1st Edition

Labyrinth and Piano Key Weirs III Proceedings of the 3rd International Workshop on Labyrinth and Piano Key Weirs (PKW 2017), February 22-24, 2017, Qui Nhon, Vietnam

    Since the first implementation by Electricité de France on the Goulours dam (France) in 2006, the Piano Key Weir has become a more and more applied solution to increase the discharge capacity of existing spillways. In parallel, several new large dam projects have been built with such a flood control structure, usually in combination with gates. Today, more than 25 Piano Key Weirs are in operation or under construction all over the world. More than 15 years of research and development have enabled detailed investigations of the hydraulic and structural behaviour of the Piano Key Weir complex structure and have provided more and more accurate design equations. Following the proceedings of the first two workshops held in Liege (Belgium – 2011) and Paris (France – 2013), Labyrinth and Piano Key Weirs III collects the contributions presented by people with varied background, from researchers to practitioners, at the 3rd International Workshop on Labyrinth and Piano Key Weirs - PKW 2017 (22-24 February 2017, Qui Nhon, Vietnam). The papers, reviewed and accepted by an International Scientific Committee, summarize the current state-of-the-art on Piano Key Weirs from a theoretical to a practical point of view, and present most of the main projects in operation or under construction.

    Labyrinth and Piano Key Weirs III is thus a reference for students, practitioners and researchers interested in Dams Engineering.

    Keynote lectures

    History and development of Piano KeyWeirs in Vietnam from 2004 to 2016
    M. Ho Ta Khanh

    Twenty years of research in Biskra University for Labyrinths and Piano KeyWeirs and associated fuse plugs
    A. Ouamane, M. Debabeche, F. Lempérière & J.P. Vigny

    Hydraulics of Piano KeyWeirs: A review
    S. Erpicum, P. Archambeau, B. Dewals & M. Pirotton

    Overview of design and construction of 11 Piano KeyWeirs spillways developed in France by EDF from 2003 to 2016
    F. Laugier, J. Vermeulen & B. Blancher

    I Research and development

    I.1 Hydraulics

    Research on Piano KeyWeirs capacity for free and submerged flows
    H. Nguyen Thanh, T. Tang Duc & M. Ho Ta Khanh

    Flow regimes over trapezoidal Piano KeyWeirs
    A. Mehboudi, J. Attari & S.A. Hosseini

    Synthesis of Piano KeyWeir experimental studies at LNHE
    G.M. Cicero, F. Laugier & J. Vermeulen

    Study of the influence of submergence on the upstream flow of Piano KeyWeir
    F. Belaabed, B. Athmani, A. Ouamane &A. Laiadi

    I.2 Geometry

    The effect of the geometric shape of the alveoli on the performance of Piano KeyWeirs
    A. Laiadi, B. Athmani, F. Belaabed &A. Ouamane

    Numerical investigation of wall thickness influence on Piano KeyWeir discharge coefficients: A preliminary study
    F.L. Bremer & M. Oertel

    Experimental study of discharge coefficient of a Piano Key SideWeir
    M. Karimi, J. Attari, M. Saneie & M.R. Jalili Ghazizadeh

    I.3 Fluid-structure interactions and aeration

    Fluid structure interaction of Piano KeyWeirs
    F.J.M. Denys, G.R. Basson & J.A.v.B. Strasheim

    Design of a Piano KeyWeir aeration network
    J. Vermeulen, C. Lassus &T. Pinchard

    Could Piano KeyWeirs be subject to nappe oscillations?
    M. Lodomez, M. Pirotton, B. Dewals, P. Archambeau & S. Erpicum

    I.4 Energy dissipation

    Toe-scour formation at Piano KeyWeirs
    M. Pfister, S. Jüstrich &A.J. Schleiss

    Experimental study for energy dissipation using stilling basin downstream of Piano KeyWeirs type A
    H. Truong Chi & M. Ho Ta Khanh

    I.5 Future applications and developments

    Piano Key and LabyrinthWeirs at German waterways: Recent and future research of the BAW
    F. Belzner, J. Merkel, M. Gebhardt & C. Thorenz

    Piano KeyWeir as overflow on sedimentation basin of wastewater treatment plant
    J.-M. Ribi, B. Spahni, D. Dorthe & M. Pfister

    Physical modeling size-scale effects for labyrinth weirs with half-round crests
    B.P. Tullis, N. Young & B.M. Crookston

    II Projects

    II.1 Studies

    A Piano KeyWeir to improve the discharge capacity of the Oule Dam spillway (France)
    S. Erpicum, P. Archambeau, B. Dewals, M. Pirotton, H. Tralli & J. Alende

