A method for re-mining old empty tunnel with structural filling and top reinforcement

Abstract

The present invention discloses a method for re-mining an old empty roadway with a structural filling reinforcement top layer, and relates to the technical field of filling and reinforcement of an old empty roadway with a thick coal seam top layer. The method comprises: starting from a certain position in the old empty roadway, opening a front slurry outlet, introducing high-water filling slurry into a grouting pipe, filling a convex structural mold through the front slurry outlet, and keeping the rear slurry outlet closed; when the front slurry outlet and the convex structural mold advance L meters to reach the next position to be filled, the rear slurry outlet is just located above the previous convex filling body; opening the front slurry outlet and the rear slurry outlet, injecting high-water filling slurry into the grouting pipe, filling the convex structural mold through the front slurry outlet, and filling the gap between the previous convex filling body and the roof of the old empty roadway through the rear slurry outlet; after the convex structural mold and the gap are filled, closing the front slurry outlet and the rear slurry outlet, etc. The present invention uses a convex structural mold to shape the high-water filling slurry, support the rock layer of the roof of the old empty roadway, and ensure the safe re-mining of the lower coal layer of the thick coal seam.

Description

Technical Field

[0001] The invention relates to the technical field of filling and reinforcing old empty tunnels at the top of thick coal seams, and in particular to a method for re-mining old empty tunnels at the top of thick coal seams with structural filling and reinforcement. Background Art

[0002] As the main energy consumption in my country, the demand for coal is still increasing. In some areas with thick coal seams, there are development and preparation tunnels left over from mining the top layer coal. Due to the high demand for coal, secondary mining of coal resources under old empty tunnels in thick coal seams has become a trend. If the coal resources under the tunnels in the old goaf are not mined, a large amount of resources will be wasted. If the old empty tunnels are re-mined, how to deal with the old empty tunnels to ensure the safety of re-mining has become a major issue of concern to researchers in related fields.

[0003] The research reports related to the prior art mainly include:

[0004] Application No. 201710225706.1 discloses a composite closed wall of an old tunnel connected to the airspace and a construction method thereof, the method comprising: setting wooden supports, rubber-coated canvas, a polymer foam material layer, a coal ash bag wall layer and a reinforced concrete wall in sequence from the goaf to the construction tunnel, fixing a grouting pipe, an online detection pipe, a manual sampling pipe, an air pressure pipe and a spare pipe on the top of the old tunnel respectively, installing valves at the outer ends of the grouting pipe, the manual sampling pipe and the spare pipe, and closing the valves, sealing the outer end of the air pressure pipe, and adding a pressure sensor or a pressure gauge, sealing the outer end of the online detection pipe, and providing a temperature sensor, a gas sensor, an oxygen sensor and an infrared camera on the inner end of the online detection pipe, and connecting the pipe to a signal input end of a monitoring computer.

[0005] Although the above-mentioned existing technology can effectively isolate the goaf subsidence area, it cannot solve the technical problem that when re-mining the lower coal layer, there is an old goaf on the upper part, and when passing under the old goaf, it is easy to have a hanging roof, which then causes accidents such as gangue falling and rock spalling. Summary of the invention

[0006] The purpose of the present invention is to provide a method for re-mining old empty tunnels with structural filling and reinforcement of top layers, which uses a convex structural mold to shape high-water filling slurry, support the rock layer of the roof of the old empty tunnel, and ensure the safe re-mining of the lower layer of the thick coal seam.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for re-mining an old empty roadway with structural filling and reinforcement top layer comprises the following steps in sequence:

[0009] a. Prepare and install the required hardware equipment

[0010] The hardware equipment includes a grouting pipe, a sliding track, a connecting rod, a convex structure mold, a front grouting outlet and a rear grouting outlet. The sliding track is installed on the upper rock mass of the old empty lane, and the grouting pipe and the convex structure mold are respectively connected to the sliding track through the connecting rod. The grouting pipe and the convex structure mold can move synchronously under the action of the sliding track;

[0011] The front slurry outlet and the rear slurry outlet are arranged on the grouting pipe, and there is a certain horizontal distance between them;

[0012] The convex structure mold is composed of a front baffle, a rear baffle, a left baffle, a right baffle, an upper baffle, and a lower baffle, wherein a convex portion is arranged on the right baffle, and the rear baffle is connected to the upper side of the left baffle by a hinge, and when the convex structure mold moves along the sliding track, the rear baffle can be opened;

[0013] b. Starting from a certain position in the old empty tunnel, the front slurry outlet is opened, and high-water filling slurry is introduced into the grouting pipe to fill the convex structural mold through the front slurry outlet, and the rear slurry outlet is kept closed. After the filling is completed, a convex filling body is formed;

[0014] c. When the front slurry outlet and the convex structure mold advance L meters to the next filling position, the rear slurry outlet is just above the previous convex filling body;

[0015] d. Open the front slurry outlet and the rear slurry outlet, inject high-water filling slurry into the grouting pipe, fill the convex structure mold through the front slurry outlet, and fill the gap between the previous convex filling body and the roof of the old empty roadway through the rear slurry outlet;

[0016] e. After the convex structure mold and the gap in step d are filled, the front slurry outlet and the rear slurry outlet are closed;

[0017] f. The grouting pipe and the convex structure mold move forward along the sliding track;

[0018] g. Repeat steps c to f. When the rear slurry outlet moves to the top of the last convex filling body, the front slurry outlet remains closed, and the rear slurry outlet is opened to fill the gap. After the filling is completed, the rear slurry outlet is closed to complete the filling.

