Pile groups are traditionally designed with similar piles in length, diameter, and property. However dissimilar piles may occur in the cases of foundation reuse and economical building design. This paper develops a fictitious pile method for the interaction factors between two dissimilar piles in a pile group that have different dimensions and properties. The effects of different pile lengths/properties on the horizontal load distribution, group efficiency factor and group reduction factor are studied here by using the fictitious pile method. Based on the principle of superposition and the concept of interaction factor, the proposed approach avoids the full analysis on pile groups and thus significantly improves the calculation efficiency. The horizontal load distributions for the fixed-head pile group with dissimilar piles by the proposed method match well with the results by the finite element method. The parametric study shows that, for stiffer pile group, the corner pile length is an important parameter affecting the fixed-head pile group behavior under horizontal loading.

桩组传统上设计为具有相似的长度、直径和特性的桩。然而，在基础再利用和经济建筑设计的情况下，可能会出现不同的桩。本文针对具有不同尺寸和特性的桩组中的两个不同桩之间的相互作用因素，开发了一种虚拟桩法。本文采用虚拟桩法研究了不同桩长/特性对水平荷载分布、群效率系数和群折减系数的影响。该方法基于叠加原理和相互作用因子的概念，避免了对桩组的全面分析，从而显着提高了计算效率。该方法得到的异种桩固定头桩组的水平荷载分布与有限元法得到的结果吻合较好。参数化研究表明，对于较硬的桩群，角桩长度是影响水平荷载作用下固定头桩群行为的重要参数。