Optimum Design of Reinforced Concrete Box Culvert by Using Deterministic Approach

Abstract

An optimum safe design is achieved for a reinforced concrete box culvert considering hydraulic, geotechnical and structural requirements and prices. To reach this intention, an optimization technique methodology is applied in estimation a safe design with a minimum price. The non-linear constrained optimization problem is generally expressed in terms of an objective function and constraints. Eleven design variables and forty constraint equations were employed in this work, with the total price of reinforced concrete box culvert as the objective function. The solution is obtained by means of developed computer software written in Visual BASIC. The computer software considers the Sequential Unconstrained Minimization Technique (SUMT), which is one of non-linear optimization techniques. In order to evaluate the influence of the input parameters on the box culvert design, the optimization program has been modified. The input design parameters are the discharge, head loss, length, entrance loss coefficient, Manning’s roughness coefficient, angle of internal friction of soil, compressive strength of concrete, yield strength of steel, unit price of concrete, unit price of excavation, unit price of filling and unit price of steel. A parametric study is formed to examine the influence and significance of each input design parameter on the total price of box culvert.