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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.
91

Geological mapping of entry roof in mines

Gu, Quanzhong. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 191 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 137-139).
92

Effect of verification core hole on the point bearing capacity of drilled shafts

Youn, Heejung, 1976- 05 October 2012 (has links)
For many projects involving drilled shafts, cores are required to be taken below the shaft base for visual identification of the underlying material. For example, the Texas Department of Transportation (TxDOT) requires a core length of at least 1.5 m (5 ft) or equal to the shaft diameter, whichever is greater, at the shaft base. Although the verification cores are to be extracted at the shaft base, The Department of Transportation of many states do not provide guidance to eliminate the effect of the verification core on the point bearing capacity. A recent study shows that the verification core hole is either filled with concrete in dry condition or with sand-gravel mixture in wet pour (Raibagkar, 2008). This finding is crucial because the point bearing capacity of drilled shafts with an empty hole at the base should be significantly lower than that of drilled shafts without verification core. Although the materials that fill in the verification core remove the risk of losing large point bearing capacity, the exposure of the core holes to air-drying may have an adverse effect on the point bearing capacity tipped in clay shales, especially when the basal material is susceptible to weathering. Therefore, the effect of the verification core on the point bearing capacity has been thoroughly investigated with emphasis on changes in the material properties of four clay shales (Del Rio Clay, Eagle Ford Shale, Taylor Marl, and Navarro Shale) in central Texas. The effect of verification core on the point bearing capacity of drilled shafts was investigated using finite element method (FEM) software, PLAXIS. The results from laboratory tests were converted to input material parameters for Mohr-Coulomb failure criterion, and the thickness of degraded zone around the core was interpreted from fullscale condition degradation tests. The load-displacement curves at the shaft base were created from PLAXIS analyses, and the point bearing capacities were obtained at 5%D and 10%D displacement from load-displacement curves. These capacities were used to calculate reduction factors that relate the point bearing capacity of the reference model (without a verification core) with that of the “core models” (with a verification core). The reduction factors are good indicators to determine if verification core had a positive or negative effect on the point bearing capacity. It was found that the reduction in point bearing capacity of “core models” is typically within 10% capacity of the reference model, and a maximum reduction of 14% was found for the Taylor Marl that was dried for 48 hours. / text
93

EXPERIMENTAL ASSESSMENT OF BOREHOLE DRILLING DAMAGE IN BASALTIC ROCKS

Fuenkajorn, Kittitep January 1985 (has links)
No description available.
94

Numerical model of a rock bit bearing seal

Xiong, Shunhe 05 1900 (has links)
No description available.
95

Analysis of cutting parameters and heat generation on bits of a continuous miner using numerical and experimental approach /

Mishra, Brijes. January 2007 (has links)
Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains ix, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 94-96).
96

Wellbore effects on pressure transient analysis /

Xiao, Jinjiang. January 1993 (has links)
Thesis (Ph.D.)--University of Tulsa, 1993. / Bibliography: leaves 179-186.
97

Prediction of wellbore trajectory considering bottom hole assembly and drillbit dynamics /

Brakel, Johannes Daniel. January 1986 (has links)
Thesis (Ph.D.)--University of Tulsa, 1986. / Bibliography: l. 104-116.
98

Monitoring air flow and water movement in the subsurface with cross-borehole resistivity and induced polarization

Schima, Susan Anastasia, January 1994 (has links) (PDF)
Thesis (M.S. - Mining and Geological Engineering)--University of Arizona. / Includes bibliographical references (leaves 149-150).
99

Simulation of a complex mix of circuit boards in a drilling environment

Schneider, Maria J. January 2008 (has links)
Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2008. / Includes bibliographical references.
100

Process selection for hole operations using a rule based approach /

Wadatkar, Ajit. January 2004 (has links)
Thesis (M.S)--Ohio University, November, 2004. / Includes bibliographical references (p. 93-95)

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