## 3 Test Results and Analysis
### Effect of \(\delta\) on the Development of Cumulative Generalized Shear Strain  
Figure 9 illustrates the relationship between cumulative generalized shear strain and the number of cycles under the same \(CSR\). According to Figure 9a, it is noted that \(\gamma_{g}\) develops almost linearly with \(N\) for a different value of \(\delta\) when \(CSR=0.03\). When \(CSR=0.05\), \(\gamma_{g}\) increases almost linearly with the increase in \(N\) for \(\delta=2\) and \(4\), while \(\gamma_{g}\) decreases almost linearly with the increase in \(N\) for \(\delta=2\) and \(4\), while \(\gamma_{g}\) decreases almost linearly with the increase in \(N\) for \(\delta=2\) and \(4\), while \(\gamma_{g}\) decreases almost linearly with the increase in \(N\) for \(\delta=2\) and \(4\).  
Figure 8: (**a**,**b**) Relationship between cumulative generalized shear strain and number of cycles under different stress paths.  
Figure 7: (**a**–**c**) Relationship between cumulative generalized shear strain and number of cycles under the same \(\delta\).  
increases nonlinearly with the increase in \(N\) for \(\delta=1\). When the sample is subjected to the small external dynamic stress level, the soil presents an inelastic working state and the cumulative generalized shear strain exhibits linear growth; however, when the sample is subjected to the large external dynamic stress level, the soil presents an elasto-plastic working state in the initial loading stage, the specimen undergoes plastic failure locally, and the axial deformation gradually increases. However, as the loading continues, the skeleton reorganizes after the failure of the specimen to form a relatively stable fabric, which leads to an increase in the rate of axial deformation, slowing shrinking. Furthermore, when \(CSR=0.065\), nonlinear developing trends of \(\gamma_{g}\) are observed with the increase in \(N\) for \(\delta=2\) and \(4\). It can be observed that the value of generalized shear strain decreases with increasing \(\delta\). This is because when \(\delta=1\), the stress path is a circular one. At this time, the seabed soil undergoes the highest stress level, which shows that the circular stress path generated by the wave load causes the deformation of the soil to be greater than that caused by a single normal stress or shear stress.  
When \(N\) reaches 2000, the cumulative generalized shear strain of the specimen is defined as the terminal generalized shear strain \(\gamma_{g2000}\). Figure 10 presents the variation in the terminal generalized shear strain versus the cyclic stress ratio of saturated silt under different stress paths. According to Figure 10, when the \(CSR\) is the same, \(\gamma_{g2000}\) decreases in sequence as \(\delta\) increases. For \(\delta=1\), the stress path is circular, and \(\gamma_{g2000}\) is the largest. For \(\delta\), the stress path is the same, and \(\gamma_{g2000}\) increases with the increase in \(CSR\). It is noteworthy that the above tendency is only correct when \(CSR<CSR_{\text{th}}\); when CSR approaches or exceeds \(CSR_{\text{th}}\), liquefaction occurs and the silt appears to be unstable, and the terminal generalized shear strain will lose its physical meaning.  
Figure 9: Relationship between cumulative generalized shear strain and number of cycles under the same \(CSR\). **(a)** The relationship between cumulative generalized shear strain and number of cycles when \(CSR=0.03\); **(b)** The relationship between cumulative generalized shear strain and number of cycles when \(CSR=0.05\); **(c)** The relationship between cumulative generalized shear strain and number of cycles when \(CSR=0.065\).