After using early grouting,the wall\'s degree of density is higher and structure is more integrity.

Construction technology of the pre-grouting small pipe in Dawoshan tunnel;

Three-dimensional FEM is used to calculate the deformation and stability of tunnel under tunnel boring machine (TBM) excavation in big fault zone after pre-grouting.

Room mining technology can be used to recover the residual ore distributing in backfill,and that pre-grouting is necessary for good working conditions.

In this paper,we introduced the pre-grouting construction program of the first tunnel construction of north trunk line of Wanjiazhai yellow river delivery project.

Based on the investigation at the site,this paper discusses the I-beam and leading injected condulet which are adopted in a tunnel collapse treatment in hard and soft joint rock area,and sums up the construction experience,which may be useful for tunnel construction under similar wall rock condition.

Some excavated methods are mainly introduced here,and the construction principal of NATM widely used at present and the principal and construction technology of the advanced grouting support with the big pipe shed are introduced emphatically.