A Sewer System Optimization Hydraulic Design Model

In this study, a branched gravity sewer system design problem is treated as a serial multi-stage multi-option system, composed of a series of sewer pipes and manholes. An optimal hydraulic design is made possible by selecting from the several different commercial pipe sizes available as options for each sewer pipe stage, which are determined by a detailed hydraulic analysis, the goal of which is to meet the design criteria at a minimal cost. In this work a 0-1 mixed integer optimization model is adopted, which uses an efficient screening algorithm, the intelligent Bounded Implicit Enumeration (BIE) algorithm, to develop the Sewer System Optimization Model (SSOM) which in turn can be used to find the optimal hydraulic design. In the modeling one also has to provide a set of design variables (corresponding to the various construction modes) for urban sewer system design problems. This approach can lead to obtaining design results that compared with other optimization models and techniques are more practical and cost-effective. Finally, a case study of a 73-manhole project is conducted to verity the optimal hydraulic design found by the SSOM model.