TABLE OF CONTENTS Ben Chie Yen
Department of Civil & Environmental Engineering
University of Illinois at Urbana-Champaign
Urbana, Illinois 61801
The desired level of hydraulics to solve sewer system flow problems varies, depending on the type of problem and accuracy required. The purposes of analysis of sewer hydraulic problems can be classified into two types: (1) design and (2) prediction for forecasting or operation (Table 6.1). The required hydraulic level of the latter is often higher than the former.
( a) Typical Design Problems
| Type of design | Design parameter | Known parameters | Hydro information needed | Required hydraulic level |
|---|---|---|---|---|
| Sewers | Pipe size | Network layout and sewer slope | Peak discharge, Q p for design return period | Low |
| Sewers | Pipe size and pipe slope | Network layout | Peak discharge, Q p for design return period | Low |
| Sewers | Network layout; pipe size and pipe slope | Locations of manholes and junctions | Peak discharge, Q p for design return period | Low |
| Junctions and manholes | Geometric dimensions | Joining pipe inverts | Preferably design hydrographs Q i( t) | Low to moderate |
| Sewer side weirs | Weir height and length | Sewer pipe size | Peak discharge Q p | Moderate to high |
| ( b) Flow Prediction Problems | ||||
| Real-time operation | Real-time regulation of flow | Predicted and/or just measured rainfall, network data | Hydrographs, Q( t, x i) | High |
| Performance evaluation | Simultion for evaluation of a system | Specific storm event, network data | Hydrographs, Q( t, x i) |
