Stability Analysis of TBM Tunnel Undercrossing Existing High-Speed Railway Tunnel: A Case Study from Yangtaishan Tunnel of Shenzhen Metro Line 6

Table 1

Physical and mechanical parameters of materials.

Material types		γ (kN·m^−3)	E (MPa)	μ	φ (°)	c (MPa)
Granite	Completely weathered region ①	9.20	4.90	0.40	23	0.02
	Highly weathered region ②-1	11.50	50	0.33	30	0.07
	Highly weathered region ②-2	15.60	160	0.31	42	0.10
	Moderately weathered region ③	20.10	5000	0.25	45	20
	Week weathered region ④	26.80	20000	0.22	55	55
Fault fracture zone		17	150	0.28	37	0.09
Lining		25	21000	0.26	—	—
Segment		25	27000	0.20	—	—
TBM shield		78	250000	0.20	—	—