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The effects of fault-induced stress anisotropy on fracturing, folding and sill emplacement: Insights from the Bowie coal mines, southern Piceance basin, western Colorado.Robeck, Eric Dean 18 March 2005 (has links) (PDF)
The recognition of fault-perturbed stress fields is an important tool in areas of mineral or hydrocarbon exploration. The Bowie underground coal mines of western Colorado expose a reverse-reactivated growth fault that perturbed the stress field during cleat (fracture) formation, rotating cleat orientations up to 500 m on both sides of the fault. Two unusual fracture types are found only in coal adjacent to the fault: (1) concentric cleats, highly curved fractures that form blocks resembling balls or eggs and (2) horsetail cleats, striated surfaces that superficially resemble shattercones and result from shear failure in coal. Numerical models created with the boundary element program Poly3D were used to estimate the magnitudes and orientations of the paleostress axes during cleat formation, taking into account the depth of burial, 3-D fault orientation, elastic rock parameters, and far-field stress states. When the elastic rock parameters and modeled orientations of the stress axes are held constant, the relative stress ratio, R = (σ_1 — σ_2)/(σ_2 — σ_3), uniquely determines the orientations of fractures forming in the fault-perturbed stress field. Comparison of the models with systematic observations on both sides of the fault allows the selection of a best-fit model. If the depth of overburden during fracture formation is known, this technique can be used to estimate the magnitude of σ_1 in fault-perturbed areas. The rotated face cleats and unusual, fault-related cleat types provide unequivocal evidence of a fault when (1) the fault predates cleat formation and (2) the far-field horizontal stress during cleat formation is oblique to fault strike. In addition, the varying spatial association of these fault-perturbed cleat styles with the fault may provide a qualitative estimate of fault location while mining. Pre-existing faults also strongly control reactivation-related folding, which at formed several low-amplitude folds, including a footwall fold. Igneous sills in three Bowie coal seams show strong preference for fault zones. The recognition of similar fracture trends in other mining or exploration areas is a valuable tool that may significantly reduce economic or human cost by helping to mitigate fault-related hazards and highlighting potentially productive zones in faulted reservoirs.
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Wind Uplift Resistance of Roof Edge ComponentsAlassafin, Wassim 18 March 2013 (has links)
A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components.
The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions.
Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.
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Wind Uplift Resistance of Roof Edge ComponentsAlassafin, Wassim 18 March 2013 (has links)
A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components.
The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions.
Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.
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Wind Uplift Resistance of Roof Edge ComponentsAlassafin, Wassim January 2013 (has links)
A roof is a critical envelope of a building. It provides protection for the building interior against various weather elements, such as snow, rain and wind. Roofs are normally composed of several components such as insulation, barriers and water proofing membrane. A roof edge is the perimetric part of a roof that serves as termination for roof components. In generic terms, a roof edge system is composed of a parapet with metal components, such as coping and cleat/clip. The edge system is typically subjected to negative pressure (suction) due to wind flow over the roof. Therefore, a roof edge is the front-line of defence against wind action. To develop testing standards and design guidelines for roof edges, a project referred as REST (Roof Edge Systems and Technologies) has been initiated in cooperation with the NSERC (Natural Sciences and Engineering Research Council). For the REST project, this thesis contributes in two folds: wind design procedure and the development of an experimental method for testing roof edge components.
The present thesis analyzes the wind load calculation procedures as per the National Building Code of Canada (NBCC) and American Society of Civil Engineers (ASCE). This has been achieved by taking side-by-side cities along Canada-USA border; wind load calculations were performed to demonstrate the differences and similarities between the NBCC and ASCE. As a part of the current contribution, the existing version of the online Wind-RCI Calculator was updated from NBCC2005 to NBCC2010 provisions.
