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

群桩分析的关键是建立桩间相互作用因子，这种相互作用因子是通过一次只考虑群内两根桩来实现的。然后采用叠加来分析群中所有桩对彼此的影响。这种方法可以替代三维的详细数值分析，大大节省了设计的时间和复杂性。本博士将从实证和理论结合的角度来研究这个问题。首先，将利用应用数学的各种特殊函数来开发单桩非线性轴向响应的封闭形式解，以及导致“t-z”乘数的不同非均匀土廓线中相应的相互作用因素。简化，近似的解决方案将发展为一般情况下的非均质土壤，并与精确的，封闭形式的解决方案进行比较。还将研究横向和扭转荷载下的单桩和群桩响应，从而得出类似的“p-y”和“t-0”乘数。然后将结果与更严格的数值解进行比较，并根据从文献和工业来源收集的桩荷载试验结果数据库进行评估。该项目的目的是尽量减少群桩分析中的不确定性，以提供成本和碳节约。这一努力符合UKCRIC的目标。

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.