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

dc.contributor.advisorVan Schalkwyk, Antoinette
dc.contributor.postgraduatePitsiou, Sofia
dc.date.accessioned2014-04-01T09:11:14Z
dc.date.available2014-04-01T09:11:14Z
dc.date.created1990-12-01
dc.date.issued1990en_US
dc.descriptionDissertation (MSc)--University of Pretoria, 1990.en_US
dc.description.abstractProblems 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.availabilityunrestricteden_US
dc.description.departmentGeologyen_US
dc.description.librariangm2014en_US
dc.identifier.citationPitsiou, 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.otherE14/4/21/gmen_US
dc.identifier.urihttp://hdl.handle.net/2263/37300
dc.language.isoenen_US
dc.publisherUniversity of Pretoriaen_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.subjectErosion in unlined spillways of damsen_US
dc.subjectErodibility of the bedrock materialen_US
dc.subjectEnvironmental and safety hazardsen_US
dc.subjectRocken_US
dc.subjectUCTDen_US
dc.titleThe effect of discontinuities on the erodibility of rock in unlined spillways of damsen_US
dc.typeDissertationen_US

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