Non-closed overlying strata grouting filling isolation method

Abstract

The invention relates to a non-closed overlying strata grouting and filling isolation method which is suitable for coal mine overlying strata grouting and filling. The method mainly comprises the following steps that the development position of a main mining-induced fracture in overlying strata is judged, a large-aperture L-shaped isolation drill hole is constructed, an expandable flexible bag is conveyed into a horizontal section of the isolation drill hole, the whole flexible bag is located in the whole horizontal section, and an inlet is formed in the end, close to a vertical section of the isolation drill hole, of the flexible bag; stoping work of the grouting and filling working face is conducted, and it is guaranteed that working face advancing, grouting and filling of grouting drilling holes and water injection and filling of isolation bags are conducted synchronously in the stoping process; and finally, high-concentration slurry is injected through the inlet to replace water in the isolation bag. By isolating and sealing the grouting filling space, the filling slurry is prevented from diffusing into the mined-out side cavity, so that the grouting filling in the mining overburden rock crack is rapidly pressurized, the waste of the filling material is reduced, and the grouting filling effect is ensured.

Description

technical field [0001] The invention relates to a method for isolating and sealing a non-closed overlying rock grouting filling cavity, and is especially suitable for unsealed mining fissure cavity under the condition that the filling working face is adjacent to the goaf in coal mine mining overlying rock grouting filling Control of the diffusion range of the filling slurry under certain conditions. Background technique [0002] In recent years, overlying rock isolation grouting filling technology has played an active role in the "three downs" coal mining, providing new ideas for coal mining enterprises to solve coal mining, and ensuring the safety of buildings (structures) above the coal mining face The basic principle of this technology is to implement multiple groups of ground drilling holes extending to the interior of the fracture cavity in the overlying rock mining fracture space below the selected key layer, and use the ground drilling to drill the mining fracture cav...

AI Technical Summary

Problems solved by technology

In engineering practice, although this method can speed up the pressure-initiating speed of filling and mining fractures, due to the high cost of modification of the slurry material, and it is very easy to cause blockage of the grouting drilling hole and interrupt the grouting, the risk is relatively high

Although the diffusion range of the slurry is reduced by modification, the magnitude of the reduction is not ideal

Due to the unsealed filling and mining fracture cavity, the filling volume is still very large, resulting in excessive waste of filling materials

Therefore, the cost of grout modified filling is high, and the purpose of accurately controlling the diffusion range of grout cannot be achieved. The existence of this problem is very unfavorable to the development and popularization of overlying rock grouting filling technology

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