de CO2 influencent sensiblement la vitesse des pellets de CO2. A partir de ces éléments, des dimensions optimales ont été évaluées. Afin d’examiner l’effet de la projection de glace carbonique sur les revêtements réalisés par projection thermique, plusieurs types de matériaux ont été considérés, trois métalliques (acier, CoNiCrAlY et aluminium pur) et trois céramiques (Al2O3, Cr2O3 et ZrO2-Y2O3). Les microstructures des revêtements metalliques réalisés avec projection de glace sèche présentent moins d'oxydes et moins de porosité par rapport à ceux déposés par APS classique. Dans certains cas l’adhérence peut aussi être améliorée. Pour les revêtements céramiques, une réduction de la porosité ainsi qu’une amélioration significative de l’adhérence des revêtements ont été constatés. Pour le dépôt de ZrO2-Y2O3, la résistance aux chocs thermiques a été améliorée en utilisant des paramètres spécifiques. La projection de CO2 peut légèrement déformer la surface des substrats de faible dureté, et nettoyer les pollutions superficielles sur le substrat et conduire à une contrainte de compression plus élevée et à un refroidissement efficace. Il est à noter toutefois qu’un problème de condensation de la vapeur d’eau peut intervenir en cas de refroidissement du substrat trop important. / The technology of atmospheric plasma spraying (APS) is widely used for industrial applications. The coatings produced by APS generally show defects. The work was conducted to investigate and develop a new method to ensure both an effective cooling during the APS process and the adaptation of the surface condition in order to develop high quality coatings. This solution is dry ice (CO2) blasting in combination with thermal spraying. Firstly, numerical simulations were carried out, which revealed that the nozzle size of dry ice blasting, the propellant pressure and the properties of CO2 pellets, significantly affect the velocity of CO2 pellets. From these elements, the optimal dimensions were evaluated. To examine the effects of dry ice blasting on the coatings produced by thermal spraying, several types of materials were considered, three metals (steel, CoNiCrAlY and pure aluminum) and three ceramics (Al2O3, Cr2O3 and ZrO2-Y2O3). The microstructure of metal coatings produced with dry ice blasting show fewer oxides and less porosity compared to those deposited by conventional APS. In some cases the adhesion can be improved. Regarding ceramic coatings, a reduction in porosity and a significant improvement in the coating adhesion were observed. For the deposition of ZrO2-Y2O3, an improvement in thermal shock resistance was achieved using specific parameters. Dry-ice blasting may slightly impact the surface of the substrates with low hardness and could clean the surface pollutions on the substrate and lead to a higher compressive stress and an effective cooling. However, it is noted that the problem of the condensation of water vapor can occur in case of intense cooling of the substrate.
122

Characterization of Hard Metal Surfaces after Various Surface Process Treatments

Hakim, Ali January 2008 (has links)
<p>The aim of this thesis is to investigate how material surfaces are affected by various surface treatments and how this relates to the adhesion of the coating. The materials that were studied were WC-Co and Cermets and the surface treatments used were polishing, grinding with coarser and finer abrasive grains, and finally wet blasting and dry blasting. Focus was on deformations and residual stresses in the surface, surface roughness and cracks. The test methods used for examining the samples included surface roughness measurements, residual stress measurements, adhesion tests using Rockwell indentation and SEM images of the surface and the cross section.<br /><br />The results concluded that polishing gives very good adhesion. Additionally, the adhesion for ground surfaces was good for WC-Co but very poor for Cermets. Furthermore, it was observed that finer abrasive grains did not result in better adhesion. In fact, the coarser grains gave slightly better results. Finally, it was concluded that wet blasting has a clear advantage over dry blasting and results in much better adhesion, especially for the Cermets. The results for the WC-Co were a bit inconsistent and so further research is required.</p>
123

