Drill bit and construction method for constructing one-time forming high-pressure rotary spraying soil anchor rod

Abstract

The invention discloses a drill bit and a construction method for constructing a once-formed high pressure jet grouting earth anchor. The drill bit comprises a drill bit point (1) and a drill bit pipe (2), wherein the drill bit pipe (2) is provided with a guniting nozzle (4), a stator sleeve (5) is rotationally sleeved outside the drill bit pipe (2), and a bearing (6) is arranged between the stator sleeve (5) and the drill bit pipe (2); a front baffle (7) and a rear baffle (8) are respectively fixed on the front and rear ends of the stator sleeve (5), and a seal ring (11) is arranged between the central hole of each baffle and the drill bit pipe (2). The construction method includes the essential steps that the stator sleeve (5) of the drill bit and an end socket disc plate (9) on the drill bit pipe (2) are not rotated in the process of rotationally advancing the drill bit in the earth, and cement paste is outwards ejected by the guniting nozzle (4) of the drill bit pipe (2) in the process of drilling by the drill bit. According to the drill bit and the construction method, the construction steps can be simplified, the construction efficiency can be improved, and the construction period can be shortened.

Description

technical field [0001] The invention relates to the construction technology of soil bolts in the field of civil engineering, in particular to a drill bit for constructing a one-time formed high-pressure rotary spraying type soil bolt and a method for using the drill bit to construct a high-pressure rotary spraying type soil bolt. Background technique [0002] The soil anchor is referred to as the soil anchor, which is a part of the foundation pit support system. It is drilled in the soil body of the side wall of the deep foundation pit. After reaching a certain depth, put steel strands and other materials into the hole, and spray Inject cement slurry to make it combine with the soil layer to become an anchor with strong pull-out bearing capacity. The outer end of the soil anchor rod is connected with the retaining pile to prevent the side wall soil from collapsing or landslide. With the development of the country's economic construction and the wide application of deep foun...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned construction method has the following defects: First, this method must be constructed twice, that is, the first drilling, and then the drill bit is withdrawn from the hole, and then the grouting pipe is replaced and the head plate is set and pushed into the hole bottom, and then retreat the grouting pipe and spray grouting, and the depth of the soil anchor is large, generally exceeding 20m, so that the construction process must go in and out of the hole twice, and the drill bit and the drill bit need to be replaced every time a soil anchor is constructed. One-time grouting pipe, the construction process is cumbersome and complicated, the work efficiency is low, the construction period is long, the cost of the mechanical shift and the labor cost are high; moreover, after the drill bit and the drill pipe are drilled and withdrawn from the hole, there is a hidden danger of collapse of the soil on the hole wall. To avoid collapse, it is necessary to inject water into the hole wall to protect the wall when drilling, but after the soil is wet with water, an isolation layer around the hole will be formed on the hole wall. During subsequent rotary jet grouting, the isolation layer around the hole will hinder the diffusion of cement slurry to the soil on the hole wall Penetration, affecting the bond between cement slurry and soil, reducing the pull-out bearing capacity of the entire soil anchor

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