A method for self-stabilization of tunnels and filling of goaf in coal pillar-free mining

Abstract

The present invention discloses a method for self-stabilization of tunnels and filling of goafs in pillar-free mining. In the filling method, two bearing devices, namely, a slurry-stopping wall and a pier, are respectively designed. Three cycles are used as one stage, that is, three slurry-stopping walls are pre-designed, and two piers are arranged in each slurry-stopping wall. The interval between the slurry-stopping walls is 20-30m. The existence of the slurry-stopping wall can prevent the filling slurry in the goaf from overflowing to the working face and affecting normal mining. The existence of the pier supports the tunnel roof on the one hand, keeps the tunnel intact, and has filling space. On the other hand, the use of the piers at intervals not only exerts the bearing function of the filling body in the tunnel but also reduces the filling cost.

Description

Technical Field

[0001] The invention relates to the field of goaf filling, and in particular to a method for self-stabilizing a tunnel and filling a goaf in coal pillar-free mining. Background Art

[0002] Traditional longwall mining requires two tunnels to be left for mining, and even four tunnels are needed for high-gas coal seams, which greatly increases the cost of coal pillars. In response to green mining, pillarless mining is currently widely used in coal mining. However, during pillarless mining, the roof of the goaf collapses very fully, which leads to the sinking of the surface. In order to avoid surface subsidence, the goaf usually needs to be filled in pillarless mining. Filling the goaf in pillarless mining alone will inevitably lead to the failure to completely fill the goaf, as the mining of the working face causes the tunnel to collapse as it is mined, and the filling space is insufficient, which makes it impossible to solve the problem of surface subsidence.

[0003] If traditional pillarless mining is adopted, in order to retain the roadway and thus retain the filling space, roadside filling bodies will be set up in the entire roadway, which will inevitably increase the filling cost. At the same time, the entire roadside filling body will even cause the roof of the goaf to be cut off along the position of the filling body and collapse, further reducing the filling space, which is not conducive to the filling of the goaf.

[0004] Based on the above analysis, we should actively invent a filling method for pillarless mining, which uses only a certain number of isolation bodies to ensure the stability of the tunnel and fills the goaf at the same time. Therefore, the present invention proposes a method for self-stabilization of tunnels and filling of goafs in pillarless mining. Summary of the invention

[0005] In order to solve the above technical problems, the present invention proposes a method for self-stabilization of tunnels and filling of goafs in pillarless mining, which adopts two bearing devices, namely, the stop wall and the pier. The stop wall prevents the goaf filling slurry from overflowing to the working face and affecting normal mining. The pier is used to ensure that the tunnel remains intact and has a filling area, and the use of intervals can play the bearing role of the filling body beside the tunnel and reduce the filling cost.

[0006] A method for self-stabilization of tunnels and filling of goafs in coal pillar-free mining, the filling method comprising the following steps:

[0007] Step 1: crush the ground gangue according to a certain particle size, mix the crushed gangue with high brine and evenly mix them through a stirring system to obtain gangue slurry, and transmit the gangue slurry to the underground slurry storage bin through a transmission system;

[0008] Step 2: Arrange the first pier column filling pile in the transport tunnel from the opening of the cut eye, and arrange the second pier column filling pile when the working face advances normally and the working face advances to the first pressure step. After the second pier column filling pile is arranged, mix the gangue slurry in the underground slurry storage bin with the high-water material consolidating agent, and use the obtained mixed filling slurry to grout the first pier column filling pile and the second pier column filling pile, thereby forming the pier;

[0009] Step 3: After the first pier and the second pier are solidified and can play a bearing role, a No. 1 stop wall is set in the transport tunnel, and a grouting pipeline for the goaf is reserved above the No. 1 stop wall. Two piers are arranged in the No. 1 area of ​​each stop wall. The gangue slurry in the underground slurry storage bin is mixed with the high-water material consolidating agent, and the obtained mixed filling slurry is used to fill the No. 1 stop wall;

[0010] Step 4, repeat step 2 to complete the arrangement and grouting operation of the third pier column filling pile and the fourth pier column filling pile in the No. 2 slurry stop wall area to form the third pier column and the fourth pier column;

[0011] Step 5: according to the pre-laid grouting pipeline, the gangue slurry in the underground slurry storage bin is mixed with the high-water material consolidating agent, and the obtained mixed filling slurry is grouted into the goaf through the grouting pipe of the goaf reserved above the No. 1 grouting stop wall. When it is found that the slurry in the goaf blocked by the No. 1 grouting stop wall flows back to the blocking area of ​​the No. 2 grouting stop wall, the grouting of the goaf through the grouting pipe reserved above the No. 1 grouting stop wall is stopped;

