Hollow self drill anchor is used for pre-support in in weak ground conditions
The advantages of hollow self drilling anchor – Hollow self drilling anchor combines functions of drilling, grouting and anchoring, is an advanced anchoring and support system, which can solve problem of hole collapse and ensure grouting effect under complex geological condition.
At aspects of bending resistance, shearing strength and surface bonding, hollow drilling rock bolt is better than mortar anchor bolt with the same section. Hollow drilling rock bolt can be cut, connected, exerted prestress and released load arbitrarily. Also, it can be used as grouting pipe.
Production process is simple and it has quite large application values.
One-off drill bit cancels withdraw of hollow self drilling anchor from drill hole, it can avoid hole collapse and rework.
Through hollow drilling bar and drill bit with holes, slurry can enter and fill in cracks of stratum, which can ensure rock consolidation and anchoring quality. When pure slurry flows out, grouting can be stopped.
Plate and nut can exert prestressed force to stratum.
Hollow self drill anchor was used for pre-support in in weak ground conditions. Hollow self drill anchor system increased the stability in the working area by transferring loads in the longitudinal direction and decrease excavation induced deformations. The system increased safety in the working area. Beside this standard usage, hollow self drill anchor is often applied to increase stability in portal sections and for the re-excavation of collapsed sections in underground construction. Another application area is ground improvement and waterproofing in combination with all tunnel construction methods.