Analyses of permanent cantilever pile system with finite element method

With advancements in construction technology, designing and constructing structures that were previously impossible have become feasible. Especially progress in excavation support structures has significantly contributed to increasing excavation depths and ensuring a safe construction process. Today, one of the fundamental topics in geotechnical engineering is the design of excavation support structures for deep excavations. In this study, a case analysis was conducted using borehole data and soil investigation reports collected from various areas in the Esenyurt district of Istanbul. Soil conditions were idealized using collected data and established correlations from the literature. Initially, preliminary dimensioning and parameter calculations for a single-row bored pile were performed. Throughout the analyses, different pile diameters were considered: 120 cm for single-row piles, and 65 cm and 80 cm for double-row piles. Analyses were individually conducted for excavation depths ranging between 18 and 25 meters for each pile diameter. The proposed excavation support structure was analyzed using PLAXIS (Finite Element for Soil and Rock Analysis) software, capable of solving stability and deformation problems through finite element methods. As a result, five different reinforced concrete cross-section designs and corresponding cost analyses were performed on models that optimally meet safety criteria. The resulting data were evaluated in terms of safety, applicability, and cost effectiveness. Based on these evaluations, models meeting minimum safety standards and offering cost advantages compared to others were recommended.