Optimal design of piled embankments with basal reinforcement

Abstract

The paper presents an optimal design for piled embankments with basal reinforcement based on multi-parametric mixed-integer non-linear programming (MINLP) optimization. For this purpose, an optimization model, PILEM, was developed. The model comprises an accurate objective function of the structure's production cost subjected to design, resistance, stiffness and settlement constraints. The intention of the model was to satisfy the requirements of the ultimate and serviceability limit states, according to the required specifications and recommendations. The optimal design of piled embankments with basal reinforcement was investigated to determine the design parameters that have a significant impact on a structure's cost. A series of MINLP optimizations were thus executed over a wide range of various parameters: different thicknesses of soft stratum, different geosynthetic strengths, alternative discrete cross-sections and different bearing capacities of deeper stable soil stratum. The results show that the proper selection of geosynthetics leads to a significant decrease in costs. As the model was developed for general use, the optimization of piled embankments with basal reinforcement can be performed for different economic conditions and different design parameters. This study can help engineers choose piled embankments and geosynthetic reinforcements that are economical in design.