The long-term consolidation settlement of soft soils under infrastructures is seriously concerned in coastal areas. In practice, soft soil ground is usually composed of multiple layers with different properties, and the effect of soil creep is nonnegligible. However, in conventional consolidation analysis, creep is seldom included during the “primary” consolidation. With conventional creep model, creep strain will reach infinity with time, which is unreasonable in the long-term view. In this study, a new simplified method based on Hypothesis B is presented to calculate both short-term and long-term consolidation settlements of multi-layered soils exhibiting non-linear creep. There are three main characteristics for this new simplified method: (a) the consolidation analysis for multi-layered soil is conducted using spectral method; (b) a nonlinear creep function with creep limit is incorporated to calculate both short-term and long-term creep settlements; (c) the “primary” consolidation and creep are calculated independently and combined with an empirical parameter $\alpha$ together with the consolidation degree U for correcting the creep settlement. Finite element analysis with a self-developed Elastic Visco-Plastic (EVP) constitutive model considering creep limit was also carried out. Verifications by field cases and finite element simulation demonstrate the efficiency and accuracy of the new simplified method in calculating the long-term settlements of soft soil ground under varied engineering conditions. Influences of major parameters selection in the calculation of the new simplified method are also discussed.

沿海地区基础设施下软土长期固结沉降问题备受关注。在实际应用中，软土地基通常由多层不同性质的地层组成，土体蠕变的影响不可忽视。然而，在传统的固结分析中，蠕变很少包括在“主要”固结过程中。传统的蠕变模型，随着时间的推移，蠕变应变会达到无穷大，从长远来看是不合理的。在这项研究中，提出了一种基于假设 B 的新简化方法来计算表现出非线性蠕变的多层土壤的短期和长期固结沉降。这种新的简化方法具有三个主要特点： (a) 多层土的固结分析是使用谱法进行的；(b) 包含蠕变极限的非线性蠕变函数，用于计算短期和长期蠕变沉降；(c) “主要”固结和蠕变是独立计算的，并结合一个经验参数$\alpha$与固结度U一起修正蠕变沉降。还使用考虑蠕变极限的自行开发的弹性粘塑性 (EVP) 本构模型进行了有限元分析。现场案例和有限元模拟的验证证明了新的简化方法在计算不同工程条件下软土地基长期沉降的效率和准确性。还讨论了主要参数选择对新简化方法计算的影响。