## 3 Experimental Results  
### Mechanical Response Characteristics of Continental Shale with Different Layer Orientations  
Since a single sample may not be sufficient to represent the failure behavior of shale under the corresponding loading angle, three samples were tested for each loading angle. The statistical results of the tests are shown in Table 1, and the displacements and loads evolution monitored are shown in Figure 4.  
As shown in Table 1 and Figure 4, the layer orientation has a significant effect on the peak load strength of continental shale. The peak load strength of continental shale increases with the increase of layer orientation. The displacement-peak load curve shows that, unlike the uniaxial compression deformation characteristics (Figure 5), the mechanical action stages of the Brazilian test of continental shale with different layer orientations are approximately the same, and all have experienced three stages of compaction, elasticity, and failure. The lack of yield stage is due to the higher brittleness index of continental shale and more developed lamination. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**No.**} & \multicolumn{6}{c}{**Layer Orientation (\({}^{\circ}\))**} \\ \cline{2-10}  & \multicolumn{2}{c}{**0**} & \multicolumn{2}{c}{**30**} & \multicolumn{2}{c}{**45**} & \multicolumn{2}{c}{**60**} & \multicolumn{2}{c}{**90**} \\ \cline{2-10}  & \multicolumn{2}{c}{**\(P\) (KN)**} & \multicolumn{2}{c}{\(\Phi\times H\) (mm)} & \multicolumn{2}{c}{\(P\) (KN)} & \multicolumn{2}{c}{\(\Phi\times H\) (mm)} & \multicolumn{2}{c}{\(P\) (KN)} & \multicolumn{2}{c}{\(\Phi\times H\) (mm)} & \multicolumn{2}{c}{\(P\) (KN)} & \multicolumn{2}{c}{\(\Phi\times H\) (mm)} \\ \hline
1 & 1.126 & 49.66 \(\times\) 24.95 & 1.837 & 49.94 \(\times\) 24.89 & 4.964 & 50.02 \(\times\) 25.22 & 6.208 & 49.96 \(\times\) 25.09 & 9.345 & 49.73 \(\times\) 25.02 \\
2 & 1.300 & 49.86 \(\times\) 24.97 & 2.195 & 50.01 \(\times\) 24.98 & 5.483 & 50.08 \(\times\) 25.09 & 6.873 & 50.10 \(\times\) 25.07 & 10.028 & 50.05 \(\times\) 25.03 \\
3 & 1.504 & 49.84 \(\times\) 25.02 & 2.574 & 49.98 \(\times\) 25.03 & 6.623 & 49.98 \(\times\) 24.95 & 7.739 & 49.96 \(\times\) 24.95 & 10.981 & 49.97 \(\times\) 24.98 \\ Mean & 1.310 & 49.82 \(\times\) 4.98 & 2.202 & 49.98 \(\times\) 24.97 & 5.690 & 50.03 \(\times\) 25.09 & 6.940 & 50.01 \(\times\) 25.04 & 10.118 & 49.92 \(\times\) 25.01 \\ SD & 0.154 & 0.118 \(\times\) 0.029 & 0.301 & 0.029 \(\times\) 0.058 & 0.693 & 0.041 \(\times\) 0.110 & 0.627 & 0.066 \(\times\) 0.062 & 0.671 & 0.136 \(\times\) 0.022 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Statistical table of Brazilian test data of continental shale. Figure 4: Peak load-displacement curves of continental shale with different layer orientations. Figure 3: Schematic diagram of lamination angle loading and AE sensors’ layout. In the initial stage of loading, the pores or micro-cracks inside the sample are compressed and deformed under the action of the load. Subsequently, under the continuously increasing loading, the deformation curve showed a concave upward trend and then is transformed into a nearly linear growth, which showed good elastic characteristics. When the loading has reached the peak, subsequently, it turns into a sharp drop in a straight, which is accompanied by the crisp sound of the sample fracturing and a little bit of debris splashing, thus, the sample is damaged. The test results and phenomena further verify that continental shale has high brittleness and poor ductility. Through the response characteristics of the characteristic point threshold value, for the load in each mechanical action stage under different layer orientations (Table 2), we found that the layer orientation has an important influence on the load response of the sample. Each characteristic threshold tends to increase with the increase of layer orientation. This is due to the lamination plane becoming closer to the horizontal distribution with the increase of layer orientation.