# Experimental Study of Material Proportioning for Similar Modeling of Brittle Rocks
## 3 Experimental Results and Analysis
### Sensitivity Analysis of Factors
#### 3.2.5 Sensitivity Analysis of the Rockburst Tendency Index  
As shown in Figure 9, the rockburst tendency index of the specimens initially increased with an increase in the quartz sand content and the rosin-alcohol solution concentration and then gradually decreased. When the quartz sand content and the rosin-alcohol solution concentration reached 10% and 20%, respectively, the rockburst tendency index attained its maximum value. The overall trend indicated that the rockburst tendency index of the specimens decreased with increasing gypsum content and rosin-alcohol solution dosage, while the refined iron powder-barite powder ratio had no significant effect on the rockburst tendency index. The rockburst tendency is closely related to the strength and deformation characteristics, microstructure, and energy storage and release capacity of the specimen, involving highly complex physical mechanisms. The cementing effect of the rosin-alcohol solution enhances the compressive strength, tensile strength, and elastic modulus of the specimen, \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Average Value** & **A** & **B (\%)** & **C (\%)** & **D (\%)** & **E (\%)** \\ \hline Average value 1 & 0.330 & 0.492 & 0.357 & 0.162 & 0.363 \\ Average value 2 & 0.359 & 0.364 & 0.310 & 0.324 & 0.343 \\ Average value 3 & 0.370 & 0.338 & 0.359 & 0.376 & 0.367 \\ Average value 4 & 0.399 & 0.342 & 0.425 & 0.389 & 0.383 \\ Average value 5 & 0.462 & 0.384 & 0.469 & 0.669 & 0.465 \\ Range & 0.132 & 0.154 & 0.159 & 0.507 & 0.122 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Range analysis of the elastic modulus. Figure 8: Sensitivity analysis of the elastic modulus. facilitating elastic energy storage. As a result, increasing the solution concentration significantly raised the rockburst tendency of the specimen. However, the strong cementation effect also reduced the specimen's brittleness, increasing energy dissipation through deformation. Consequently, a higher solution dosage reduced the likelihood of a sudden brittle failure, leading to an overall decline in the rockburst tendency. Gypsum increased the brittleness and elastic modulus of the specimen while exerting minimal influence on its strength. This resulted in a limited deformation of the specimen, restricting energy storage before reaching its peak strength. Quartz sand, as a reinforcing material, enhances the overall stiffness of the specimen and improves its energy storage capacity. As the quartz sand content increases, an insufficient bonding strength or interface weakening between the particles may occur, leading to greater energy dissipation. When the quartz sand content reaches a higher threshold, the mutual support between particles is significantly enhanced, leading to an increase in the proportion of internal particle cracking and a higher porosity. This results in greater instability of the specimen's skeletal structure and heightened destructiveness of the failure. These mechanisms collectively contribute to the nonlinear characteristics of rockburst tendency. Refined iron powder and barite powder, as fine aggregates, improve the strength and modulus of the specimen while also influencing its microstructure. However, their overall effect on rockburst tendency is not significant. The range analysis of the rockburst tendency index (as shown in Table 8) indicated that the concentration of the rosin-alcohol solution had the most significant impact on the rockburst tendency index, with a range of 0.99. In contrast, the refined iron powder-barite powder ratio showed the least influence, with a range of 0.33. The sensitivity ranking of the factors affecting the rockburst tendency index is as follows: D > E > B > C > A.