Steady Flow HEC-RAS

The objective of the course is to enable the participants to perform water surface profile computations, for steady flow hydraulic analyses, using computer program HEC-RAS in a sound and effective manner.

This course teaches the concepts of open channel flow concepts, hydraulic model data requirements, HEC-RAS input requirements, laying out cross sections for 1D hydraulic modeling, application of bridge and culvert routines, calibration of a steady flow hydraulics model, floodway determination, an overview of Optional capabilities, and output analysis. The HEC-RAS software will be included in lectures and workshops. Participants have an opportunity to prepare input and analyze output during workshops.

M:\_Projects\HEC-RAS\Classes\2023\PROSPECT #114 - Steady Flow

Modeling River Hydraulics with HEC-RAS

Topic	Video	Material
Steady Flow Overview, Applications, and Components (L1.1) Case studies (why steady flow is important). Model selection between 1D and 2D. Steps in setting up a model and RAS file management.	Video (31m)
Geometric Data Requirements for Water Surface Profile Calculations (L1.2) Study limit determination; defining the river system schematic; cross section geometry and locations; optional cross section properties: ineffective flow areas, levees, and blocked obstructions; defining the reach lengths between sections; energy loss coefficients; stream junction data.	Video (66m)
Laying out Cross Sections Workshop (W1.3)
Geometric Data Development with RAS Mapper (L1.4) This lecture will go through developing an HEC-RAS terrain model, river network, and entering and editing data tools in RAS Mapper.	Video (44 min)
Developing HEC-RAS Geometry Workshop (W1.5)	Students will create a new HEC-RAS terrain layer, layout the model schematic and cross sections.
Water Surface Profile Calculation (L1.6)	Classifications of open channel flow; velocity distribution in a channel; energy principles; cross section subdivision for conveyance calculations; friction loss equations; contraction and expansion losses; computational procedure; critical depth determination; and applications of the momentum equation

Developing a Model and HEC-RAS Bridge Analysis

	Topic	Objective
L2.1	Steady Flow Data Requirements	Discussions about flow regime; boundary conditions; discharge information
L2.2	Resistance to Flow	Discussions about Manning’s equation; uniform flow equations; methods for computing n values: tables, pictures, and equations; examples of calibrated n values for various streams.
L2.3	Viewing Results	Viewing results; cross section plots; profile plot; X-Y-Z plot; summary tables; errors, warnings, and notes, and floodplain maps in RAS Mapper.
W2.4	1D Model Development and Evaluating Results	Students will learn to create an HEC-RAS model, complete geometry, enter flow data, perform the hydraulic computations, and view results
L2.5	Bridge Hydraulics for 1D Modeling	Nature of flow through bridges; components of bridge losses; cross-section locations; defining ineffective flow areas; contraction and expansion losses.
L2.6	Bridge Modeling Approaches in HEC-RAS	Available approaches to bridge loss computations within HEC-RAS; selecting the appropriate bridge modeling approach for various situations of low flow bridge hydraulics; selecting the appropriate bridge modeling approach for various situations under high flow bridge hydraulics.
D2.7	Application of HEC-RAS to Bridge Hydraulics	Demonstration of how to enter and edit bridge data; defining a bridge modeling approach; bridge modeling options; pertinent bridge output.
W2.8	Bridge Development Workshop	Students will learn to enter and edit bridge data for performing bridge hydraulic computations.

HEC-RAS Bridge and Culvert Hydraulics

	Topic	Objective
W3.1	Bridge Analysis Workshop	Students will focus on solving the bridge solution for mass conservation.
L3.2	Overview of Culvert Hydraulics	Definition of terms; input requirements: cross section locations, ineffective flow areas, expansion and contraction coefficients; inlet control; outlet control; solution logic
D3.3	Application of HEC-RAS to Culvert Hydraulics	Demonstration of how to enter and edit culvert data; culvert modeling options; review of culvert output
W3.4	Culvert Analysis	Students will learn how to enter and edit culvert data, perform culvert hydraulic computations; and review pertinent output
L3.5	Inundation Map Tools	Students will learn to use RAS Mapper tools for improving inundation mapping
L3.6	Overview of Optional Capabilities	Cross section interpolation; mixed flow regime calculations; flow distribution calculations; lateral structures and optimization; Inline Weirs and Gated Spillways.

Model Calibration, Optimal Capabilities and Floodway Determination

	Topic	Objective
L4.1	Calibrating a Steady Flow Model	Students will learn what data is required for model calibration and how to modify Manning’s n values to calibrate the model to observed data.
W4.2	Model Calibration Workshop	Students will learn how to modify Manning’s n values to calibrate the model to observed data
L4.3	Troubleshooting with HEC-RAS	This lecture will provide students with information on how to interpret HEC-RAS output messages (errors, warnings, and notes); diagnose common data input mistakes; and how to use the HEC-RAS Log File to understand more about the computations and possible problems
W4.4	Troubleshooting Workshop	This workshop will teach students how to analyze the HEC-RAS output in order to detect common hydraulic modeling problems.

HEC-RAS Trouble Shooting and Output Analysis

	Topic	Objective	Material
L5.1	Floodplain and Floodway Determination	Floodway definitions; general guidelines; computer procedures; program input requirements for floodway calculations; available output.
W5.2	Floodway Determination	Students will learn how to enter and edit encroachment data and perform a floodway analysis.