Course 3

Experimental Research and Modelling of Embankment Dams

(LNEC Library)

About the Course

Embankment dams are complex structures consisting of several types of geotechnical materials, having complex interactions and loading conditions. This course covers some of the most important aspects of the experimental research and modelling of embankment dams, such as: internal erosion, discrete element modelling of rockfill behaviour, characterization and modelling of soil and rockfill mixtures and dam behaviour assessment using monitoring data.

The first module of the course will address the types of internal erosion that may arise in embankment dams, and how results from laboratory tests can improve the knowledge about each phase of the internal erosion process, leading to dam failure.

The second module will introduce the mechanics of rockfill materials and will present the Discrete Element Method (DEM), as well as its ultimate goal of obtaining parameters used in continuum numerical models.

In the third module, due to a considerable increase in the use of soil‑rockfill mixtures (SRM) in embankments of high dams and other structures, a selection of the most important parameters regarding the behaviour of SRM are introduced. Another important objective is to address constitutive models capable of incorporate the most relevant aspects of the behaviour of these materials.

In the last module, the fundaments of the statistical models, based on monitoring data, are presented and some case studies are explained, providing a reference to the application of these concepts in dam safety evaluations and risk analyses.

Speakers

Laura Caldeira is Head of the Geotechnical Department of the National Laboratory for Civil Engineering and Principal Research Officer at LNEC. She has an extensive experience with consultation for design, construction and safety evaluation of embankment dams and development and practical application of risk-informed approaches to dam safety management. She was President of Geotechnical Portuguese Society, a member of ICOLD Dam Safety Committee, the Portuguese Dam Safety Commission and the Portuguese Commission for the Revision of the Dam Safety Code and Norms.

João Marcelino is a Civil Engineer, Senior Research Officer with Habilitation and Head of the Geotechnics of Hydraulic Works Unit, of the Geotechnics Department of LNEC, PhD (FEUP, Oporto, 1996) with about 30 years of experience in embankment dams modelling, monitoring and safety control.

João Portugal is a Civil Engineer, Research Officer, of the Geotechnics of Hydraulic Works Unit, of the Geotechnics Department of LNEC, PhD (IST, Lisbon, 1999) in Civil Engineering, with about 30 years of experience in embankment dams monitoring and safety control.

Ricardo Correia dos Santos is a Civil Engineer and Researcher of the Geotechnics of Hydraulic Works Unit, of the Geotechnical Dpt of LNEC, and PhD (IST, Lisbon, 2014) in Civil Engineering. Since 2004, he has experience in Embankment Dams Engineering, namely, with regard to dams safety due to internal erosion threats.

Andrea Brito is a Civil Engineer, Postdoctoral Research Fellow, of the Geotechnics of Hydraulic Works Unit, of the Geotechnics Department of LNEC, PhD (IST, Lisbon, 2015) in Civil Engineering, with about 15 years of experience in embankment dams monitoring and safety control.

João Manso is a Civil Engineer, Postdoctoral Research Fellow of the Geotechnics of Hydraulic Works Unit, of the Geotechnics Department of LNEC, PhD (IST, Lisbon, 2017) in Civil Engineering, with about 12 years of experience in numerical modelling (both continuous and discrete), embankment dams monitoring and its safety control.

Final Programme

9:00 - Welcome remarks (Laura Caldeira)

9:15 - How laboratory testing can aid in the identification of threats in each phase of the internal erosion process (R. Correia dos Santos)

    • Definition of the types of internal erosion that may arise in embankment dams, and the sequence of events that can lead to dam failure
    • Description of some laboratory tests on filtering and internal erosion of soils
    • Characterisation of how to evaluate the potential of occurring each phase of the internal erosion process, based on the results from the laboratory tests

11:00 - Coffee break

11:30 - An Introduction to the Discrete Element Method (João Manso)

    • Brief description of the background and definition of Discrete Element Method
    • Modelling approaches: continuum and discrete
    • Material Calibration
    • Statistical analysis of experimental tests
    • Examples and case studies

13:00 - Lunch

14:00 - Use of Soil-rockfill Mixtures in embankment dams (Andrea Brito and Laura Caldeira)

    • Review of some embankments with soil-rockfill mixtures
    • Description of construction techniques for soil-rockfill mixtures
    • Hydro-mechanical characterization of soil-rockfill mixtures
    • Modelling of soil-rockfill mixtures
    • Numerical analysis of a dam with soil-rockfill mixtures

16:00 - Coffee break

16:30 - Dam behaviour assessment using monitoring data (João Marcelino and João Portugal)

    • Monitoring of dams
    • Conceptual models
    • Statistical models
    • Examples