LINKED SIMULATION-OPTIMIZATION MODEL FOR OPTIMUM HYDRAULIC DESIGN OF WATER RETAINING STRUCTURES CONSTRUCTED ON PERMEABLE SOILS

Hydraulic Water Retaining Structures (HWRS), such as dams, weirs and regulators are important projects and necessary for water management. Seepage analysis under HWRS substantially influences the design of HWRS. One of the biggest challenges in design of HWRS is to determine the accurate seepage characteristics with complex flow conditions, and simultaneously to find the optimum design considering safety and cost. Therefore, this study concentrates on developing a linked simulation-optimization (S-O) model for non-homogenous anisotropic soil properties. This is achieved via linking the numerical seepage simulation (Geo-Studio/SEEPW) with the Genetic Algorithm (GA) evolutionary optimization solver. Since, a direct linking of numerical model with optimization model is computationally expensive and time consuming, accurate surrogate models are integrated instead of a numerical simulation model within the S-O model. A Support vector machine (SVM) based surrogate model is linked with the optimization model to achieve the optimum hydraulic design of HWRS. The seepage characteristics of optimum design obtained by S-O are evaluated by comparing these with the numerical seepage modeling (SEEPW) solutions. The comparison, in general, shows good agreements. Accordingly, the S-O methodology is potentially applicable for providing safe, efficient and economical design of HWRS constructed on a complex seepage flow domain.