Composite coal pillar construction and side wall and roof coordination control method for small coal pillar along goaf

Abstract

The application discloses a kind of composite coal pillar construction and side top coordination control method of small coal pillar along goaf, belong to mine roadway supporting technical field.This method is established by filling space in the coal pillar side close to goaf, and the solid filling body is established by pouring concrete, and the small coal pillar side is reinforced;When constructing filling space, the original anchor rod is connected by using continuation anchor rod, so that the coal pillar side and the filling body after filling form a composite coal pillar, increase stability, and the filling body is used as a stable anchoring point;After the filling body is formed, the inclined long anchor cable is set on the inclined roof in the isolation pipe reserved in it, and the roof pre-supporting of the goaf along roadway to be excavated is carried out, and after the goaf along roadway is excavated, long anchor rod is set vertically to the roof, thereby forming the roof support structure combined vertically and obliquely.The application can effectively control the deformation of surrounding rock and improve the supporting capacity of roadway by side top coordination control and the establishment of composite coal pillar.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mine roadway support, in particular to a composite coal pillar construction and side and roof coordinated control method for a small coal pillar gob-side entry. BACKGROUND

[0002] The small coal pillar gob-side entry is a kind of entry which is excavated along the edge of the goaf and has a narrow coal pillar with a width of only a few meters. This kind of entry makes full use of the low mining-induced pressure near the goaf, and has the advantages of weakening the mine pressure, improving safety, increasing flexibility of entry layout, improving resource recovery rate, and speeding up entry excavation. However, since the entry is adjacent to the goaf, a large number of secondary cracks are formed in the coal and rock mass during the mining of the previous working face, which leads to the difficulty in meeting the standard of the anchoring force of the anchor rod during the excavation of the gob-side entry, and the surrounding rock is prone to deformation and failure, so the support is more difficult than the conventional non-gob-side entry. This support difficulty is particularly embodied in the small coal pillar side and roof of the gob-side entry, which are also the most important parts of the entry support. At the same time, the coal mass on the side of the entry is often irregular due to spalling, and the unilateral spalling depth can reach 0.6-1.0 m, which not only further reduces the effective width of the coal pillar, but also seriously reduces the anchoring force of the anchor rod.

[0003] At present, in order to improve the support quality of the small coal pillar side and roof of the gob-side entry, the existing technology mainly adopts three ways: (1) After the entry is excavated, the support density and strength of the small coal pillar side and roof are increased. This method can improve the deformation of the coal and rock mass to a certain extent, but high-density support has the following problems: first, the anchor rods and anchor cables are too close to each other and are prone to interference; second, the support workload is large, which reduces the excavation speed and leads to tight construction period; third, after increasing the length of the anchor rod on the coal pillar side, the anchor rod will be anchored into the broken zone, the anchoring force will be weak, and the support will be prone to failure. (2) After the entry is excavated, the small coal pillar side is grouted and reinforced. This method has obvious effect on controlling the deformation of the small coal pillar, but since the grouting work must be delayed for a distance from the excavated working face, and the strength of the grout also needs time to form, the front end is still the ungrouted coal mass, so the excavation deformation is still large. (3) The roof is cut to release part of the roof pressure. Since the small coal pillar entry is in a low pressure area, it can only further alleviate part of the mining-induced pressure, and the improvement effect on the excavation deformation is not as good as the previous two methods. SUMMARY

[0004] The purpose of the present application is to provide a composite coal pillar construction and side and roof coordinated control method for a small coal pillar gob-side entry, which supports the filling body constructed on the small coal pillar side and serves as the anchoring force point for the original anchor rod in the coal pillar and the new anchor rod of the gob-side entry excavated later, thereby enhancing the support and support functions of the coal pillar.

[0005] The technical scheme adopted by the present application is as follows: the present application provides a composite coal pillar construction and side roof coordination control method for a small coal pillar along a gob roadway, comprising the following steps:

[0006] Step S1, during the mining of the first coal mining face, the coal pillar side is filled by modeling in the roadway:

[0007] Step S11, before modeling, a continuation anchor rod is installed on the exposed section of the original anchor rod of the coal pillar side;

[0008] Step S12, at the starting point of the first cycle filling, a masonry wall is constructed as a starting end, a plurality of adjusting narrow plates are stacked from bottom to top to form a board wall to block the other end, and a filling space is formed in the roadway by cooperating a mold frame bottom bracket and a mold frame top bracket;

[0009] Step S13, a plurality of reserved holes are arranged in the mold frame top bracket, and an isolation pipe is installed in the reserved hole;

[0010] Step S2, concrete is poured into the filling space through the filling opening at the top of the board wall, the filling height is observed through the observation opening at the top of the board wall, when the filling height reaches the observation opening, the observation opening is closed, and the concrete is connected to the top until the end of the current cycle filling;

[0011] Step S3, after the concrete posture is stable, demolding is performed, and the mold frame bottom bracket, the mold frame top bracket and the plurality of adjusting narrow plates are moved to the position of the next filling cycle.

