HEC RAS - One Dimensional (Basic)
This is a refresher and primer for one-dimensional (Basic) HEC RAS or open channel hydraulics. Much more information is included in the course description.
Description
- Refresher/Primer on 1D open-channel hydraulics:
- Context and Governing Equations
- Hydraulic Section Properties
- Steady vs Unsteady flow
- Uniform vs Varied flow
- Gradually Varied Flow vs Rapidly Varied Flow
- Subcritical vs Supercritical flow
- Energy Equation
- Manning’s Equation
- Limitations of HEC-RAS 1D steady-state model
- Step-backwater calculations
- Cross-section layout
- Manning’s roughness
- RASMapper Example Model Walkthrough
- Gathering data for the new model:
- Existing hydraulic modeling
- Effective FEMA Flood zone
- Terrain data
- Aerial imagery
- Design Flow Criteria
- ADT
- Estimating Flow data
- Boundary conditions
- Manning’s n roughness values
- Gathering data for the new model:
- Creating and adding geometry data to HEC-RAS
- Determining downstream study limit
- Cross-section layout
- Stream centerline, overbank flow lines, and bank station lines
- Inputting the bridge geometry
- Determining modeling parameters
- Determining ineffective flow areas
- Bridge Hydraulics Overview
- Bridge hydraulic computations in HEC-RAS
- Running HEC-RAS and Reviewing Results
- Review Cross-sections
- Overtopping
- Ineffectives
- Review Cross-sections
- Review Modeling Parameters
- Boundary Conditions
- Manning’s roughness
- Bank Stations
- Iterative Bridge Modeling Solution
- Adjusting based on new b/B values
- Review Profiles
- Check reach lengths
- Investigate Critical Depths
- Crossing profiles
- Adverse water surface slopes
- Review Summary of errors, warnings, and notes
- Review Summary and Detailed Output Tables
- Setting up and using RASMapper
- Set Coordinate System
- Bring in aerial imagery
- Create Terrain
- Generating and Viewing Results
- Alternative Geometry Pre-Processors for HEC-RAS
- ArcGIS/HEC-GeoRS