## 4 Conclusions  
A series of laboratory tests, namely, the CU triaxial, bender-element, and permeability tests of silt, mucky silty clay, and silty sand in the lateral unloading and unloading-reloading stress paths with different unloading intensity levels were carried out. The following conclusions could be drawn from the test results:  
1. The lateral unloading and reloading of reconstituted Hangzhou soil containing silty particles reduced the shear strength and stiffness parameters. Ultimate deviator stress, effective cohesion, effective internal friction angle, initial elastic modulus, and small strain shear stiffness of soil decreased as unloading intensity increased. Unloading intensity had a more noticeable effect on the shear properties of silt and mucky silty clay.
2. In the unloading-reloading path, the shear strength and stiffness parameters of the silt, silty sand, and mucky silty clay were essentially consistent with those of conventional triaxial tests, indicating that the soil was not significantly disturbed. Increases in unloading intensity resulted in significant decreases in shear strength and stiffness parameters. The strength parameters of silt decreased the most (up to 7%), while the stiffness parameters of mucky silty clay decreased the most (up to 15%).
3. The permeability coefficients of all three types of reconstituted soils increased as unloading intensity increased, and the permeability coefficients of mucky silty clay and silt were more significantly affected.  
Figure 11: Normalized permeability coefficient-unloading intensity relationship of three soils in different stress paths.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Properties**} & \multirow{2}{*}{**Soils**} & \multicolumn{8}{c}{**Stress Path**} \\ \cline{3-10}  & & **A\(-\)0** & **B\(-\)1** & **B\(-\)2** & **B\(-\)3** & **C\(-\)1** & **C\(-\)2** & **C\(-\)3** \\ \hline \multirow{3}{*}{
\begin{tabular}{c} Permeability coefficient \\ (\(\times 10^{-6}\) cm/s) \\ \end{tabular} } & Silt & 188.50 & 188.84 & 195.81 & 210.24 & 192.31 & 204.32 & 219.32 \\  & Silty sand & 382.99 & 384.62 & 402.65 & 406.32 & 349.62 & 352.38 & 361.21 \\ \cline{1-1}  & Mucky silty clay & 2.71 & 2.27 & 2.36 & 2.85 & 1.99 & 2.02 & 2.11 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Permeability coefficient of soil.  
**Author Contributions:** Conceptualization, C.X. and F.M.; methodology, C.X. and M.Z.; software, F.M. and Y.T.; validation, C.X. and F.M.; formal analysis, C.L.; investigation, C.X. and M.Z.; resources, C.X. and F.M.; data curation, F.M. and Y.T.; writing--original draft preparation, C.X.; writing--review and editing, C.X., F.M. and M.Z.; visualization, C.X. and F.M.; supervision, C.X. and F.M.; project administration, C.X., F.M. and M.Z.; funding acquisition, C.X., F.M. and M.Z. All authors have read and agreed to the published version of the manuscript.  
This research was funded by China Postdoctoral Science Foundation grant number 2021T140475; Zhejiang Science and Technology Planning Project grant number 2013C31034; National Natural Science Foundation of China grant numbers 52090084, 52108329, and 52008263; and Shenzhen Science and Technology Program grant number KQTD20200909113951005.  
Not applicable.  
**Data Availability Statement:** Data are contained in the article.  
The authors declare no conflict of interest.