Creating and Troubleshooting HEC-RAS Unsteady Flow Bridge Models in 1-D

Learn how to create a 1-D unsteady flow bridge model using HEC-RAS.

1 PDH / 0.1 CEU

HEC-RAS is a rather complicated 1-Dimensional (1-D) and 2-D hydraulics program that can be easily put together but also easily—and unknowingly—misused. The most common mistakes we see are related to bridge modeling. Although 2-D models are getting popular, 1-D models are still the most prevalent hydraulic models.

Join us for this educational webinar as prolific speaker Dr. David T. Williams (who has taught HEC-RAS and bridge hydraulics to the Federal Highway Administration as well as state and local departments of transportation) presents information on how to create a 1-D unsteady flow bridge model using HEC-RAS. Programming Note: Since most HEC-RAS models are still performed in 1-D, this course will concentrate on only 1-D unsteady flow bridge applications.

We will first do a quick review of setting up a basic bridge model and the proper placement of cross sections within an HEC-RAS model to simulate the hydraulic effects of a bridge. We will also detail how some of the input parameters should be determined and provide insight on how to use ineffective flow areas for optimum stability and accuracy.

Additionally, Dr. Williams will present a precise procedure on how to troubleshoot problems related to 1-D bridge modeling under unsteady flow conditions. Although concentrating on 1-D bridge models, much of the presentation material is applicable to 2-D unsteady flow modeling since even in a 2-D model the water surface immediately upstream and downstream of a bridge is still 1-D.

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

More HEC content from Dr. Williams:


Learning Objectives 

  • Review cross section creation and placement for bridge modeling
  • Obtain additional information specific to unsteady flow modeling
  • Examine the features of the Hydraulic Property Table with suggested inputs
  • Learn various ways to emulate ineffective flow areas and their pros and cons
  • Receive a suggested methodology for troubleshooting unstable 1-D HEC-RAS unsteady flow bridge models

* Presentations are scheduled for approximately 1 hour with a 15-20 minute question and answer session to follow. Presentation may exceed scheduled time.
* Each state and certification agency has different requirements; it is your responsibility to know what they are. Note that 1 PDH = 0.1 CEU.
* Purchase of this course allows you access to the presentation(s) for 6 months from the order date.

About Instructors

David T. Williams

President, DTW and Associates

Not Enrolled

Course Includes

  • 1 Lesson
  • 1 Quiz
  • Course Certificate