DESIGN OF BASAL REINFORCED EMBANKMENTS SUPPORTED BY GEOTHERMAL ENERGY PILES

Abstract

TThis paper compares the optimal design of embankments reinforced at the base with geosynthetics and supported by geothermal piles and non-geothermal piles using optimization. An optimization model was created to complete this analysis. The model is based on the fabrication cost of the structure, which consists of various materials such as geosynthetics, gravel fill, concrete and steel reinforcement. It was subjected to the limit state and serviceability conditions according to the Eurocode design rules and recommendations for the analysis of conventional and geothermal piles, taking into account geotechnical, structural and settlement constraints. To consider all limit states for embankment along with the piles and geosynthetic, the most important analyses were performed: Stresses in the geosynthetic reinforcement, bearing resistance of the pile, group resistance of the pile, pile group extent, vertical load transfer, lateral sliding, strain/stiffness of the geosynthetic reinforcement, double shear capacity/punching, and the geometric constraints recommended based on the design experience gained from the past project. The optimization model developed in this paper was applied to an example with selected design parameters to demonstrate the usefulness of the optimization model. The results show that the correct determination of the structure geometry, pile dimensions and geosynthetics leads to a significant cost reduction. The construction of geothermal piles for piled embankments support is very economical due to the low vertical load on the piles, if there is a possibility of using energy in the surrounding buildings.