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

Table 4

Settlements of ground surface and the pipeline with different rigidities.

Material	(GPa)	(m)		Surface settlement	Pipeline settlement
PVC	2.5	8	0.4	W	W
Concrete	25	9	1.9	W	U
Cast iron	150	11	6.6	W	V
Steel	200	12	8.8	U	V