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Numerical modeling of brittle rock failure around underground openings under statis and dynamic stress loadingsGolchinfar, Nader 09 October 2013 (has links)
Stability of underground excavations is a prerequisite for the proper functioning of all other systems in a mining environment. From a safety point of view, the lives of people working underground rely on how well the support systems installed underground are performing. The ground control engineer cannot design an effective support system unless the area of the rock mass around the opening, prone to failure, is well identified in advance, even before the excavation of the tunnel.
Under high stress conditions, usually experienced at deep mining levels, stress-induced rock failure is the most common type of instability around the underground openings. This thesis focuses firstly on the use of the finite difference numerical tool FLAC to simulate brittle rock failure under static in-situ stresses. Brittle failure of the rock mass around underground openings is a particular type of stress-induced failure, which can result in notch-shaped breakouts around the boundary of the tunnel. Generation of these breakout zones is a discontinuum process and approximating this process using FLAC, which is a continuum tool, requires careful consideration of the stress conditions and the stress related behavior of rock material. Based on plasticity theory, this thesis makes an effort to estimate the breakout formation using an elastic – brittle - plastic material model.
Due to seismic challenges that deep mining operations are currently experiencing, rockbursting is a major hazard to the stability of underground structures. Therefore in this research, brittle failure of rock in the vicinity of the underground excavations is approximated also under dynamic loading conditions. The numerically modeled results of two different material models
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are compared with each other along with a previously developed empirical graph. This assessment, when further validated by field observations, may provide a different perspective for underground support design under burst-prone conditions.
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DEVELOPMENT OF A NEW METHODOLOGY FOR MEASURING DEFORMATION IN TUNNELS AND SHAFTS WITH TERRESTRIAL LASER SCANNING (LIDAR) USING ELLIPTICAL FITTING ALGORITHMSDelaloye, Danielle 16 May 2012 (has links)
Three dimensional laser scanning, also known as Light Detection and Ranging (LiDAR) has quickly been expanding in its applications in the field of geological engineering due to its ability to rapidly acquire highly accurate three dimensional positional data. Recently is has been shown that LiDAR scanning can be easily integrated into an excavation sequence in an underground environment for the purpose of collecting rockmass and discontinuity information. As scans are often taken multiple times of the same environment, the next logical application of LiDAR scanning is for monitoring for change and deformation.
Traditionally, deformation and change in an underground environment is measured using a series of five or more permanent control points installed around the profile of an excavation. Using LiDAR for profile analysis provides many benefits as compared to traditional monitoring techniques. Due to the high density of the point cloud data, the change in profile is able to be fully characterized, and areas of anomalous movement can easily be separated from overall closure trends. Furthermore, monitoring with LiDAR does not require the permanent installation of control points, therefore monitoring can be completed more quickly after excavation, and scanning is non-invasive therefore no damage is done during the installation of temporary control points.
The main drawback of using LiDAR scanning for deformation monitoring is that the raw point accuracy is generally the same magnitude as the smallest level of deformations that need to be measured. To overcome this, statistical techniques for profile analysis must be developed. This thesis outlines the development one such method, called the Elliptical Fit Analysis (EFA) and LiDAR Profile Analysis (EFA) for tunnel and shaft convergence analysis. Testing of the EFA and LPA has proved the robustness of this technique in its ability to deal with accuracy and precision issues associated with LiDAR scanning. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-05-15 13:24:28.398
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CFD Simulation of Underground Coal GasificationSarraf Shirazi, Ahad Unknown Date
No description available.
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Energy conservation in underground buildings through the use of insulating materialsManson, John Michael 12 1900 (has links)
No description available.
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Experimental predictions of thermal instability in the soil surrounding underground power cablesBush, Richard Alan 05 1900 (has links)
No description available.
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A feasibility study for increasing the production of residential earthen-sheltersMitchell, Joseph L. January 1982 (has links)
This thesis has inquired as to the social and economic factors which are necessary for an industrialization process. The study has concentrated on defining industrialization and building systems; the chronological development of earthen-shelters; and the energy, contractor, and financing issues which are prevalent in the existing earthen-sheltered housing market. In addition, the thesis addresses issues such as the social perception of earthen-sheltered space, comparative cost analysis to conventional housing, and land development ethics. / Department of Landscape Architecture
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Geological And Morphological Investigations Of The Underground Cities Of Cappadocia Using GisAyhan, Arda 01 December 2004 (has links) (PDF)
The purpose of this study is to investigate the effect of rock types and morphologic classes on the locations of underground cities existing in Cappadocia. To achieve this purpose four databases are created that contain related information of underground cities, present settlements, rock types and morphologic classes.
Four main analyses are carried out using the data created fort the study. These analyses are: 1) Distance analysis to determine the distances between underground cities and present settlements, 2) Density analysis to inspect the areas where the underground cities are concentrated, 3) Distribution analysis to explore the spatial distribution of underground cities within the rock types and morphologic classes, and 4) Neighbourhood analysis to examine whether the underground cities within rock types and morphologic classes are located along or far inside the marginsof the polygons.
The conclusions reached after the analyses are as follows: 1) The mean distance between two underground cities is about 4 km. 2) The mean distance between an underground city and the nearest present settlement is about 700 m. 3) Underground cities are concentrated in Derinkuyu-NevSehir-Ö / zkonak belt. Present settlements, on the other hand, are concentrated along Aksaray-Ortakö / y-HacibektaS. 4) For the underground cities, pyroclastic dominant Neogene sequences are preferred whereas all other units are avoided. 5) In terms of morphology, the class defined as &ldquo / mesa&rdquo / is strongly preferred for underground cities. 6) Neither lithology nor morphology played a role in the site selection for present settlements.
7) Both for rock types and morphologic classes the underground cities are located along margins of the polygons.
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The woman who was (not) there :Furler, Loene. Unknown Date (has links)
The purpose of the thesis is to reflect upon the female nude imagery in the counterculture publication London Oz 1967 - 1968, with the retrospective understanding that the alienation involved had a profoundly detrimental effect on my art practice at the time. My aim is to interrogate the past with a view to informing creatively my present work. My thesis is a body of paintings accompanied by an exegesis and a catalogue, from the shed to the dining room and back, 2002, as a work in progress of the MVA. / Thesis (MVisualArts)--University of South Australia, 2005.
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Appraisal and assessment of factors involved in the maintenance of the integrity of pipelinesRahman, Matiur January 1992 (has links)
Thesis (MEng) -- University of South Australia, 1992
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Appraisal and assessment of factors involved in the maintenance of the integrity of pipelinesRahman, Matiur January 1992 (has links)
Thesis (MEng) -- University of South Australia, 1992
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