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Workshops - HecRAS

Synopsis

This course instructs the trainee in the use of the Corps of Engineers water surface profile analysis program HecRAS.  The program was developed by the Hydrologic Engineering Center in Davis CA, with "RAS" standing for "River Analysis System".  HecRAS is a one-dimensional hydraulic model which can be employed to compute water surface profiles for subcritical or supercritical flow or both.  Steady flow and unsteady flow analyses may be obtained.  The program is capable of modeling almost any physical scenario of a river system, including bridges and culverts, weirs and drop structures, levees, energy dissipation structures, pump stations, off-channel storage areas, and dam breaks, as well as channel networks involving split flows and junctions.  It can be used to design streambank protection measures such as riprap or stream barbs, or scour prevention at bridge piers and abutments.

The course covers not only the operation of the software tool, but also the basic physics and hydraulics that the program is based upon.  For example, the concepts of energy, mass, and momentum conservation are discussed, as well as Bernoulli's and Manning's equations, orifice flow, and weir flow.  Information about how to obtain important field data, such as roughness coefficients and cross-section surveys is discussed.

The course is usually offered as either Basic or Advanced, with the latter generally tailored to the specific needs of the hosting NRCS state office. 

Objectives 

  • Upon completion of this workshop, the participants will be able to:
  • Calculate water surface profiles in natural rivers and canals
  • Model river structures such as bridges, culverts, weirs, and drops
  • Determine Manning's roughness coefficients and other survey data
  • Critically examine output, troubleshoot, and make model adjustments

Prerequisites 

Generally, a degree in Civil or Agricultural Engineering is recommended, training in fluid mechanics, surveying, physics, and good computer skills. 

Duration 

24 class hours, expandable to 32 hours. 

Target Audience

Field engineers and state hydraulic engineers involved river analysis and design.