## 3 Test Results and Analysis
### Analysis of Orthogonal Test Results
#### 3.1.2 Analysis of Variance  
Extreme variance analysis processed the data briefly to derive a hierarchy of factors to obtain the optimal blending ratio in the case of multiple selected variables. However, the precision of the extreme variance analysis was insufficient, and the magnitude of the experimental error could not be estimated. In addition, it was not possible to give a precise quantitative estimate of the magnitude of the effect of the factors on the results of the experiment, nor could a criterion be proposed for determining whether the role of the factors examined was significant or not. Therefore, in order to compensate for the shortcomings of the extreme variance analysis, the ANOVA method was used. The results of the analysis are shown in Tables 4-6. Analysis of the ANOVA table incorporating 3d, 7d, and 28d compressive strengths using software showed that the F-ratio of cement at any age was greater than the F-critical value (a = 0.05). The effect of cement on the compressive strength of cured soil at 3d, 7d, and 28d was proven to be significant. The F-ratio of slag, shown in Tables 4 and 6, was \begin{table}
\begin{tabular}{l l l l l l l} \hline \hline \multirow{2}{*}{**Source of Variance**} & **Sum of Squared Deviations** & **Degrees of Freedom** & **Mean Square** & **F-Ratio** & **F-Critical Value (a = 0.05)** & **Significance** \\ \hline Cement & 3238.36 & 3 & 1079.45 & 26.06 & 9.28 & * \\ Fly ash & 22.49 & 3 & 7.50 & 0.18 & 9.28 & * \\ Blast furnace slag & 1140.03 & 3 & 380.01 & 11.59 & 9.28 & * \\ Phosphogypsum & 168.46 & 3 & 56.15 & 1.36 & 9.28 & \\ Inaccuracies & 124.27 & 3 & & & & \\ \hline \hline \end{tabular}  
* ** indicates that the factor has a significant effect on the compressive strength of cured soil in the variance test.  
\end{table} 
Table 4: Variance analysis table of 3d compressive strength. Figure 4: Analysis graph of the average unconfined compressive strength. greater than the F-critical value of 9.28 (a = 0.05), and the F-ratio of 7d slag was slightly less than the F-critical value of 5.39 (a = 0.1). This shows that among the industrial waste fractions, slag had a significant effect on the 3d and 28d compressive strength of cured soil. However, the F-ratios of fly ash and phosphogypsum were less than the F-critical values (a = 0.1), indicating that the effects of fly ash and phosphogypsum on the compressive strength of cured soil were not significant at 3d, 7d, and 28d. Based on the above ANOVA results, it can be proved that the results for the four different factors were chiefly consistent with the results of the extreme variance analysis. The optimal level combination of each factor still followed the extreme variance analysis results of A\({}_{4}\)B\({}_{4}\)C\({}_{4}\)D\({}_{1}\) (3d, 7d) and A\({}_{4}\)B\({}_{1}\)C\({}_{4}\)D\({}_{1}\) (28d). In addition to the effect on mechanical properties, economic indicators are also a factor to be considered. The prices of test materials required for local tests in Hengyang are 120 RMB/ton for fly ash, 115 RMB/ton for slag, 240 RMB/ton for phosphogypsum, and 345 RMB/ton for cement. The price per ton using curing agent Ratio I was RMB 237.9, and the price per ton of material using curing agent Ratio II was RMB 262.4. The prices of the two curing agents were 31.1% and 24.0% lower than that of pure cement. The Effect of Changes in Water Content on the Mechanical Properties and Workability of Fluid-Consolidated Soil  
We selected the orthogonal test results for Ratio I and Ratio II, with a curing agent mixing control at 35%. From the folded data in Figure 5, it can be seen that the mobility of the fluid-consolidated soil decreased substantially with a decreasing water content. The initial moisture content of Ratios I and II decreased from 220% to 140%, and the flow rate decreased from 104.2 mm and 95.5 mm, respectively. When the water content of the cured soil mix was less than or equal to 180%, the flows of both ratios were less than 160 mm (loss of pumpability).