A Static Expansion Crack Roof Cutting and Pressure Relief Method for Goaf Side of Narrow Coal Pillars in Gob-side Driving

Abstract

The invention discloses a method of roof cutting pressure relief of the narrow coal pillar gob side through static bursting for gob-side entry driving. According to the method, firstly, the drilling position and drilling relevant parameters of the separation distance, the diameter, the angle and the depth are determined; secondly, drilling construction and hole sealing operation are conducted; thirdly, slurry grouting of a static bursting agent is conducted, and roof cutting pressure relief is conducted through static bursting; and fourthly, gob-side entry driving is conducted. According to the method, recovery of an upper section working face and forward groove driving of a lower section working face are conducted simultaneously, and the problem of intense linkage of mine excavation is effectively relieved; and after entry-side roof cutting pressure relief, the stress environment of gob-side entry driving surrounding rock is greatly improved, surrounding rock deformation is greatly reduced in the entry driving process and after entry forming, the engineering quantity of entry supporting is small, and the repair rate is low.

Description

technical field [0001] The invention relates to a method for static expansion, cracking, roof cutting and pressure relief on the goaf side of narrow coal pillars in gob-side excavation, in particular to an advanced upper section working face, which is close to the narrow coal pillar along the groove of the upper section working face Boreholes are arranged axially along the roof and static expansion agent is injected to destroy the basic roof cantilever structure of the goaf, which can effectively alleviate the surrounding rock stress concentration and the difficulty of surrounding rock deformation control when the lower section of the working face is excavated along the gob. big way. Background technique [0002] Gob-side entry is one of the technologies for the layout and maintenance of mining roadways in our coal mine. That is, a 3-10m narrow coal pillar is left along the edge of the goaf in the upper section of the working face to excavate the lower section of the working...

AI Technical Summary

Problems solved by technology

[0007] To sum up, the existing technology mainly uses fire blasting to cut off the connection between the cantilever structure of the goaf’s basic roof and the roof of the gob-side roadway. However, the country has strict restrictions on the production and use of fire offerings, and they will be used in high-gas mines. There are safety hazards and many restrictions; although the use of chemical expansion agents is mentioned, the corresponding hole layout parameters and specific construction process are not given. The roof pressure relief method and the specific construction process have important theoretical and practical significance for improving the theory of surrounding rock control for narrow coal pillar gob-side excavation.

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