The settlement of ground-supported transportation infrastructures may vary greatly depending on the uncertainties related to compressibility properties and overconsolidation of clay. These uncertainties can be considered systematically by means of reliability analysis where the probability distribution of consolidation settlement is evaluated. Hence, this paper applies two well-known reliability methods, first-order second-moment method (FOSM) and Monte Carlo simulation, to various theoretical consolidation scenarios and three case studies of test embankments founded on normally consolidated (NC) or overconsolidated (OC) clay subsoil. The aim is to assess the accuracy and limitations of FOSM when applied to estimate the mean, the standard deviation, or the upper 95th percentile of the settlement. According to the results, the accuracy of FOSM is adequate for most serviceability limit state (SLS) purposes if the clay is normally consolidated. On the other hand, large relative errors may be introduced for OC clays where the relative contribution of OC and NC strains creates a strongly non-linear problem. It is concluded that FOSM, combined with second-order mean, may be applied to preliminary settlement estimation of OC clays. However, in the actual SLS verification with certain target reliability, Monte Carlo simulation should be used to ensure high enough accuracy.

地面支撑的交通基础设施的沉降可能会因与可压缩性和粘土过度固结相关的不确定性而有很大差异。这些不确定性可以通过可靠性分析系统地考虑，其中评估固结沉降的概率分布。因此，本文将两种众所周知的可靠性方法，一阶二阶矩法 (FOSM) 和蒙特卡罗模拟应用于各种理论固结方案和基于正常固结 (NC) 或超固结 (OC) 的测试路堤的三个案例研究) 粘土底土。目的是评估 FOSM 在用于估计均值、标准差或结算的第 95 个百分位数时的准确性和局限性。根据结果​​，如果粘土是正常固结的，则 FOSM 的准确性足以满足大多数使用极限状态 (SLS) 目的。另一方面，OC 粘土可能会引入较大的相对误差，其中 OC 和 NC 应变的相对贡献会产生强烈的非线性问题。结论是，FOSM 结合二阶平均值，可用于 OC 粘土的初步沉降估计。但在具有一定目标可靠性的实际SLS验证中，应采用蒙特卡罗模拟来保证足够高的精度。结合二阶均值，可用于OC粘土的初步沉降估算。但在具有一定目标可靠性的实际SLS验证中，应采用蒙特卡罗模拟来保证足够高的精度。结合二阶均值，可用于OC粘土的初步沉降估算。但在具有一定目标可靠性的实际SLS验证中，应采用蒙特卡罗模拟来保证足够高的精度。