[0012] Step S4, steps S2 and S3 are repeated until the filling work of the coal pillar side is completed.

[0013] Step S5, during the implementation of step S4, for the filled body that has been consolidated at the rear, a drilling hole is constructed obliquely upward through the isolation pipe, and then an oblique long anchor cable is arranged on the roof; this step is repeated until the oblique long anchor cable is completely installed;

[0014] Step S6, after the first coal mining face 1 is mined and the overburden rock movement is stable, a small coal pillar is left along the edge of the goaf, the gob roadway is implemented, and the anchor rod cable support is performed on the surrounding rock of the roadway.

[0015] As a further improvement of the present application, the continuation anchor rod is tightly connected with the original anchor rod by a continuation nut, and the main body of the continuation anchor rod is located in the space to be filled and has a length not exceeding the mold frame bottom bracket and the mold frame top bracket.

[0016] As a further improvement of the present application, the mold frame bottom bracket comprises a slot and a bottom limiting slot, the mold frame top bracket comprises a plate and a top limiting slot, the plate is inserted into the slot when the slot and the plate are connected, and the bottom limiting slot and the top limiting slot are on the same vertical line.

[0017] As a further improvement of the present application, reinforcing ear plates I and II are arranged between the two straight corner surfaces of the bottom frame and the two straight corner surfaces of the top frame respectively.

[0018] As a further improvement of the present application, a single column is arranged between the bottom frame and the top frame, the top of the single column is connected with the top limiting slot, and the bottom is fixed on the bottom limiting slot; the single column is used to support the bottom frame and the top frame, and the combined height of the two is adjusted by the extension of the single column.

[0019] As a further improvement of the present application, the width b2 of the filling body is not less than 300 mm.

[0020] As a further improvement of the present application, in step S5, the length of the oblique long anchor cable (15) is L, and the calculation formula is:

[0021]

[0022] In the formula, a is the installation angle of the oblique long anchor cable; h1 is the distance from the reserved hole in the top frame to the roof of the roadway; h2 is the height at which the oblique long anchor cable needs to be anchored into the roof; and L0 is the exposed length of the oblique long anchor cable.

[0023] As a further improvement of the present application, in step S5, the maximum support depth of the roof exceeds the maximum height h2 of the oblique long anchor cable.

[0024] As a further improvement of the present application, in step S6, when the anchor rod and cable support is performed on the surrounding rock of the roadway, the anchor rod of the small coal pillar side is anchored in the small coal pillar or anchored into the filling body, and the anchor cable is anchored into the filling body.

[0025] As a further improvement of the present application, in step S6, the sum of the width b1 of the small coal pillar and the width b2 of the filling body is not less than 0.3 times the mining height of the second coal mining face.

[0026] Compared with the prior art, the present application has the following technical effects:

[0027] (1) Strengthening the support and stability of the coal pillar: by constructing a concrete filling body on the coal pillar side, filling the side space, and utilizing the characteristics of dense structure and high strength of the concrete, a powerful support is formed on the side of the goaf of the coal pillar;

[0028] The filling body firmly bonds the original anchor rod and the extension anchor rod, fully plays the supporting role of the original anchor rod, and enhances the anchoring force of the original anchor rod in the coal pillar because the extension anchor rod is located in the solid filling body, so that the small coal pillar and the filling body form a composite coal pillar, and the overall stability is significantly improved;

[0029] (2) Provide reliable anchoring points: The filling body provides reliable anchoring points for the newly installed anchor cables in the coal pillars along the goaf roadway, solving the problem of weak anchoring force and easy failure caused by anchor cables being anchored into the fractured area in traditional support;

[0030] After the original anchor bolt is connected to the continued anchor bolt, it forms a tension fastening for the small coal pillar, further strengthening the support force for the small coal pillar;

[0031] (3) Optimize the roof support effect: The anchoring point of the inclined long anchor cable is located above the goaf roadway to be excavated, which plays a pre-support role on the roof of the goaf roadway to be excavated in advance, and improves the stability of the roof coal and rock mass; during the goaf roadway, vertical anchor cables are installed on the roof, forming a two-way three-dimensional support structure with the inclined long anchor cable, which effectively controls the roof deformation and improves the reliability of the roof support.

