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Instructor:  David T. Williams, P.E., PH, CFM, BC.WRE, F.ASCE

Course Length: 90 minutes

Purpose and Background

This webinar is the second of a two part presentation on HEC-RAS Culvert Modeling.

HEC-RAS is a rather complicated 1-D and 2-D hydraulics program that can be easily put together but also easily—and unknowingly—misused. The most common hydraulic structures modeled are related to culvert modeling.

Join Dr. David T. Williams (who has taught HEC-RAS and bridge and culvert hydraulics to the Federal Highway Administration as well as state and local departments of transportation) present examples of common geometric mistakes and misunderstandings of culvert parameters using HEC-RAS that could have potentially significant effects on a culvert project’s hydraulic results. Note: Since most HEC-RAS models are still performed in 1-D, this course will concentrate on only 1-D culvert applications; however, most of the presentation is applicable to 2-D HEC-RAS modeling.

Part 1 will discuss common 1-D geometric misrepresentations, the proper placement of cross sections within an HEC-RAS model, and initial coefficients to use to properly simulate the hydraulic effects of a culvert.

Part 2 will detail how some of the input parameters should be refined, where within the 1-D model they should be placed, and a step-by-step creation of an HEC-RAS culvert model with a real culvert.

Course material is be based upon Dr. Williams’ review of submitted models, his discussions with experienced users, his blogs on hydraulic and culvert modeling topics, and his HEC-RAS Steady and Unsteady course lecture notes.

Benefits and Learning Outcomes

Upon completion of this course, you will be able to:

• Explain refinement of expansion and contraction coefficients
• Determine weir coefficients
• Recognize placement refinement of the four cross sections to model a culvert
• List the details of a culvert that are required inputs to HEC-RAS
• Apply the step-by-step creation of a culvert model in HEC-RAS
• Check for flow consistency of a culvert model
• Improve on the first estimation of expansion and contraction coefficients, and the distances of the cross sections upstream and downstream of the culvert.
• Construct a HEC-RAS culvert model
• Apply the procedure to select the proper FHWA culvert coefficients for your culvert.

Assessment of Learning Outcomes

Students' achievement of the learning outcomes will be assessed via a short post-assessment (true-false, multiple choice and fill in the blank questions).

Who should attend?

• Water resources engineers
• HEC-RAS modelers
• Water resources planners
• Project Engineers
• Project Managers
• Staff Engineers
• Q/A and Q/C reviewers

Outline

• Expansion Ratio (ER) – Refine with Equations Iterative Procedure to Determine Le
• Selecting a Value for the Expansion Coefficient
• Selecting a Value for the Contraction Coefficient
• Culvert Shapes and Sizes Available in HEC-RAS
• Manning’s Roughness Coefficient
• FHWA Full Flow Equations
• Entrance Loss Coefficient
• Exit Loss Coefficient
• Flow Analysis for Culverts within HEC-RAS
• FHWA Chart and Scale Numbers
• Examples of Inlet Types of Culverts
• FHWA Chart and Scale Numbers
• Example - Typical Culvert Design Form
• Specific Information for Culvert Example

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 on-line post-test and receive a passing score of 70% or higher within 1 year of purchasing the course.

How do I convert CEUs to PDHs?

1.0 CEU = 10 PDHs [Example: 0.1 CEU = 1 PDH]