# The Influence of Radial Stress on Mechanical Properties of Anchorage Structure
## 5 Conclusions  
In this paper, according to the phenomenon of radial splitting of the samples found in the laboratory model test, the effects of radial stress on the mechanical properties of the anchorage structure and the rock around the borehole were analyzed by using the maximum tensile stress criterion and the Mohr-Coulomb criterion. The main conclusions are as follows:  
\begin{table}
\begin{tabular}{l c c c c c c} \hline Confining pressures (MPa) & 0 & 1 & 2 & 4 & 8 & 16 \\ \hline Ultimate bearing capacity (kN) & 250 & 330 & 400 & 510 & 850 & 1140 \\ Maximum displacement (mm) & 4.2 & 14.7 & 18.5 & 23.5 & 38.7 & 51.5 \\ \hline \end{tabular}
\end{table}
Table 6: The ultimate bearing capacity and maximum displacement under different confining pressures.  
Figure 12: Relationship between confining pressure and ultimate bearing capacity of anchorage structure.  
1. The radial stress of anchorage section had a significant effect on the mechanical properties of anchorage structure, and the influence on the mechanical properties of the rock around the borehole cannot be ignored;
2. The confining pressure had little effect on the distribution of interfacial shear stress, but with the increase of confining pressure, the maximum value of interfacial shear stress increased obviously;
3. With the increasing of confining pressure, the anchorage structure was more adaptable to deformation and less prone to failure. The ultimate bearing capacity of anchorage structure increased linearly with the increase of confining pressure, and the effect of confining pressure on the ultimate bearing capacity was very significant;
4. According to the results of numerical analysis, the relationship between the confining pressure and the ultimate bearing capacity of anchorage structure was obtained. Although the specific values in the fitting curve needed to be further studied, it could be seen from the relationship between the two that the confining pressure on the anchorage section had a significant impact on the mechanical properties of anchorage structure.  
In this laboratory test, there was no confining pressure around the samples, which is different from the actual situation. However, many samples were split in the test, which further shows the influence of radial stress on the bearing capacity of anchorage structure was very significant. Therefore, this laboratory test is very valuable. In the follow-up research, we should develop a test method which can accurately reflect the influence of radial stress on the mechanical properties of anchorage structure, so as to further study the relationship between the two. These research work will provide theoretical basis for fully tapping the bearing capacity potential of an anchorage structure, saving support cost and promoting the development of anchorage theory.  
Conceptualization: Y.Z.; project administration: Y.Z.; methodology, Y.Z. and P.Z.; software, H.W.; validation, Y.Z. and H.W.; formal analysis, Y.Z.; investigation, H.W.; writing--original draft preparation, Y.Z.; writing--review and editing, Y.Z.; funding acquisition, Q.W. All authors have read and agreed to the published version of the manuscript. This research was funded by the National Natural Science Foundation of China (51804182) and the SDUST Research Fund (No. 2018 TDJH101). The authors declare no conflict of interest.