Abstract Spudcan foundations have been widely used in offshore oil and gas engineering for jack-up rigs. During penetration into seabed soil, spudcan foundations may encounter large uncertainties in soil properties, which have a strong impact on its bearing capacity. A large number of studies have been conducted to demonstrate the failure mechanisms and the bearing capacity of spudcan foundations in soils with deterministic properties, but the influence of spatially variable soil properties on spudcan foundations remains unclear and should be accounted for. In this study, we aimed to investigate the failure mechanisms and the bearing capacity of a spudcan foundation embedded in soils where the mean undrained shear strength increased linearly with depth. The spectral representation method (SRM) was used to generate a non-stationary non-Gaussian random field. The random finite element method (RFEM) in conjunction with Monte Carlo simulations was carried out to evaluate the statistical characteristics of the bearing capacity for spudcan foundations, followed by a series of comparisons and discussion. The results indicated that the mean bearing capacity for the spatial variability of undrained shear strength was smaller than that obtained from the corresponding deterministic case. The probability of failure decreased slightly with an increase in the degree of non-stationarity under the constant coefficient of variation (COV) condition. Upon comparing the results obtained from different random field models, we found that the probability of failure under the non-constant condition was smaller than that under the stationary and constant COV conditions.

中文翻译：

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不排水平均抗剪强度线性增加的土中桩基概率承载力分析

摘要 Spudcan基础已广泛应用于海上油气工程自升式钻井平台。在渗入海床土壤过程中，马蹄铁地基可能会遇到土壤性质的较大不确定性，这对其承载能力有很大影响。已经进行了大量研究来证明具有确定性特性的土壤中桩靴地基的破坏机制和承载能力，但空间可变的土壤特性对桩靴地基的影响仍不清楚，应该加以考虑。在这项研究中，我们旨在研究埋入土壤中的桩靴基础的破坏机制和承载能力，其中平均不排水抗剪强度随深度线性增加。谱表示法 (SRM) 用于生成非平稳非高斯随机场。采用随机有限元法（RFEM）结合蒙特卡罗模拟对桩桩基础承载力的统计特性进行评估，并进行了一系列的比较和讨论。结果表明，不排水抗剪强度空间变异性的平均承载力小于从相应确定性情况获得的承载力。在恒定变异系数（COV）条件下，随着非平稳度的增加，失效概率略有下降。在比较从不同随机场模型获得的结果后，