1st Edition
INTERNAL EROSION OF EXISTING DAMS, LEVEES AND DIKES, AND THEIR FOUNDATIONS / L’ÉROSION INTERNE DANS LES BARRAGES ET DIGUES EN EXPLOITATION ET LEUR FONDATION Case histories, Investigations, Testing, Remediation and Surveillance / Études de cas, Reconnaissances, Essais, Réparation et Surveillance
TABLE DES MATIÉRES
TABLEAUX & FIGURES
PRÉFACE ET REMERCIEMENTS
RÉSUMÉ
1. GÉNÉRALITÉS
1.1 CE QUE DIT LE VOLUME 1 SUR L’ÉROSION INTERNE
1.2 PROCESSUS D’ÉROSION INTERNE
1.3 NEUF POINTS FUNDAMENTAUX DE L’ÉROSION INTERNE
1.4 JUSTIFICATION DES NEUFS POINTS FONDAMENTAUX DE L’ÉROSION INTERNE
1.5 UTILISER LA COMPRÉHENSION RÉCENTE DES MÉCANISMES D’ÉROSION
2. ÉTUDES DE CAS
2.1 LEÇONS APPRISES DES RUPTURES ET INCIDENTS
2.2 RUPTURES ET INCIDENTS DUS À L’ÉROSION DE CONDUIT
2.3 RUPTURES ET INCIDENTS DUS À L’ÉROSION RÉGRESSIVE LOCALE ET GLOBALE
2.4 RUPTURES ET INCIDENTS D’EROSION DE CONTACT
2.5 RUPTURES ET INCIDENTS DE SUFFUSION
2.6. RUPTURES ÉVITÉES PAR DES FILTRES À ÉROSION LIMITÉE OU IMPORTANTE ET AUTRES MATÉRIAUX DE REMBLAI
3. RECONNAISSANCES
3.1 PRINCIPES D’INVESTIGATION DE L’ÉROSION INTERNE
3.2 CAROTTAGES POUR ÉCHANTILLONS INTACTS SOUS LA NAPPE
3.3 DETECTION DES FUITES: MÉTHODES DIRECTES
3.4 DETECTION DES FUITES: MÉTHODES GÉOPHYSIQUES
4. ESSAIS DE LABORATOIRE
4.1 INTRODUCTION
4.2 ÉROSION DE CONDUIT: MESURES DE LA CONTRAINTE CRITIQUE (TC)
ET DU COÉFFICIENT D’ÉROSION (CE)
4.3 ESSAIS DE SUFFUSION
4.4 ESSAI D’ÉROSION DE CONTACT
4.5 ESSAIS DE PERMÉABILITÉ, ÉRODABILITÉ ET CAPACITÉ FILTRANTE DES REMBLAIS ET DES FILTRES
5. RÉHABILITATION
5.1 INTRODUCTION
5.2 RÉPARATION DE L’ÉROSION DE CONDUIT
5.3 RÉPARATION DE L’ÉROSION RÉGRESSIVE
5.4 RÉPARATION EN CAS D’ÉROSION DE CONTACT
5.5 RÉPARATION EN CAS DE SUFFUSION
6. SURVEILLANCE
6.1 OBJECTIFS ET PRINCIPES DE LA SURVEILLANCE DÉDIÉE A L’ÉROSION INTERNE
6.2 SURVEILLANCE ET AUSCULATION À LONG TERM
6.3 PIÉZOMÈTRES, PRESSIONS ET GRADIENTS HYDRAULIQUES
6.4 DÉTECTION DES FUITES
7. REFERENCES
TABLE OF CONTENTS
TABLES & FIGURES
FOREWORD AND ACKNOWLEDGEMENTS
EXECUTIVE SUMMARY
1. OVERVIEW
1.1 WHAT VOLUME 1 (ICOLD, 2017) TELLS US ABOUT INTERNAL EROSION
1.2 INTERNAL EROSION PROCESSES
1.3 NINE FUNDAMENTAL POINTS ABOUT INTERNAL EROSION
1.4 JUSTIFICATION OF THE NINE FUNDAMENTAL POINTS
1.5 USING THE NEW UNDERSTANDING OF INTERNAL EROSION MECHANICS
2. CASE HISTORIES
2.1 LESSONS FROM FAILURES AND INCIDENTS
2.2 FAILURES AND INCIDENTS FROM CONCENTRATED LEAK EROSION
2.3. FAILURES AND INCIDENTS FROM BACKWARD EROSION AND GLOBAL
BACKWARD EROSION
2.5. FAILURES AND INCIDENTS FROM SUFFUSION
2.6. FAILURE PREVENTED BY ‘SOME-’ AND ‘EXCESSIVE-’ EROSION FILTER
AND FILL MATERIALS IN EXISTING DAMS
3. INVESTIGATIONS
3.1 FUNDAMENTALS OF INTERNAL EROSION INVESTIGATIONS
3.2 DRILLING FOR COMPLETE GRANULAR SAMPLES BELOW WATER TABLE
3.3 LEAKAGE DETECTION: DIRECT METHOD
3.4 LEAKAGE DETECTION: GEOPHYSICAL METHODS
3.5 IN-SITU PERMEABILITY AND VELOCITY
4. LABORATORY TESTS
4.1 INTRODUCTION
4.2 CONCENTRATED LEAK EROSION: TESTS TO DETERMINE CRITICAL SHEAR STRESS (TC) AND COEFFICIENT OF EROSION (CE)
4.3 SUFFUSION TESTS
4.4 CONTACT EROSION TESTS
4.5 TESTS ON PERMEABILITY, ERODIBILITY AND FILTERING CAPABILITY OF FILLS AND FILTERS
4.6 CRACK EROSION TEST (CRET)
5. REMEDIATION
5.1 INTRODUCTION
5.2 REMEDIATION TO RESIST CONCENTRATED LEAK EROSION
5.3 REMEDIATION TO RESIST BACKWARD EROSION
5.4 REMEDIATION TO RESIST CONTACT EROSION
5.5 REMEDIATION TO RESIST SUFFUSION
6. SURVEILLANCE
6.1 SURVEILLANCE IN RELATION TO INTERNAL EROSION
6.2 LONG-TERM SURVEILLANCE AND MONITORING
6.3 PIEZOMETERS, PORE PRESSURES AND HYDRAULIC GRADIENTS
6.4 LEAKAGE DETECTION
7. REFERENCES
Biography
The Commission Internationale des Grands Barrages (CIGB) / International Commission on Large Dams (ICOLD) is a non-governmental International Organization which provides a forum for the exchange of knowledge and experience in dam engineering.
The Organization leads the profession in ensuring that dams are built safely, efficiently, economically, and without detrimental effects on the environment. Its original aim was to encourage advances in the planning, design, construction, operation, and maintenance of large dams and their associated civil works, by collecting and disseminating relevant information and by studying related technical questions.
Since the late sixties, focus was put on subjects of current concern such as dam safety, monitoring of performance, reanalysis of older dams and spillways, effects of ageing and environmental impact. More recently, new subjects include cost studies at the planning and construction stages, harnessing international rivers, information for the public at large, and financing.
