The effect of discontinuities on the erodibility of rock in unlined spillways of dams

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dc.contributor.advisor Van Schalkwyk, Antoinette
dc.contributor.postgraduate Pitsiou, Sofia
dc.date.accessioned 2014-04-01T09:11:14Z
dc.date.available 2014-04-01T09:11:14Z
dc.date.created 1990-12-01
dc.date.issued 2014 en_US
dc.description Dissertation (MSc)--University of Pretoria, 1990. en_US
dc.description.abstract Problems with erosion in unlined spillways of dams, have caused environmental and safety hazards, and necessitate the development of reliable scientific methods to assess the erodibility of the bedrock material. In an attempt to analyze the causes and effects of different geological, geotechnical, hydraulic, hydrological and engineering design parameters on erosion of unlined spillways, a number of dam spillways in the R.S.A. were studied. All the parameters considered important for the erosion resistance of the rock were collected and correlated with hydraulic factors and observed extent of erosion. Rock type, strength, weathering and uniformity of the geological conditions are important geotechnical considerations while velocity and energy of the water flow are the main hydraulic parameters. The main consideration of the study was the effect of the discontinuities. All the properties of the jointing of the rock mass, such as number of joint sets, RQD, joint spacing, joint separation, joint orientation, roughness and filling material, were surveyed. Joints. weaken the rock mass and induce removal of the rock blocks if the joint properties are unfavourable to stability. The jointed bedrock is much less resistant to flowing or falling water, the result being an extensive and quickly formed scour. Various rock mass classification systems have been applied and a reasonable correlation between rock class and extent of erosion was established by means of slightly modified Kirsten (1982) and Weaver (1975) rippability classifications. A number of methods for the prevention and repair of erosion damage have been proposed. en_US
dc.description.availability unrestricted en_US
dc.description.department Geology en_US
dc.description.librarian gm2014 en_US
dc.identifier.citation Pitsiou, S 1990, The effect of discontinuities on the erodibility of rock in unlined spillways of dams, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/37300> en_US
dc.identifier.other E14/4/21/gm en_US
dc.identifier.uri http://hdl.handle.net/2263/37300
dc.language.iso en en_US
dc.publisher University of Pretoria en_ZA
dc.rights © 1990 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. en_US
dc.subject Erosion in unlined spillways of dams en_US
dc.subject Erodibility of the bedrock material en_US
dc.subject Environmental and safety hazards en_US
dc.subject Rock en_US
dc.subject UCTD en_US
dc.title The effect of discontinuities on the erodibility of rock in unlined spillways of dams en_US
dc.type Dissertation en_US


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