## 5 Results and Discussion  
### Water Environment  
The soil samples were saturated by different amounts of slurry without CMC. The water environment was deionized water. The electrical resistivity of soil samples is shown in Figure 5. For comparison purposes, the electrical resistivity of the slurry concentrations is also presented in this figure. Due to the increased number of ions, the electrical resistivity of soil samples and slurry decreased with the increase in slurry concentration. However, the slurry viscosity increased with the increase in the slurry concentration, which resulted in blocking the ionic migration in the soil pore space. Therefore, the decrease rates of the soil resistivity gradually slowed down when the slurry concentrations in the soil reached a high value. The electrical resistivity of soil samples and slurry can be fitted well by power functions with coefficients of determination \(R^{2}\) = 0.96 and 0.98, respectively, as a function of the slurry concentration, as shown below,  
\[\rho_{1}\ =\ 2.7504c^{-0.6636} \tag{2}\]  
where \(c\) refers to the slurry concentration. According to Equation (1), the formation factor \(F\) of the saturated soil can be expressed as,  
\[F\ =\ \frac{\rho}{\rho_{1}}\ =\ \alpha\varphi^{-m} \tag{3}\]  
The formation factor \(F\) reflects the influence of the soil structure on the electrical resistivity. A smaller value of \(F\) indicates that the soil structure is easier for the ions to pass through. Figure 6 shows the change in formation factors of soil with different amounts of slurry mixture. Micrographs of the soil samples with a 5\(\times\) magnification are also shown in this figure. They show that the \(F\) of soil samples increased with the increase in the slurry concentration. The microscope images show that the size of the slurry particles increased with the increase in slurry concentration. Although the mixture of the bentonite slurry can significantly increase the number of free ions, the soil structure can also be changed due to the aggregation of the bentonite particles. With the increase in the number and size of the slurry particles, it is much easier to clog the pore space of soil samples, which can reduce the free space of ion migration in the soil-slurry mixture samples. Therefore, the magnitude of soil resistivity is a result of competition between the soil formation factor and electrolytes. The slurry-induced changes in soil structure cannot be ignored when the slurry penetration is assessed in practical engineering, otherwise the magnitude as well as the migration distance of the slurry will be overestimated. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Soil Gradation**} & \multirow{2}{*}{**Water Environment**} & \multicolumn{2}{c}{**Slurry Penetration**} \\ \cline{3-4}  & & **Contents of CMC** & **Contents of** \\  & & **Solution** & **Bentonite** \\ \hline \multirow{4}{*}{I} & \multirow{4}{*}{0\%-Deionized water} & 0\% & 1–8\% \\  & & 1\% & 1–8\% \\ \cline{1-1}  & & 4\% & 1–8\% \\ \cline{1-1}  & 25\%-Searwater & 0\% & 1–8\% \\ \cline{1-1}  & 100\%-Searwater & 0\% & 1–8\% \\ \hline II & \multirow{4}{*}{0\%-Deionized water} & 0\% & 1–8\% \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \cline{1-1}  & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Test groups with different influence factors. As shown in Figure 6, the relation between the formation factor \(F\) and slurry concentrations \(c\) can be described by an exponential function as,  
\[F\ =\ \alpha(c)\cdot\varphi^{-m} \tag{4}\]  
where \(\alpha(c)=c^{0.2292}\) and \(m=1.64\) in this group of tests. Due to the influence of bentonite particles on the soil structure, the coefficient \(\alpha\) in Equation (4) was considered as a variable value instead of a constant. With the increased amount of offshore engineering, slurry has been applied more prevalently in the environment of seawater.