[0019] h. After the filling body is stable, resume mining of the lower coal layer.

[0020] As a preferred solution of the present invention, the rear baffle can be rotated at a certain angle under the action of the hinge.

[0021] As another preferred embodiment of the present invention, the front slurry outlet, the rear slurry outlet and the convex structure mold move synchronously.

[0022] Preferably, when the front slurry outlet is filling the convex structure mold, the rear slurry outlet is filling the gap between the convex filling body and the top plate.

[0023] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0024] The present invention provides a method for re-mining an old empty tunnel with a top layer reinforced by structural filling. The method utilizes the characteristics of high-water filling materials such as fast solidification, small compression deformation and high strength. When mining the lower coal seam of the old empty tunnel, if dynamic pressure impact occurs, the high-water material filling body can play a good supporting and resisting role; when the tunnel is impacted, the high-water material filling body can control the overlying rock strata with its own good bearing performance, so as to solve the problem of tunnel impact ground pressure prevention and control.

[0025] Combination Figure 3-Figure 5 As shown, in the process description (3) of structural filling to reinforce the top layered old empty tunnel, the front and rear slurry outlets and the convex structural mold move synchronously. In the process description (4) of structural filling to reinforce the top layered old empty tunnel, the front and rear slurry outlets are filled synchronously. While the front slurry outlet fills the mold, the rear slurry outlet fills the gap between the convex filling body and the roof. In the process description (5) of structural filling to reinforce the top layered old empty tunnel, the front and rear slurry outlets finish filling at the same time. The front and rear slurry outlets are filled at the same time by adjusting the flow rate. High-water filling is easy to construct, and filling and recovery do not affect each other; the filling system has a high degree of automation, low labor intensity, and is simple and reliable; a large amount of underground sewage can be used, which greatly reduces drainage costs, and has significant economic, environmental and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the accompanying drawings:

[0027] Figures 1 to 10 A schematic diagram of a cycle process of a method for re-mining an old empty roadway with structural filling and reinforcement at the top layer according to the present invention;

[0028] Figure 2 for Figure 1 AA section view;

[0029] Figure 4 for Figure 3 AA section view;

[0030] Figure 6 for Figure 5 AA section view;

[0031] Figure 8 for Figure 7 AA section view;

[0032] Fig.10 for Fig. 9 AA section view;

[0033] Figures 11 to 13 It is a schematic diagram of a convex structure mold;

[0034] In the figure:

[0035] 1. Lower coal body; 2. Old empty tunnel; 3. Grouting pipe; 4. Sliding track; 5. Upper rock mass; 6. Connecting rod; 7. Front slurry outlet; 8. Convex structural mold; 9. Rear slurry outlet; 10. Convex filling body; 11. Filling top part; 12. Hinge. DETAILED DESCRIPTION

[0036] The present invention discloses a method for re-mining an old empty tunnel with a structured filling and reinforcement top layer. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is further described below in conjunction with specific embodiments.

[0037] The "convex structure mold" mentioned in the present invention refers to a rectangular parallelepiped with a convex portion on one side. Figures 11 to 13 As shown, the specific structure is composed of a front baffle, a rear baffle, a left baffle, a right baffle, an upper baffle, and a lower baffle, wherein a protrusion is set on the right baffle, and the rear baffle is connected to the upper side of the left baffle through a hinge 12. When the convex structure mold moves along the sliding track, the rear baffle can be opened or rotated at a certain angle along the hinge axis.

[0038] The "high water filling slurry" mentioned in the present invention specifically comprises material A and material B. Material A is composed of aluminate, sulphoaluminate and a variety of admixtures for retarding and regulating; material B is composed of gypsum, lime, clay and accelerator. A certain amount of water is added to material A and material B respectively to make mortar, and the high water filling slurry is prepared after being mixed and stirred evenly in a ratio of 1:1.

[0039] High-water filling slurry is used for filling. When mining the lower coal seam of old empty tunnels, if dynamic pressure shock occurs, it can play a good supporting and resisting role to ensure the safe re-mining of the lower coal seam.

