Wormhole Culverts

This is one of the coolest workaround ideas for HEC-RAS that I’ve seen in a long time.  One of my joys in teaching HEC-RAS to professionals and students around the world is seeing the clever ways that people use and apply HEC-RAS.  Whether in a training class, giving technical support, or just simply over discussions […]

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Bridges in 2D Areas-Important Update!

***Update:  I received a few very important comments about this post that I want to share.   First, and this is very important:  These methods are not meant to be used to do any kind of detailed bridge design or bridge scour analysis (contraction, abutment, or pier scour).  The methods I present in this post are […]

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Using User-Defined Curves for Gates

HEC-RAS allows for four different gate types that will compute the stage-discharge relationship of that gate for you based on the physical size/shape of the gate and a few empirical coefficients:  Sluice Gates, Radial Gates, Overflow Gates (closed top) and Overflow Gates (open air).  However, sometimes the built-in gate types don’t quite fit the gate […]

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Lateral Structure Coefficients

Lateral structures can be used in HEC-RAS to transfer flow from a river/reach to a storage area, or to another river/reach.  With the coming release of HEC-RAS with 2D capabilities (estimated beta release January/February 2014), you’ll be able to hook a river/reach to a 2-D area using a lateral structure. Although its primary function in […]

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Advanced Rules for Unsteady Flow

This is a great presentation put together by Mr. Steven Piper of the Hydrologic Engineering Center that discusses in detail the use of “Rules” at inline structures.  Dr. Michael Gee forwarded this presentation to me after seeing some discussion on the forum about the use of Rules for inline structures.  Thanks for the suggestion Dr. […]

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Overflow Gates

In modeling irrigation canals in HEC-RAS, a typical structure that is encountered is a check gate. Check gates are designed to back the water up behind them in an effort to keep the water level immediately upstream of these gates at a constant level. As the flow rates change in the canal, the gate openings […]

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Bridge on a Spillway

Written by Chris Goodell, P.E., D. WRE | WEST ConsultantsCopyright © RASModel.com. 2010. All rights reserved.I just got an interesting question. How do I model a bridge that has a spillway just downstream of it? Here’s an example of what I’m talking about: As I see it, there are a three ways to approach this. […]

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