## 4 Conclusions  
In this paper, the results of a wide range of tests were presented to evaluate the behavior of compacted sandy silt soil. Knowledge about soil response to dynamic loads is essential for road and earth construction designers. Based on these results, the following conclusions may be presented: \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Index** & **Model (16)** & **Model (17)** & **Model (18)** & **Model (19)** & **Model (21)** \\ \hline ME & 14.83 MPa & 14.07 MPa & -7.97 MPa & 7.95 MPa & -2.80 MPa \\ MPE & 10.37\% & 9.92\% & -0.16\% & 14.27\% & 2.44\% \\ MAE & 20.97 MPa & 20.79 MPa & 36.11 MPa & 68.18 MPa & 9.84 MPa \\ MAPE & 14.89\% & 14.85\% & 26.60\% & 46.73\% & 7.43\% \\ \(\rm I^{2}\) & 0.0371 & 0.0356 & 0.0883 & 0.5243 & 0.0078 \\ \(\rm I_{1}^{2}\) & 30.51\% & 28.72\% & 3.66\% & 0.61\% & 5.18\% \\ \(\rm I_{2}^{2}\) & 6.77\% & 5.69\% & 77.67\% & 79.24\% & 0.01\% \\ \(\rm I_{3}^{2}\) & 62.72\% & 65.59\% & 18.67\% & 20.15\% & 94.81\% \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Ex-post analysis result for maximum shear modulus models. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Sample No. ** & **Test Results** & **Model (16)** & **Model (17)** & **Model (18)** & **Model (19)** & **Model (21)** \\ \hline Bender Element test & 125.3 & 149.6 & 150.9 & 0.0 & 0.0 & 137.0 \\  & 132.2 & 149.6 & 150.9 & 0.0 & 0.0 & 143.1 \\  & 138.0 & 151.7 & 153.4 & 203.2 & 103.5 & 152.2 \\  & 145.3 & 151.7 & 153.4 & 222.7 & 97.9 & 152.2 \\  & 165.1 & 151.7 & 153.4 & 228.8 & 95.8 & 152.2 \\  & 184.3 & 153.8 & 155.9 & 251.2 & 171.1 & 167.3 \\  & 197.1 & 153.8 & 155.9 & 261.3 & 316.3 & 197.6 \\  & 213.1 & 153.8 & 155.9 & 263.8 & 312.0 & 197.6 \\  & 222.7 & 153.8 & 155.9 & 271.4 & 591.8 & 258.1 \\
1.1 & 87.6 & 68.9 & 68.9 & 67.2 & 102.7 & 100.7 \\
1.2 & 104.9 & 84.4 & 84.3 & 82.6 & 102.7 & 107.4 \\
1.3 & 122.6 & 97.5 & 97.4 & 96.4 & 102.7 & 114.0 \\
2.1 & 91.6 & 72.1 & 72.0 & 68.7 & 68.0 & 98.4 \\
2.2 & 102.7 & 88.3 & 88.2 & 84.9 & 68.0 & 105.71. The soil compacted with the Proctor method in this study was tested to find preconsolidation stress. The oedometric test results clearly showed that the preconsolidation stress increased with the increase of moisture content during the compaction, and higher soil dry density resulted in higher preconsolidation pressure, which was equal to 450 kPa in optimal moisture content. The soil suction in optimum moisture content was equal to 4-5 kPa, which was also favorable during the compaction process. 2. The resonant column test revealed a high correlation of shear modulus degradation and damping characteristics with the maximum shear modulus value G\({}_{0}\). As presented in this article, modeling of the soil's reaction to dynamic loading showed that if the information about \(G_{0}\) were provided, the stiffness and damping characteristics could be modeled with the use of commonly known models. 3. The \(G_{0}\) values also rose with the increase of soil compaction. The lowest values of \(G_{0}\) were between 82 and 87 MPa (for samples compacted with moisture content other than optimum and in \(\sigma^{\prime}_{3}\) equal to 30 kPa). The highest \(G_{0}\) was registered for the sample with optimum moisture content (equal to 123.9 MPa in \(\sigma^{\prime}_{3}\) equal to 60 kPa), but we also noted the impact of \(\sigma^{\prime}_{3}\) on the maximum shear modulus value where for \(\sigma^{\prime}_{3}\) equal to 150 kPa, \(G_{0}\) was equal to 163.1 MPa. 4. The bender element suction-controlled unsaturated triaxial test showed the impact of the suction on \(G_{0}\) where for \(S_{r}=\)0.41 (suction \(s\) equal to 200 kPa), \(G_{0}\) was equal to 222.7 MPa (the soil sample was compacted in optimum moisture content, \(\sigma^{\prime}_{3}=100\) kPa). 5. Finally, we made the effort in the mathematical modeling of \(G_{0}\) using known equations for saturated and unsaturated soils. The results of the calculation were then evaluated with the use of ex post methods.