# Experimental Study on Engineering Properties of Cemented Soil with High Water Content
## 3 Test Results  
### Stress-Strain Curve  
The stress-strain curves of the cemented soil with 18% cement content after being cured for 28 days are shown in Figure 3, where \(\varepsilon\) is the axial strain, \(q\) is the deviatoric stress and \(\sigma_{3}\) is the confining pressure. As shown in Figure 3, the stress-strain curves of cemented soil under different confining pressures all showed softening behavior, and the stress-strain curve could be divided into three stages. In the first stage, the deviatoric stress initially grew linearly with strain; in the second stage, the deviatoric stress exhibited elastic-plastic characteristics when approaching the peak strength, and the brittle failure then occurred; in the third stage, the deviatoric stress almost remained stable as the strain kept increasing. Furthermore, the deviatoric stress of the cemented soil increased with the confining pressure in the first stage, while the growth rate decreased with confining pressure. The maximum deviatoric stress increased from 2353 kPa to 2605 kPa when the confining pressure increased from 0 to 400 kPa. The maximum deviatoric stress increased from 2605 kPa to 2738 kPa when the confining pressure increased from 400 kPa to 1600 kPa. Moreover, Figure 3 also indicates that the residual strength of deviatoric stress also increased with confining pressure. The stress-strain curves of cemented soil with different cement content are shown in Figure 4. The specimens were all under a 400 kPa confining pressure after being cured for 28 days. According to Figure 4, the cement content had a great impact on the peak strength of the cemented soil. The maximum deviatoric stress was 1047 kPa when the cement content was 6%, and the maximum deviatoric stress increased to 1977 kPa when the cement content was 12%. The maximum deviatoric stress finally increased to 2633 kPa when the cement content was 18%. Moreover, the softening feature also increased with the cemented soil strength. The residual deviatoric stress of cemented soil with 6% cement content was 774 kPa when the axial strain reached 15%, and the value of the residual/peak deviatoric stress was 0.74. The value of the residual deviatoric stress was 1110 kPa, and the value of residual/peak deviatoric stress decreased to 0.56 when the cement content of the cemented soil was 12%. The residual deviatoric stress was 1243 kPa, and the value of the residual/peak deviatoric stress was only 0.47 when the cement content of the cemented soil was 18%. Figure 3: Stress–strain curves of cemented soil after being cured for 28 days (cement content: 18%). The stress-strain curves of the cemented soil under 400 kPa confining pressure when the cement content was 18% are presented in Figure 5. As shown in Figure 5, the cemented soil strength increased with curing time. The maximum deviatoric stresses were 1440 kPa, 1929 kPa, 2284 kPa, and 2605 kPa, respectively, when the curing time was 3, 7, 14, and 28 days. Moreover, the softening feature of the cemented soil was more obvious with the increase in its strength. The values of the residual/peak deviatoric stress were 0.69, 0.67, 0.57 and 0.47, respectively, as the curing time increased from 3 to 28 days. [PERSON] and [PERSON] introduced the concept of the brittleness index \(I_{B}\) to quantify the behavior of a sharp decrease in the cemented soil after reaching the peak value [21], as shown in Equation (1):  
\[I_{B}=\frac{q_{p}-q_{r}}{q_{p}} \tag{1}\]  
where \(q_{p}\) is the peak strength of cemented soil and \(q_{r}\) is the residual strength of cemented soil. The brittleness index indicates the brittleness of the cemented soil. Figure 4: Stress–strain curves of the cemented soil under a 400 kPa confining pressure (curing time: 28 days). Figure 5: Stress–strain curves of the cemented soil under a 400 kPa confining pressure (cement content: 18%). The variation in the brittleness index of the cemented soil with confining pressure is presented in Figure 6. The cemented soil specimens were all cured for 28 days.