Computer Application in Hydraulic Engineering-7th Edition

Table of Contents Revision History..............................................................................................................xii Foreword ........................................................................................................................xiv

CHAPTER 1 BASIC HYDRAULIC PRINCIPLES 1 1.1 General Flow Characteristics..................................................................................1 Flow Conveyance.......................................................................................................1 Area, Wetted Perimeter, and Hydraulic Radius .........................................................1 Velocity......................................................................................................................2 Steady Flow................................................................................................................3 Laminar Flow, Turbulent Flow, and Reynolds Number ............................................3 1.2 Energy .......................................................................................................................5 The Energy Principle..................................................................................................5 The Energy Equation..................................................................................................6 Hydraulic Grade.........................................................................................................6 Energy Grade .............................................................................................................7 Energy Losses and Gains ...........................................................................................7 1.3 Orifices and Weirs....................................................................................................8 Orifices.......................................................................................................................8 Weirs ........................................................................................................................10 1.4 Friction Losses........................................................................................................13 Manning’s Equation .................................................................................................14 Chézy’s (Kutter’s) Equation.....................................................................................14 .....................14 Hazen-Williams Equation ........................................................................................15 Darcy-Weisbach (Colebrook-White) Equation ........................................................15 Typical Roughness Factors ......................................................................................16 1.5 Pressure Flow .........................................................................................................17 1.6 Open-Channel Flow. ..............................................................................................18 Uniform Flow...........................................................................................................18 Specific Energy and Critical Flow ...........................................................................20 1.7 Computer Applications..........................................................................................22 1.8 FlowMaster .............................................................................................................23 1.9 Tutorial Example ...................................................................................................24 1.10 Problems .................................................................................................................27

CHAPTER 2 BASIC HYDROLOGY 35 2.1 Rainfall....................................................................................................................35 Basic Rainfall Characteristics ..................................................................................35 Return Period and Frequency...................................................................................35 Types of Rainfall Data .............................................................................................36 2.2 Rainfall Abstractions and Runoff Volume...........................................................45 Bentley In vi stitute Press Watershed Area ........................................................................................................45 Rainfall Abstractions................................................................................................45 Determining Runoff Volume....................................................................................46 Horton Infiltration Equation.....................................................................................48 Runoff Coefficient....................................................................................................49  NRCS (SCS) Curve Number Method.... ............... ................... ............... ................. .51 2.3 Computing Peak Runoff Flow Rate......................................................................56 Time of Concentration..............................................................................................56 The Rational Method................................................................................................60  NRCS (SCS) Peak Flow Estimation...... .......... ................ ................. ................. .......64 2.4 Computing Hydrographs.......................................................................................67 Creating Runoff (Effective Rainfall) Hyetographs...................................................69 Unit Hydrographs.....................................................................................................72 Discrete Convolution................................................................................................77

2.5 Problems................................................................................................................. .82

CHAPTER 3 INLETS, GRAVITY PIPING SYSTEMS, AND STORM SEWER DESIGN 89 3.1 Inlet Design Overview............................................................................................89 3.2 Gutter Sections on Grade ......................................................................................90 3.3 Inlets on Grade .......................................................................................................92 Grate Inlets on Grade ...............................................................................................92 Curb Inlets on Grade ................................................................................................93 Combination Inlets on Grade ...................................................................................95 3.4 Inlets in Sag.............................................................................................................96 3.5 Inlet Design Overview............................................................................................98 Inlet and Gutter Problems Using FlowMaster..........................................................98 Inlet and Gutter Network Problems Using StormCAD............................................99 3.6 Gradually Varied Flow ..........................................................................................99 Flow Classification.................................................................................................100 Energy Balance ......................................................................................................103 3.7 Mixed Flow Profiles .............................................................................................104 Sealing Conditions .................................................................................................104 Rapidly Varied Flow ..............................................................................................104 3.8 Storm Sewer Applications ...................................................................................105 Hydrology Model ...................................................................................................105 3.9 StormCAD ............................................................................................................106 How Can You Use StormCAD?.............................................................................107 Analysis and Design...............................................................................................107 Profiles ...................................................................................................................107 3.10 Tutorial Examples................................................................................................108 Tutorial 1 —   Design of a Network with Auto Design............................................108 Tutorial 2 —   Alternatives Analysis with Scenario Manager..................................113 Computer Applications in Hydraulic Engineering vii Tutorial 3 —   Cost Estimating ................................................................................114 3.11 Problems ...............................................................................................................116

CHAPTER 4 CULVERT HYDRAULICS 135 4.1 Culvert Systems....................................................................................................135 Culvert Hydraulics .................................................................................................136 4.2 Outlet Control Hydraulics...................................................................................136 Friction Losses .......................................................................................................138 Entrance Minor Loss ..............................................................................................138 Exit Minor Loss .....................................................................................................140 Gradually Varied Flow Analysis............................................................................140 4.3 Inlet Control Hydraulics......................................................................................140 Unsubmerged Flow ................................................................................................142 Submerged Flow ....................................................................................................142 4.4 CulvertMaster ......................................................................................................144 How Can You Use CulvertMaster?........................................................................144 4.5 Tutorial Example .................................................................................................144 4.6 Problems ...............................................................................................................147

CHAPTER 5 DETENTION POND DESIGN 153 5.1 Overview of Stormwater Detention ....................................................................153 5.2 Basic Design Considerations ...............................................................................154 Pre-Development versus Post-Development Criteria and Recurrence Frequency .154 Types and Configurations of Stormwater Detention Facilities ..............................155 5.3 Detention Pond Modeling Concepts ...................................................................156 5.4 Components of Detention Facilities ....................................................................157