[0032] (4) Improve construction efficiency and reduce workload: During the mining of the first working face, the inclined long anchor cable pre-support and concrete wall construction are carried out in advance. In the later stage of the goaf roadway, the support density can be appropriately reduced to reduce the mutual interference between anchor bolts and anchor cables, reduce the support workload, and speed up the tunneling speed. The concrete wall construction time is advanced by a large amount. The concrete strength has reached its maximum when the goaf roadway is in progress, which avoids the problem of large deformation of the front-end un-grouted coal body in the delayed grouting reinforcement. Moreover, there is no need to carry out roof cutting work during the goaf roadway, which significantly reduces the workload.

[0033] (5) Coordinated control of surrounding rock deformation: Through the reinforcement of coal pillars and walls (composite coal pillar construction) top coordination control system, the deformation of surrounding rock can be effectively controlled, the support capacity of roadway can be greatly improved, and it can adapt to the complex support environment of small coal pillar roadway. Attached Figure Description

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 A top-view diagram of the construction of composite coal pillars and the method for roof and sidewall coordination in small coal pillar roadways for implementing the present invention.

[0036] Figure 2 for Figure 1 A sectional view along the AA direction.

[0037] Figure 3 for Figure 1 BB-direction sectional view.

[0038] Figure 4 This is a schematic diagram showing the connection between the extension nut and the extension anchor rod and the original anchor rod in this invention.

[0039] Figure 5 This is a schematic diagram of the structure of the mold frame base and the mold frame top of the present invention.

[0040] Figure 6 A sectional view (a) and a plan view (b) of the present application after the advance concrete filling and the installation of the inclined long anchor cable.

[0041] Figure 7 A sectional view (a) and a plan view (b) of the present application after the support of the gob-side entry.

[0042] The reference signs are as follows: 1-first coal mining face; 2-entry; 3-original anchor rod; 4-continuation nut; 5-continuation anchor rod; 6-masonry wall; 7-adjusting narrow plate; 8-plate wall; 9-mold frame bottom bracket; 10-mold frame top bracket; 11-single column; 12-top adjusting narrow plate; 13-filling port; 14-observation port; 15-inclined long anchor cable; 16-isolation pipe; 17-concrete; 18-small coal pillar; 19-gob-side entry; 20-anchor rod; 21-anchor cable; 22-second coal mining face; 91-insertion slot; 92-reinforcing lug plate I; 93-bottom limiting slot; 101-insertion plate; 102-reinforcing lug plate II; 103-top limiting slot; 104-reserved hole. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0044] A composite coal pillar construction and side and top coordinated control method of a small coal pillar gob-side entry of the present application, comprising the following steps:

[0045] Step S1: During the mining of the first coal mining face 1, the coal pillar side is filled with a mold in the entry 2. There is a spalling condition in the coal pillar side, and the original anchor rod 3 is set in the coal seam with spalling as a temporary support, as shown in Figure 2 . The mold filling will be described in detail below. Figures 1-5 First, before the mold is built, the continuation anchor rod 5 is prepared, and the continuation nut 4 is connected with the original anchor rod 3 to make the two stable and finally form a row of combined anchor rods extending into the entry 2. Secondly, at the starting point of the first cycle filling, the masonry wall 6 is built as the starting end, and the plate wall 8 is formed by stacking multiple adjusting narrow plates 7 from bottom to top to block the other end, and the filling space is formed by the mold frame bottom bracket 9 and the mold frame top bracket 10 in the entry 2. The filling port 13 and the observation port 14 are opened on the top adjusting narrow plate 12 at the top end of the plate wall 8. Specifically, the lengths of the adjusting narrow plates 7 are different, and they are spliced with each other with the outer ends aligned, as shown in Figure 3As shown in the figure. Between the outer ends of the masonry wall 6 and the panel wall 8, a segment of the space to be filled is built by using the formwork bottom frame 9 and the formwork top frame 10 to cooperate to form the facade. Figure 5 As shown in the figure, the formwork bottom frame 9 and the formwork top frame 10 are respectively composed of two straight-angled connecting guard plates, the formwork bottom frame 9 is provided with a slot 91 on the vertical guard plate, a reinforcing lug I 92 is arranged at the angle between the two guard plates, and a bottom limiting slot 93 is arranged on the bottom plate. The formwork top frame 10 is provided with a plug-in plate 101 below the vertical plate, a reinforcing lug II 102 is arranged at the angle between the two guard plates, and a top limiting slot 103 is arranged below the top plate. The bottom limiting slot 93 and the top limiting slot 103 are on the same vertical line. When the formwork bottom frame 9 and the formwork top frame 10 cooperate, the plug-in plate 101 is inserted into the slot 91, and the outer facade of the filling space is formed. A single column 11 is also arranged between the formwork bottom frame 9 and the formwork top frame 10. The single column 11 is a hydraulic prop, which is placed in the top limiting slot 103 at the top and in the bottom limiting slot 93 at the bottom. The single column 11 can be adjusted in height between the formwork bottom frame 9 and the formwork top frame 10, that is, the height of the outer facade of the filling space, to adapt to different filling space requirements, because the height of the roadway on site is not a fixed value and will change due to excavation errors and deformation of surrounding rock in the later period. At the same time, when the formwork top frame 10 contacts the top plate, the single column 11 can also play a role in temporary support.

