Design parameters of non-prestressed rock anchoring system in projects with different types should be determined by formation conditions and stability analysis.
Design calculation of prestressed rock bolting structures should include:
1. Tension capacity calculation of rock bolting’s reinforced body.
2. At anchorage section, tension capacity calculation between grouting and reinforced body, between grouting and stratum.
3. Pressured-type rock anchoring or pressure-dispersion rock anchoring should conduct compressive capacity calculation of grouting’s cross section.
4. Rock bolting should be arranged in shape of rhombus or rectangle. Separation distance between two rock boltings should be not more than a half of length of rock bolting.
5. Thickness of cement paste or cement mortar protective layer on the surface of permanency non-prestreesed rock anchoring should not less than 20mm.
6. Strength grade of cement paste or cement mortar concretion between rock bolting and hole wall should not be less than M20.