## 3 Numerical Simulation on Deformation of Embankment Combined with Subgrade
### Analysis of Numerical Results  
According to the finite element simulation, the stress strain diagram is obtained from different stages of the model. Figures 10 and 11 show the vertical and horizontal displacement of the cloud 1 year after the preloading of the drainage line model and equivalent sand-wall model. According to the practical positions of CJ1-1 and CJ1-2 in field, feature points C and H were chosen and the outputs of their vertical displacements are shown in Figure 12.  
As is shown in Table 7, at 1 year after preloading, as calculated by the drainage line model, the vertical displacement of C is \(-1465.97\) mm, and that of H is \(-1433.42\) mm. If calculated by the equivalent sand-wall model, the vertical displacement of C is \(-1460.87\) mm, and that of H is \(-1427.22\) mm. After 1 year of operation, at the time when construction is completed, as calculated by the drainage line model, the vertical displacement of C is \(-1502.21\) mm, and that of H is \(-1468.37\) mm. If calculated by the equivalent sand-wall model, the vertical displacement of C is \(-1497.00\) mm, and that of H is \(-1462.17\) mm. After operating for 30 years as calculated by the drainage line model, the vertical displacement of C is \(-1618.49\) mm, and that of H is \(-1581.07\) mm. If calculated by the equivalent sand-wall model, the vertical displacement of C is \(-1612.77\) mm, and that of H is \(-1573.11\) mm. According to the project experience, the settlement after operating for 30 years to the time that the road damages are small, the settlement from the time that the operation begins to the time of operating for 30 years is nearly called the settlement after construction. As calculated by the drainage plate model, the settlement after construction of C is \(146.18\) mm, and the vertical displacement of H is \(142.08\) mm. If calculated by the equivalent sand-wall model, the settlement after construction of C is \(146.64\) mm, and the vertical displacement of H is \(141.31\) mm. \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Settlement (mm)**} & \multicolumn{2}{c}{**Drainage Line Model**} & \multicolumn{2}{c}{**Equivalent Sand-Wall Model**} \\ \cline{2-5}  & **C Point** & **H Point** & **C Point** & **H Point** \\ \hline
1 year after preloading & \(-1465.97\) & \(-1433.42\) & \(-1460.87\) & \(-1427.22\) \\
1 year of operation & \(-1502.21\) & \(-1468.37\) & \(-1497.00\) & \(-1462.17\) \\
30 years of operation & \(-1618.49\) & \(-1581.07\) & \(-1612.77\) & \(-1573.11\) \\ Settlement after construction & \(146.18\) & \(142.08\) & \(146.64\) & \(141.31\) \\ \hline \end{tabular}
\end{table} 
Table 7: Variation of settlements of the field test section. Figure 11: Vertical and horizontal displacement of the equivalent sand-wall model after preloading by 1 year (m): (**a**) vertical displacement; (**b**) horizontal displacement. Figure 10: Vertical and horizontal displacement of the drainage line model after preloading by 1 year (m): (**a**) vertical displacement; (**b**) horizontal displacement. Therefore, using the drainage consolidation method to settle the soft soil embankment can achieve a good reinforcement effect and can effectively reduce the settlement after construction. Meanwhile, it can be seen that, as calculated by the drainage plate model, the settlement of the middle of the embankment is larger than that calculated by the equivalent sand-wall model, but the settlement curves of both models are highly similar. According to Figure 12, at a height of 7 m, comparing the settlements by the drainage plate model and equivalent sand-wall model at the finish of preloading, 1 year after preloading, and 30 years after operation, shows a high degree of fitting. The calculation of the soft consolidation of the creep model of soft is taken from the equivalent sand-wall model and drainage line model, and it is feasible to use just the equivalent sand-wall model.