## 3 Results and Discussion
### Mechanical Parameters  
#### 3.2.1 Unconfined Compressive Strength and Failure Strain  
Figure 4 shows the unconfined compressive strength \(q_{\text{u}}\) variations under different cement contents and curing time. As the cement content increased, the strength exhibited a roughly linear increase in Figure 4a. Additionally, the \(q_{\text{u}}\) also increased with the increasing curing time in Figure 4b. This strength enhancement is primarily attributed to binding compounds, such as calcium silicate hydrates (C-S-H), calcium aluminate hydrates (C-A-H), and Ettringite (AFt), produced by hydration and the pozzolanic reaction of cement [36]. This positive correlation between the unconfined compressive strength and cement content, as well as the curing time, aligns with previous observations in solidified soil [37]. The \(q_{\text{u}}\) of the soil-based CLSMs for different cement contents and curing time periods ranged from 564.0 to 3436.6 kPa, which did not exceed 8300 kPa, facilitating future excavation [38]. Significantly, after a curing time period of 7 days, the \(q_{\text{u}}\) values of T1 and T2 were 930.3 kPa and 564.0 kPa, respectively. The \(q_{\text{u}}\) of T1 was higher than that of T2, as illustrated in Figure 4. This trend persisted across different curing time periods. It is crucial to note  
Figure 4: Strength \(q_{\text{u}}\) under different (a) cement contents and (b) curing time. Figure 3: Flow value and fresh density under different (**a**) cement contents and (**b**) initial water contents. that the T1 samples were prepared by compaction in molds, resulting from the lack of flowability. In contrast, the T2 samples were prepared by casting in molds, benefiting from good flowability. The presence of compaction energy led to higher strength in the T1 specimens. Additionally, [PERSON], et al. [39] pointed out that PCE is adsorbed on the surface of binder particles and inhibits the hydration reaction. The PCE mass was determined based on the total mass of the dry soil and cement. The high dosage of PCE in soil-based CLSMs, combined with cement particles, may form local groups of entangled polymers, leading to the entrapment of additional water otherwise used for hydration reactions [40]. The relationships among the initial water content, curing time, and the \(q_{\text{u}}\) are shown in Figure 5. As the initial water content increased, the \(q_{\text{u}}\) of the soil-based CLSMs decreased significantly in Figure 5a. The \(q_{\text{u}}\) increased with the higher curing time in Figure 5b. Furthermore, the increasing rates of \(q_{\text{u}}\) for the initial water content of 38.8% and 46.5% were higher than those of \(q_{\text{u}}\) for the initial water content of 62% and 80%. Mixtures with an initial water content of 38.8% and 80% had the same flowability, as shown in Figure 3, whereas the strength corresponding to the initial water content of 38.8% was 2.6\(\sim\)2.8 times the strength corresponding to the initial water content of 80% for different curing ages. This indicated that a large amount of water was added to increase the flow value, while the consumption of the hydration reaction of cement was limited; the excess water ultimately leads to a reduction in the strength of soil-based CLSMs. [PERSON], et al. [41] pointed out that flowable soil-based CLSMs have an especially higher water content due to the requirement of flowability, compared to cemented soil. Therefore, compared with an increasing water content, the addition of PCE could effectively increase the flow value and strength of soil-based CLSMs. The failure strain \(\varepsilon_{\text{f}}\) is an important parameter for assessing the deformation characteristics of geotechnical materials [42]. In Figure 6, \(\varepsilon_{\text{f}}\) predominantly fell within the range of 1.0% to 2.0%, corresponding to \(q_{\text{u}}\) values ranging from 0.11 to 3.44 MPa. According to [PERSON], et al. [43], a failure strain of less than 2% indicates a typical brittle failure in the specimens.