Safety Assessment of Tunnel Shield Construction for Existing Adjacent Bridges

Table 3

Calculated vertical and differential settlement for each construction stage.

Bearing platform number	Double-line construction completed
	Vertical displacement (mm)	Differential settlement (mm)	Character space, L (m)	Differential settlement rate (‰)
P177	0.17	1.49	30.0	0.0496
P178	1.66
		0.65	40.0	0.0163
P179	1.01
		0.85	30.0	0.0283
P180	0.16

Note. Vertical settlement is the value taken at the top surface of the central point of the bearing.