## 3 Experimental Design
### Result Analysis
#### 3.3.5 Analysis of Pull-Out Capacity  
As an important component of the anchor-shotcrete support, anchor bolts must have a certain anchorage and pull-out capacity. For a water-absorbing and compaction anchoring bolt, as a new type of functional anchor bolt, its ultimate pull-out capacity is also an important parameter of concern in its design. Figure 15 shows the ultimate load-displacement curves of anchor bolts 1#, 2#, 3#, and 4#. As can be seen from Figure 15, the load-displacement curve of the anchor bolts is nonlinear. With the uniform increase in the load, the displacement of the anchor bolts gradually increases. The ultimate pull-out capacity of the mortar-bonded anchor bolt 1# is 9.2 kN, while the ultimate pull-out capacities of the water-absorbing and compaction anchoring bolts 2#, 3#, and 4# are 11.6 kN, 12.2 kN, and 12.8 kN, respectively. The ultimate pull-out capacity of the water-absorbing and compaction anchoring bolts is better than that of the mortar-bonded anchor bolt. Compared to anchor bolt 1#, the pull-out capacities of anchor bolts 2#, 3#, and 4# are increased by 26.1%, 32.6%, and 39.1%, respectively. Figure 14: Measurement of the diameter and surrounding soil moisture content after expansion in the water-absorbing and compaction anchoring section. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & \multicolumn{2}{c}{**Radius**} & \multicolumn{4}{c}{**Moisture Content**} & \multicolumn{2}{c}{**Density**} \\  & \multicolumn{2}{c}{**2\(\mathbf{r_{0}}\) (cm)**} & \multicolumn{4}{c}{**\(\mathbf{\omega}\) (\%)**} & \multicolumn{4}{c}{**\(\mathbf{\rho}\) (g/cm\({}^{3}\))**} \\ \cline{2-10}
**Number** & \begin{tabular}{c} **Before** \\ **the Experiment** \\ \end{tabular} & \begin{tabular}{c} **After the** \\ **Experiment** \\ \end{tabular} & \begin{tabular}{c} **Growth** \\ **Rate** \\ \end{tabular} & \begin{tabular}{c} **Before** \\ **the Experiment** \\ \end{tabular} & \begin{tabular}{c} **After the** \\ **Experiment** \\ \end{tabular} & \begin{tabular}{c} **Decase** \\ **Rate** \\ \end{tabular} & \begin{tabular}{c} **Before** \\ **the Experiment** \\ \end{tabular} & \
\begin{tabular}{c} **After the** \\ **Experiment** \\ \end{tabular} &
\begin{tabular}{c} **Growth** \\ **Rate** \\ \end{tabular} \\ \hline
1\# & 7.5 & 7.5 & / & 22.97 & 23.1 & / & 1.43 & 1.42 & / \\
2\# & 7.5 & 8.3 & 10.6\% & 22.98 & 22.21 & 3.3\% & 1.43 & 1.48 & 3.5\% \\
3\# & 9.0 & 12.1 & 34.4\% & 23.1 & 22.14 & 4.2\% & 1.43 & 1.54 & 7.7\% \\
4\# & 10.0 & 13.5 & 35\% & 23.2 & 22.06 & 4.9\% & 1.43 & 1.58 & 10.5\% \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparative analysis of the soil physical properties before and after expansion in the water-absorbing and compaction anchoring section. The variation patterns of temperature, pore water pressure, and compaction stress around the soil mass surrounding the water-absorbing and compaction anchoring anchor rod, as well as the physical property parameters of the soil mass in the consolidation zone, are generally consistent with those observed around lime piles in composite foundations [31; 34] and micro-lime piles and soil-nailing composite supporting structures [35; 39]. This truly reflects the qualitative laws of water-heat-force changes during the water absorption, curing, and exothermic reaction process of the water-absorbing and compaction anchoring anchor rod. The water-absorbing and compaction segment of the anchor rod effectively improves the density of the soil mass in the water-absorbing and compaction consolidation zone and enhances the soil strength parameters. On the other hand, the mortar-anchored anchor rod does not have a water-absorbing and compaction consolidation effect, and there is no significant change in the density and strength parameters of the soil mass above it.