[0040] The hardware equipment required for the method of the present invention includes a grouting pipe 3, a sliding track 4, a connecting rod 6, a convex structure mold 8, a front grouting outlet 7 and a rear grouting outlet 9. The sliding track is installed on the upper rock mass 5 of the old empty tunnel 2, and the grouting pipe and the convex structure mold are respectively connected to the sliding track through the connecting rod. The grouting pipe and the convex structure mold can move synchronously under the action of the sliding track;

[0041] The front slurry outlet and the rear slurry outlet are arranged on the grouting pipe 3, and there is a certain horizontal distance between them.

[0042] The following is a detailed description of a method for re-mining an old empty tunnel with structural filling and reinforcement at the top layer according to the present invention.

[0043] Combination Figures 1 to 10As shown, the figure shows the lower coal body 1, the filling top part 11, and the convex filling body 10. The process of structural filling and reinforcing the top layered old empty roadway is described as follows:

[0044] (1) Starting from a certain position in the old empty lane, the front slurry outlet is opened to fill the convex structure mold, and the rear slurry outlet remains closed;

[0045] (2) After the front slurry outlet has filled the mold, the front slurry outlet is closed; after the filling is completed, a convex filling body is formed;

[0046] (3) When the front slurry outlet and the mold advance L meters to the next filling position, the rear slurry outlet is just above the previous convex filling body, that is, above the convex filling body 10 filled in step (2);

[0047] (4) Open the front and rear slurry outlets and inject high-water filling slurry; the front slurry outlet fills the convex structure mold, and the rear slurry outlet fills the gap between the previous convex filling body and the roof of the old empty roadway;

[0048] (5) After the convex structure mold and the gap are filled, the front and rear slurry outlets are closed;

[0049] (6) The slurry discharge pipe and the convex structure mold move forward along the sliding track, and steps (3) to (6) are repeated.

[0050] (7) When the rear slurry outlet moves to the top of the last filling body, the front slurry outlet remains closed, and the rear slurry outlet is opened to fill the gap. After the filling is completed, the rear slurry outlet is closed to complete the filling;

[0051] (8) After the filling body is stabilized, the lower coal layer will be mined again.

[0052] Parts not described in the present invention can be implemented by referring to the existing technology.

[0053] It should be noted that any equivalent method or obvious variation method made by those skilled in the art under the guidance of this specification should be within the protection scope of the present invention.

Claims

1. A method for re-mining old empty tunnels with structural filling and reinforcement top layers, characterized in that: The following steps are included in sequence: a. Prepare and install the required hardware equipment The hardware equipment includes a grouting pipe, a sliding track, a connecting rod, a convex structure mold, a front grouting outlet and a rear grouting outlet. The sliding track is installed on the upper rock mass of the old empty lane, and the grouting pipe and the convex structure mold are respectively connected to the sliding track through the connecting rod. The grouting pipe and the convex structure mold can move synchronously under the action of the sliding track; The front slurry outlet and the rear slurry outlet are arranged on the grouting pipe, and there is a certain horizontal distance between them; The convex structure mold is composed of a front baffle, a rear baffle, a left baffle, a right baffle, an upper baffle, and a lower baffle, wherein a convex portion is arranged on the right baffle, and the rear baffle is connected to the upper side of the left baffle by a hinge, and when the convex structure mold moves along the sliding track, the rear baffle can be opened; b. Starting from a certain position in the old empty tunnel, the front slurry outlet is opened, and high-water filling slurry is introduced into the grouting pipe to fill the convex structural mold through the front slurry outlet, and the rear slurry outlet is kept closed. After the filling is completed, a convex filling body is formed; c. When the front slurry outlet and the convex structure mold advance L meters to the next filling position, the rear slurry outlet is just above the previous convex filling body; d. Open the front slurry outlet and the rear slurry outlet, inject high-water filling slurry into the grouting pipe, fill the convex structure mold through the front slurry outlet, and fill the gap between the previous convex filling body and the roof of the old empty roadway through the rear slurry outlet; e. After the convex structure mold and the gap in step d are filled, the front slurry outlet and the rear slurry outlet are closed; f. The grouting pipe and the convex structure mold move forward along the sliding track; g. Repeat steps c to f. When the rear slurry outlet moves to the top of the last convex filling body, the front slurry outlet remains closed, and the rear slurry outlet is opened to fill the gap. After the filling is completed, the rear slurry outlet is closed to complete the filling. h. After the filling body is stable, resume mining of the lower coal layer.

2. A method for re-mining old empty roadway with structural filling and reinforcement top layer according to claim 1, characterized in that: The rear baffle can be rotated at a certain angle under the action of the hinge.

3. The method for re-mining old empty roadway with structural filling and reinforcement top layer according to claim 1 is characterized by: The front pulp outlet, the rear pulp outlet and the convex structure mold move synchronously.

4. The method for re-mining old empty roadway with structural filling and reinforcement top layer according to claim 1 is characterized by: When the front slurry outlet is filling the convex structure mold, the rear slurry outlet is filling the gap between the convex filling body and the top plate.

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