## 6 Conclusions  
The basic mechanical parameters (i.e., Poisson's ratio \(\mu\), elastic modulus \(E\), uniaxial compressive strength \(\sigma_{c}\), and uniaxial tensile strength \(\sigma_{t}\)) and bursting liability indices (i.e., elastic strain energy index \(W_{ET}\), bursting energy index \(W_{\mathit{cf}}\), dynamic fracture duration time \(DT\), and brittleness index \(B\)) of coals and non-coal rocks are compared in detail in this study. The main conclusions are as follows:  
1. The basic mechanical parameters (\(\sigma_{c}\), \(E\), and \(\sigma_{t}\)) of coal and non-coal rocks are quite different in distribution range. The \(\sigma_{c}\), \(E\), and \(\sigma_{t}\) maximum values of coals are 50 MPa, 46 GPa, 4 MPa, respectively. The maximum value of \(\sigma_{c}\) of non-coal rocks is six times higher than that of coals, and the maximum values of \(E\) and \(\sigma_{t}\) of non-coal rocks are about two and five times higher than that of coals, respectively. The \(\mu\) values of coal and non-coal rocks share a similar distribution range.
2. The \(W_{ET}\), \(W_{\mathit{cf}}\) and \(B\) of coals and non-coal rocks share similar distribution ranges, and the distribution ranges of \(\sigma_{c}\) and \(DT\) for coals are much smaller than these for non-coal rocks. It can be concluded that the classification criteria of \(W_{ET}\) and \(W_{\mathit{cf}}\) for coals are suitable for non-coal rocks, while that of \(\sigma_{c}\) and \(DT\) are not suitable.
3. The consistency rate of the bursting liability evaluation results of coals is only about 32-58%, and it is necessary to define a comprehensive method to evaluate the bursting liability of rocks.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Rock Type**} & **Underground** & **Geo-Stress** & \multirow{2}{*}{\(\sigma_{c}\)/MPa} & \multirow{2}{*}{**Depth/m**} & **Rockburst** & \multirow{2}{*}{**Literature**} \\  & **Engineering** & **(the Max)/MPa** & & & & **(y/n)** & \\ \hline \multirow{8}{*}{Coal} & Goajapu Coal Mine & 37.29–38.67 & 18.18–20.47 & 820–1089 & y & \\  & Huijahe Coal Mine & 18.04–33.87 & 24.27–24.35 & 600–750 & y & \\  & Meng  
* For non-coal rocks, the classification criterions of brittleness index \(B\) and strength decreases rate \(SDR\) (the ratio of uniaxial compressive strength \(\sigma_{c}\) and fracture duration time \(DT\)) have been redefined in this study as follows:
* The classification criterion of the brittleness index \(B\): heavy bursting liability with \(B\geq 17\); weak bursting liability with \(9\leq B<17\); no bursting liability with \(B<9\).
* The classification criterion of the strength decrease rate \(SDR\): heavy bursting liability with \(SDR>0.3\) MPa/ms; weak bursting liability with \(0.015<SDR\leq 0.3\) MPa/ms; no bursting liability with \(0<SDR\leq 0.015\) MPa/ms.  
The following are available online at [[https://www.mdpic.com/2076-341](https://www.mdpic.com/2076-341)]([https://www.mdpic.com/2076-341](https://www.mdpic.com/2076-341)) 7/11/6/2641/s1, Table S1: Basic mechanical parameters of coals in China, Table S2: Basic mechanical parameters of non-coals in China, Table S3: Rockburst indices data of coals in China, Table S4: Rockburst indices data of non-coals in China.  
Conceptualization, K.D. and S.W.; Formal analysis, Y.S.; Funding acquisition, K.D. and S.W.; Investigation, Y.S.; Methodology, K.D. and S.L.; Supervision, K.D. and S.W.; Writing--Original draft, Y.S. and S.Y.; Writing--Review & Editing, K.D. and S.W. All authors have read and agreed to the published version of the manuscript.  
This study was funded by the National Natural Science Foundation of China (Nos: 51904333, 51774326 and 41702350), and the Fundamental Research Funds for the Central Universities of Central South University (No. 2020 zzts/714).  
Not applicable.  
The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.