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与桩之间的相互作用系数，这是通过在群桩内一次只考虑两个桩来实现的。然后采用叠加法分析群桩之间的相互影响。这种方法作为三维详细数值分析的替代方法，为设计节省了大量时间和复杂性。本博士学位将从经验和理论相结合的基础上解决这一问题。首先，利用应用数学中的各种特殊函数，推导出不同非均质土剖面中单桩的非线性轴向响应以及相应的相互作用系数的闭合形式解，从而得到“t-z”乘子。对于非均质土的一般情况，将推导出简化的近似解，并与精确的闭合解进行比较。单桩和群桩在水平和扭转荷载作用下的响应也将被研究，从而得到类似的“p-y”和“t-0”乘数。然后将结果与更严格的数值解进行比较，并对照从文献和行业来源收集的桩载荷测试结果数据库进行评估。该项目的目的是将群桩分析中的不确定性降至最低，以节省成本和碳排放。这一努力与英国审评委的目标是一致的。

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.