## 3 Results and Discussion
### Significance Analysis of Influencing Factors on Resilient Modulus  
The effect of confining pressure, deviator stress, and F-T cycles on resilient modulus is worth comparing and discussing. The variance of confining pressure, deviator stress, and F-T cycles on resilient modulus is analyzed using SPSS (Statistical Product and Service Solutions) 20.0 software. The resilient modulus is regarded as a dependent variable. Confining pressure, deviator stress, and F-T cycles are fixed factors. The results are listed in Table 7.  
From Table 7, the significance analysis results for the two materials are similar. It illustrates that confining pressure, deviator stress, and F-T cycles all have a significant influence on the resilient modulus, which is consistent with the previous analysis. Furthermore, the magnitude of the F value reflects the level of significance. The greater value of F, the greater the significance of the effect. Based on the confidence interval of 95%, the significance result for the two materials is slightly different. For unmodified SC, the significance of confining pressure is the greatest, followed by F-T cycles and deviator stress. For the modified soil, the significance of confining pressure is also the greatest, then followed by deviator stress and F-T cycles. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Process**} & \multicolumn{2}{c}{**Deviator**} & \multicolumn{3}{c}{**F-T Cycles**} & \multicolumn{3}{c}{**Fitting Equations**} \\  & **Stress (kPa)** & **1** & **3** & **5** & **7** & \\ \hline \multirow{4}{*}{40-1} & 25 & 35.76\% & 36.11\% & 37.46 & 36.64\% & y = 0.3674 \(-\) 0.3674e\({}^{\ast}\)(\(-\)n/0.2756), R\({}^{2}\) = 0.99 \\  & 15 & 31.38\% & 32.72\% & 30.59\% & 30.85\% & y = 0.3056 \(-\) 0.3010e\({}^{\ast}\)(\(-\)n/0.0224), R\({}^{2}\) = 0.98 \\  & 5 & 25.94\% & 25.06\% & 23.80\% & 26.24\% & y = 0.2506 \(-\) 0.2503e\({}^{\ast}\)(\(-\)n/0.0080), R\({}^{2}\) = 0.98 \\ \hline \multirow{4}{*}{50-2} & 25 & 33.09\% & 34.33\% & 34.76\% & 32.45\% & y = 0.3385\(-\) 0.3385e\({}^{\ast}\)(\(-\)n/0.2630), R\({}^{2}\) = 0.99 \\  & 15 & 27.58\% & 27.03\% & 28.25\% & 26.26\% & y = 0.2718 \(-\) 0.2718e\({}^{\ast}\)(\(-\)n/0.0253), R\({}^{2}\) = 0.99 \\  & 5 & 17.40\% & 18.20\% & 18.64\% & 18.06\% & y = 0.1830 \(-\) 0.1830e\({}^{\ast}\)(\(-\)n/0.3327), R\({}^{2}\) = 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Damage ratio of resilient modulus for the modified SC after F-T cycles. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Process**} & \multicolumn{2}{c}{**Deviator**} & \multicolumn{3}{c}{**F-T Cycles**} & \multicolumn{3}{c}{**Fitting Equations**} \\  & **Stress (kPa)** & **1** & **3** & **5** & **7** & \\ \hline \multirow{4}{*}{40-1} & 25 & 19.49\% & 36.18\% & 44.57\% & 49.09\% & y = 0.5077 \(-\) 0.5024e\({}^{\ast}\)(\(-\)n/2.3014), R\({}^{2}\) = 0.99 \\  & 15 & 17.95\% & 32.52\% & 39.13\% & 44.38\% & y = 0.4524 \(-\) 0.4461e\({}^{\ast}\)(\(-\)n/2.2711), R\({}^{2}\) = 0.99 \\  & 5 & 14.80\% & 29.20\% & 35.96\% & 38.93\% & y = 0.4074 \(-\) 0.4056e\({}^{\ast}\)(\(-\)n/2.3252), R\({}^{2}\) = 0.99 \\ \hline \multirow{4}{*}{50-2} & 25 & 17.49\% & 37.61\% & 46.67\% & 50.46\% & y = 0.5393 \(-\) 0.5400e\({}^{\ast}\)(\(-\)n/2.5156), R\({}^{2}\) = 0.99 \\  & 15 & 16.20\% & 36.37\% & 44.19\% & 46.25\% & y = 0.4928 \(-\) 0.4967e\({}^{\ast}\)(\(-\)n/2.3014), R\({}^{2}\) = 0.99 \\ \cline{1-1}  & 5 & 13.36\% & 28.70\% & 36.10\% & 38.23\% & y = 0.4103 \(-\) 0.4113e\({}^{\ast}\)(\(-\)n/2.4765), R\({}^{2}\) = 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Damage ratio of resilient modulus for unmodified SC after F-T cycles. The obtained results show that stress states are the most important factors affecting the resilient modulus, especially confining pressure. The effect of F-T cycles on the resilient modulus is determined by the property of materials. In comparison, the effect of F-T cycles on the resilient modulus of the modified SC is less significant than on that of unmodified SC.