[0012] Step 6: According to the construction process of No. 1 slurry stop wall, No. 2 slurry stop wall is constructed, and a grouting pipeline for the goaf area is reserved above No. 2 slurry stop wall;

[0013] Step 7, repeat the grouting operation of step 5, and perform grouting filling through the grouting pipeline in the goaf above the No. 2 stop wall. When the speed of the slurry flowing into the goaf drops significantly, start the construction of the pier column in the No. 3 stop wall area;

[0014] Step 8: transfer the grouting pipeline of the goaf area reserved above the No. 1 stop wall to the No. 3 stop wall, and carry out the construction of the No. 3 stop wall and the filling of the goaf area corresponding to the No. 3 stop wall;

[0015] Step 9. As the working face advances, repeat steps 2-8, using three slurry stop walls as one stage to complete the filling of the entire goaf.

[0016] Furthermore, the interval between two adjacent piers is 10-15m.

[0017] Furthermore, the interval between two adjacent slurry stopping walls is 20-30m.

[0018] Furthermore, the preparation method of the filling slurry obtained by mixing the gangue slurry and the high-water material consolidating agent is as follows:

[0019] Step a, conveying the gangue slurry obtained by mixing on the ground to the underground slurry storage bin through the gangue slurry conveying pipe;

[0020] Step b, separating the gangue slurry in the slurry storage bin into two parts, gangue slurry A and gangue slurry B, through a slurry suction separation pipeline;

[0021] Step c, mixing the gangue slurry A with a 70% concentration high-water material consolidating agent, and transporting the mixture to the corresponding pier column and stop wall grouting locations via a slurry delivery pipeline;

[0022] Step d: Mix the gangue slurry B with a 30% concentration high-water material consolidating agent, and transport it to the corresponding grouting location in the goaf through a slurry pipeline.

[0023] Beneficial effects: The present invention adopts two bearing devices, namely, the slurry-stopping wall and the pier column. The existence of the slurry-stopping wall prevents the filling slurry in the goaf from overflowing to the working face and affecting normal mining. The existence of the pier column can keep the tunnel intact and provide a filling area. On the other hand, the use of the pier column at intervals can not only play the bearing role of the filling body beside the tunnel but also reduce the filling cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 , the filling arrangement diagram of the goaf area in the pillarless coal mining of the present invention; DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the embodiments described are only part of the embodiments of the present invention, rather than all of the embodiments.

[0026] The following is combined with Figure 1 The present invention is further described;

[0027] First, the ground gangue is crushed to a certain particle size, mixed with high-salt water, and transported to the underground slurry storage bin through the transmission system;

[0028] Depend on Figure 1 As shown, two bearing devices, namely, a slurry stop wall 1 and a pier 2, are designed in the present invention. It is worth mentioning that in order to make the filling of the goaf 5 efficient, three cycles are used as a stage, that is, three slurry stop walls are designed in advance, two piers are arranged in each slurry stop wall, and the interval between the slurry stop walls is 20-30m.

[0029] Arrange the first pier column filling pile in the transport tunnel 4 from the opening of the cut eye. As the coal mining machine cuts coal, the second pier column filling pile is set when the working face advances to the first pressure step. Mix the gangue slurry in the underground slurry storage bin with 70% high-water material consolidating agent, and use the mixed filling slurry to grout the pier column filling piles in the No. ① slurry stop wall area to form a pier column; after the pier column 2 can play a bearing role, grout the No. 1 slurry stop wall area in the No. ① slurry stop wall area, so that the No. ① slurry stop wall area is in a closed state; Repeat the above operation to complete the arrangement and grouting operation of the third pier column filling pile and the fourth pier column filling pile in the No. 2 stop wall area, and form the third pier column and the fourth pier column; mix the gangue slurry in the underground slurry storage bin with 30% high-water material consolidating agent to obtain a mixed filling slurry, and inject the mixed filling slurry into the goaf through the grouting pipe of the goaf reserved on the No. 1 stop wall. When it is found that the slurry in the grouting pipeline above the No. 1 stop wall flows back through the goaf to the No. 2 stop wall area, stop grouting the goaf through the No. 1 stop wall;

[0030] Start the construction of No. 2 slurry stop wall in the area of ​​No. ② slurry stop wall, and then carry out grouting filling for the goaf within No. 2 slurry stop wall. When the slurry inflow rate drops significantly, start the construction of the piers in the area of ​​No. ③ slurry stop wall. After the construction is completed, transfer the grouting pipeline of the goaf reserved in No. 1 to No. 3 slurry stop wall, and then carry out the construction of No. 3 slurry stop wall and filling until the filling is completed.

