Abstract This study aimed to numerically evaluate the strength parameter of the soil–pile interface in the lateral direction. A 3D numerical model of a single pile in sandy soil was built to analyse the interface strength parameter, which was defined as the ratio of the lateral force mobilised on the interface to the confining stress multiplied by the pile perimeter. Results showed that the interface strength parameter increased with the embedment depth ratio and converged to a constant value at a depth of four times the pile diameter. This relationship can be expressed using a bilinear formula that can be adopted to define the strength of springs connecting soil and pile elements in the lateral direction. The applicability of the proposed strength parameter to seismic analysis was validated by performing 3D numerical simulations of centrifuge tests. The simulation targeted single and group piles installed in a level ground of dry silica sand. The simulation results agreed well with the measured data, indicating the reasonable applicability of the proposed strength parameter of the soil–pile interface in the lateral direction.

中文翻译：

---

砂土抗震分析的横向土桩界面特性评价

摘要 本研究旨在数值评价土桩界面横向强度参数。建立了沙土中单桩的3D数值模型来分析界面强度参数，该参数定义为界面上动员的侧向力与围压之比乘以桩周长。结果表明，界面强度参数随着埋置深度比的增加而增加，并在四倍桩径的深度处收敛到一个恒定值。这种关系可以使用双线性公式表示，该公式可用于定义横向连接土壤和桩单元的弹簧强度。通过执行离心机试验的 3D 数值模拟，验证了所提出的强度参数对地震分析的适用性。模拟针对安装在干硅砂水平地面上的单桩和群桩。模拟结果与实测数据吻合较好，表明土桩界面侧向强度参数的合理适用性。