[0046] A group of reserved holes 104 are arranged transversely on the vertical plate of the formwork top frame 10, and the reserved holes 104 have a certain inclination and are inclined upward. An isolation tube 16 is installed in the reserved hole 104, the bottom end of the isolation tube 16 is exposed, the top end is provided with a light wood plug, and the top end abuts against the coal seam on the coal pillar side. Then the isolation tube 16 is fixed at the reserved hole 104.

[0047] The formwork filling method has obvious advantages: compared with the metal frame type filling, it has higher flexibility and can be adjusted in height flexibly according to the change of the height of the roadway; compared with the sprayed concrete, the strength of the concrete wall constructed is higher. Since the formwork filling is completed during the recovery of the first coal mining face 1 and in advance of the recovery of the working face, it belongs to advanced filling, and the establishment of the concrete wall in this process does not affect the normal recovery of the working face. At the same time, after the recovery of the first coal mining face 1 is completed, the gob-side roadway 19 is usually implemented after an interval of more than three months, so from the time dimension of the gob-side roadway 19, the filling method also shows the advancement.

[0048] Step S2: Pouring concrete 17 into the filling space through the filling port 13 at the top of the panel wall 8, and observing the filling height through the observation port 14 at the top of the panel wall 8. When the filling height reaches the observation port 14, the observation port 14 is closed until the concrete 17 reaches the top, and the cycle filling is completed.

[0049] Step S3: After the concrete 17 has stabilized, demold it and move the base frame 9, top frame 10, and multiple adjusting narrow plates 7 to the position of the next filling cycle.

[0050] Step S4: Repeat steps S2 and S3 until the filling work of the coal pillar is completed.

[0051] Step S5: During the implementation of step S4, for the already consolidated backfill, drill holes obliquely upwards through the isolation pipe 16, and then drive oblique long anchor cables 15 into the top slab. Repeat this step until all oblique long anchor cables 15 are installed. Specifically, the length of the oblique long anchor cable 15 is L, calculated using the following formula:

[0052]

[0053] In the formula, α is the installation angle of the inclined long anchor cable 15; h1 is the distance between the reserved hole 104 in the top frame 10 and the top plate of the roadway 2; h2 is the height at which the inclined long anchor cable needs to be anchored into the top plate; and L0 is the exposed length of the inclined long anchor cable 15.

[0054] Through formula calculation, the total length L of the anchor cable can be accurately calculated based on the actual working conditions on site (such as the height of the roadway roof, the thickness of the roof rock layer to be reinforced, and the required anchor cable installation angle). This ensures that the anchoring depth h2 (to guarantee anchoring force) is met, the reserved hole position h1 (to accommodate the drilling channel on the backfill body) is adapted, and a reasonable exposed length L0 is reserved. This avoids support failure or resource waste caused by length estimation. Through quantitative design, it is ensured that the inclined long anchor cable 15 can adapt to the structural characteristics of the backfill body and meet the mechanical requirements of roof pre-support. Ultimately, it forms a joint control between the roof and sidewall reinforcement of the composite coal pillar, jointly solving the pain points of large deformation of the surrounding rock and high support difficulty in roadways with small coal pillars.