Characterization of Hard Metal Surfaces after Various Surface Process Treatments

Hakim, Ali January 2008 (has links)
The aim of this thesis is to investigate how material surfaces are affected by various surface treatments and how this relates to the adhesion of the coating. The materials that were studied were WC-Co and Cermets and the surface treatments used were polishing, grinding with coarser and finer abrasive grains, and finally wet blasting and dry blasting. Focus was on deformations and residual stresses in the surface, surface roughness and cracks. The test methods used for examining the samples included surface roughness measurements, residual stress measurements, adhesion tests using Rockwell indentation and SEM images of the surface and the cross section.<br /><br />The results concluded that polishing gives very good adhesion. Additionally, the adhesion for ground surfaces was good for WC-Co but very poor for Cermets. Furthermore, it was observed that finer abrasive grains did not result in better adhesion. In fact, the coarser grains gave slightly better results. Finally, it was concluded that wet blasting has a clear advantage over dry blasting and results in much better adhesion, especially for the Cermets. The results for the WC-Co were a bit inconsistent and so further research is required.
124

Energia nas operações de desmonte de rocha e suas influências na moagem de minérios

Carlos, Marcelo Ribeiro January 2017 (has links)
Energia é um insumo estratégico na mineração, pois é fundamental na viabilidade das operações mineiras e importante na manutenção de custos operacionais baixos e competitivos. Por esse motivo, toda iniciativa que visa a busca por eficiência no consumo de energia é importante para a competitividade das mineradoras. Vários insumos energéticos são utilizados nas operações unitárias de mineração. Os exemplos mais comuns são diesel, eletricidade, gás natural, carvão e explosivos. O objetivo desse trabalho é estudar, do ponto de vista energético, as atividades realizadas no processo de desmonte de rochas, em um complexo minerador de minério de ferro, visando a melhor utilização da energia no desmonte de rocha para aperfeiçoar as operações unitárias subsequentes de processamento de minérios. Um foco maior foi dado à economia de energia nas moagens de bolas da planta de beneficiamento e concentração, provocada pelas modificações e melhorias realizadas no desmonte de rocha. A metodologia consistiu na análise de diversos desmontes de rocha variando a razão de carga de explosivos no complexo minerador alvo desse trabalho. Os produtos desses desmontes foram acompanhados até a sua entrada na planta de beneficiamento. Durante o processamento desses materiais nas moagens da planta, foram coletadas e analisadas as grandezas elétricas resultantes e comparadas com uma linha de base gerada antes do início do trabalho. Os dados foram analisados com o objetivo de visualizar a influência do aumento da razão de carga na performance energética da operação de moagem. Em paralelo, também, foram analisadas as situações operacionais e dificuldades existentes nas medições de campo e nos acompanhamentos de consumos energéticos dos processos unitários, assim como a infraestrutura necessária para que uma variável tão importante como energia elétrica possa ser monitorada de forma adequada. Por fim, foi abordada a importância, a metodologia e os resultados da redução de emissões de CO2 provenientes da economia de energia de todo o trabalho realizado em campo. Os resultados apresentados mostram que mesmo com um aumento significativo da alimentação de material compacto (maior WI) nas moagens, o consumo energético total dessa operação unitária não aumentou. Isso gerou uma potencial economia específica de energia e a consequente redução de emissões de CO2 na atmosfera, além de viabilizar o processamento de material mais compacto nas mesmas linhas de processo. Esse comportamento sugere que uma melhor energia gasta no desmonte de rocha pode impactar positivamente na produtividade e nos custos de produção do minério ao longo de sua cadeia produtiva. / Energy is a mining strategic source, critical in mining operations feasibility and important to maintain low operational costs in a competitive level. For this reason, any initiative aimed at searching for energy efficiency is important for mining companies’ competitiveness. Mining operations need several energy sources. Most common examples are diesel, electricity, natural gas, coal and explosives. This text aims to address, from an energy perspective, a study carried out in an iron ore mining complex, which had as main objective to reach a better rock blasting energy utilization to improve subsequent mining operations. A greater focus was given to energy savings in ball mills operations of a beneficiation and concentration plant, impacted by modifications and improvements made in rock blasting. Methodology consisted in monitoring several rock blasting, carried out in this mining complex, varying explosive charge ratio. Products of those rock blasting were monitored until they entered the processing plant. During ore processing in plant´s ball mills, electrical variables were collected and analyzed, comparing to a baseline generated before the beginning of this research. All data were analyzed to show influence of explosive charge ratio increase on energy performance of the milling operation. In parallel, operational issues and difficulties in field measurements of energy consumptions were described, as well as the necessary infrastructure that allows the variable electricity to be adequately monitored. Besides, the methodology and results of CO2 emissions reduction from energy savings of all fieldwork were discussed. The research data shows that even with a significant increase in compact feed (higher Work Index), total energy consumption of mill operation did not increase. This scenario generate a potential specific energy savings and consequent reduction in CO2 emissions in the atmosphere. In addition, enables more compact material to be processed in the same process lines. This behavior suggests that a better energy spent on rock blasting can positively affect productivity and ore production costs along its production chain.
125

