Optimum Design of Large Sewer Networks

Abstract

A linear programming, diameter discretization, heuristic approach is presented for the optimum design of large gravity sewer networks. The mathematical model contains a nonlinear convex function relating pipeline diameter and slope, which is approximated by piecewise linear segments. This approach uses a modified Hazen‐Williams hydraulic model at part‐full flow conditions, along with a newly developed universal expression to determine the coefficient of roughness. Moreover, the hydraulic formulation contains a regression equation to determine Darcy's friction factor based on the depth of flow in the pipe. The developed model has been extensively and successfully used to design several large sewer networks.