Influence of Different Excavation Sequence of Double-Side Heading Method on Supporting Structure

Table 3

Stress value of each monitoring point of tunnel supporting structure unit: MPa.

Scheme	Maximum stress value of initial support	Stress value at the completion of initial support excavation	Maximum stress value of temporary inverted arch	Stress value at the completion of temporary inverted arch excavation	Maximum stress value of middle wall	Stress value at the completion of middle wall excavation
I	0.39	−0.05	1.95	0.72	7.77	6.17
II	0.42	−0.17	5.33	1.45	8.73	6.51