Supporting structure for stoping of stope under weak rock condition and construction method

Abstract

The invention discloses a supporting structure for stope stoping under weak rock conditions and a construction method, the supporting structure comprises a plurality of groups of positioning pieces, an extrusion gap is formed between two adjacent positioning pieces in a single group, and a central through hole is formed in the middle part surrounded by the plurality of positioning pieces in the single group; the reinforcing blocks are installed between every two adjacent sets of positioning pieces, the outer diameter of each reinforcing block is smaller than the diameter of the center through hole before the anchor rod main body support is installed, and after the anchor rod main body support is installed, radial stress is reduced, so that the center through hole is reduced accordingly. Under the limiting effect of the positioning piece, the multiple reinforcing blocks are evenly distributed in the inner cavity of the anchor rod body, and therefore the situations that the anchor rod body is bent, fractured, invalid and the like are avoided; and after the supporting mechanism is installed, chemical grout is injected from the tail end of the anchor rod body, the grout overflows outwards to a rock stratum gap from a grout outlet hole along an inner cavity of the anchor rod body, a reinforcing mesh is buckled and fixed through cooperation with a tray, the strength of surrounding rock is improved, and the integrality of the surrounding rock is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of stope support, and in particular relates to a support structure and a construction method for stope recovery under weak rock conditions. Background Art

[0002] The design and application of support structures are crucial in the mining process, especially in stope recovery operations under weak rock conditions, where support structures face the complex mechanical behavior of weak, fractured surrounding rock. Surrounding rock in weak rock conditions typically exhibits low strength and poor integrity, and is highly sensitive to groundwater, susceptible to moisture-induced softening and mudification. This change significantly degrades the mechanical properties of the rock formation, increasing the complexity and risk of support structure design, especially during stope recovery.

[0003] Weak rock conditions in mining, including hanging wall faults and fracture zones, severely impact roof stability. Because the roof is prone to collapse, the stability of the support structure faces significant challenges. In these environments, traditional support methods, particularly traditional pipe-slit anchor bolts, are no longer effective in addressing rock support issues.

[0004] While traditional pipe-slit anchors can provide some support for rock formations, their performance in weak surrounding rock conditions is often unsatisfactory. First, after insertion, the anchors are susceptible to radial stress concentration due to rock deformation and unevenness, causing them to bend, break, or fail, directly impacting the stability of the support system. Second, the anchor installation method and structural form are not fully adapted to the complex geological conditions of the surrounding rock, such as softening, mudification, and fault zones. This results in unstable support and an inability to effectively prevent ore body damage and rock collapse. Summary of the Invention

[0005] The present invention aims to solve the problems in the prior art and proposes the following technical solutions:

[0006] The support structure for mining in a stope under weak rock conditions includes a steel mesh and a support mechanism. The support mechanism includes an anchor body and a tray. The support structure also includes:

[0007] Multiple groups of positioning members are fixedly connected to the inner wall of the anchor body at equal intervals along the axial direction of the anchor body; a single group of positioning members includes multiple positioning members coaxial with the anchor body and distributed circumferentially, an extrusion gap is formed between two adjacent positioning members in a single group, and a central through hole is formed in the middle of the circumference surrounded by the multiple positioning members in a single group;

[0008] A slurry outlet hole is provided on the annular wall of the anchor body and is located between two adjacent sets of positioning members;

[0009] The reinforcement block is installed between two adjacent groups of positioning parts. The outer diameter of the reinforcement block is smaller than the diameter of the center through hole before the anchor rod main body support is installed. After the anchor rod main body support is installed, the radial force is reduced, so that the center through hole is reduced accordingly, and at this time the diameter of the center through hole is smaller than the outer diameter of the reinforcement block.

[0010] As a preferred embodiment of the above technical solution, the supporting mechanism further includes an anchor rod tip, and a connecting portion is provided between the anchor rod tip and the top end of the anchor rod body.

