## 4 Results and Discussion  
### Disintegration Processes  
The morphological features of soil sample E3 without MICP treatment are shown in Figure 4. When the soil sample is immersed in water, numerous bubbles appear on the surface of the soil sample, as shown in Figure 4a. At this stage, the soil disintegration rate is lower than the water absorption rate, resulting in a continuous increase in the balance reading. Due to the continuous absorption of water, the soil sample gradually saturates. Afterward, violent disintegration occurs, and cracks appear on the surface of the soil sample, as shown in Figure 4b. The sample collapses from the side to the center. Large bubbles are generated, and the water becomes turbid. At \(t=300\) s, the soil almost completely fell into the bottom of the box (complete disintegration). Water enters the pores between soil particles, leading to an increase in soil moisture content and a decrease in \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample Number**} & **Bacterial Solution** & **Cementation Solution** & **Treatment Cycle** \\  & **(OD\({}_{600}\))** & **Concentration (mol/L)** & **Treatment Cycle** \\ \hline A1\(\sim\)A4 & 0.25 & 0.4, 0.8, 1.2, 1.6 & 1 \\ \hline A5\(\sim\)A8 & 0.5 & 0.4, 0.8, 1.2, 1.6 & 1 \\ \hline A9\(\sim\)A12 & 0.75 & 0.4, 0.8, 1.2, 1.6 & 1 \\ \hline A13\(\sim\)A16 & 1.0 & 0.4, 0.8, 1.2, 1.6 & 1 \\ \hline B1\(\sim\)B4 & 0.25 & 0.4, 0.8, 1.2, 1.6 & 3 \\ \hline B5\(\sim\)B8 & 0.5 & 0.4, 0.8, 1.2, 1.6 & 3 \\ \hline B9\(\sim\)B12 & 0.75 & 0.4, 0.8, 1.2, 1.6 & 3 \\ \hline B13\(\sim\)B16 & 1.0 & 0.4, 0.8, 1.2, 1.6 & 3 \\ \hline C1\(\sim\)C4 & 0.25 & 0.4, 0.8, 1.2, 1.6 & 5 \\ \hline C5\(\sim\)C8 & 0.5 & 0.4, 0.8, 1.2, 1.6 & 5 \\ \hline C9\(\sim\)C12 & 0.75 & 0.4, 0.8, 1.2, 1.6 & 5 \\ \hline C13\(\sim\)C16 & 1.0 & 0.4, 0.8, 1.2, 1.6 & 5 \\ \hline D1\(\sim\)D4 & 0.25 & 0.4, 0.8, 1.2, 1.6 & 7 \\ \hline D5\(\sim\)D8 & 0.5 & 0.4, 0.8, 1.2, 1.6 & 7 \\ \hline D9\(\sim\)D12 & 0.75 & 0.4, 0.8, 1.2, 1.6 & 7 \\ \hline D13\(\sim\)D16 & 1.0 & 0.4, 0.8, 1.2, 1.6 & 7 \\ \hline E1\(\sim\)E4 & 0 & 0 & \(1,3,5,7\) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental schemes. suction, ultimately leading to disintegration. The disintegration processes can be divided into three processes: water absorption, exhaust, and disintegration. Figure 5 depicts the disintegration process of soil treated by MICP technology. Due to the cementation and filling effect of calcium carbonate crystals on surface soil particles, the disintegration process of soil samples treated with MICP is different from that of soil samples without treated samples. The disintegration time of soil samples with one cycle of treatment is considerably longer than those without treatment, and the soil sample is also completely disintegrated. The disintegration process of soil sample B11 shows that its water absorption rate has slowed down, and the water absorption time has been significantly prolonged. Due to the formation of a reinforcement layer on the surface of the soil after MICP treatment, which allows the sample to remain relatively complete after absorbing water, the turning point from water absorption to collapse is significantly prolonged. The residual quality of the soil sample decreases, but the speed is relatively slow. When the residual mass decreases to around 40 g, the sample remains stationary on the wire mesh and no longer disintegrates. As shown in Figure 5, due to the cementation effect of the reinforcement layer, the soil particles are tightly bound, resulting in incomplete disintegration. Figure 4: Disintegration process without treatment (complete disintegration). Figure 5: Disintegration process of incomplete disintegration. Soil sample D11 has no traditional disintegration processes within 300 s. After the water enters the soil sample, only a slow water-absorption process occurs. This is because the surface reinforcement layer of the soil sample can fully wrap the entire soil sample to prevent disintegration after multiple cycles of MICP treatment.