Relating measured physical roughness of hydropower waterways to

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  • Faculty of Civil- and Environmental EngineeringUniversity of Iceland

    2013

    Faculty of Civil- and Environmental EngineeringUniversity of Iceland

    2013

    Relating measured physicalroughness of hydropower

    waterways to hydraulic roughness

    Anna Heiur Eydsardttir

  • RELATING MEASURED PHYSICALROUGHNESS OF HYDROPOWER WATERWAYS

    TO HYDRAULIC ROUGHNESS

    Anna Heiur Eydsardttir

    60 ECTS thesis submitted in partial fulfillment of aMagister Scientiarum degree in Environmental Engineering

    AdvisorsDr. Kristn Martha HkonardttirDr. Sigurur Magns Gararsson

    Faculty RepresentativeHelgi Jhannesson

    Faculty of Civil- and Environmental EngineeringSchool of Engineering and Natural Sciences

    University of IcelandReykjavik, June 2013

  • Relating measured physical roughness of hydropower waterways to hydraulic roughnessRoughness in hydropower waterways60 ECTS thesis submitted in partial fulfillment of a M.Sc. degree in Environmental En-gineering

    Copyright c 2013 Anna Heiur EydsardttirAll rights reserved

    Faculty of Civil- and Environmental EngineeringSchool of Engineering and Natural SciencesUniversity of IcelandHjararhagi 2-6107, Reykjavik, ReykjavikIceland

    Telephone: 525 4000

    Bibliographic information:Anna Heiur Eydsardttir, 2013, Relating measured physical roughness of hydropowerwaterways to hydraulic roughness, M.Sc. thesis, Faculty of Civil- and Environmental En-gineering, University of Iceland.

    Printing: Hsklaprent, Flkagata 2, 107 ReykjavkReykjavik, Iceland, June 2013

  • To my little family

  • Abstract

    The main focus of this study was to examine the different methods used for connect-ing measured tunnel roughness to hydraulic roughness, for tunnel boring machine(TBM) tunnels and drill and blast tunnels.

    For TBM tunnels, a couple of different methods have been suggested for connectingmeasured tunnel roughness to hydraulic roughness. The results of a previous studyindicate that the best fitting method for this conversion, for tunnels where thecharacteristic roughness moves in and out of the average pipe surface, overestimatesthe effect on head loss from tunnels characterized by groove roughness elements. Inthis study attempts were made to decrease the depth of groove roughness elements,to investigate if the same method could be used for tunnels with these two types ofcharacteristic roughness. The decrease of the depth of the grooves was based on acomparison between a back-calculated friction factor from measured head loss, andfriction factor calculated with the best fitting method for tunnels with roughnessmoving in and out of the average pipe surface. The results show that it is possibleto decrease the depth of the grooves and use the same method.

    When connecting the measured physical roughness of drill and blast tunnels to hy-draulic roughness, the IBA-method is the most commonly used method. A compar-ison was made between friction factors and head losses found with design estimate,calculated with the IBA-method and from measured head loss, for the headracetunnels of three hydroelectric power plants (HEP). The purpose was to assess thevalidity of the IBA-method and the design estimates. The results indicate that theIBA-method gives a good estimation of the measured head loss and back-calculatedfriction factor. The design estimates are further from the measured values, mainlybecause the design calculations underestimate the tunnel diameter.

    This study also includes calculations aimed at monitoring the reservoir water level ina HEP where it is not measured directly. This process entails finding a location for apressure meter in the headrace tunnel of a HEP, and calculating the reservoir waterlevel from measured pressure, measured discharge and calculated tunnel roughness,for another HEP.

    vii

  • tdrttur

    Aal herslan essu verkefni var a fjalla um r mismunandi aferir sem notaareru til ess a tengja saman mlt hrfi gngum og straumfrilegt hrfi, fyrirheilboru gng annars vegar og boru og sprengd gng hins vegar.

    Nokkrar mismunandi aferir hafa veri settar fram fyrir heilboru gng, til essa tengja saman mlt hrfi gngum og straumfrilegt hrfi. Niurstur fyrriathugana hafa leitt ljs a mismunandi aferir eru best til ess fallnar a tengjasaman essa tti fyrir mismunandi tegundir hrfis gngum. S afer sem bestpassar fyrir gng ar sem hrfi gengur inn og t r yfirborinu ofmetur hrif grpa falltapi, fyrir gng ar sem hrfi einkennist af grpum. essu verkefni vorugerar tilraunir til ess a stytta dpt grpanna annig a mgulegt vri a notasmu afer fyrir essar tvr tegundir af gngum. Stytting grpanna kvaraistt fr samanburi nningsstuli reiknuum t fr mldu falltapi og nningsstulireiknuum me eirri afer sem best passai fyrir gng sem einkennast af hrfisem gengur inn og t r yfirboinu. Niursturnar sna a a er mgulegt astytta grpirnar og nota smu afer.

