# Seismic Response of Aeolian Sand High Embankment Slopes in Shaking Table Tests
## 4 Failure Mode Analysis of Models  
[PERSON] [45] classified the instability mechanism of natural slopes under strong earthquakes into several types, in which tension-shattering sliding mainly occurs in the toppling slopes or in transverse structural slopes. The failure process is that under strong earthquakes, vertical tensile cracks form in the slope. Meanwhile, horizontal cracks, which are generated by tensile shear destruction, also form inside the slope due to horizontal acceleration. Then, the collapse area was formed by the connection of vertical cracks and horizontal cracks, which resulted in tension-shattering sliding. Such landslides are usually characterized by a rough steep sliding surface [46; 47; 48; 49].  
According to the failure mode of models under sinusoidal waves, it was found that the instability mechanism of model 2 and model 3 belong to the tension-shattering sliding type (Figure 13). Moreover, the instability mechanism of these two models is in accordance with the defined destruction stages. At the AMA stage, horizontal cracks that extend to the slope surface were formed and these cracks connected with the vertical tensile cracks, resulting in tension-shattering sliding. The tension-shattering sliding is dominated by the properties of sand, especially the internal friction angle. The collapse accumulation includes accumulation under strong earthquakes and accumulation under gravity.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Magnifications under E3 Condition**} & \multicolumn{6}{c}{**Magnifications under L3 Condition**} \\ \hline  & \multicolumn{2}{c}{**Relative Height/mm**} & **Inside** & **Surface** & **Difference** & **Average** & **Inside** & **Surface** & **Difference** & **Average** \\ \hline \multirow{3}{*}{**Model 1**} & 300 & 1.080 & 1.162 & 0.082 & & 1.159 & 1.249 & 0.09 & \\  & 500 & 1.174 & 1.260 & 0.086 & 0.0723 & 1.310 & 1.383 & 0.073 & 0.0810 \\  & 700 & 1.332 & 1.381 & 0.049 & & 1.448 & 1.528 & 0.08 & \\ \hline \multirow{3}{*}{**Model 2**} & 300 & 1.423 & 1.417 & 0.006 & & 1.243 & 1.259 & 0.016 & \\  & 500 & 1.588 & 1.622 & 0.034 & 0.0147 & 1.415 & 1.417 & 0.002 & 0.0090 \\  & 700 & 1.722 & 1.718 & 0.004 & & 1.550 & 1.541 & 0.009 & \\ \hline \multirow{3}{*}{**Model 3**} & 300 & 1.449 & 1.443 & 0.006 & & 1.331 & 1.309 & 0.022 & \\  & 500 & 1.648 & 1.647 & 0.001 & 0.0030 & 1.486 & 1.488 & 0.002 & 0.0110 \\ \cline{1-1}  & 700 & 1.726 & 1.728 & 0.002 & & 1.634 & 1.625 & 0.009 &Model 1 only shows partial collapse during the test as shown in Figure 14. According to the above-mentioned context, model 1 only experienced the RWE stage and the RWS stage. The micro cracks that were generated at the RWS stage cannot lead to the collapse of model 1, but these micro cracks connect with small tensile cracks at the slope surface; then, the instability of this part happened under gravity, and a partial collapse occurred.  
On the other hand, it also shows that the slope ratio has a significant influence on the seismic capacity of aeolian sand high embankments.  
Figure 14: Partial collapse of model 1.  
Figure 13: Tension-shattering sliding of model 2 and model 3.