An optimization model for urban sewer system hydraulic design

• Published in: Journal of the Chinese Institute of Engineers Vol. 30; no. 1; pp. 31 - 42
• Main Authors: Weng, Huahn-Tyng, Liaw, Shu-Liang
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2007
• Subjects: a 0-1 mixed integer programming; Bounded Implicit Enumeration; commercial standard diameter; multi-stage multi-option system
• ISSN: 0253-3839; 2158-7299
• DOI: 10.1080/02533839.2007.9671228

A gravity sewer system is a multi-stage multi-option system composed of a series of pipes and manholes. For each sewer pipe stage, there are several different commercial pipe sizes available as options. A comparison of optimum design alternatives thus becomes very complex, due to the number of combinations of commercial pipe sizes and slopes that must be evaluated in terms of hydraulics. Therefore, a Sewer System Optimization Model (SSOM) for hydraulic designs is developed. The model uses 0-1 mixed integer programming (MIP) and an efficient screening algorithm, the bounded implicit enumeration (BIE) algorithm. The first consideration is to provide a set of design variables for urban sewer system design problems corresponding to the various construction modes. A 73-manhole open-cut method model is tested. The results indicate that this approach is more cost-effective than other previously developed optimization models and techniques. As well, a practical sewer system construction case in Taipei is selected, to compare with the traditional design approach. The obtained design results show that the SSOM program, based on tunnel jacking construction, can be used for this practical design. It has the effect of saving 12% on piping and 40% on pumping heads during construction.