Towards the experimental contribution, the current study presents a new experimental method for testing and evaluating wind uplift resistance of roof edge systems by simulating wind loads in a lab environment on full-scale mock-ups. The test apparatus had a gust simulator device to mimic wind gusting (dynamic loading). This research investigates three widely used edge systems in North America: Continuous Cleat Configuration (CCC), Discontinuous Cleat Configuration (DCC) and Anchor Clip Configuration (ACC). Preliminary data show that CCC edge system has higher resistance in comparison to DCC and ACC edge systems. The experiments also revealed the need for experimental setup enhancement. Additional investigations by using the enhanced experimental setup were performed on both CCC and DCC edge systems.
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Enhancement of a Rolling Resistance Rig for Force and Moment Testing of TiresRamdasi, Surabhi Suhas 23 June 2016 (has links)
Tire testing has been one of the important aspects of the tire industry because it helps identify the tire behavior which further helps in improving the design of tires. It also helps automotive manufacturers choose the best tire for their automobiles. Indoor tire testing helps in relating the data better because of greater repeatability of the testing setup as compared to outdoor testing. This study focusses on modifying a rolling resistance machine to make it capable of force and moment and cleat testing along with the standard rolling resistance test. Additionally, the design of a mechanical loading mechanism (used to apply normal force on the tire) in place of the previous one using dead weights is also discussed.
This study also talks about the structural and vibrational finite element analysis of a tire testing machine. Since the machine was designed to conduct different tire tests, different structural requirements of the tire positioning mechanism pertaining to each test were taken into consideration, and the structure was analyzed for maximum forces and moments acting on the assembly. Cleat testing subjects the tire as well as the structure to an impulse force which calls for the vibrational analysis of the assembly to avoid the structure from resonating.
The design was modified to get it easily manufactured and assembled. These design changes and the aspects taken into consideration have also been discussed. / Master of Science
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Examination of Ancient Scandinavian Archaeological Findings : From Tortuna in Västerås, SwedenBlinke, Jacob, Geiger, Evelynne, Edlund, Amanda January 2018 (has links)
This study concerns the examinations of archaeological steel-objects from the Iron Ages, found in Tortuna outside Västerås, Sweden. Not many metallurgical analyses have been made on steel objects from the Iron Ages, most likely in order to preserve the findings. Therefore, very little knowledge about old steel materials exists.The main goal of this study was to investigate how steel-made items from the Iron Ages were created, what they have been used for, and determine what kind of metallurgical knowledge the blacksmiths of the Iron Ages had. The experiments were conducted with light optical microscopy in order to investigate the morphology of the materials and with Vickers hardness test, to investigate the hardness of the materials. The investigation gave varying results for the different iron-made objects. All of the objects have been forged in some way. Most of the objects, were made of heterogeneous low carbon steel with a mainly ferritic structure. Some items also showed a martensitic structure with a ferritic core, which concludes that the smiths probably knew how to quench and temper steel. Due to heavy corrosion on many ofthe items, further investigation is needed to strengthen the conclusions made in this report. / Denna studie behandlar undersökningar av arkeologiska stålobjekt från järnåldern,hittade i Tortuna utanför Västerås, Sverige. Det har inte gjorts många metallurgiska analyser på stålobjekt från järnåldern, troligen för att bevara föremålen. Därför finnsdet lite kunskap om gamla stålmaterial. Huvudsyftet med denna studie var att undersöka hur föremål i stål från järnåldern tillverkades, vad de har använts för och bestämma vilken typ av metallurgisk kunskap dåtiens smed besatt. Experimenten utfördes med hjälp av ljus optisk mikroskop för att undersöka materialets morfologi och med hjälp av Vickers hårdhetsprov för att undersöka materialens hårdhet. Undersökningen gav olika resultat för föremålen. Alla föremål är smidda på något sätt. De flesta föremålen bestod av heterogent kolstål med huvudsakligen ferritisk struktur. Vissa föremål visade också en martensitisk struktur med en ferritisk kärna,vilket visar på att smeden troligen visste hur man härdar och anlöper stål. På grund av stor korrosion på många av föremålen krävs ytterligare analyser för att stärka slutsatserna i denna rapport.
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