FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W31173281> ?p ?o ?g. }

• W31173281 abstract "Introduction The stability along joint planes is one of the most important characteristics of a rock mass forming the foundation of a concrete dam. The shear strength of discontinuities within the foundation rock is probably the most important characteristic. Objectives and Purpose of the study The objectives of this research project were to determine and to analyse the shear strength of joints in a number of rock types, sampled at different locations, and to link these strengths to the condition in the foundations of dams and, in particular, the condition of the surfaces of the rock joints. The information so obtained can then serve as a databank for the design of new dams and for the evaluation of the safety of existing dams. Stages of investigation The study was carried out in four identifiable phases. The first phase that took place during 1992 and 1993 was a literature study in order to determine the shear strength characteristics of different rock types world-wide and in southern Africa. The literature study was updated during 2002/3. During this stage a visit was undertaken to the UK, Norway and the USA to study shear apparatus and the rock testing methods in these countries. The second phase was to determine the shear strength characteristics of important southern African rock types. During the period 1993 to 1995 the shear apparatus and surface-scanning device to be used in the third stage were designed and constructed. The third phase (1994 to 1999) comprised of direct shear tests on NX-size borehole core samples and the testing and characterisation oflarge shear surfaces. The last phase (1999 to 2003) consisted of updating the literature survey and compilation of the thesis. Several delays were encountered mainly due to the following reasons: (a) the late delivery of the large shearbox and subsequent problems with the computer controlling the shearbox, (b) resignation of the technician working full-time on the project and (c) illness of the researcher during 1996. It was impossible to determine the true peak and residual shear strength due to practical limitations. Sa discussed in chapter four the peak values are therefore approximated by PhD-Abstract-2003.1wp determining the post-peak strength, whilst residual values were approximated by post-peak values. Format of the thesis The text of the thesis starts by stating the problems to be investigated, followed by Chapter two containing the findings of a literature study. Chapter three describes the experimental stage of the study: the methods used and a description of the equipment. Chapter four contains the presentation and discussion of the results. This is followed by Chapter five showing a classification of shear strength using a geotechnical characterization of the joint surface followed by Chapters six and seven with the conclusions, recommendations and references. The Compact Disc (CD) contains the appendices (reports, graphs and photo's) in electronic format. Results A literature study on the test methods and shear strength characteristics of different rock types was conducted. It was found that although shear strength characteristics of rock material have been investigated on a regular basis for civil and other engineering applications, this information is not readily available to the engineering community at large for safety use in dams. It is often regarded as confidential information by clients and filed for possible use against claims. This document is probably the most comprehensive source of shear strength characteristics of southern African rock types available today. This report describes the shear strength characteristics of quartzite, shale, sandstone, dolerite, mudstone, granite, rhyolite and tillite. Chapter four describes each of these rock types in detail. These rock types were selected because they cover a very large portion of the surface area of southern Africa, and as such, many dams and other civil engineering structures have been built on them. Emphasis was placed on the shear strength parameters of joints, especially the angle of friction. Two types of joints are recognised in nature: (a) joints with no or little fill material where the shear strength is determined by the characteristics of the rock material and (b) joints with fill material where the shear strength is determined by the characteristics of the fill material. The major part ofthis research concentrated on joints with no or little fill material listed under (a). 11 PhD-Abstract-2003.1wp The three major characteristics determining the shear strength parameters of this type of joint are (i) the base shear strength of the rock material, (ii) the roughness profile along the joint surface and (iii) the hardness of the material on the joint surface. The basic shear strength parameters of the different rock materials were determined as part of the determination of rock material characteristics. The basic angle of friction obtained for the different materials corresponds very well to those published in the literature. The values for cohesion obtained through testing is zero to very small. As part of this research project, a laser-scanning device was developed. This device measure the x, y and z co-ordinates on a rock joint surface on a grid pattern. This information can be analyzed with software on a computer to produce a contour diagram of the joint surface area. From this contour diagram, joint roughness profiles were obtained. These, as well as profiles obtained with a carpenter's comb, were compared visually, with an overlay, to typical roughness profiles as published by Barton (1977). The relationship between joint roughness coefficient (JRC) and shear displacement was investigated during this study. The influence of high normal stresses were not taken into consideration as testing was limited to normal stresses with a maximum of 1 MPa. An exponential regression was fitted to the points plotted. After a cumulative shear displacement of more than 2,0 meter will be required to smooth the joint surface as a result of friction. It was found that after a shear displacement of 2,0 meters the friction angle was equal to the residual friction angle. Conclusions This study provides a guide to shear strength characteristics of several important rock types in southern Africa for planning and preliminary design of dams. It is probably the most comprehensive document describing the rock material, the testing procedure, and the shear strength characteristics of so many rock types in southern Africa. This research project was the first attempt to determine the shear strength characteristics of joints in southern African rock types with a large shear apparatus. iii PhD-Abstract-2003.lwp This study also contributes to the knowledge on shear strength of southern African rocks, in particular on (i) the sampling and preparation of specimens for testing in the large shear apparatus, (ii) the measurement of the roughness of the joint surfaces and (iii) the testing procedure and (iv) interpretation and application of friction angle as desigu parameter in the analysis of stability of dam foundations. The shear strength characteristics of the rock joints of southern African rocks are described joints were classified using a geotechnical description of the joint surface. Geotechnical parameters include rock type, roughness, hardness, and a description of fill joint material was used in the classification. This classification is a first attempt to use these parameters and further work still needs to be done in this regard. Further research It is recommended that a project be initiated to investigate the shear strength of southern African rock types in further detail. Such an investigation can build on the knowledge obtained in this investigation. It is important to keep the variables such as rock type, weathering, and hardness to a minimum to investigate influence of joint roughness. An appropriate rock type to start with could be mudstone from the Qeduzisi Dam area near Ladysmith. This is a relative soft rock with smooth joints that gave low shear strength results during testing. These results of this study could be confirmed. The investigation could then be extended to other rock types once the influence of roughness has been established. Acknowledgement The author whishes to express his gratitude to the Water Research Commission for funding this project and hope that the report will contribute to dams and other civil engineering structures being built more cost effectively and safely. Contributions by the following persons are acknowledged: ProfG Pegram of the Department of Civil Engineering of the University of Natal who assisted with the development and building of the laser scanning device. Mr. UW Vogler who assisted with the interpretation of the test results of the different phases of testing. Mr. A van der Walt of the Department of Water Affairs and Forestry for the assistance with the desigu and building as well as the use of the large shear box. Prof A van Schalkwyk for his guidance and contribution to enhancing the quality of the final thesis. iv PhD-Abstract-2003.1wp" @default.
