**5. Conclusions**

This study analyses the experimental data of <sup>τ</sup>-δ and <sup>σ</sup>-δ constitutive relationships of Nmcs, and examines its characteristics under various conditions. Two mathematical models, i.e., REP (reinforced exponential and power function) and CEL (coupled exponential and linear) models, are proposed to overcome the shortcomings of conventional models in the modeling of hardening, modified falling, S-type falling, and strong softening stress–strain behaviors. Some key findings are summarized as below:


The applicability of the proposed method of this study in practice mainly include two parts. As introduced in the study, the seashore soft soil discussed herein was collected from coastal areas in Shaoxing, Zhejiang Province, China. Thus, for the regions with similar seashore soft soil, e.g., the Yangtze river delta region of China, the reported methods in this study could be used directly. On the other hand, for regions with di fferent seashore soft soil (i.e., the soil specific gravity, LL, PL vary a lot), the proposed expressions are still applicable if the specific soil stress–strain behavior was exhibited, e.g., strong softening behavior. However, it should be noted that, for the latter scenario, the corresponding calculation parameters should be re-calibrated through laboratory tests.

**Author Contributions:** Investigation, C.Z.; writing-original draft, Y.F.; writing-review and editing, W.W.; validation, N.L. and A.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Natural Science Foundation of China, gran<sup>t</sup> number 41772311 and the Zhejiang Provincial Natural Science Foundation of China, gran<sup>t</sup> number LY17E080016.

**Conflicts of Interest:** The authors declare no conflict of interest.
