The Ground Settlement and the Existing Pipeline Response Induced by the Nonsynchronous Construction of a Twin-Tunnel

Table 3

Settlements of the ground surface and the pipeline with different spaces.

	Settlement range width (m)		Maximum settlement (mm)		Maximum settlement location (m)		Settlement curve shape
	Surface	Pipeline	Surface	Pipeline	Surface	Pipeline	Surface	Pipeline
	60	52	−13.0	−10.5	x = 0	x = 0	V	V
	65	54	−12.6	−10.3	x = 4	x = 0	U	V
	68	58	−12.3	−9.7	x = 6	x = 1	U	U
	72	62	−11.4(−9.9)	−9.0	x = 8(−8)	x = 6	W	U
	73	66	−11.1(−9.6)	−8.7 (−8.1)	x = 10(−10)	x = 8(−8)	W	W

Note: there were two maximum settlements in the W-shape, and the other maximum settlement was in the bracket.