Table 2 Summary of experimental test modes.
Test phase | Mode description | Excavation depth (mm) |
|---|---|---|
Condition 1 | Excavation from the top of the pit to the first strut level | 50 |
Condition 2 | Excavation zone A and zone B | 300 |
Condition 3 | Excavation zone C | 500 |
Condition 4 | Failure of strut no. 1 | 500 |
Condition 5 | Simultaneous failure of struts no. 1 and 2 | 500 |
Condition 6 | Complete failure of struts no. 1, 2, and 3 | 500 |