[0031] Subsequently, according to the above process, three slurry stop walls are used as one stage, and the goaf is filled one by one as the working face is mined.

[0032] The preparation of the filling slurry comprises the following steps:

[0033] Step a, conveying the gangue slurry obtained by mixing on the ground to the underground slurry storage bin through the gangue slurry conveying pipe;

[0034] Step b, separating the gangue slurry in the slurry storage bin into two parts, gangue slurry A and gangue slurry B, through a slurry suction separation pipeline;

[0035] Step c, mixing the gangue slurry A with a 70% concentration high-water material consolidating agent, and transporting the mixture to the corresponding pier column and stop wall grouting locations via a slurry delivery pipeline;

[0036] Step d: Mix the gangue slurry B with a 30% concentration high-water material consolidating agent, and transport it to the corresponding grouting location in the goaf through a slurry pipeline.

[0037] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for self-stabilization of tunnels and filling of goafs in coal pillar-free mining, characterized in that: The filling method comprises the following steps: Step 1: crushing the ground gangue according to a certain particle size, mixing the crushed gangue with high-salt water evenly to obtain gangue slurry, and transferring the gangue slurry to an underground slurry storage bin; Step 2: Arrange the first pier column filling pile in the transport lane from the opening of the cut, and arrange the second pier column filling pile when the working face advances normally and the working face advances to the first pressure step, mix the gangue slurry with the high-water material consolidating agent, and use the obtained mixed filling slurry to grout the first pier column filling pile and the second pier column filling pile, thereby forming the pier; Step 3: After the first pier and the second pier are solidified, a No. 1 stop wall is set in the transport tunnel, a grouting pipeline for the goaf is reserved above the No. 1 stop wall, two piers are arranged in the area between the two adjacent stop walls, and the gangue slurry is mixed with a high-water material consolidating agent to fill the No. 1 stop wall with the obtained mixed filling slurry; Step 4, repeat step 2 to complete the arrangement and grouting operation of the third pier column filling pile and the fourth pier column filling pile in the No. 2 slurry stop wall area to form the third pier column and the fourth pier column; Step 5: Mix the gangue slurry with the high-water material consolidating agent according to the pre-laid grouting pipeline, and inject the mixed filling slurry into the goaf through the goaf grouting pipeline reserved above the No. 1 grouting stop wall. When it is found that the slurry in the goaf blocked by the No. 1 grouting stop wall flows back to the blocking area of ​​the No. 2 grouting stop wall, stop grouting; Step 6: According to the construction process of No. 1 slurry stop wall, No. 2 slurry stop wall is constructed, and a grouting pipeline for the goaf is reserved above No. 2 slurry stop wall; Step 7, repeat the grouting operation of step 5, and perform grouting filling through the grouting pipeline in the goaf above the No. 2 stop wall. When the speed of the slurry flowing into the goaf drops significantly, start the construction of the pier column in the No. 3 stop wall area; Step 8: transfer the grouting pipeline of the goaf area reserved above the No. 1 stop wall to the No. 3 stop wall, and carry out the construction of the No. 3 stop wall and the filling of the goaf area corresponding to the No. 3 stop wall; Step 9. As the working face advances, repeat steps 2-8, using three slurry stop walls as one stage to complete the filling of the entire goaf.

2. A method for self-stabilization of tunnels and filling of goafs in coal pillar-free mining according to claim 1, characterized in that: The interval between two adjacent piers is 10-15m.

3. The method for self-stabilization of tunnels and filling of goafs in coal pillar-free mining according to claim 1, characterized in that: The interval between two adjacent slurry stopping walls is 20-30m.

4. The method for self-stabilization of tunnels and filling of goafs in pillar-free mining according to claim 1, characterized in that: The preparation method of the filling slurry obtained by mixing the gangue slurry and the high-water material consolidating agent is as follows: Step a, conveying the gangue slurry obtained by mixing on the ground to the underground slurry storage bin through the gangue slurry conveying pipe; Step b, separating the gangue slurry in the slurry storage bin into two parts, gangue slurry A and gangue slurry B, through a slurry suction separation pipeline; Step c, mixing the gangue slurry A with a 70% concentration high-water material consolidating agent, and transporting the mixture to the corresponding pier column and stop wall grouting locations via a slurry delivery pipeline; Step d: Mix the gangue slurry B with a 30% concentration high-water material consolidating agent, and transport it to the corresponding grouting location in the goaf through a slurry pipeline.

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