Optimização das operações de desmonte de rocha com uso de explosivos em câmaras transversais (sublevel stoping)

Bundrich, Lauro Augusto January 2017 (has links)
O desmonte de rocha com uso de explosivos, aplicado à extração subterrânea de recursos minerais é uma tarefa impar que exige perícia e planejamento detalhado. Nesse contexto, essa dissertação tem sua relevância devido à apresentação de metodologias que visam aprimorar os processos envolvidos com o desmonte de rocha com uso de perfurações radiais, aplicado ao método de mineração subterrânea câmaras transversais, variante do método sublevel stoping. Para cumprir esse objetivo foram estabelecidas metodologias embasadas na utilização de registros sismográficos dos desmontes, mapeamento por laser das câmaras de lavra, registros operacionais da mina estudada. As metodologias aplicadas nas operações de mina incluíram: a segregação entre as atividades de perfuração e desmonte de rocha para assim aprimorar o ciclo operacional, a implantação de desmontes massivos como forma de aumentar a taxa de produção. A mudança na geometria das câmaras, a fim preservar o teto das mesmas. Um experimento com diferentes arranjos de retardo nos desmontes, como forma de determinar a configuração temporal menos nociva em termos de vibração, e por fim, a aplicação de uma nova malha de perfuração baseada no método dos triângulos reorientados de Hagan (1988), que visava diminuir a necessidade de perfuração e melhorar a distribuição energética dos desmontes em leque. As modificações propostas geraram resultados positivos, respectivamente quanto: aumento da eficiência dos ciclos de perfuração em 49% e aumento de 54% na produtividade das câmaras no período estudado, devido a implementação de desmontes massivos somados a segregação das atividades de perfuração e desmonte. Observou se a diminuição significativa da sobre-quebra (back break) do teto, da mesma forma os danos aos cabos de ancoragem (cable-bolts) foram reduzidos, resultados estes oriundos das modificações na geometria das câmaras. Os testes com diferentes arranjos de retardos demonstraram que o arranjo: 50ms entre furos e 200ms entre linhas, gerou a menor intensidade de vibração. O teste com o padrão de perfuração baseado na técnica de Hagan apresentou melhor índice de perfuração específica, porém, resultou em uma recuperação menor do que a média usual das câmaras, (76% contra 85%). Pode-se concluir que as metodologias propostas foram validas como medidas de aprimoramento das operações de perfuração e desmonte de rocha, a exceção da técnica dos triângulos reorientados de Hagan. Também foi possível concluir que a razão entre os valores de retardos intra linhas (L-L) e intra furos (F-F) influi diretamente na intensidade de vibração. / The blasting of rocks, applied to the underground extraction of mineral resources is a difficult task that requires expertise and detailed planning. In this context, this dissertation has its relevance due to the presentation of methodologies that aim to improve the processes involved with the blasting of rocks utilizing ring drilling, applied to the underground mining method transversal stopes, a variant of the method sublevel stoping. To fulfill this objective, methodologies based on the use of seismographic records of the blasting events, laser scanners of the stopes and operational records of the mine were used, as well as the use of Micromine software. The methodologies applied in mine operations included: segregation between rock drilling and blasting activities to improve the operational cycle, the implantation of the concept of mass blasting as a way to increase the production rate, the change in the drilling pattern in order to preserve the roof of the stopes, an experiment with different arrangements of delays for the blasting, as a way to determine the less harmful configuration in terms of vibration and finally the application of a new drilling pattern based on the reoriented triangles method of Hagan (1988), which aimed to reduce the need for drilling and to improve the energy distribution of the rings of drilling. The proposed modifications generated positive results, respectively: increase in the efficiency of the drilling cycles by 49% and a 54% increase in the productivity of the studied period, due to the implementation of mass blasting concept added to the segregation of drilling and blasting activities. It was observed that the significant decrease of the back break of the roof, in the same way the damages to the cables of reinforcement (cable-bolts) were reduced, as a result from the modifications in the drillings. The tests with different delay arrangements showed that the arrangement: 50ms between holes and 200ms between rows, generated the lowest vibration intensity. The Hagan technique-based drilling test showed a better specific drilling index, but resulted in a lower ore recovery than the usual to the stopes mean (76% vs. 85%). It can be concluded that the proposed methodologies were valid as measures of improvement of the operations of drilling and blasting of rock, except for the technique of the reoriented triangles of Hagan. It was also possible to conclude that the ratio between inter ring and inter-hole delays directly influences the vibration intensity.
126

