# Post-Cyclic Mechanical Behaviors of Undisturbed Soft Clay with Different Degrees of Reconsolidation
## 6 Conclusions  
A series of static and dynamic triaxial tests were conducted to study the post-cyclic mechanical behavior of soft clay in the Pearl River Estuary. The effects of confining pressure, cyclic stress ratio, and degree of reconsolidation were investigated. The main conclusions are obtained as follows:  
1. The trends in the stress-strain curves during the post-cyclic shear process under different conditions are similar. Compared with undrained shear strength without cyclic loading, the shear strength after cyclic loading with full reconsolidation increases. Furthermore, with increasing of confining pressure, cyclic stress ratio, and degree of reconsolidation, the undrained shear strength increases. Meanwhile, a critical degree of reconsolidation at which the post-cyclic shear strength equals the static shear strength was found.
2. The excess pore water pressure increases rapidly at the beginning of the post-cyclic shear process, then decreases with increasing strain, but the excess pore water pressure remains positive during post-cyclic shear. S-shaped effective stress paths are observed, in which the terminal points of effective stress paths cross the CSL line.
3. The microstructures of undisturbed soil and specimens with different degrees of reconsolidation were ascertained. Compared with the undisturbed soil, the number of pores of post-cyclic specimens increases significantly, and the large, interconnected pores became small and scattered. Furthermore, with increasing degree of reconsolidation, the void ratio of the soil decreases.
4. The effect of the degree of reconsolidation on the post-cyclic shear strength of soft clay in the Pearl River Estuary is the most significant. The post-cyclic shear strength increases with the increase of degree of reconsolidation. Good drainage conditions will effectively improve the bearing capacity after cyclic loading. The post-cyclic  
Figure 17: Comparison of predicted post-cyclic undrained shear strength and measured data for specimens with full reconsolidation.  
shear strength of the soil without reconsolidation can be reduced by up to 29%. The predicted results obtained using the model proposed by [PERSON] et al. [15; 16] match the measured data, implying that the model applies to the prediction of the post-cyclic undrained strength of the soft soil located in the Pearl River Estuary. This study provides a rough reference for the range of post-cyclic shear strength with different degree of reconsolidation compared with the strength without cyclic loading history for the engineering design of soft soil in the Pearl River Estuary.  
[PERSON] performed the tests, processed the data, and wrote the manuscript; [PERSON] designed the tests and modified the manuscript; [PERSON] modified the manuscript; [PERSON] provided the technique support; [PERSON] provided soils; [PERSON] provided the technique support; [PERSON] provided the technique support. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (Grant No. 52079135, 51909259, 52008122) and the International Partnership Program of the Chinese Academy of Sciences (Grant No. 131551 KYSB20180042).  
The data presented in this study are available on request from the corresponding author.  
The authors declare no conflict of interest.