    Piano KeyWeirs on a lateral spillway: From an analytical preliminary design to a detailed design validated by a physical model
    A. Chapuis, M. Thomas, L. Deroo, C. Richit & C. Touzet

    Estimation of discharge coefficient and optimization of Piano KeyWeirs
    K. Azizi, J. Attari &A. Moridi

    A comparison of side weirs and labyrinth weirs at Ilmenau river
    M. Gebhardt, J. Merkel, F. Belzner & C. Thorenz

    II.2 Construction

    The raising of Hazelmere Dam by means of Piano KeyWeir
    D. Booyse

    Construction and testing of two Piano KeyWeirs at Charmines dam
    P. Valley & B. Blancher

    Construction of a Piano KeyWeir spillway at La Raviège dam
    M. Cubaynes, F. Laugier &V. Nagel

    Construction of a Piano KeyWeir spillway at Record dam
    F. Dabertrand, J. Vermeulen & B. Blancher

    Study, design and construction of the Van Phong Piano KeyWeirs
    Q. Dinh Sy, A. Nguyen Luong & H. Nguyen Manh

    Adoption of a type D Piano KeyWeir spillway with tapered noses at Rambawa Tank, Sri Lanka
    H.M. Jayatillake & K.T.N. Perera


    Sebastien Erpicum is Assistant Professor at the Laboratory of Engineering Hydraulics – HECE, University of Liege. He graduated in Civil Engineering at the University of Liege (ULg), Belgium, in 2000. After joining the HACH research unit at the ULg as a research engineer, he obtained his PhD on the subject of free surface turbulent flow numerical modelling with multiblock grids in 2006. He then worked as a senior researcher, involved in many combined numerical / physical studies of dams and hydropower plants all over the world, and spent 6 months at the IWW-RWTH in Germany. Since 2010, he is in charge of the Laboratory of Engineering Hydraulics in the new research group on Hydraulics in Environmental and Civil Engineering – HECE of the ULg and has been appointed as Assistant Professor in 2015. His field of activities covered the complementary domains of education, research and services in applied hydraulics, considering both numerical and physical modelling approaches.

    Frédéric Laugier is head of the Structural Branch of the Technical Direction at Electricité de France – Hydro Engineering Center, EDF-CIH. He graduated in Civil Engineering from the Ecole Nationale of the Ponts and Chaussées (ENPC) in Paris (France) in 1996. His final year was spent at Imperial College, London, through the Erasmus exchange programme. He joined the EDF Hydro Engineering Centre in 1998. As a design engineer and project leader he has taken part in various civil engineering and hydro engineering projects, including the rehabilitation and maintenance of existing EDF dams. He was the Project Leader of the design and construction of the first two PK Weirs built on the Goulours and Saint-Marc dams in France. From 2008 to early 2011 he also was General Secretary of the French Committee of Large Dams. He is currently head of structural branch of technical direction of EDF Hydro Engineering Center.

    Michel Ho Ta Khanh is an independent expert, retired from Electricité de France. He graduated in Civil Engineering from the Ecole Nationale des Ponts and Chaussées (ENPC) in Paris (France) in 1966. He has 35 years of experience in the fields of design and construction of hydropower structures, in particular concerning dams and the associated hydraulic structures (bottom outlets, spillways, tunnels). He has participated in the studies and construction of nearly 80 projects, both in France and abroad, and particularly in Africa and Asia. He was the "Secrétaire du Comité de l’Hydraulique d’EDF" in charge of the review of all the main EDF dam projects. He is at present an independent expert in France, Morocco and Vietnam. He has participated in particular during these last 12 years to the study and design of the Vietnamese P.K weirs. He is member of the CFBR, VNCOLD and two Technical Committees of ICOLD.

    Prof. Dr. Michael Pfister works at the Haute école d’ingénierie et d’architecture HEIA-FR. He graduated in Civil Engineering from ETH Zurich, Switzerland, in 2002. He then joined the Laboratory of Hydraulics, Hydrology and Glaciology (VAW) of ETH Zurich as a Research Assistant, and obtained a Doctorate in Sciences in 2007. In 2010 he joined the Laboratory of Hydraulic Constructions (LCH) of EPFL, as a Research and Teaching Associate. In 2016 he was appointed Full Professor for Hydraulic Engineering at Haute école d’ingénierie et d’architecture Fribourg (HEIA-FR). His activity mainly focuses on research related to wastewater hydraulics, spillway hydraulics and high-speed two-phase air-water flows. Further, he is active as an expert in practice and related to physical model studies. He is a member of the Leadership Team of the IAHR Hydraulic Structures Committee, and of several national commissions.