A self-drilling combined grouting bolt with stop plug suitable for soft rock formation

Abstract

The invention belongs to the technical field of geotechnical engineering anchoring, in particular to a self-drilling combined grouting anchor with a grout stopper suitable for soft rock formations, comprising a grouting anchor body and a grouting anchor installed on the top of the grouting anchor body The drill bit and the expansion rubber grout stop pipe installed at the tail of the grouting anchor body, the inside of the grouting anchor body is provided with a grouting cavity, and the inside of the grouting cavity is connected with a grouting pipe, the The end of the grouting anchor body away from the drill bit is equipped with an outer grout stop mechanism, and a support mechanism is installed on one side of the outer grout stop mechanism, and the anchor rod is drilled into the rock formation through the set grout anchor rod body and the drill bit, and then Cooperate with the expansion rubber grout stop pipe and the grouting cavity, without pulling out the grouting anchor body, directly seal the hole and grout, avoid the re-collapse in the drilled hole after drilling and make it difficult to lower the grouting pipe, through the set outer grout stop mechanism and support With the cooperation of the mechanism, when the surrounding rock where the drilling is located is highly broken and there are many cracks, the drilling hole is well sealed to ensure a high grouting pressure 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,...

AI Technical Summary

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

Images