Support method for bolt-grouting composite crushing dynamic-pressure roadway soft rock roof by high-pre-stressed anchor cable

Abstract

The invention discloses a support method for bolt-grouting a composite crushing dynamic-pressure roadway soft rock roof by a high-pre-stressed anchor cable. The support method comprises the following steps of: after excavating a roadway, keeping up with a roadway driving head for drilling a deep part in a roadway roof, sending a deep hole camera shooting detecting instrument to the bottom of a drilled hole, recording inner wall lithological characters, fracture spacing and crushing region thickness range of surrounding rocks of different depths; keeping up with the roadway driving head, firstly drilling grouted holes in the surfaces of surrounding rocks, installing grouting pipes, then spraying thin-layer concrete on the surfaces of the surrounding rocks of the roadway for closing the surfaces of the surrounding rocks of the roadway to prevent slurry from overflowing; grouting the insides of the surrounding rocks through the grouting pipes, after slurry is solidified, drilling anchor cable holes in the surfaces of the surrounding rocks of the roadway, and when the depths of the anchor cable holes exceed the range of a crushing region, installing an anchor cable for reinforcing. The support method has the advantages of being simple in operation, bringing convenience for construction, saving secondary or multi-time support procedure, lowering the cost, saving the time and manpower, increasing the working efficiency, realizing dual-anchoring, and achieving the strong support effect, and is especially suitable for the roof which is difficult to support under the condition of dynamic pressure.

Description

technical field [0001] The invention relates to a new method for supporting the roof of broken soft rock in mine roadway and tunnel engineering, in particular to a method for supporting the soft rock roof of roadway with high prestressed anchor cable anchoring and grouting combined with broken dynamic pressure, which is suitable for large mining depth, high stress, composite Obstinate support problems such as broken dynamic pressure roadway soft rock roof. Background technique [0002] At present, the depth of mine excavation is getting deeper and deeper, and the unique mechanical properties of deep surrounding rocks appear. The complex mechanical environment of deep three-high and one-disturbance and the improvement of the mechanization level required for mining meet the large-size requirements of the roadway section, showing obvious different mechanical properties and engineering responses of deep rock mass. At the same time, rock burst, roof collapse, Disastrous mine acc...

AI Technical Summary

Problems solved by technology

[0004] (1) Excessive pursuit of mechanical properties of support materials, resulting in high support costs;

[0005] (2) Relying on experience for support, the scope of the crushing area cannot be accurately positioned;

[0006] (3) Breaking away from the relationship between the support body and the surrounding rock, only starting from the support, without considering the self-supporting capacity of the surrounding rock, resulting in too high design support strength, resulting in unnecessary waste;

[0007] (4) The initial support effect is obvious, but the late deformation is serious, and the section shrinkage rate is large

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