Nonlinear Analysis of Piles and Pile Groups in Inhomogeneous Soil evaluated through Case Histories

Key to the analysis of pile groups is developing pile-to-pile interaction factors which is achieved by considering only two piles at a time within the group. Superposition is then employed to analyse the effect of all piles in the group on each other. This method acts as an alternative to a detailed numerical analysis in three dimensions that saves significant time and complexity to the design. This PhD will approach the problem from a combined empirical and theoretical basis. First, closed-form solutions will be developed using a variety of special functions of applied mathematics for the nonlinear axial response of single piles and corresponding interaction factors in different inhomogeneous soil profiles leading to "t-z" multipliers. Simplified, approximate solutions will be developed for the general case of inhomogeneous soil and compared against the exact, closed-form solutions. Single pile and pile group response under lateral and torsional loading will also be investigated leading to analogous "p-y" and "t-0" multipliers. Results will then be compared with more rigorous numerical solutions and evaluated against a database of pile load test results gathered from the literature and industry sources. The aim of this project is to minimise uncertainty in pile group analysis to provide cost and carbon savings. This effort is in line with UKCRIC objectives.