Energia nas operações de desmonte de rocha e suas influências na moagem de minérios

Carlos, Marcelo Ribeiro January 2017 (has links)
Energia é um insumo estratégico na mineração, pois é fundamental na viabilidade das operações mineiras e importante na manutenção de custos operacionais baixos e competitivos. Por esse motivo, toda iniciativa que visa a busca por eficiência no consumo de energia é importante para a competitividade das mineradoras. Vários insumos energéticos são utilizados nas operações unitárias de mineração. Os exemplos mais comuns são diesel, eletricidade, gás natural, carvão e explosivos. O objetivo desse trabalho é estudar, do ponto de vista energético, as atividades realizadas no processo de desmonte de rochas, em um complexo minerador de minério de ferro, visando a melhor utilização da energia no desmonte de rocha para aperfeiçoar as operações unitárias subsequentes de processamento de minérios. Um foco maior foi dado à economia de energia nas moagens de bolas da planta de beneficiamento e concentração, provocada pelas modificações e melhorias realizadas no desmonte de rocha. A metodologia consistiu na análise de diversos desmontes de rocha variando a razão de carga de explosivos no complexo minerador alvo desse trabalho. Os produtos desses desmontes foram acompanhados até a sua entrada na planta de beneficiamento. Durante o processamento desses materiais nas moagens da planta, foram coletadas e analisadas as grandezas elétricas resultantes e comparadas com uma linha de base gerada antes do início do trabalho. Os dados foram analisados com o objetivo de visualizar a influência do aumento da razão de carga na performance energética da operação de moagem. Em paralelo, também, foram analisadas as situações operacionais e dificuldades existentes nas medições de campo e nos acompanhamentos de consumos energéticos dos processos unitários, assim como a infraestrutura necessária para que uma variável tão importante como energia elétrica possa ser monitorada de forma adequada. Por fim, foi abordada a importância, a metodologia e os resultados da redução de emissões de CO2 provenientes da economia de energia de todo o trabalho realizado em campo. Os resultados apresentados mostram que mesmo com um aumento significativo da alimentação de material compacto (maior WI) nas moagens, o consumo energético total dessa operação unitária não aumentou. Isso gerou uma potencial economia específica de energia e a consequente redução de emissões de CO2 na atmosfera, além de viabilizar o processamento de material mais compacto nas mesmas linhas de processo. Esse comportamento sugere que uma melhor energia gasta no desmonte de rocha pode impactar positivamente na produtividade e nos custos de produção do minério ao longo de sua cadeia produtiva. / Energy is a mining strategic source, critical in mining operations feasibility and important to maintain low operational costs in a competitive level. For this reason, any initiative aimed at searching for energy efficiency is important for mining companies’ competitiveness. Mining operations need several energy sources. Most common examples are diesel, electricity, natural gas, coal and explosives. This text aims to address, from an energy perspective, a study carried out in an iron ore mining complex, which had as main objective to reach a better rock blasting energy utilization to improve subsequent mining operations. A greater focus was given to energy savings in ball mills operations of a beneficiation and concentration plant, impacted by modifications and improvements made in rock blasting. Methodology consisted in monitoring several rock blasting, carried out in this mining complex, varying explosive charge ratio. Products of those rock blasting were monitored until they entered the processing plant. During ore processing in plant´s ball mills, electrical variables were collected and analyzed, comparing to a baseline generated before the beginning of this research. All data were analyzed to show influence of explosive charge ratio increase on energy performance of the milling operation. In parallel, operational issues and difficulties in field measurements of energy consumptions were described, as well as the necessary infrastructure that allows the variable electricity to be adequately monitored. Besides, the methodology and results of CO2 emissions reduction from energy savings of all fieldwork were discussed. The research data shows that even with a significant increase in compact feed (higher Work Index), total energy consumption of mill operation did not increase. This scenario generate a potential specific energy savings and consequent reduction in CO2 emissions in the atmosphere. In addition, enables more compact material to be processed in the same process lines. This behavior suggests that a better energy spent on rock blasting can positively affect productivity and ore production costs along its production chain.
127

