Fixed-length anchoring system and method for roadway roof in slow seepage or water spraying state

Abstract

The invention discloses a fixed-length anchoring system and method for a roadway roof in a slow seepage or water spraying state, and belongs to the field of roadway supporting engineering under the condition of slow seepage or water spraying of the roof. The fixed-length anchoring system comprises a drill hole, a hollow grouting anchor cable, a resin anchoring agent, a lock, a tray, a water-swelling grout stop belt, a grouting binding material, a trapezoidal baffle ring, a roof rock stratum and a grout outlet. The method specifically comprises the steps that a water-swelling grout stop belt is wound at the demarcation point of a preset free section and an anchoring section in a hollow grouting anchor cable rod body, primary anchoring of a traditional resin cartridge is sequentially achieved, the tray and the lock are installed, designed pre-tension force is applied, and after top plate spraying water flows through the water-swelling grout stop belt to promote expansion of the water-swelling grout stop belt, a grouting binding material is injected, so that pre-stress precise fixed-length anchoring is realized. The structure is simple, the construction process is convenient and fast, the economic cost is low, the performance and rigidity of an anchoring system are greatly improved, the technical effect is obvious, and the application value is very high.

Description

technical field [0001] The invention relates to a fixed-length anchoring system and method for a roadway roof under slow seepage or water spraying conditions, and is especially suitable for the field of well roadway support engineering under slow seepage or water spraying conditions of the roof. Background technique [0002] Prestressed bolt support technology has been widely used at home and abroad because of its advantages of effectively controlling the deformation of surrounding rock and reducing the cost of roadway support. At present, coal mine bolting technology can be divided into end anchoring, lengthening anchoring and full-length anchoring according to the anchoring length. Among them, end anchoring and lengthening and adding anchors have been widely used in coal mine roadway support. With the gradual increase of mining depth, the increasingly complex mining stress environment, and the severe corrosion of the bolt and cable anchorage system due to water spraying on...

AI Technical Summary

Problems solved by technology

[0003] The existing technologies for improving the reliability of the anchoring system mainly include adding metal steel particles (full stirring) to the resin anchoring agent to achieve lengthened anchoring technology, full-length anchoring technology, etc., in which metal steel particles are added to the resin anchoring agent It has a certain positive effect on the breaking of the anchoring agent, but its complex process seriously restricts the construction efficiency

For the full-length anchoring technology, its anchoring mechanism is not yet fully mature, and when the full-length anchoring is not required for certain roof occurrence conditions, choosing this anchoring method is also an excessive consumption of support costs

In terms of roof water prevention and control, the current technologies mainly include applying anti-corrosion liquid on the anchor rod body and supporting components, grouting inside the roof rock layer, and grouting on the roof rock layer surface. These technologies reduce the impact of water spraying to a certain extent. The adverse effects of the anchoring system, but its high cost and complicated construction technology make it difficult to popularize and apply

In terms of grouting at the tail of the hollow grouting anchor cable, the current technology mainly uses some rubber sleeves or cloth wrapping tapes that have no water-swellable performance, and the diameter of the rubber sleeve is between the diameter of the drill hole and the diameter of the anchor cable rod. There is a large gap between the wall of the drilled hole and the leak cannot be completely plugged, resulting in the loss of slurry; for fabric wrapping, its water absorption and water permeability are good, and it cannot achieve a good plugging and slurry effect. The process is complicated, the cost is high, and it is difficult to achieve accurate quantification, etc.

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