Self-drilling type combined grouting anchor rod with grout-stopping plug and suitable for soft rock stratum

Abstract

The invention belongs to the technical field of geotechnical engineering anchoring, and particularly relates to a self-drilling type combined grouting anchor rod with a grout-stopping plug and suitable for a soft rock stratum. The self-drilling type combined grouting anchor rod comprises a grouting anchor rod body, a drill bit mounted at the top end of the grouting anchor rod body and an expansion rubber grout-stopping pipe mounted at the tail part of the grouting anchor rod body; a grouting cavity is formed in the grouting anchor rod body; a grouting pipe is connected to the interior of the grouting cavity; an outer side grout-stopping mechanism is installed at the end, away from the drill bit, of the grouting anchor rod body; and a supporting mechanism is installed on one side of the outer side grout-stopping mechanism. The grouting anchor rod body is matched with the drill bit to drill the anchor rod into the rock stratum, and the expansion rubber grout-stopping pipe and the grouting cavity are matched, so that the grouting anchor rod body does not need to be pulled out, hole sealing grouting is directly conducted, the situation that the grouting pipe is difficult to descend due to the fact that the interior of a drilled hole collapses again after drilling is avoided; and through cooperation of the outer side grout-stopping mechanism and the supporting mechanism, when the crushing degree of surrounding rock where the drilled hole is located is relatively high and cracks are relatively more, the drilled hole is well sealed, relatively high grouting pressure is guaranteed, and the anchoring effect is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering anchoring, and in particular relates to a self-drilling combined grouting anchor rod with a grout stopper suitable for soft rock formations. Background technique [0002] Geotechnical engineering anchoring is used in complex geology such as weak surrounding rock, fault fracture zone, high ground stress deformation, etc., especially when the collapse hole is serious and the surrounding rock fault is relatively deep. It is a main support technology to reinforce the stratum due to instability and endangering safety. Through the high-strength tensile capacity of the anchor rod installed in the stratum and through the grouting body around the anchor rod and the stratum In terms of the grouting bolt support technology, the higher grouting pressure can ensure a larger diffusion range of the grout in the broken rock mass and achieve better surrounding rock reinforcement support. However,...

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Problems solved by technology

[0002] Geotechnical engineering anchoring is used in complex geology such as weak surrounding rock, fault fracture zone, high ground stress deformation, etc., especially when the collapse hole is serious and the surrounding rock fault is relatively deep. It is a main support technology to reinforce the stratum due to instability and endangering safety. Through the high-strength tensile capacity of the anchor rod installed in the stratum and through the grouting body around the anchor rod and the stratum In terms of the grouting bolt support technology, the higher grouting pressure can ensure a larger diffusion range of the grout in the broken rock mass and achieve better surrounding rock reinforcement support. However, the increase of grouting pressure puts forward higher requirements for the grouting system. A good grouting system can effectively block the hole of the bolt hole and increase the grouting pressure in the borehole. Commonly used common grout stoppers are mostly round-shaped rubber stoppers or round-truncated hard plastic stoppers. The common type of grout stoppers has a limited deformation range during actual use. The extrusion capacity of the drilled hole is limited, and it is impossible to effectively block the higher grouting pressure hole. When the surrounding rock where the drilled hole is located is a soft rock formation with a high degree of fragmentation and is easy to collapse, the drilled hole is not easy to form. A gap is easily formed between the outer edge of the grout plug and the wall of the borehole, which makes it impossible for the grout stopper to ensure good airtightness during grouting. The internal grout pressure cannot reach the design value, which greatly affects the effect of grouting support

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