Method for enhancing grouting effect of working face bottom plate detected through audio frequency electric perspective method

Abstract

The invention discloses a method for enhancing the grouting effect of a working face bottom plate detected through an audio electric perspective method. A coal mine under-pressure coal face often needs to be grouted to reinforce a bottom plate, but the project belongs to a hidden project, the effect of the grouting project is difficult to intuitively understand after the grouting project is finished, and if the effect of the grouting project does not meet the design requirement, huge hidden dangers are brought to safety production. According to the method, an enhanced audio electric perspective method is used for detecting original resistivity before grouting and actual resistivity at the optimal window time after grouting in a working face bottom plate, and the area where high resistance abnormity is displayed is the grouting influence range. The optimal window time of different grouting liquids is used for detection, accuracy of the detection result is improved, and the cost is lower than one tenth of that of drilling.

Description

technical field [0001] The invention belongs to the technical field of geophysical prospecting and detection in coal mines, and in particular relates to a method for detecting the grouting effect of the bottom plate of a working face by enhancing the audio-frequency electroscopic method. Background technique [0002] It is often necessary to strengthen the floor by grouting in coal mine under pressure coal mining face, the purpose is to thicken and strengthen the effective water-resisting layer of the floor. However, this type of project is a hidden project. Due to its concealment and complexity, it is difficult to intuitively understand the effect of the grouting project after the grouting project is completed. If the effect of the grouting project does not meet the design requirements, it will bring huge harm to safe production. Hidden dangers are likely to cause water inrush accidents and affect the safety of coal mine production. According to the relevant regulations of ...

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Problems solved by technology

However, this type of project is a hidden project. Due to its concealment and complexity, it is difficult to intuitively understand the effect of the grouting project after the grouting project is completed. If the effect of the grouting project does not meet the design requirements, it will bring huge harm to safe production. Hidden dangers are likely to cause water inrush accidents and affect the safety of coal mine production. According to the relevant regulations of the "Coal Mine Water Prevention and Control Rules", coal mines must stop mining and continue to drill and grout to strengthen the floor, resulting in many more drills in the coal mine, which seriously affects the production progress and production. safety, greatly increasing production costs

[0003] At present, the commonly used grouting reinforcement effect inspection methods mainly include drilling inspection, mining inspection, geophysical inspection, water pressure test, etc.; drilling inspection takes a long time, requires a lot of drilling, and costs a lot; mining inspection is the grouting reconstruction work face Carry out test mining and compare it with the floor water inrush situation of the working face with similar conditions but without grouting transformation; this method is risky, in case a hidden water inrush structure is not reinforced by grouting, a water inrush accident will occur ; In terms of geophysical inspection, the transient electromagnetic prospecting method has a good application effect in the detection of fault water content and grouting effect, but in actual underground construction, conductors such as drilling sites and metal objects in the roadway interfere with the detection results. It is difficult to obtain a good signal-to-noise ratio, and the results are often very inaccurate; with the increase of coal mining depth, the water pressure is getting higher and higher, and the conventional pressure water test can no longer accurately reflect the rock mass permeability under the actual water head. , the high-pressure water test should be carried out to check the single-hole grouting effect, but the high-pressure water test requires high technology and equipment

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