Combined with practical project,it introduces the fixing of constructing plans,elaborates the constructing methods during the secondary bricking course after the formation of large cross-section digging contacting line early supporting structure,discusses constructing supervision of each supervising item in the cave,so as to offer reference for familiar project.

Analyzing reasons of large deformation of early supports of Liangfengya Tunnel,the author states treatment measures of large deformation of early supports of the tunnel.

Aften preliminary bracing,support deformation and cracking occurred in partial sections.

Combined with major works of covered culverts in south-to-north water transfer project, from reinforcement treatment, soil excavation, preliminary bracing, monitoring measurement and other aspects the construction technology of shallow underground excavation method is introduced in order to promote the application of this method in hydraulic tunnel works in city.

Taking the Fenghuangling Tunnel as an example,this paper introduces the bracing method for the loess tunnel and the requirements for the apparent smoothness quality control of the preliminary bracing,and connecting with the construction practice,puts forward some suggestions and opinions.

Wide span underground chamber excavation and primary supportin intensely weathered rocks;

Treatment technology of clearance-intrusion in primary support of Huangguoshu tunnel;

FLAC~(3D) program and its applications in couple problem between primary support design and rock wall condition in double-arch tunnel;

Optimum analysis on the initial support structure of double-arch tunnel in partial pressure;

Discussion on influence of initial support to stability and deformation of surrounding rock mass in soft rock tunnel;

Initial Support for Qinling Railway Tunnel Constructed by Open TBM;

This paper based on a engineering example about Nanwutai tunnel(The fifth bidding section) s construction,including excavation,preliminary support,measurement in-situ and secondary lining,the application of NATM theory in the tunnel s design and construction is introduced.

But considering the actual traffic need,in the course of construction,we widen the tunnel,meanwhile the tunnel has been constructed by the preliminary support.