[0055] Step S6: After the first coal mining face 1 is completed and the overburden movement is stable, small coal pillars 18 are left along the edge of the goaf, and goaf roadways 19 are constructed, and the surrounding rock of the roadways is supported by anchor bolts.

[0056] like Figure 6 Figure (a) and Figure 6 As shown in Figure (b), the width of the filling body is b2, and its size is not less than 300mm to ensure its stability. The roof support depth must exceed the maximum height h2 of the inclined long anchor cable 15. That is, in the new goaf roadway 19, the anchoring point of the vertically driven long anchor rod must be higher than the maximum height of the inclined long anchor cable 15, thereby forming a three-dimensional support structure of vertical anchor rods and inclined long anchor cables 15 at different anchoring points on the roof.

[0057] In the new gob-side entry 19, when the anchor rod and cable are set to the side of the small coal pillar 18, the anchor rod 20 on the small coal pillar side is anchored in the small coal pillar 18 or to the filling body, and the anchor cable 21 is anchored in the filling body, as shown in Figure 7 (a) of Fig. and Figure 7 (b) of Fig.

[0058] In the embodiment, the sum of the small coal pillar width b1 and the filling body width b2 is not less than 0.3 times the height of the second coal mining face 22. The sum of the small coal pillar width b1 and the filling body width b2 is associated with the height of the second coal mining face 22, and when the sum is not less than 0.3 times the height, sufficient lateral support force can be provided for the entry. Moreover, the above limitation enables the design of the small coal pillar and the filling body width to be flexibly adjusted according to the height. This can better adapt to various mining conditions, whether it is thin seam mining or thick seam mining, and the composite coal pillar can meet the entry support requirements by reasonable setting of the width, thereby improving the universality and applicability of the technical solution and expanding the application range thereof in different coal mining environments.

[0059] In the present application, in a first aspect, the small coal pillar 18 side is reinforced by constructing a filling body of concrete pouring on the side of the coal pillar; the small coal pillar 18 and the filling body form a composite coal pillar through the firm connection of the continuation anchor rod 5 and the original anchor rod 3, and this composite coal pillar has good firmness and stability. After the gob-side entry 19 is excavated beside the small coal pillar 18, when the anchor rod and cable are set to the entry face of the small coal pillar 18, there is a stable anchoring point, thereby strengthening the support of the entry surrounding rock. After the original anchor rod 3 is connected with the continuation anchor rod 5, the small coal pillar 18 can be formed into a tension fastening, so as to strengthen the support force of the small coal pillar 18. In a second aspect, the present application is provided with a reserved hole 104 on the model frame top frame 10, and is provided with an isolation pipe 16 inside, which is used as a setting channel of the inclined long anchor cable 15, and the anchoring point thereof is placed on the roof on the left side of the small coal pillar 18, so as to perform roof pre-supporting on the to-be-excavated gob-side entry 19. Meanwhile, the surface of the concrete wall is flat, which ensures that the inclined long anchor cable tray is in flat contact with the wall, and ensures the installation quality of the anchor cable. After the gob-side entry 19 is excavated, when the entry is supported, the long anchor cable is vertically set upward, and the anchoring point thereof is on the roof, thereby forming a three-dimensional support structure of the inclined roof support and the vertical roof support, which provides good support for the support stability of the entry.

[0060] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited thereto, and various changes can be made within the knowledge range of those skilled in the art without departing from the purpose of the present application, which are all within the protection scope of the claims of the present application.