Optimização das operações de desmonte de rocha com uso de explosivos em câmaras transversais (sublevel stoping)

Bundrich, Lauro Augusto January 2017 (has links)
O desmonte de rocha com uso de explosivos, aplicado à extração subterrânea de recursos minerais é uma tarefa impar que exige perícia e planejamento detalhado. Nesse contexto, essa dissertação tem sua relevância devido à apresentação de metodologias que visam aprimorar os processos envolvidos com o desmonte de rocha com uso de perfurações radiais, aplicado ao método de mineração subterrânea câmaras transversais, variante do método sublevel stoping. Para cumprir esse objetivo foram estabelecidas metodologias embasadas na utilização de registros sismográficos dos desmontes, mapeamento por laser das câmaras de lavra, registros operacionais da mina estudada. As metodologias aplicadas nas operações de mina incluíram: a segregação entre as atividades de perfuração e desmonte de rocha para assim aprimorar o ciclo operacional, a implantação de desmontes massivos como forma de aumentar a taxa de produção. A mudança na geometria das câmaras, a fim preservar o teto das mesmas. Um experimento com diferentes arranjos de retardo nos desmontes, como forma de determinar a configuração temporal menos nociva em termos de vibração, e por fim, a aplicação de uma nova malha de perfuração baseada no método dos triângulos reorientados de Hagan (1988), que visava diminuir a necessidade de perfuração e melhorar a distribuição energética dos desmontes em leque. As modificações propostas geraram resultados positivos, respectivamente quanto: aumento da eficiência dos ciclos de perfuração em 49% e aumento de 54% na produtividade das câmaras no período estudado, devido a implementação de desmontes massivos somados a segregação das atividades de perfuração e desmonte. Observou se a diminuição significativa da sobre-quebra (back break) do teto, da mesma forma os danos aos cabos de ancoragem (cable-bolts) foram reduzidos, resultados estes oriundos das modificações na geometria das câmaras. Os testes com diferentes arranjos de retardos demonstraram que o arranjo: 50ms entre furos e 200ms entre linhas, gerou a menor intensidade de vibração. O teste com o padrão de perfuração baseado na técnica de Hagan apresentou melhor índice de perfuração específica, porém, resultou em uma recuperação menor do que a média usual das câmaras, (76% contra 85%). Pode-se concluir que as metodologias propostas foram validas como medidas de aprimoramento das operações de perfuração e desmonte de rocha, a exceção da técnica dos triângulos reorientados de Hagan. Também foi possível concluir que a razão entre os valores de retardos intra linhas (L-L) e intra furos (F-F) influi diretamente na intensidade de vibração. / The blasting of rocks, applied to the underground extraction of mineral resources is a difficult task that requires expertise and detailed planning. In this context, this dissertation has its relevance due to the presentation of methodologies that aim to improve the processes involved with the blasting of rocks utilizing ring drilling, applied to the underground mining method transversal stopes, a variant of the method sublevel stoping. To fulfill this objective, methodologies based on the use of seismographic records of the blasting events, laser scanners of the stopes and operational records of the mine were used, as well as the use of Micromine software. The methodologies applied in mine operations included: segregation between rock drilling and blasting activities to improve the operational cycle, the implantation of the concept of mass blasting as a way to increase the production rate, the change in the drilling pattern in order to preserve the roof of the stopes, an experiment with different arrangements of delays for the blasting, as a way to determine the less harmful configuration in terms of vibration and finally the application of a new drilling pattern based on the reoriented triangles method of Hagan (1988), which aimed to reduce the need for drilling and to improve the energy distribution of the rings of drilling. The proposed modifications generated positive results, respectively: increase in the efficiency of the drilling cycles by 49% and a 54% increase in the productivity of the studied period, due to the implementation of mass blasting concept added to the segregation of drilling and blasting activities. It was observed that the significant decrease of the back break of the roof, in the same way the damages to the cables of reinforcement (cable-bolts) were reduced, as a result from the modifications in the drillings. The tests with different delay arrangements showed that the arrangement: 50ms between holes and 200ms between rows, generated the lowest vibration intensity. The Hagan technique-based drilling test showed a better specific drilling index, but resulted in a lower ore recovery than the usual to the stopes mean (76% vs. 85%). It can be concluded that the proposed methodologies were valid as measures of improvement of the operations of drilling and blasting of rock, except for the technique of the reoriented triangles of Hagan. It was also possible to conclude that the ratio between inter ring and inter-hole delays directly influences the vibration intensity.
128

