## 5 Test Data Analysis
### Analysis of the Strain Data  
In this test, six rock strain gauges were arranged at the surface of the rock strata to monitor the deformation inside the slope; the specific layout is presented in Figure 3. After observing the slope failure characteristics and the location of the strain gauges in this test, it was found that the strain gauges s1, s2, and s5 were closer to the toppling-bending zones, the strain gauge s4 was the closest to the strong toppling deformation zone near the crest of the slope, and the strain gauges s3 and s6 were located in the un-toppling zone below the toppling-bending zone. The variation curves for strain rate with time are shown in Figure 10, and the analysis was as follows:  
From the perspective of strain curve shape (Figure 11), the strain curves for s1 and s5, s3 and s6, and s2 and s4 had similar moving trends, related to the deformation positions they were located at. The strain gauges s1 and s5 were the closest to the toppling-bending zone, and the corresponding strain curves fluctuated the most dramatically. All the curves increased sharply (indicating rock mass failure) as the centrifugal acceleration increased to nearly 60 g, and the deformation response of the model with a slope angle of 75\({}^{\circ}\) was the fastest among the three slope models. The steep increase in the strain curves was the result of the instantaneous release of the strain energy when the rock mass toppled and broke. The rock strata, where the strain gauges s3 and s6 were located, almost had no toppling deformation; thus, the strain curves they corresponded to changed gently and did not indicate the trend of increasing with increasing centrifugal acceleration. The strain curves  
Figure 9: Curve of LVDT3 monitoring point, (**a**) displacement vs. time, (**b**) displacement changing ratio vs. centrifugal acceleration. even presented a certain number of negative values because of the effect of self-weight and overburden pressure. The shapes of the strain curves for s2 and s4 were similar to the change curve for the centrifugal acceleration, which showed a step-like growth shape. This indicated that the strain rate at the same site of the other slope models showed a gradual trend with time and acceleration changes, except for s4 located near the crest of the model with a slope angle of 75\({}^{\circ}\), which showed a steep increase in the strain due to intense deformation. The steeper the slope angle was, the faster the deformation response to centrifugal acceleration. The toppling-bending rupture zone and the crest of the slope are the parts inside the slope with serious deformation. It was found that strain gauge s1 near the slope foot was always the first to present mutation, earlier than strain gauge s5 located on the  
Figure 11: Model slope strain curves. (**a**) S1 and S5 strain curve, (**b**) S2 and S4 strain curve, (**c**) S3 and S6 strain curve. Figure 10: Model slope strain rate curves, (**a**) acceleration values and strain rate of key nodes in the development of the toppling bending zone, 1 rupture of 55\({}^{\circ}\) slope foot, 2 rupture of 65\({}^{\circ}\) slope foot, 3 rupture of 75\({}^{\circ}\) slope foot, 4 first-level toppling zone of 55\({}^{\circ}\) slope, 5 first-level toppling zone of 65\({}^{\circ}\) slope, 6 first-level toppling zone of 75\({}^{\circ}\) slope, 7 s-level toppling zone of 75\({}^{\circ}\) slope, 8 centrifugal acceleration curve, 9 S4 strain rate of 75\({}^{\circ}\) slope, 10 S1 strain rate of 55\({}^{\circ}\) slope, 11. S1 strain rate of 65\({}^{\circ}\) slope, 12. S1 strain rate of 75\({}^{\circ}\) slope, 13. S5 strain rate of 55\({}^{\circ}\) slope, 14. S5 strain rate of 65\({}^{\circ}\) slope, 15. S5 strain rate of 75\({}^{\circ}\) slope, 16. curve crest corresponding to rupture of slope foot. (**b**) slope of S3 strain rate curves, (**c**) slope of S4 strain rate curves. upper part of the slope. Comparing the steep increase in the strain curves, strain curve s4 showed the last mutation.