Investigation of soil pile interaction parameters in piled foundations

Piled foundation is one of the most widely used deep foundation types for important civil engineering structures such as bridges, dams, nuclear power plants. The process in which soil behavior and structure-pile behavior affect each other is explained by the phenomenon of structure-pile-soil interaction. Kinematic interaction analysis has been compulsory with the Turkish Building Earthquake Codes. In this study, soil-pile interaction is investigated by applying the calculation steps of Method III, which is one of the kinematic interaction calculation methods in the Turkish Building Earthquake Codes 2018. Analyzes are made for single pile penetrating on sand, clay and layered soils below the ground water level and pile group penetrating on clay soil. Pile diameter, pile length, pile elastic modulus and soil type are chosen as variable parameters in the models. For the pile group; β coefficients in TBEC-2018 regulation and group efficiency coefficient in FHWA (The Federal Highway Administration) regulation for weak clay soils are compared. When the results are evaluated; it is observed that pile length, pile diameter and pile elasticity modulus increase, moment values are increase. The behavior of the piles under dynamic loads is found as different than the behavior under static loads. Therefore, it is determined that only static analyzes would be insufficient in earthquake zones and dynamic structure-soil-pile interaction analyzes should be performed during the design. In addition, it is recommended that, it is necessary to identify project-specific inputs, to set parameters and analyze for each project.