Application of reinforcement mesh in tunnel lining

　　According to the national standard code for design of highway tunnel jtgd70-2004.

　　Ribbed steel welded mesh shall be set in the shotcrete, which is conducive to improving the shear and bending strength of shotcrete, improving the punching shear capacity and bending capacity of concrete, improving the integrity of shotcrete, reducing the shrinkage crack of shotcrete and preventing local block falling.

　　The steel welded mesh shall be arranged in a rectangle, and the reinforcement spacing of the steel welded mesh shall be 150 ~ 300mm. 150mm may be used × 150mm，200mm × 200mm，200mm × 250mm，250mm × 300mm，300mm × 300mm combination. The overlapping length of reinforcement mesh shall not be less than 30d (D is the diameter of reinforcement).

　　The thickness of shotcrete protective layer of steel welded mesh shall not be less than 20mm. When double-layer steel welded mesh is adopted, the spacing between two layers of steel welded mesh shall not be less than 60mm.