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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.
11

Development of an Improved and Internally-Consistent Framework for Evaluating Liquefaction Damage Potential

Upadhyaya, Sneha 04 December 2019 (has links)
Soil liquefaction continues to be one of the leading causes of ground failure during earthquakes, resulting in significant damage to infrastructure around the world. The study presented herein aims to develop improved methodologies for predicting liquefaction triggering and the consequent damage potential such that the impacts of liquefaction on natural and built environment can be minimized. Towards this end, several research tasks are undertaken, with the primary focus being the development of a framework that consistently and sufficiently accounts for the mechanics of liquefaction triggering and surface manifestation. The four main contributions of this study include: (1) development of a framework for selecting an optimal factor of safety (FS) threshold for decision making based on project-specific costs of mispredicting liquefaction triggering, wherein the existing stress-based "simplified" model is used to predict liquefaction triggering; (2) rigorous investigation of manifestation severity index (MSI) thresholds for distinguishing cases with and without manifestation as a function of the average inferred soil-type within a soil profile, which may be employed to more accurately estimate liquefaction damage potential at sites having high fines-content, high plasticity soils; (3) development of a new manifestation model, termed Ishihara-inspired Liquefaction Severity Number (LSNish), that more fully accounts for the effects of non-liquefiable crust thickness and the effects of contractive/dilative tendencies of soil on the occurrence and severity of manifestation; and (4) development of a framework for deriving a "true" liquefaction triggering curve that is consistent with a defined manifestation model such that factors influential to triggering and manifestation are handled more rationally and consistently. While this study represents significant conceptual advance in how risk due to liquefaction is evaluated, additional work will be needed to further improve and validate the methodologies presented herein. / Doctor of Philosophy / Soil liquefaction continues to be one of the leading causes of ground failure during earthquakes, resulting in significant damage to infrastructure around the world (e.g., the 2010-2011 Canterbury earthquake sequence in New Zealand, 2010 Maule earthquake in Chile, and the 2011 Tohoku earthquake in Japan). Soil liquefaction refers to a condition wherein saturated sandy soil loses strength as a result of earthquake shaking. Surface manifestations of liquefaction include features that are visible at the ground surface such as sand boils, ejecta, cracks, and settlement. The severity of manifestation is often used as a proxy for damage potential of liquefaction. The overarching objective of this dissertation is to develop improved models for predicting triggering (i.e., occurrence) and surface manifestation of liquefaction such that the impacts of liquefaction on the natural and built environment can be minimized. Towards this end, this dissertation makes the following main contributions: (1) development of an approach for selecting an appropriate factor of safety (FS) against liquefaction for decision making based on project-specific consequences, or costs of mispredicting liquefaction; (2) development of an approach that allows better interpretations of predictions of manifestation severity made by the existing models in profiles having high fines-content, high plasticity soil strata (e.g., clayey and silty soils), given that the models perform poorly in such conditions; (3) development of a new model for predicting the severity of manifestation that more fully accounts for factors controlling manifestation; and (4) development of a framework for predicting liquefaction triggering and surface manifestation such that the distinct factors influential to each phenomenon are handled more rationally and consistently.
12

Studies upon the hydrogenation of Kansas coals

Nienstedt, John F. January 1931 (has links)
Call number: LD2668 .T4 1931 N51
13

An investigation into the suitability of intermediate and low rank coals for solvent and supercritical gas extraction

Cahill, P. January 1987 (has links)
No description available.
14

DRAG REDUCTION AND FLOW PROPERTIES OF CONCENTRATED COAL SLURRIES.

Kaufman, Dov Bruno. January 1983 (has links)
No description available.
15

Solvolysis liquefaction of Kansas coals

Ewert, Warren Matthew January 2011 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
16

Direct liquefaction of coal with coal-derived solvents to produce precursors for carbon products

Fenton, David. January 2001 (has links)
Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains xvi, 135 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 107-109).
17

Numerical formulation for a dynamic analysis of the plastic behavior in saturated granular soils

Song, Chi-Yong, January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xix, 246 p.; also includes graphics. Includes abstract and vita. Advisor: William E. Wolfe, Dept. of Civil Engineering. Includes bibliographical references (p. 137-142).
18

Development of a direct test method for dynamically assessing the liquefaction resistance of soils in situ

Cox, Brady Ray 28 August 2008 (has links)
Not available / text
19

Construction and testing of a hydrogen liquefier

Newell, Oswald 08 1900 (has links)
No description available.
20

Measurement of total emissivity of surfaces at low temperatures

Cheung, Harry 08 1900 (has links)
No description available.

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