HY8:HY-8

HY-8 Versions 3.1, 4.1, and 6.0 were developed by Philip L. Thompson and were provided to the Federal Highway Administration (FHWA) for distribution. HY-8 Versions 1.1, 2.1, and 3.0 were produced by the Pennsylvania State University in cooperation with FHWA. The HY-8 Versions 3.0 and earlier versions were sponsored by the Rural Technical Assistance Program (RTAP) of the National Highway Institute under Project 18B administered by the Pennsylvania Department of Transportation. Version 6.0 (Energy, HYD and Route) was produced by GKY and Associates under contract with FHWA. Version 7.0 of HY-8 has been developed by Brigham Young University in cooperation with FHWA. The primary purpose of the first Windows compatible version is to provide graphical user interface (GUI) for the same hydraulic calculations performed in version 6.1 of HY-8. In the course of the development all program functions have been translated to C++. Several minor bugs in version 6.1 have been corrected in HY-8 version 7.0.

HY-8 automated the design methods described in HDS No. 5, "Hydraulic Design of Highway Culverts" dated September 1985, FHWA-IP-85-15; HEC No. 14. Version 6.1 is the last version of the MS-DOS program that was distributed. Future versions will likely incorporate revisions and updates to HEC-14, which was the basis for HY-8 energy dissipation. Hydrologic calculations are available in the Watershed Modeling System (WMS). Publications on the HY-8 version 7.0 theory are found in HDS-5, which is packaged with the program.

The software has been structured to be self-contained and requires no user's manual. This facilitates its use by roadway design squads. However, the knowledgeable hydraulic engineer will also find the software package useful because it contains advanced features. This help file provides necessary instructions and clarifications.

Related Topics

Introduction

• Introduction
• HY-8 Getting Started
• Differences from DOS HY-8
• Limitations

Building a Project

• Building a Project
• Locate Project
• Culvert Crossing Data
• Run Analysis
• Report Generation

Crossings Data

• Crossings
• Discharge Data

Roadway Data

• Roadway Data
• Roadway Profile

Tailwater Data

• Tailwater Data
• Channel Shape
• Rating Curve
• Constant Tailwater Elevation

Irregular Channel

• Irregular Channel
• Irregular Channel Error

Culvert Data

Culvert Data

• Culvert Data
• Shapes
• Material
• Plastic Pipe Materials
• Concrete Open-Bottom Arch
• Inlet Type
• Inlet Edge Conditions
• Inlet Depression
• Embedment Depth

Site Data

• Site Data Input Option
• Culvert Invert Data
• Embankment Toe Data

Analysis

• Project Units
• Roadway Overtopping

Head Water Computations

Inlet Control

• Inlet Control Computations
• Polynomial Generation
• Polynomial Coefficients

Outlet Control

• Outlet Control Computations
• Exit Loss Options

Tables and Plots

• Tables and Plots
• Crossing Summary
• Culvert Summary
• Water Surface Profiles
• Improved Inlet
• Customized
• Controlling Plot Display Options

Energy Dissipation

• Energy Dissipators

Scour Hole Geometry

• Scour Hole Geometry

Internal Energy Dissipators

• Increased Resistance in Box Culverts
• Increased Resistance in Circular Culverts
• Tumbling Flow in Box Culverts
• Tumbling Flow in Circular Culverts
• USBR Type IX Baffled Apron

External Dissipators

Drop Structures

• Drop Structures
• Box Inlet Drop Structure
• Straight Drop Structure

Stilling Basin

• Stilling Basins
• USBR Type III Stilling Basin
• USBR Type IV Stilling Basin
• Saint Anthony Falls (SAF Stilling Basin)

Streambed level Structures

• Streambed Level Structures
• Colorado State University (CSU) Rigid Boundary Basin
• Riprap Basin and Apron
• Contra Costa Basin
• Hook Basin
• USBR Type VI Impact Basin