Instability Mechanism of Cavity-Bearing Formation under Tunnel Excavation Disturbance

Table 4

Maximum settlement value at the same unloading level (cm).

Working conditions	Unloading pressure
	0.02	0.04	0.06	0.08
1	3.6	4.2	4.7	5.2
2	6.5	8.2	9.0	10.5