Návrh robotické buňky pro obsluhu tryskače pro čištění odlitků / Design of a Robotic Cell for Operating a Jet Machine for Cleaning Castings

Vrána, Vojtěch January 2021 (has links)
The main goal of this master’s thesis is to create a design of robotic cell for operating of blasting machine. Operation of blasting machine consists of robotic manipulation of aluminium castings from input container to the blasting machine conveyor. After blasting operation aluminium castings are manipulated by robot from conveyor to output container. The part of the master's thesis is proposal of several variants of solution of design of robotic cell. Afterwards the best option is selected. The thesis also deals with design and selection of functional components in robotic cell. Functional verification of robotic cell is made in software Tecnomatix Process Simulate. Technical-economics evaluation is also part of this master’s thesis.
129

Militär användning av civila sprängämnen för att öka förmågan till förstöring

Kagebeck, Samuel January 2022 (has links)
I näringslivet nyttjas dagligen sprängämnen för att uträtta sprängarbeten främst inom bygg- och gruvbranschen. Dessa sprängämnen tillverkas i och utanför Sverige. I samhället finns det åtskilliga aktörer som nyttjar stora volymer utav sprängämnen. Vid en konflikt på svenskt territorium finns det alltså en möjlighet att tillföra sprängämnen som nyttjas i näringslivet till de militära förbanden. Studien syftar till att beskriva hur förmågan att förstöra objekt skulle öka om civila sprängämnen kunde nyttjas av militära förband. För att påvisa detta måste civila sprängämnen värderas i militära kontexter.  För att beskriva hur väl de civila sprängämnena skulle kunna öka de stridande förbandens förmåga till förstöring genomfördes en undersökning av sju civila sprängämnen samt en värdering av dessa utifrån militära krav. Dessa sprängämnen jämfördes sedan med sprängdeg för att på ett tydligt sätt beskriva hur väl de olika sprängämnena uppfyllde kraven. Slutligen diskuterades resultaten utifrån grundförmågorna verkan, uthållighet och tillgänglighet. Resultaten visar att tack vare det breda utbudet av civila produkter kan de flesta militära sprängarbeten utföras med civila sprängämnen, om rätt sprängämne nyttjas till rätt objekt. Över lag passar civila sprängämnen bäst till inneslutna laddningar på grund av den höga relativ arbetsförmåga.  För att öka förmågan till förstöring måste verkan säkerställas genom praktiska prov. Tillgängligheten måste säkerställas genom utbildning för militär personal samt krigsplanering av sprängämnen. Uthålligheten ökar genom att de militära förbanden kan ersätta förbrukade sprängämnen. När förbanden får tillgång till mer sprängämnen kan de lösa fler uppgifter och förmågan till förstöring ökar. / Explosives are used daily in business by construction sites and mines. These explosives are made both in and outside of Sweden. In the society, there are several actors who deal in large quantities explosives. In a conflict on Swedish territory, there are accordingly a possibility to add commercial explosives to the armed forces.  The aim of this study is there for to describe how the ability to demolish objectives will increase if the armed forces where to use commercial explosives. To demonstrate this the commercial explosives must be rated in a military context.  To describe how well the use of commercial explosives will increase the ability to demolish, survey was implemented where seven different commercial explosives from the Swedish market were rated by military requirements. These explosives where then compared with blasting dough to, in a distinct way, describe how well the commercial explosives preformed. Lastly the results were discussed in terms of the military abilities effect, endurance and availability.  The results shows that thanks to the great deal of different explosives that the market provides, most of the military tasks can use commercial explosives if the right explosive is used for the right task. Overall, the commercial explosives are best suited for enclosed charges due to its ability to throw away masses.  To increase the ability to demolish, the effect must be proven by practical tests. The availability must be ensured through education for military personal and war plans for commercial explosives. Endurance increases by the replacement of consumed explosives to the military units. When the units can use more explosives, they can complete more tasks and the ability to demolish increases.
130

