View Important Policies and System Requirements for this course
Interested in registering 5 or more engineers for a course? Contact us for information and rates.
INSTRUCTORS:
Bret Lingwall, PhD, PE, BG.GE, F.ASCE
Calvin Tohm, PhD, M.ASCE
Peter Irey, P.E.
Dennis Hanneman, PE
Bryant Robbins, PE, PhD, M.ASCE
Purpose and Background
These presentations were recorded at the Geo-Institute Web Conference 2025.
Mechanisms and Mechanics of Scour as a Singular Phenomenon (28 minutes)
This presentation examines scour as a fundamental hydraulic and geotechnical process affecting civil infrastructure. It focuses on the physical mechanisms governing soil particle detachment, transport, and erosion under flowing water. The speaker discusses how hydraulic forces, soil properties, and boundary conditions interact to initiate and propagate scour. Emphasis is placed on viewing scour as a unified phenomenon rather than a collection of isolated failure modes. Analytical and conceptual models are used to explain scour development across different structures and environments. The presentation provides a framework for understanding scour behavior applicable to bridges, foundations, and hydraulic structures.
Scour and External Erosion, New Perspectives on Influence of Material Weathering and Aging (26 minutes)
This presentation explores how material weathering and aging influence susceptibility to scour and external erosion. It examines changes in soil and rock properties over time due to chemical, physical, and environmental processes. The speaker discusses how aging affects strength, cohesion, permeability, and erosion resistance. Case studies and experimental observations are used to demonstrate differences between intact and weathered materials under hydraulic loading. The presentation highlights the importance of accounting for long-term material degradation in erosion risk assessments. These insights provide improved understanding for evaluating the performance of aging infrastructure.
Internal Erosion of Dams (26 minutes)
This presentation addresses internal erosion as a critical failure mechanism for embankment dams and levees. It reviews the primary modes of internal erosion, including concentrated leaks, contact erosion, and suffusion. The speaker explains the hydraulic and soil conditions that initiate internal erosion and allow it to progress. Monitoring techniques, design considerations, and material selection strategies are discussed to reduce erosion risk. Historical case examples are used to illustrate warning signs and failure progression. The presentation emphasizes the importance of internal erosion control in dam safety and risk management.
New Findings on Backwards Erosion Piping of Dams (29 minutes)
This presentation presents recent research findings related to backward erosion piping beneath dams and levees. It explains the initiation and progression of piping channels from downstream to upstream under seepage forces. The speaker discusses experimental results, field observations, and updated conceptual models that improve understanding of piping behavior. Key factors such as hydraulic gradients, soil gradation, and filter performance are examined. The presentation also reviews implications for design, assessment, and remediation of hydraulic structures. These findings contribute to more accurate evaluation of piping risk and improved dam safety practices.
Benefits and Learning Outcomes
Upon completion of these sessions, you will be able to:
- Explain the fundamental mechanisms and mechanics governing scour as a singular erosion phenomenon.
- Discuss how material weathering and aging affect scour resistance and external erosion processes.
- Describe the primary mechanisms and risk factors associated with internal erosion in embankment dams.
- Identify the key mechanisms and controlling factors involved in backward erosion piping of dams.
Assessment of Learning Outcomes
Learning outcomes are assessed and achieved through passing a 10 multiple-choice question post-test with at least a 70%.
Who Should Attend?
- Geotechnical Engineers
- Engineering Geologists
- Road Designers
- Practitioners
- Geosynthetic Manufacturers
- Contractors
- Graduate Students
How to Earn your CEUs/PDHs and Receive Your Certificate of Completion
To receive your certificate of completion, you will need to complete a short post-test online and receive a passing score of 70% or higher within 365 days of course purchase.
How do I convert CEUs to PDHs?
1.0 CEU = 10 PDHs [Example: 0.1 CEU = 1 PDH]