# Compression Law and Settlement Calculation Method of Over-Wet Soil Based on Large Samples
## 3 Results and Discussion  
### Analysis of Compression Deformation of Over-Wet Soil  
The graphical method proposed by [PERSON] was employed to calculate the samples' pre-consolidation pressures [16]. Figure 7 shows the \(d-\log\)\(P\) curves for five samples, and sample 3 is used as an example for the calculation. The abscissa of point A, determined using the graphical method, represents the maximum stress experienced historically. Table 4 lists the results for the five samples, indicating that the pre-consolidation pressure increases with increasing compaction. \begin{table}
\begin{tabular}{p{42.7 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt} p{56.9 pt}} \hline \hline
**Number** & **Target Water Content/\%** & **Actual Water Content, \(w\)/\%** & **Dry Density/g-cm\({}^{-3}\)** & **Compaction Degree, \(K\)/\%** & **Humidity/\%** \\ \hline
1 & 8 & 7.80 & 1.702 & 96.4 & 112 \\
2 & 13 & 13.09 & 1.728 & 97.9 & 100 \\
3 & 18 & 17.65 & 1.687 & 95.6 & 90 \\
4 & 21 & 21.13 & 1.675 & 94.9 & 82 \\
5 & 26 & 26.06 & 1.578 & 89.4 & 71 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Soil sample parameters. Figure 6: Thermogravimetric analysis system. Figure 8 shows the \(d-\)log\(t\) curves of the standard compression test (\(h=20\) mm) with sample number 3. It can be seen from the figure that the \(d-\)log\(t\) curve of the standard compression specimen is not significantly different from that of general soft soil, which conforms to the anti-\"\(S\)\" deformation law. Figure 9 shows the \(d-\)log\(t\) curves of large samples. The deformation curves of samples 1 and 2 conform to the anti-\"\(S\)\" deformation law when the load is less than the pre-consolidation pressure. The anti-\"\(S\)\" shape of sample 2 disappears when the load exceeds the pre-consolidation pressure. Samples 3, 4, and 5 do not exhibit an inverse \"\(S\)\" deformation law at any loads. As the deformation increases, the \(d-\)log\(t\) curves gradually approach a stable secondary consolidation stage because samples 1 and 2 are non-over-wet soils with high compaction. Thus, the long-term deformation is insignificant. However, when the load was low, the deformation of the over-wet soil gradually increased as the compaction degree decreased. When the load exceeded the pre-consolidation pressure, the deformation of the sample was no longer positively correlated with the compaction degree but increased as the water content increased. \begin{table}
\begin{tabular}{l l} \hline \hline
**Number** & **Pre-Consolidation Pressure/kPa** \\ \hline
1 & 304 \\
2 & 316 \\
3 & 297 \\
4 & 281 \\
5 & 257 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Pre-consolidation stress of the samples. Figure 8: \(d-\)log\(t\) curves of standard samples (Number 3). Figure 7: \(d-\)log\(P\) curves of the samples. Because the x-axis of the \(d-\)logf curve is a logarithmic function of time, analyzing the compression law of over-wet soil based on this curve results in the compression of the x-axis, weakening the characteristics of long-term deformation. Therefore, the conventional analysis methods for the primary and secondary consolidation stages have limitations with excessively wet soil. A significant difference between the compression process of over-wet soil and general soft soil exists, as shown in Figure 9, which is similar to that of peat soil with a similarly high water content (Figure 9f). [PERSON] et al. [19] proposed a three-stage compression method based on the long-term creep process of peat soil, as shown in Figure 10, in which the third consolidation stage is a uniformly slow creep stage. Figure 9: \(d-\)logf curves of five samples [17; 18; 19]. To analyze the creep process of over-wet soils, the division method of the three stages of compression was employed to draw the \(d-t\) curve, similar to that in Figure 10, using 300 kPa as an example (Figure 11).