## 3 Results and Discussion
### Experimental Results and Analysis
#### 3.2.1 Results of Cyclic Triaxial Tests
Figure 11 illustrates the normalized relationship between the PWP ratios and cyclic numbers of the specimens with Liugui FCs of 15% and 30%. The curves of S-FC15-01, S-FC15-02, and S-FC15-03 in the initial stage were shifted to the right. As indicated in Table 4, when Ru was 0.5, the cyclic numbers of S-FC15-01, S-FC15-02, and S-FC15-03 were 10, 7, and 5, respectively, which were all greater than the cyclic numbers of the specimens with FCs of 30%. The cyclic numbers increased until Ru reached 0.9, at which point the cyclic numbers of some of the specimens with FCs of 30% were higher. When Ru was 1.0, the cyclic numbers of the specimens with FCs of 30% were all higher. Figure 11 presents the results of the tests performed on the specimens containing mudstone fines. As in the tests performed on the specimens containing Liugui fines, the curves of M-FC15-01, M-FC15-02, and M-FC15-03 in the initial stage were shifted to the right. As indicated in Table 3, when Ru was 0.5, the cyclic numbers of M-FC15-01, M-FC15-02, and M-FC15-03 were 17, 8, and 4, respectively, all of which were greater than the cyclic numbers of specimens with FCs of 30%. When Ru was 1.0, the cyclic numbers of specimens with FCs of 30% were all higher. The required cyclic number of M-FC30-01 and M-FC15-01 were 168 and 83, respectively, and the cyclic numbers of M-FC30-02 and M-FC15-02 were similar. Figure 11d presents the results of the tests performed on the six specimens containing kaolinite fines. The results in Table 3 indicate that the effects of the fines were not obvious in the initial stage. Nevertheless, when Ru was 0.5, the cyclic numbers of the specimens with FCs of 30% were greater and remained so until Ru reached 1.0. Furthermore, the liquefaction resistance and required cyclic numbers of the specimens with kaolinite FCs of 30% were considerably higher than those of the other specimens, suggesting that kaolinite is extremely resistant to liquefaction. [PERSON] et al. (2019) mentioned that in repeated triaxial tests, plastic and non-plastic specimens exhibit different PVP excitation behaviors. Therefore, four types of specimens were used in the present study. The first type was clean Liugui sand. The PWPs of the non-plastic sandy soils under dynamic loading were obtained from the results of the repeated triaxial tests, whereas those of specimens containing Liugui fines, mudstone, and kaolinite were obtained from the results of testing low-plasticity soils to high-plasticity soils. The results of the tests performed on Sand-02, S-FC30-02, M-FC30-01, and K-FC30-01 are compiled in Figure 12. As indicated in the figure, the PVP excitation behavior of the non-plastic sandy soils (FC = 0%) differed considerably from those of the specimens with FCs of 30%, which was consistent with the results reported by [PERSON] et al. (2019). [PERSON] et al. (2019) used a direct simple shear device to perform repeated loading tests. When the CSR was 0.2, the cyclic numbers were 0-5, and the PVP ratio reached 0.7-0.8. When the CSR was 0.15, the cyclic numbers were 35-40, and the PVP ratio decreased to 0.4-0.6. By performing strain-controlled cyclic triaxial tests, [PERSON] et al. (2018) discovered that when the cyclic number of specimens with an FC 20% was 50, the PVP ratio reached 0.56. Figure 11: The process of liquefaction as the PWPs of the specimens increased during cyclic triaxial testing. (**a**) Clean sands. (**b**) Liugui fines. (**c**) Mudstone fines. (**d**) Kaolinite fines. As indicated in Figure 11, each specimen had a different CSR and required a different cyclic number to reach initial liquefaction. Therefore, the figure reveals the distinct trends in the PWP of each specimen. However, the complete WP excitation behavior of all the specimens could not be determined. The data from all the tests performed in the present study were therefore normalized. The PWP ratios (Ru) and cyclic ratios (N/N\({}_{\text{L}}\)) are compiled in Figure 13. [PERSON] et al.