| 摘要 |
An injection drilling anchor (1) intended for use in particularly low-cohesion rock is distinguished in that, in its frontal region, i.e. that adjacent to the core bit (8), there are at least two pressure injection valves (11) operating in the manner of check valves through which mortar suspension can emerge from a longitudinal channel passing through the injection drilling anchor (1) but not in the reverse direction. To set the injection drilling anchor, it is first used as a drilling rod and drilling fluid is passed via the longitudinal channel and leaves via corresponding drillings in the region of the core bit (8). A mortar suspension is then fed via the longitudinal channel into the borehole to fill it, whereupon a ram introduced into the channel forces the remaining mortar suspension inside the channel to the region of the core bit (8). Fresh mortar suspension is fed in via the pressure injection valves (11) after the initial setting of the suspension in the borehole, which has an explosive effect on the mortar in the valves or penetrates into any cracks and gaps, causes the borehole to widen in the base region, thus producing a considerable enlargement of the penetration range of the mortar and the surrounding rock with the result that the injection drilling anchor (1) can be reliably secured in said surrounding rock. |
