According to national standard "road tunnel design specification" JTGD70-2004 requirements.
Shotcrete should be located within the ribbed welded steel, concrete help to improve the jet shear and flexural strength, the ability to improve concrete's resistance to punching, bending capacity, enhance the integrity of sprayed concrete, sprayed concrete to reduce shrinkage cracks, prevent local off blocks. Welded steel grid should press the rectangular layout, steel welded steel spacing of 150 ~ 300mm. Can be 150mm × 150mm, 200mm × 200mm, 200mm × 250mm, 250mm × 300mm, 300mm × 300mm combinations. Lap length of welded steel not less than 30d (d is the bar diameter).
Welded steel protective layer of sprayed concrete thickness of not less than 20mm, when using double-welded steel, the welded steel between two layers of the interval distance of not less than 60mm.

6x6 Reinforcing Welded Wire Mesh
Imperial available,
6x6 10/10
6x6 8/8
6x6 6/6
6x6 4/4
6x6 2/2
6x6 0/0

Size available,
4' x 8'
6' x 12'
8' x 12'
8' x 20'
8' x 14'