• W31173281 created "2016-06-24" @default.
• W31173281 creator A5034159809 @default.
• W31173281 date "2008-09-25" @default.
• W31173281 modified "2023-09-26" @default.
• W31173281 title "The shear strength of rock joints with special reference to dam foundations" @default.
• W31173281 cites W1522274608 @default.
• W31173281 cites W1965620801 @default.
• W31173281 cites W1972380841 @default.
• W31173281 cites W1974819257 @default.
• W31173281 cites W1975924406 @default.
• W31173281 cites W1977566824 @default.
• W31173281 cites W1985082252 @default.
• W31173281 cites W2000472224 @default.
• W31173281 cites W2011095864 @default.
• W31173281 cites W2017796196 @default.
• W31173281 cites W2022990785 @default.
• W31173281 cites W2031215564 @default.
• W31173281 cites W2039708512 @default.
• W31173281 cites W2048628678 @default.
• W31173281 cites W2049715667 @default.
• W31173281 cites W2054629690 @default.
• W31173281 cites W2059793389 @default.
• W31173281 cites W2063680241 @default.
• W31173281 cites W2064237567 @default.
• W31173281 cites W2067883270 @default.
• W31173281 cites W2070848967 @default.
• W31173281 cites W2088640326 @default.
• W31173281 cites W2101363352 @default.
• W31173281 cites W2101888982 @default.
• W31173281 cites W2159974833 @default.
• W31173281 cites W2163692101 @default.
• W31173281 cites W2165402148 @default.
• W31173281 cites W2256830279 @default.
• W31173281 cites W2340998520 @default.
• W31173281 cites W2366162094 @default.
• W31173281 cites W2498045941 @default.
• W31173281 cites W3173123556 @default.
• W31173281 cites W91344114 @default.
• W31173281 cites W2467979146 @default.
• W31173281 hasPublicationYear "2008" @default.
• W31173281 type Work @default.
• W31173281 sameAs 31173281 @default.
• W31173281 citedByCount "0" @default.
• W31173281 crossrefType "dissertation" @default.
• W31173281 hasAuthorship W31173281A5034159809 @default.
• W31173281 hasConcept C127313418 @default.
• W31173281 hasConcept C127893833 @default.
• W31173281 hasConcept C159390177 @default.
• W31173281 hasConcept C159750122 @default.
• W31173281 hasConcept C187320778 @default.
• W31173281 hasConcept C5900021 @default.
• W31173281 hasConcept C96035792 @default.
• W31173281 hasConceptScore W31173281C127313418 @default.
• W31173281 hasConceptScore W31173281C127893833 @default.
• W31173281 hasConceptScore W31173281C159390177 @default.
• W31173281 hasConceptScore W31173281C159750122 @default.
• W31173281 hasConceptScore W31173281C187320778 @default.
• W31173281 hasConceptScore W31173281C5900021 @default.
• W31173281 hasConceptScore W31173281C96035792 @default.
• W31173281 hasLocation W311732811 @default.
• W31173281 hasOpenAccess W31173281 @default.
• W31173281 hasPrimaryLocation W311732811 @default.
• W31173281 hasRelatedWork W1498994953 @default.
• W31173281 hasRelatedWork W1558035287 @default.
• W31173281 hasRelatedWork W178749790 @default.
• W31173281 hasRelatedWork W1926283805 @default.
• W31173281 hasRelatedWork W1975692409 @default.
• W31173281 hasRelatedWork W1980083302 @default.
• W31173281 hasRelatedWork W2028213382 @default.
• W31173281 hasRelatedWork W2160082477 @default.
• W31173281 hasRelatedWork W2203995160 @default.
• W31173281 hasRelatedWork W2321528092 @default.
• W31173281 hasRelatedWork W2390755392 @default.
• W31173281 hasRelatedWork W2928531701 @default.
• W31173281 hasRelatedWork W2946243471 @default.
• W31173281 hasRelatedWork W2954610858 @default.
• W31173281 hasRelatedWork W2993232174 @default.
• W31173281 hasRelatedWork W3022615310 @default.
• W31173281 hasRelatedWork W56288668 @default.
• W31173281 hasRelatedWork W598388421 @default.
• W31173281 hasRelatedWork W659288878 @default.
• W31173281 hasRelatedWork W166357158 @default.
• W31173281 isParatext "false" @default.
• W31173281 isRetracted "false" @default.
• W31173281 magId "31173281" @default.
• W31173281 workType "dissertation" @default.