Composite supporting structure for coal mine

Abstract

The utility model discloses a coal mine composite supporting structure which comprises a U-shaped shed, the U-shaped shed is fixed on the inner side wall of a roadway, an iron back plate is fixed on the periphery of the U-shaped shed in the extending direction of the roadway, an anchor net is laid on the lower edge of the U-shaped shed, the coal mine composite supporting structure further comprises a hollow grouting anchor cable fixed on the side wall of the roadway, and a guniting layer is filled between the anchor net and the side wall of the roadway. The supporting effect is improved, the roadway maintenance amount is reduced, the service period is prolonged, and the cost is saved.

Description

Technical Field

[0001] The utility model relates to a composite supporting structure for a coal mine, belonging to the technical field of coal mine supporting technology. Background Art

[0002] The roof and floor of the main exploitable coal seams in a certain mine are mostly muddy siltstone or silty mudstone, which are easy to swell when exposed to water and have poor stability. With the mining of the middle coal group, the coal seams are more concentrated, and the mining pressure has an increasingly greater impact on the main stone gates and coal transportation up the mountain, causing serious disrepair of the tunnels and labor shortage. The existing support structure includes a U-shaped shed, wooden fir poles are fixed on the outer periphery of the U-shaped shed, and at most a layer of anchor net is laid on the edge below the U-shaped shed, which cannot meet the support needs. It is necessary to explore a new tunnel support structure. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a composite support structure for a coal mine to solve the technical problems existing in the above-mentioned prior art.

[0004] The technical solution adopted by the utility model is: a composite support structure for a coal mine, comprising a U-shaped shed, wherein the U-shaped shed is fixed on the inner wall of the tunnel, an iron back plate is fixed on the outer periphery of the U-shaped shed along the extension direction of the tunnel, an anchor net is laid on the lower edge of the U-shaped shed, and the U-shaped shed also comprises a hollow grouting anchor cable fixed on the side wall of the tunnel, and a shotcrete layer is filled between the anchor net and the side wall of the tunnel.

[0005] Preferably, the number of U-shaped sheds is set to be multiple and they are erected along the lane, and two adjacent U-shaped sheds are overlapped and fixed.

[0006] Preferably, the iron back plate is a rectangular steel plate.

[0007] Preferably, the hollow grouting anchor cable comprises a top hollow grouting anchor cable and a side hollow grouting anchor cable, the hollow grouting anchor cable has Φ=21.6mm, L=8000mm, and the spacing between rows is 1300×2000mm; the side hollow grouting anchor cable has Φ=21.6mm, L=4300mm, and the spacing between rows is 1300×2000mm.

[0008] Preferably, the thickness of the sprayed layer is 250 mm.

[0009] Preferably, the overlapped parts at both ends of the iron back plate extend beyond the U-shaped shed by 50 mm.

[0010] Beneficial effects of the utility model: compared with the prior art, the utility model improves the supporting effect, reduces the amount of tunnel maintenance, increases the service cycle, and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the utility model.

[0012] Figure 2 It is a cross-sectional view of the utility model cut from the top of the tunnel downwards.

[0013] Figure 3 This is the deformation trend chart of the tunnel at measuring point No. 6.

[0014] Figure 4 This is the deformation trend chart of the tunnel at measuring point No. 7.

[0015] Figure 5 This is the deformation trend chart of the tunnel at measuring point No. 9.

[0016] Figure 6 This is the deformation trend chart of the tunnel at measuring point No. 10. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] The reference numerals in the drawings of the specification include: U-shaped shed 1, iron back plate 2, anchor net 3, top hollow grouting anchor cable 4, side hollow grouting anchor 5, and shotcrete layer 6.

[0019] Embodiment 1:

[0020] Composite support structure in coal mines, such as Figure 1-Figure 2 As shown, it includes a U-shaped shed 1, which is fixed on the inner wall of the lane. The number of U-shaped sheds 1 is set to be multiple and erected along the lane, and two adjacent U-shaped sheds 1 are overlapped and fixed; an iron back plate 2 is fixed on the outer periphery of the U-shaped shed 1 along the extension direction of the lane, and the iron back plate 2 is a rectangular steel plate. The overlap of the two ends of the iron back plate 2 exceeds the length of the U-shaped shed 1 by 50mm. The interval and width of the iron back plate 2 are related to the shed distance and are adjusted according to actual conditions; an anchor net 3 is laid on the lower edge of the U-shaped shed 1. It also includes hollow grouting anchor cables fixed on the side walls of the tunnel, the hollow grouting anchor cables include top hollow grouting anchor cables 4 and side hollow grouting anchor cables 5, the hollow grouting anchor cables are Φ=21.6mm, L=8000mm, and the spacing between rows is 1300×2000mm; the side hollow grouting anchor cables 5 are Φ=21.6mm, L=4300mm, and the spacing between rows is 1300×2000mm; a shotcrete layer 6 is filled between the anchor net 3 and the side walls of the tunnel, and the thickness of the shotcrete layer 6 is 250mm.

