# 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 deformation of samples 1 and 2 tended to stabilize quickly, as shown in Figure 11. However, samples 3, 4, and 5 of over-wet soil exhibited a slow and long-lasting tertiary consolidation stage with time, meeting the criteria for dividing the three stages of compression. Figure 12a-c shows the relationship between the deformation and load in the three stages of compression of the over-wet soil. According to Equation (  
\[C_{i}=\frac{d_{t,i}}{d_{i}}\times 100\%, \tag{3}\]  
where \(C_{i}\) = proportion of creep at the \(i\)th load (%). \(d_{t,\ i}\) = deformation during the tertiary consolidation stage (i.e., creep) at the \(i\)th load (mm). \(d_{i}\) = total deformation at the \(i\)th load (mm). As shown in Figure 12, the deformations of the three samples during the primary consolidation stage differs slightly at 50 kPa. As the load increases, the deformation during the primary consolidation stage gradually increases and stabilizes, slightly decreasing at 400 kPa. The deformation during the secondary consolidation stage gradually increases as the load increases, and the increase rate is proportional to the water content. When the load exceeds the pre-consolidation pressure, the deformation increases rapidly. For the creep generated in the tertiary consolidation stage, when the load was below the pre-consolidation pressure, the creep of the over-wet soil was insignificant (<0.5 mm). When the load exceeded the pre-consolidation pressure, the creep variable rapidly increased by >3 mm, and the creep of specimen 5 reached 4.3 mm. As shown in Figure 12 (d), the proportion of creep deformation in the over-wet soil first decreased and then increased as the load increased. When the load was 400 kPa, the creep proportion exceeded 60% and increased as the water content increased. The total creep amount of the wet soil was calculated from 50 to 400 kPa (Table 5). Table 5 indicates a strong correlation between the creep deformation, creep strain, and water content of the over-wet soil. Figure 13 shows the creep curve of the over-wet soil with increasing water content. As the water content increases, the creep of over-wet soil increases linearly, with linear correlation coefficients exceeding 0.94 and an average value of 0.966, as shown in Figure 13. When the load is low, the creep rate decreases. As the load increases, the creep rate significantly increases when the load exceeds the pre-consolidation pressure. Figure 12: Analysis of the compression stage of over-wet soil. (**a**) Deformation during the primary consolidation stage. (**b**) Deformation during the secondary consolidation stage. (**c**) Deformation during the tertiary consolidation stage. (**d**) Proportion of creep. \begin{table}
\begin{tabular}{l l l l} \hline \hline
**Number** & **3** & **4** & **5** \\ \hline Water content/\% & 17.65 & 21.13 & 26.06 \\ Creep deformation/mm & 4.58 & 4.51 & 5.09 \\ Creep strain & 0.014 & 0.034 & 0.016 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Creep of three specimens. The creep coefficient of over-wet soil was proposed based on the data in Figure 13 and Table 6 as the ratio of creep strain to water content, as shown in the following Equation (4):  
\[\varepsilon_{c}=\lambda w, \tag{4}\]  
where \(\varepsilon_{c}=\) creep strain of over-wet soil. \(\lambda=\) creep coefficient of over-wet soil. \(w=\) water content (%). The compression data of large-sized specimens indicate that the data of small-sized specimens [10; 11] underestimated the creep deformation of over-wet soil, which can mislead the disposal measures and affect the progress and quality of the project. On the other hand, during the experimental process, the water content of the sample needs to be given special attention.