Interaction of Building Frame with Pile Foundation

The study deals with physical modeling of a typical building frame resting on a pile group embedded in cohesive soil mass using complete three-dimensional finite element analysis. The elements of the superstructure frame and that of the pile foundation are discretized using twenty node isoparametric continuum elements. The interface between the pile and pile cap is idealized using sixteen node isoparametric surface elements. The more improved finite element mesh is used for modeling soil element as compared to the one used in the study reported in the literature. The soil elements are discretized using eight node, nine node and twelve node continuum elements. Both the elements of superstructure and substructure (i.e., foundation) including soil are assumed to remain in elastic state at all the time. The interaction analysis is carried out using sub-structure approach to attempt a parametric study. The effect of the parameter such as spacing between the piles in a group and diameter of pile is evaluated on the response of superstructure. The response includes the displacement at the top of the frame. The effect of the soil-structure interaction is observed to be significant for the type of foundation and soil considered in the present study.

Numerical and theoretical analysis on soil arching effect of prefabricated piles as deep foundation pit supports

This study presents a detailed investigation into the soil arching effects within deep foundation pits(DFPs),focusing on their mechanical behavior and implications for structural design.Through rigorous 3D finite element modeling and parameter sensitivity analyses,the research explores the formation,geometric characteristics,and spatial distribution of soil arching phenomena.The investigation encompasses the influence of key parameters such as elastic modulus,cohesion,and internal friction angle on the soil arching effect.The findings reveal that soil arching within DFPs exhibits distinct spatial characteristics,with the prominent arch axis shifting as excavation depth progresses.Optimal soil arching is observed when the pile spacing approximates three times the pile diameter,enhancing soil retention and minimizing deformation risks.Sensitivity analyses highlight the significant impact of soil parameters on soil arching behavior,underscoring the critical role of cohesive forces and internal friction angles in shaping arching characteristics.By elucidating the interplay between soil parameters and soil arching effects,the research provides insights for optimizing pile spacing and structural stability.