Each pile in an offshore wind farm may be designed solely on the results of a single cone penetration test (CPT) positioned at its center or based on sample statistics calculated from multiple investigated locations in the same geotechnical unit. This study investigates quantitatively the effects of spatial variability of soil on the efficacy of the two approaches to achieve a reliable design. Random field theory is used to generate sets of cone tip resistance profiles with different characteristics to represent different seabed conditions and piles are ‘designed’ using the above two approaches and the partial factor method to withstand a given vertical drained design load distribution. The effects of the inaccuracies in prediction of pile capacity from the CPT data are quantified in terms of the scatter in calculated reliability (or probability of failure). Outputs of the parametric statistical analysis demonstrate that the ability of the two CPT-based approaches to produce a reliable foundation design is dependent on the ratio between the horizontal scale of fluctuation and the pile diameter, and the overall variability (coefficient of variation) of the seabed properties. Modifications to deterministic, partial factor design approaches are suggested to account for these uncertainties to ensure target reliabilities are achieved.

海上风电场中的每个桩都可以仅根据位于其中心的单个圆锥体渗透测试（CPT）的结果来设计，也可以基于从同一岩土单位中多个调查位置计算出的样本统计信息来设计。本研究定量研究了土壤空间变异性对两种方法的有效性的影响，以实现可靠的设计。随机场理论用于生成具有不同特征的圆锥体尖端阻力曲线集，以代表不同的海底条件，并使用上述两种方法和偏因法对桩进行“设计”，以承受给定的垂直排水设计载荷分布。根据CPT数据预测桩容量的不准确度的影响，是根据计算出的可靠性（或失效概率）的分散性来量化的。参数统计分析的输出表明，两种基于CPT的方法产生可靠基础设计的能力取决于波动的水平尺度和桩直径之间的比率以及桩的总体变化性（变化系数）。海底属性。建议对确定性的局部因素设计方法进行修改，以解决这些不确定性，以确保实现目标可靠性。参数统计分析的输出表明，两种基于CPT的方法产生可靠基础设计的能力取决于波动的水平尺度和桩直径之间的比率以及桩的总体变化性（变化系数）。海底属性。建议对确定性的局部因素设计方法进行修改，以解决这些不确定性，以确保实现目标可靠性。参数统计分析的输出表明，两种基于CPT的方法产生可靠基础设计的能力取决于波动的水平尺度和桩直径之间的比率以及桩的总体变化性（变化系数）。海底属性。建议对确定性的局部因素设计方法进行修改，以解决这些不确定性，以确保实现目标可靠性。