Dam Embankments ................................................................................................158 Freeboard ...............................................................................................................158 Pond Bottoms and Side Slopes...............................................................................158 Outlet Structures.....................................................................................................158 Overflow Spillways................................................................................................159 5.5 Routing Data: Storage and Hydraulic Relationships........................................159 Stage versus Storage Volume.................................................................................159 Stage versus Discharge ..........................................................................................165 Composite Stage versus Discharge Relationships..................................................167 5.6 Storage Indication Method..................................................................................171 5.7 Stormwater Detention Analysis Procedure........................................................175 5.8 PondPack ..............................................................................................................180 What Is PondPack? ................................................................................................180 How Can You Use PondPack for Windows? .........................................................180 5.9 Tutorial Example .................................................................................................181 5.10 Problems ...............................................................................................................186 Bentley In viii stitute Press

CHAPTER 6 PRESSURE PIPING SYSTEMS AND WATER QUALITY ANALYSIS 195 6.1 Pressure Systems ..................................................................................................195 Water Demands ......................................................................................................195 6.2 Energy Losses .......................................................................................................197 Friction Losses .......................................................................................................197 Minor Losses..........................................................................................................198 6.3 Energy Gains  —   Pumps.......................................................................................200 Variable-Speed Pumps ...........................................................................................201 Constant Horsepower Pumps .................................................................................202 6.4 Control Valves ......................................................................................................202 Check Valves (CVs)...............................................................................................202 Flow Control Valves (FCVs) .................................................................................202 Pressure Reducing Valves (PRVs) .........................................................................202 Pressure Sustaining Valves (PSVs) ........................................................................202 Pressure Breaker Valves (PBVs)............................................................................203 Throttle Control Valves (TCVs).............................................................................203 6.5 Pipe Networks.......................................................................................................203 Conservation of Mass —   Flows and Demands ......................................................203 Conservation of Energy..........................................................................................204 6.6 Network Analysis..................................................................................................205 Steady-State Network Hydraulics ..........................................................................205 Extended-Period Simulation...................................................................................205 6.7 Water Quality Analysis........................................................................................205 Age.........................................................................................................................206 Trace.......................................................................................................................206 Constituents............................................................................................................206 Initial Conditions....................................................................................................207  Numerical Methods .......... ................. ................. ................ ................. ................. ..208 Discrete Volume Method .......................................................................................208 Time-Driven Method..............................................................................................208 6.8 Automated Optimization .....................................................................................209 Model Calibration ..................................................................................................210 System Design........................................................................................................210 6.9 WaterGEMS .........................................................................................................211 What Does WaterGEMS Do?.................................................................................211 How Can You Use WaterGEMS? ..........................................................................212 6.10 Tutorial Example..................................................................................................213

Tutorial 1 –   Three Pumps in Parallel......................................................................213 Tutorial 2 –   Water Quality .....................................................................................219 Tutorial 3 –   Pumping Costs....................................................................................228 Tutorial 4 –  Capital Cost Estimating using Darwin Designer ................................229 Computer Applications in Hydraulic Engineering ix Model Calibration using Darwin Calibrator...........................................................232 6.11 Problems ...............................................................................................................236

CHAPTER 7 SANITARY SEWER DESIGN 255 7.1 Sanitary Sewer Systems.......................................................................................255 Common Sanitary Sewer Elements........................................................................256 7.2 Loading .................................................................................................................256 Common Load Types.............................................................................................257 Sanitary Unit Loading ............................................................................................259 Extreme Flow Factors ............................................................................................261 Common Variable Peaking Factors (PF)................................................................261 Wet-Weather Loading............................................................................................263 7.3 Extended Period Simulations ..............................................................................264 Overview................................................................................................................264 Routing Overview ..................................................................................................264 Hydrologic and Hydraulic Time Steps...................................................................266 7.4 SewerCAD.............................................................................................................266 What Does SewerCAD Do?...................................................................................266 How Can You Use SewerCAD? ............................................................................267 7.5 Tutorial Examples................................................................................................268 Tutorial 1 –   Pump Size for Peak Flows..................................................................268 Tutorial 2 –   24-Hour Simulation of Dry Weather Flow.........................................274 Tutorial 3 –   Constructing a Profile.........................................................................277 Tutorial 4 –   Capital Cost Estimating......................................................................278 7.6 Problems ...............................................................................................................281

CHAPTER 8 DYNAMIC MODELING 297 8.1 Introduction..........................................................................................................297 System of Units......................................................................................................298 8.2 Dynamic Modeling ...............................................................................................299 St Venant Equations...............................................................................................299  Numerical Solution ........ ................ ................. ................. ............... ................. ......300 Initial and Boundary Conditions ............................................................................301 8.3 Hydrograph Routing Effects ...............................................................................303 8.4 Simplified Routing Models ..................................................................................303 Diffusion Wave ......................................................................................................304 Kinematic Wave.....................................................................................................305 Muskingum Routing...............................................................................................305 Muskingum-Cunge Method ...................................................................................306 8.5 Why Use an Unsteady Flow Model?...................................................................307 8.6 SewerGEMS .........................................................................................................308 What Does SewerGEMS Do? ................................................................................308 Bentley In x stitute Press How Can You Use SewerGEMS?..........................................................................309 8.7 Tutorial Examples................................................................................................310 Tutorial 1 –   Stormwater Conveyance System Performance...................................310 Tutorial 2 –  Pump Stations and Force Mains in a Sanitary Sewer System.............318 8.8 Problems................................................................................................................325