Claims

1. A composite coal pillar construction and side top coordination control method for a small coal pillar gob roadway, characterized in that, The method comprises the following steps: Step S1, during the mining of the first coal mining face (1), the coal pillar side in the roadway (2) is filled by modeling; Step S11, before modeling, a continuation anchor rod (5) is installed on the exposed section of the original anchor rod (3) of the coal pillar side; Step S12, at the starting point of the first cycle of filling, a masonry wall (6) is constructed as a starting end, a plurality of adjusting narrow plates (7) are stacked from bottom to top to form a board wall (8) to block the other end, a mold frame bottom bracket (9) and a mold frame top bracket (10) are used to form a filling space in the roadway (2); Step S13, a plurality of reserved holes (104) are arranged in the mold frame top bracket (10), and an isolation pipe (16) is installed in the reserved hole (104); Step S2, concrete (17) is poured into the filling space through the filling port (13) at the top of the board wall (8), the filling height is observed through the observation port (14) at the top of the board wall (8), when the filling height reaches the observation port (14), the observation port (14) is closed until the concrete (17) is topped, and the current cycle of filling is completed; Step S3, after the posture of the concrete (17) is stable, the mold frame bottom bracket (9), the mold frame top bracket (10) and the plurality of adjusting narrow plates (7) are moved to the position of the next filling cycle; Step S4, steps S2 and S3 are repeated until the filling work of the coal pillar side is completed; Step S5, during the implementation of step S4, for the filled body that has been consolidated at the rear, a drilling hole is constructed obliquely upward through the isolation pipe (16), and then an oblique long anchor cable (15) is arranged on the roof; the step is repeated until the oblique long anchor cable (15) is completely installed; the length L of the oblique long anchor cable (15) is calculated according to the following formula: ， In the formula, α is the installation angle of the oblique long anchor cable; h1 is the distance from the reserved hole in the mold frame top bracket to the roof of the roadway; h2 is the height at which the oblique long anchor cable needs to be anchored into the roof, and L0 is the exposed length of the oblique long anchor cable; Step S6, after the first coal mining face (1) is mined and the overburden rock movement is stable, a small coal pillar (18) is left along the edge of the goaf, an along-gob roadway (19) is implemented, and the anchor rod and cable support is implemented on the surrounding rock of the roadway.

2. The method according to claim 1, wherein, The continuation anchor rod (5) is tightly connected with the original anchor rod (3) through a continuation nut (4), and the main body of the continuation anchor rod (5) is located in the space to be filled and has a length not exceeding the mold frame bottom bracket (9) and the mold frame top bracket (10).

3. The method according to claim 1, wherein the method further comprises the steps of: determining the position of the small coal pillar along the gob-side entry; and determining the position of the small coal pillar along the crossheading. The mold frame bottom bracket (9) comprises a slot (91) and a bottom limiting slot (93), the mold frame top bracket (10) comprises a plug-in plate (101) and a top limiting slot (103), the plug-in plate (101) is inserted into the slot (91) when the slot (91) and the plug-in plate (101) are connected, and the bottom limiting slot (93) and the top limiting slot (103) are on the same vertical line.

4. The small-pillar composite coal-pillar construction and side top coordination control method for a gob-side entry according to claim 3, characterized in that, A reinforcing lug I (92) and a reinforcing lug II (102) are arranged between the two right-angle surfaces of the mold frame bottom bracket (9) and the two right-angle surfaces of the mold frame top bracket (10).

5. The small-pillar composite coal-pillar construction and side top coordination control method for a gob-side entry according to claim 4, characterized in that, A single column (11) is arranged between the mold frame bottom bracket (9) and the mold frame top bracket (10), the top of the single column (11) is connected with the top limiting groove (103), and the bottom is fixed on the bottom limiting groove (93); the single column (11) is used for supporting the mold frame bottom bracket (9) and the mold frame top bracket (10), and the combined height of the two is adjusted through the expansion and contraction of the single column (11).

6. The small-pillar composite coal-pillar construction and side top coordination control method for a gob-side entry according to claim 1, characterized in that, The filling body width b2 is not less than 300mm.

7. The method of claim 1, wherein the method further comprises: In step S5, the maximum support depth of the top plate exceeds the height h2 of the oblique long anchor cable anchored into the top plate.

8. The method of claim 1, wherein the method further comprises: In step S6, when the roadway surrounding rock is anchored and supported, the anchor rod (20) of the small coal pillar side is anchored in the small coal pillar (18) or anchored into the filling body, and the anchor cable (21) is anchored into the filling body.

9. The method according to claim 6, wherein the method further comprises the steps of: determining the position of the small coal pillar and the position of the composite coal pillar; and determining the position of the support and the position of the small coal pillar. In step S6, the sum of the small coal pillar (18) width b1 and the filling body width b2 is not less than 0.3 times the mining height of the second coal mining face (22). In step S5, the maximum support depth of the top plate exceeds the height h2 of the oblique long anchor cable anchored into the top plate. In step S6, when the roadway surrounding rock is anchored and supported, the anchor rod (20) of the small coal pillar side is anchored in the small coal pillar (18) or anchored into the filling body, and the anchor cable (21) is anchored into the filling body. In step S6, the sum of the small coal pillar (18) width b1 and the filling body width b2 is not less than 0.3 times the mining height of the second coal mining face (22).

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