Ground Settlement of High-Permeability Sand Layer Induced by Shield Tunneling: A Case Study under the Guidance of DBN

Table 3

Engineering control standards.

Monitoring project	Control value (mm)	Cumulative warning value
		Yellow	Orange	Red
Ground settlement	-30 mm	-21 mm	-25.5 mm	-30 mm
(Bulge)	+10 mm	+7 mm	+8.5 mm	+10 mm
Segment uplifting	+20 mm	+10 mm	+15 mm	+20 mm