The design and construction of prestressed anchor rod in accordance with the provisions of

1, anchor rod material can Strand, HRB335 grade, HRB400 grade level or HRB500 rebar, finishing rebar and seamless steel tubes.
2, the vertical layout of the prestressed anchor should be laid in the upper pit, bolt spacing should not be less than 1.5m.
3, the hole diameter is preferably 110mm ~ 150mm, and the horizontal angle is preferably 10 ° ~ 25 °.
4, anchor free length is preferably 4m ~ 6m, and shall set the isolation sleeve; 1m ~ 2m provided a positioning support drilling grouting prestressed anchor in the longitudinal direction at intervals.
5, the exposed length of the anchor rod bolt tensioning lock should meet the needs of anchor type and size of the pad section stiffness should meet the prestress stability requirements.
6, the anchor hole grouting process should adopt the secondary high-pressure grouting, grouting strength grade not less than 20MPa.
7, the maximum tensile load anchor bolt is preferably of axial strength design value of 1.1 times (Robin Acceptance Test) or 1.2 times (multi-cycle acceptance test) and not greater than 80% of the standard values of tensile strength of the rod the locking bolt bearing capacity values appropriate for the design value of 60% to 90%.