Mechanical and Deformation Characteristics and Optimization of Support Parameters for Superlarge-Span Tunnel: A Case Study from Laohushan Tunnel

Table 2

Site section monitoring scheme.

Lining type	Construction method	Stress monitoring section	Deformation monitoring section	Buried depth (m)	Space (m)	Lithology	Component quantity
Strengthening	Upper bench CD method	YK2 + 449	YK2 + 444	165	31	Gravel soil + strongly weathered limestone	80
Section in grade			YK2 + 449
IV rock mass			YK2 + 453