It is widely accepted that the presence of compressible layers beneath pile groups can substantially increase the settlement of a pile group. Furthermore, as the size of the pile group increases this effect is magnified and further complicated by the load distribution across the pile group. A number of simplified methods, such as the equivalent raft or equivalent pier method, are often employed to estimate the settlement of pile groups founded over a compressible layer, however, such methods can lead to both overly conservative and un-conservative results and large variations in results between methods. More recent methods have explored the use of power law functions or energy principles to analyse piles and pile groups in non-homogeneous soil conditions, however, these methods can be difficult to apply in practice. With the availability of modern computers and the advancement of commercially available numerical analyses packages, it is now possible to use the finite element method to analyse pile groups overlying compressible soil layers in order to better understand this problem. This technical note presents some initial results and associated design charts based on the finite element method to provide preliminary estimates of settlement of pile groups overlying compressible layers. Some dimensionless design charts are provided for a range of commonly encountered geotechnical conditions and pile group geometries.

人们普遍认为，桩组下方可压缩层的存在会大大增加桩组的沉降。此外，随着桩组尺寸的增加，由于桩组上的载荷分布，这种影响会放大并进一步复杂化。通常使用许多简化方法（例如等效筏或等效墩方法）来估算可压缩层上的桩组沉降，但是，这些方法可能会导致过于保守和不保守的结果以及较大的差异方法之间的结果。最近的方法已经探索了使用幂律函数或能量原理来分析非均质土壤条件下的桩和桩组，但是，这些方法在实践中可能难以应用。随着现代计算机的可用性和市售数值分析软件包的发展，现在可以使用有限元方法来分析覆盖可压缩土层的桩组，以便更好地理解该问题。本技术说明基于有限元方法提供了一些初步结果和相关的设计图表，以提供对可压缩层上的桩组沉降的初步估算。提供了一些无量纲设计图，以适用于一系列常见的岩土条件和桩组几何形状。本技术说明基于有限元方法提供了一些初步结果和相关的设计图表，以提供对可压缩层上的桩组沉降的初步估算。提供了一些无量纲设计图，以适用于一系列常见的岩土条件和桩组几何形状。本技术说明基于有限元方法提供了一些初步结果和相关的设计图表，以提供对可压缩层上的桩组沉降的初步估算。提供了一些无量纲设计图，以适用于一系列常见的岩土条件和桩组几何形状。