Salvdimensionering för vibrationsalstrande undermarksprojekt : Framtagning av beräkningsark och standardrapport / Round dimensioning for vibration generating underground projects : Production of calculation sheet and a standard report

Bjartell, Erik, Karlsson, Per January 2021 (has links)
Sprängningar utförs ofta vid tunneldrivningar och som en följd av detta uppstår markvibrationer. Dessa vibrationer beror av flera faktorer och kan upplevas som störande för omgivningen och ge upphov till skador på närliggande byggnader. Markvibrationernas storlek begränsas enligt Svensk Standard, som har riktlinjer för maximalt tillåten svängningshastighet vid sprängningsarbeten i närheten av byggnader. För att prognostisera vibrationer vid sprängningsarbeten kan skallagssamband tillämpas. Det finns olika skallagssamband men vad de har gemensamt är att de uppskattar maximal svängningshastighet som funktion av en skalfaktor innehållande avstånd från sprängsalva till mätpunkt och samverkande laddningsmängd. I ett första steg har vibrationsmätvärden analyserats och sammanställts med avseende på berggrund och närliggande bergtunnel. Utifrån borrhålens dimensionering och sprängämnets densitet kan den samverkande laddningsmängden för varje salva beräknas och sammanställas med svängningshastigheten för en viss mätpunkt. Med utgångspunkt från dessa värden har empiriska konstanter tagits fram genom regressionsanalys och således har prognossamband för uppkomna markvibrationer vid byggnader grundlagda på olika berggrunder och närliggande bergtunnel bestämts. Med dessa prognossamband givna har ett beräkningsark och en standardrapport tagits fram som tillsammans utgör en grund för kommande undermarksprojekt. / Blasting is often performed during tunnel projects and as a result, ground vibrations will occur. These vibrations depend upon several factors and can be experienced as disturbing for the surrounding area and may cause damage to buildings nearby. The guidelines published by the Swedish Institute for Standards determine the permitted magnitude of such ground vibrations, by imposing a maximum oscillation speed for any blasting works that take place in proximity of buildings. To predict vibrations during blast work, scaled factor relations can be applied. There are different kinds of scaled factor relations, but what they have in common is that they estimate the maximum oscillation speed as a function of distance between the round and measuring point, and charge per delay. As a first step, the measured vibration value has been analysed and drawn up with respect to rock foundation and tunnel nearby. Based on the dimensions of the drillhole and the density of the explosive, the charge per delay can be calculated and compiled whit the oscillation speed at a specific measuring point. Based on these values, empirical constants have been produced through regression analysis, and therefore predictions for ground vibrations at buildings on different types of rock foundations and nearby tunnel can be determined. Given these predictions, a calculation sheet and a standard report have been produced which together form a basis for future underground projects.

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