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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.
21

The shear strength of rock masses

Douglas, Kurt John, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2002 (has links)
The first section of this thesis (Chapter 2) describes the creation and analysis of a database on concrete and masonry dam incidents known as CONGDATA. The aim was to carry out as complete a study of concrete and masonry dam incidents as was practicable, with a greater emphasis than in other studies on the geology, mode of failure, and the warning signs that were observed. This analysis was used to develop a method of very approximately assessing probabilities of failure. This can be used in initial risk assessments of large concrete and masonry dams along with analysis of stability for various annual exceedance probability floods. The second and main section of this thesis (Chapters 3-6) had its origins in the results of Chapter 2 and the general interests of the author. It was found that failure through the foundation was common in the list of dams analysed and that information on how to assess the strength of the foundations of dams on rock masses was limited. This section applies to all applications of rock mass strength such as the stability of rock slopes. Methods used for assessing the shear strength of jointed rock masses are based on empirical criteria. As a general rule such criteria are based on laboratory scale specimens with very little, and often no, field validation. The Hoek-Brown empirical rock mass failure criterion was developed in 1980 for hard rock masses. Since its development it has become virtually universally accepted and is now used for all types of rock masses and in all stress regimes. This thesis uses case studies and databases of intact rock and rockfill triaxial tests collated by the author to review the current Hoek-Brown criterion. The results highlight the inability of the criterion to fit all types of intact rock and poor quality rock masses. This arose predominately due to the exponent a being restrained to approximately 0.5 to 0.62 and using rock type as a predictor of mi. Modifications to the equations for determining the Hoek-Brown parameters are provided that overcome these problems. In the course of reviewing the Hoek-Brown criterion new equations were derived for estimating the shear strength of intact rock and rockfill. Empirical slope design curves have also been developed for use as a preliminary tool for slope design.
22

A relationship between wave dispersion and fracture strength for a composite material /

Ilcewicz, Larry Bert. January 1984 (has links)
Thesis (Ph. D.)--Oregon State University, 1984. / Typescript (photocopy). Includes bibliographical references (leaves 222-232). Also available on the World Wide Web.
23

The development of a general buckling theory for rings and arches with applications to circular arches

Kesti, Norman Emil, 1938- January 1962 (has links)
No description available.
24

Investigation of an oblique shock wave-boundary layer interaction

Loffert, George Ulrich, 1931- January 1964 (has links)
No description available.
25

The influence of loading frequency on dynamic soil properties

Meng, Jiewu 08 1900 (has links)
No description available.
26

The shear strength of rock masses

Douglas, Kurt John, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2002 (has links)
The first section of this thesis (Chapter 2) describes the creation and analysis of a database on concrete and masonry dam incidents known as CONGDATA. The aim was to carry out as complete a study of concrete and masonry dam incidents as was practicable, with a greater emphasis than in other studies on the geology, mode of failure, and the warning signs that were observed. This analysis was used to develop a method of very approximately assessing probabilities of failure. This can be used in initial risk assessments of large concrete and masonry dams along with analysis of stability for various annual exceedance probability floods. The second and main section of this thesis (Chapters 3-6) had its origins in the results of Chapter 2 and the general interests of the author. It was found that failure through the foundation was common in the list of dams analysed and that information on how to assess the strength of the foundations of dams on rock masses was limited. This section applies to all applications of rock mass strength such as the stability of rock slopes. Methods used for assessing the shear strength of jointed rock masses are based on empirical criteria. As a general rule such criteria are based on laboratory scale specimens with very little, and often no, field validation. The Hoek-Brown empirical rock mass failure criterion was developed in 1980 for hard rock masses. Since its development it has become virtually universally accepted and is now used for all types of rock masses and in all stress regimes. This thesis uses case studies and databases of intact rock and rockfill triaxial tests collated by the author to review the current Hoek-Brown criterion. The results highlight the inability of the criterion to fit all types of intact rock and poor quality rock masses. This arose predominately due to the exponent a being restrained to approximately 0.5 to 0.62 and using rock type as a predictor of mi. Modifications to the equations for determining the Hoek-Brown parameters are provided that overcome these problems. In the course of reviewing the Hoek-Brown criterion new equations were derived for estimating the shear strength of intact rock and rockfill. Empirical slope design curves have also been developed for use as a preliminary tool for slope design.
27

Development of numerical approaches to predict ductile and cleavage fracture of structural materials

Zhang, Guihua. January 2007 (has links)
Dissertation (Ph. D.)--University of Akron, Dept. of Mechanical Engineering, 2007. / "December, 2007." Title from electronic dissertation title page (viewed 03/27/2008) Advisor, Xiaosheng Gao; Committee members, T.S. Srivatsan, Fred Choy, Wieslaw Binienda, Kevin Kreider; Department Chair, Celal Batur; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
28

The shear strength of rock masses /

Douglas, Kurt John. January 2002 (has links)
Thesis (Ph. D.)--University of New South Wales, 2002. / Also available online.
29

An analysis of farm mechanics knowledge and skills needed by Wisconsin farmers

Jensen, Arthur Kenneth, January 1961 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1961. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 106-110).
30

A simple shear machine for soil

Pickering, D. J. January 1969 (has links)
The new shear machine enforces more uniform deformations than the conventional triaxial test. A low compliance pore pressure measuring device is an integral part of the machine. The machine described is capable of applying cyclic normal stress up to 1000 lb. per sq. in. and alternating cyclic shear stress up to ± 500 lb. per sq. in. Static loads can be taken 50 percent higher. The test specimen can be cut from an ordinary undisturbed drill hole sample, being 2 ins. square and 1 1/8 in. high. Height variation of ± 1/8 in. is permitted during testing, but there is no "dead" zone; the entire sample is subjected to the applied shear. An analytic solution is presented, for the boundary value problem of an anisotropic elastic sample in the tests to be described. This solution shows the variation of the stress field and deformations throughout the sample. For the benefit of any future simple shear machine designs, the theoretical relationship was also examined between the ratio of sample length to height and the uniformity of stresses and displacements within the sample. In comparing test results from the new machine with conventional triaxial tests, it was found that the measured strengths are different. Some of the results suggest that the triaxial test could over-estimate the strength of undrained sand. The difference between simple shear and triaxial conditions is, therefore, of more than theoretical interest. Liquefaction of undrained sand was readily induced by alternating shear in the new machine. It was found that liquefaction alters the structure of a sand sample, rendering it more susceptible to re-liquefaction. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

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