[0021] The specific implementation process is as follows:

[0022] A U-shaped shed 1 is set up along the tunnel, and two adjacent U-shaped sheds 1 are overlapped with each other; an iron back plate is fixed on the outer periphery of the U-shaped shed 1 along the extension direction of the tunnel; an anchor net is laid on the lower edge of the U-shaped shed 1, a top hollow grouting anchor cable and a side hollow grouting anchor cable are driven on the side wall of the tunnel, and a grouting layer is formed between the anchor net and the side wall of the tunnel, and finally grouting is injected into the hollow grouting anchor cable.

[0023] The use effect of this embodiment is as follows:

[0024] (1) Comparative analysis of composite support and ordinary support for main stone gates

[0025] In January 2020, composite support was used for the 154 transport stone gate, and the construction was completed in May. The two points with the largest deformation of the 154 transport stone gate, points 6# and 7#, were compared with points 9# and 10#, where the deformation was the smallest when ordinary support was used for the 154 transport stone gate in 2019, and the results are as follows: Figure 3 , Figure 4 , Figure 5 , Figure 6 .

[0026] Depend on Figure 3-Figure 6 It can be clearly seen that the support effect of the 154 transport stone gate using composite support has been greatly enhanced, the service period has been significantly extended, and the deformation of the roadway has been uniformly reduced. This is because through composite support, an anchored composite bearing body is formed around the roadway, which bears a considerable amount of stress in the roadway. Within a certain period of time, the deformation amount and deformation speed of the roadway have a decreasing trend, which is enough to show the outstanding support effect and is worthy of promotion.

[0027] (1) Application of new technology of “five-in-one” support

[0028] In 2019, a mine first used the "five-in-one" support technology of scaffolding + anchor net + anchor cable + shotcrete + grouting at the 155 track stone gate in the fourth mining area, which improved the support stability of the 155 track stone gate tunnel. After 6 months of observation and monitoring, the crushing and deformation of the tunnel roof were controlled to a great extent. For this reason, from the second half of 2019 to 2021, the entire mine vigorously promoted the "five-in-one" support method in the main stone gates and up and down the mountain, and now it has achieved remarkable results. The statistics of the tunnel repair in a mine in the past three years are shown in Table 1.

[0029] Table 1 Statistics of tunnel repair in a mine in the past three years

[0030]

[0031] It can be seen from Table 1 that after the comprehensive implementation of the "five-in-one" composite support from 2019 to 2020, by 2021, the average monthly tunnel repair volume was 886.7 m, accounting for 68.4% of the average monthly tunnel repair volume in 2020 and 70% of the average monthly tunnel repair volume in 2019, greatly reducing the tunnel repair volume.

[0032] (2) Application of “composite support” in the third coal mining area

[0033] The composite support construction of 141712 coal transportation uphill (185m) was completed from January to the end of April 2020, and the composite support construction of 145 track stone gate and connecting tunnel (180m) was completed from October 2019 to March 2020. The current conditions of the two tunnels are shown in Table 2.

[0034] Table 2 Repair status of composite support tunnel

[0035]

[0036]

[0037] Table 3 Cost analysis of composite support and ordinary scaffolding support

[0038]

[0039] Note: The general unit price of scaffolding tunnel repair is 3985 yuan / m, the unit price of composite support is 6464 yuan / m, and the labor cost is 300 yuan / worker.

[0040] From Table 3, we can see that: (1) During the same period, the material and labor costs per meter of tunnel were saved by RMB 11,000. (2) The tunnel service life was extended by 3-4 times.

[0041] The above description is only a specific implementation method of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present utility model, which should be included in the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be based on the protection scope of the claims.

Claims

1. The composite support structure of coal mine is characterized by: It includes a U-shaped shed, which is fixed on the inner wall of the tunnel, an iron back plate is fixed on the outer periphery of the U-shaped shed along the extension direction of the tunnel, an anchor net is laid on the lower edge of the U-shaped shed, and it also includes a hollow grouting anchor cable fixed on the side wall of the tunnel, and a shotcrete layer is filled between the anchor net and the side wall of the tunnel; the iron back plate is a rectangular steel plate; the overlap at both ends of the iron back plate exceeds the length of the U-shaped shed by 50mm.

2. The composite support structure for coal mines according to claim 1, characterized in that: The number of U-shaped sheds is set to be multiple and erected along the lane, and two adjacent U-shaped sheds are overlapped and fixed.

3. The composite support structure for coal mines according to claim 1, characterized in that: The hollow grouting anchor cable comprises a top hollow grouting anchor cable and a side hollow grouting anchor cable, wherein the hollow grouting anchor cable has Φ=21.6mm, L=8000mm, and a spacing of 1300×2000mm; the side hollow grouting anchor cable has Φ=21.6mm, L=4300mm, and a spacing of 1300×2000mm.

4. The composite support structure for coal mines according to claim 1, characterized in that: The thickness of the spraying layer is 250 mm.

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