# Numerical Investigation of the Pile-Soil Interaction Problem under Dynamic Loads
It was observed that when the inclined pile inclination angle was 5\({}^{\circ}\), the deformation resistance of the inclined pile group foundation was improved, and the load distribution at the pile head was more reasonable. [PERSON] et al. [21] investigated the effects of two types of improvement methods with cement mixture in terms of reducing and redistributing the forces occurring in piles. In the study, the dynamic response of the soil-pile-structure interaction system of a high-rise building under seismic load was investigated using numerical analysis. Real-time earthquake motion was used in the analysis. According to the results obtained, it was observed that in the case of improvement, the bending moment and shear force magnitude in the piles decreased and were distributed equally along the upper region of the piles. This shows that the contact between piles reduces the bending moment and shear forces. Engineering design references regarding pile-soil interactions generally consist of different regulations and codes. There are regulations and codes in the literature such as the National Earthquake Hazards Reduction Program (NEHRP) [22], American Association of State Highway and Transportation Officials (AASHTO) [23], Europe Code (EUROCODE) [24], and Turkish Building Earthquake Regulations (TBDY) [25]. In these regulations and codes, the methods to be followed in the design of kinematic interactions are presented, but there is no directly recommended design approach. Although it is recommended in NEHRP to consider the base plate average, embedment depth, and the effect of pile foundations in kinematic interaction analyses, no analytical relationship is presented. In the regulation prepared by AASHTO, nonlinear behavior methods that are valid for offshore oil platforms are proposed. Although this regulation refers to the creation of p-y curves for sand and clays, no direct correlation is presented for the kinematic interaction. In Eurocode and Turkish regulations, rules regarding the conditions under which kinematic interaction analyses should be performed are included, and references are made to the methods to be used. There is no direct analytical method available in either regulation. When studies in the literature are evaluated, the studies generally focus on numerical modeling and use the finite element program in the analyses. In some of these studies, case studies were discussed, while in others, the effects of various parameters were investigated by verifying an experimental study. In parametric studies, issues such as pile placement, group effects, and geometric effects were mostly addressed. The results obtained from studies in the literature show that the damage caused by kinematic interactions occurs at the pile head in soft soils and in the intermediate ground layers where strength differences occur. Studies on kinematic interaction analyses in the literature that take parametric effects into consideration are limited. In this study, an experimental study in the literature was verified with a finite element program, and then the effects of soil stratification, groundwater level, pile stiffness, and earthquake acceleration parameters were investigated. In these parameters investigated within the scope of the study, the effect of material properties and earthquake magnitude were emphasized. Kinematic effects, which are among the most important factors affecting the pile-soil interaction problem, are mostly affected by material properties and earthquake magnitudes. The most important innovation that adds a difference to this study is the investigation of the parameters that will directly affect the kinematic interaction with numerically verified experimental data.