STATIC AND SEISMIC BEHAVIOR OF A LATERALLY LOADED PILE IN COHESIONLESS SOIL SLOPES

Abstract

In recent years, rapid infrastructure development has led to an increase in the construction of high-rise buildings, bridges, wind chimneys, transmission towers, and offshore structures. These complex structures require pile foundations that can support both vertical loads, as well as lateral loads from the superstructures. Hence, the design of pile foundations must consider the lateral loads in addition to vertical loads to ensure the safety and cost-effectiveness of the structures. Further, the construction of these structures near slopes has intensified due to the scarcity of level ground. As a result, understanding the behavior of laterally loaded piles near slopes has become a key interest in pile foundation design. Pile-soil interaction in level grounds is complex, and presence of sloping ground adds intricacy to lateral load behavior. Moreover, the occurrence of earthquakes worldwide has significantly increased, highlighting the need to carefully design pile foundations on sloping grounds considering both static and seismic loads. A comprehensive review of the existing literature on laterally loaded piles on sloping ground reveals a dearth of research on sandy soil slopes. Most of the available studies often overlook the influence of edge distance and other important parameters on the laterally loaded pile behavior in soil slopes under static conditions. Further, research related to dynamic behavior of piles primarily focused on piles in liquefiable sandy slopes. There is a lack of comprehensive studies addressing the dynamic behavior of piles in non-liquefiable sandy slopes, accounting for both the kinematic and inertial effects. Consequently, a complete understanding of the behavior of piles situated in dry sandy soil slopes, considering static and seismic conditions, is currently lacking. To address the existing research gap, a comprehensive investigation was undertaken using the finite element software, PLAXIS 3D, to analyze the behavior of piles situated in sandy soil slopes. This study has encompassed both static and seismic loading conditions. In the static case, the lateral load behavior of piles was examined under both free head and fixed head conditions. A parametric analysis was conducted, encompassing various pile-soil slope parameters that affect the lateral load behavior of piles in slopes. Furthermore, the influence of pile location with reference to slope crest and direction of loading was also investigated. Prior to the parametric analysis, mesh convergence studies were performed to assess the impact of the soil domain and mesh element size on numerical simulations. Moreover, validation was carried out by comparing the obtained results with previous centrifuge test findings, ensuring the accuracy of the step-bystep modeling and selection of material models.