    Fyrir boru og sprengd gng er algengast a nota IBA-aferina, til a tengja mlthfi vi straumfrilegt hrfi. Samanburur var gerur milli nningsstula ogfalltapa reiknaa me hnnunartreikningum, me IBA-aferinni og fundna t frmldu falltapi, fyrir rjr vatnsaflsvirkjanir. Niursturnar gefa til kynna IBA-aferin gefur gott mat mldu falltapi og nningsstuli reiknuum t fr mldufalltapi. Gildin sem reiknu voru me hnnunartreikningunum voru lengra frrttum gildum. Aal orskinn er talin vera a hnnunartreikningunum er notaof lti verml.

    essu verkefni voru einnig framkvmdir treikningar sem nota m til ess areikna vatnsh lni, ar sem lnshamlir er ekki tilstaar. etta ferli felur sr a stasetja rstimli arennslisgngum einnar vatnsaflsvirkjanar og reiknalnhina annarri virkjun, t fr mldum rstingi, mldu rennsli og reiknuuhrfi.

    ix

  • Acknowledgments

    First and foremost I would like to thank my two advisors Dr. Kristn MarthaHkonardttir and Dr. Sigurur Magns Gararsson for their guidance, advice andsupport.

    I would also like to thank gir Jhannsson, orbergur Steinn Leifsson and lf RsKradttir at Verks consulting engineers, Bjarni Mr Jlusson and lfar Linnetat Landsvirkjun and Gumundur rarson at stak for their willingness to answermy questions and for providing the necessary data for my calculations.

    Finally, my gratitude goes to Verks consulting engineers for allowing me to conductmy work at their facilities, which has been a great opportunity to me. Workingamongst great people is an invaluable experience.

    xi

  • Contents

    Abstract vii

    rdrttur ix

    Acknowledgments xi

    List of Figures xv

    List of Tables xix

    1. Introduction 11.1. Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2. Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3. Literature review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.4. Organisation of the study . . . . . . . . . . . . . . . . . . . . . . . . 31.5. Hydroelectric power plants . . . . . . . . . . . . . . . . . . . . . . . . 4

    2. Methods 72.1. Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

    2.1.1. Head loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72.1.2. Converting measured roughness to hydraulic roughness in TBM

    bored tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.1.3. Converting measured roughness to hydraulic roughness in drill

    and blast tunnels . . . . . . . . . . . . . . . . . . . . . . . . . 112.1.4. Flow regimen and boundary layer . . . . . . . . . . . . . . . . 132.1.5. Fully developed flow . . . . . . . . . . . . . . . . . . . . . . . 162.1.6. Boundary layer separation . . . . . . . . . . . . . . . . . . . . 172.1.7. Wall roughness elements in conduits . . . . . . . . . . . . . . 202.1.8. Conservation of energy . . . . . . . . . . . . . . . . . . . . . . 24

    2.2. Excavation methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 252.2.1. Choice of excavation method . . . . . . . . . . . . . . . . . . . 27

    2.3. Calculation approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 282.3.1. TBM tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . . 282.3.2. Reservoir water level . . . . . . . . . . . . . . . . . . . . . . . 322.3.3. Drill and blast tunnels . . . . . . . . . . . . . . . . . . . . . . 37

    xiii

  • Contents

    3. Results and discussions 433.1. TBM tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433.2. Reservoir water level . . . . . . . . . . . . . . . . . . . . . . . . . . . 493.3. Drill and blast tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . 513.4. Comparison of the methods . . . . . . . . . . . . . . . . . . . . . . . 55

    4. Conclusions 574.1. TBM tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574.2. Reservoir water level . . . . . . . . . . . . . . . . . . . . . . . . . . . 584.3. Drill and blast tunnels . . . . . . . . . . . . . . . . . . . . . . . . . . 594.4. Future work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

    References 64

    A. The R program 65

    xiv

  • List of Figures

    1.1. Location of the town of Sisimiut and Sisimiut HEP (stak, n.d.; stak& Verks, 2010) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

    1.2. Location of the town of Ilulissat and Ilulissat HEP (stak & Verks,2010) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

    1.3. Overview of Sultartangi HEP (Landsvirkjun, n.d.a) . . . . . . . . . . 5

    1.4. Overview of Krahnjkar HEP (Hkonardttir, Tmasson, Kaelin &Stefnsson, 2009). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

    2.1. The equivalent sinusoid of a measured tunnel profile (Pegram & Pen-nington, 1996) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

    2.2. An illustrati