Minimum cost design of lined canal sections

Though the minimum area section is generally adopted for lined canals, it is not the best section as it does not involve lining cost, and the cost of earthwork which varies with the excavation depth. On account of complexities of analysis, the minimum cost design of lined canal sections has not been attempted as yet. In this investigation, explicit equations and section shape coefficients for the design variables of minimum cost lined canal sections for triangular, rectangular, trapezoidal, and circular shapes have been obtained by applying the nonlinear optimization technique. Application of the proposed design equations along with the tabulated section shape coefficients results directly in the optimal dimensions of a lined canal without going through the conventional trial and error method of canal design. The optimal cost equation along with the corresponding section shape coefficients is useful during the planning of a canal project.