Optimum Design of Lined Channel Sections

Abstract

The channel design problem can be treated as an optimization problem in which the objective function is minimization of construction cost. In this definition, the optimum values of section variables, i.e. side slope, bottom width, flow depth and radius, can be computed by minimizing the total cost subjected to a hydraulic flow constraint formula, i.e. the Manning’s equation. In a general scope, the total cost comprises lining, earthwork cost and the additional excavation cost accounting for the depth of earthwork under the ground surface. In this paper, a novel optimization technique, invariably called the Modified Honey Bee Mating Optimization (MHBMO) algorithm, was utilized to solved the defined design problem. By investigation of the affection of different cost values on the optimal results, a new explicit model for common channel shapes, i.e. triangular, rectangular, trapezoidal and circular, was proposed utilizing the MHBMO algorithm to directly design the channel cross sections. The proposed model was compared to the present models in literature using four design examples. The results demonstrate that, despite of simplicity of the new model, it achieves more precise values than the present models for all common channel shapes.