Analysis of Laterally Loaded Piles in Inhomogeneous Soil

Abstract

The slender nature of piles increases their tendency to buckle especially in soft or liquified soil. Over the past years, several analytical, numerical, and experimental solutions were presented in the literature to estimate the buckling capacity of piles. The solutions included piles with different boundary conditions subjected to axial and lateral loads and under different soil conditions (i.e., homogenous, inhomogeneous, and layered soil profiles). This study aims to provide analytical solutions for fully embedded single piles with different boundary conditions and soil profiles. The stiffness of the soil is presented using Winkler’s springs and the pile is subjected to axial and lateral static loading. First, analytical solutions are derived for infinite and finite piles in a homogeneous soil profile. For finite piles, sixteen different cases of boundary conditions were considered; exact analytical solutions are derived for four of them. Meanwhile, for the other cases, the analytical solution includes one numerical step. Then, energy solutions are derived for infinitely long and finite piles. The proposed energy method uses the virtual work method where the unitary deflection of the piles is presented using shape functions that satisfy the deflected shape of the pile. For infinitely long and four cases of finite piles, exact shape functions are used. However, in other cases, the theory of vibration of beams is used to derive the shape functions. The solutions for homogeneous soil are compared to the analytical solutions derived in this work. Then, the critical buckling load is computed for piles in soil with parabola-increasing stiffness. After that, the critical buckling load is computed for finite piles in two-layer soil profiles with different stiffness of the soil and layer thickness. Lastly, the proposed energy solution is used to find the critical buckling load of piles embedded in realistic soil profiles.

Date of Award	Aug 2023
Original language	American English
Supervisor	GEORGE Mylonakis (Supervisor)