[0011] As a preferred embodiment of the above technical solution, the positioning member is provided with an inclined surface;

[0012] Along the axial direction of the anchor rod body, the lower edge of the inclined surface is in contact with the inner wall of the anchor rod body, and the upper edge of the inclined surface is in contact with the upper edge of the positioning piece.

[0013] As a preferred embodiment of the above technical solution, the slurry outlet hole is a tapered opening, and the opening diameter of the slurry outlet hole located on the inner wall of the anchor rod body is larger than the opening diameter of the slurry outlet hole located on the outer wall of the anchor rod body;

[0014] The opening direction of the slurry outlet hole is perpendicular to the central axis of the anchor rod body.

[0015] As a preferred embodiment of the above technical solution, the tail end of the anchor rod body is fixedly connected to a limiting ring, and an anti-slip disc movably sleeved on the outer periphery of the anchor rod body is provided between the limiting ring and the tray;

[0016] The inner diameter of the anti-slip disk is smaller than the outer diameter of the limiting ring, and the inner diameter of the tray is smaller than the outer diameter of the anti-slip disk.

[0017] As a preferred embodiment of the above technical solution, a buckle groove is provided on a side of the pallet away from the anti-slip plate, and the buckle groove matches the steel mesh.

[0018] As a preferred embodiment of the above technical solution, the reinforcement block includes a reinforcement block main body, a through-type slurry hole is opened in the middle of the reinforcement block main body along its axial direction, and a plurality of circumferentially distributed elastic skirts are fixedly connected to the tail end of the reinforcement block main body, and the lower edge of the elastic skirt is flush with the bottom of the reinforcement block main body.

[0019] A construction method is applied to a support structure for stope recovery under the above-mentioned weak rock conditions, and the construction method comprises the following steps:

[0020] S1. Preparation before support: Put multiple reinforcement blocks into the inner cavity of the anchor body from the tail end of the anchor body, so that there is a reinforcement block between two adjacent sets of positioning pieces. Then insert the tray from the top of the anchor body and clamp it to the tail end of the anchor body;

[0021] S2. Support: First, a borehole with an inner diameter slightly smaller than the outer diameter of the anchor bolt body is drilled perpendicular to the rock surface. The anchor bolt body is then inserted into the borehole until the tray contacts the rock surface. The inner wall of the hole radially squeezes the anchor bolt body, and the radial force on the anchor bolt body is reduced, causing the central through hole to shrink accordingly. At this time, the diameter of the central through hole is smaller than the outer diameter of the reinforcement block, and the reinforcement block is constrained and fixed between two adjacent sets of positioning pieces.

[0022] S3. Grouting: Chemical slurry (including cement slurry, polyurethane grouting, etc.) is injected from the tail end of the anchor body. The slurry flows out from the slurry hole along the inner cavity of the anchor body to the cracks in the rock formation, filling the broken gaps, improving the strength of the surrounding rock, and enhancing the integrity of the surrounding rock.

[0023] The beneficial effects of the present invention are:

[0024] 1. Under the limiting action of the positioning member, the present invention allows multiple reinforcement blocks to be evenly distributed in the inner cavity of the anchor rod body. In this way, even if a certain area of ​​the anchor rod body is subjected to concentrated stress, the reinforcement blocks and the positioning member can support the anchor rod body, thereby preventing the anchor rod body from bending, breaking, or failing.

[0025] 2. After the support mechanism of the present invention is installed, chemical slurry (including cement slurry, polyurethane grouting, etc.) is injected from the tail end of the anchor rod body. The slurry flows outward from the slurry outlet along the inner cavity of the anchor rod body to the cracks in the rock formation, filling the broken gaps. The tray is used to fasten and fix the steel mesh, thereby increasing the strength of the surrounding rock and enhancing the integrity of the surrounding rock. At the same time, the excess slurry fills the redundant gaps, further ensuring the structural stability of the support mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure shows the overall three-dimensional structure of the support structure for stope recovery under weak rock conditions in the embodiment;

[0027] Figure 2 The figure shows a three-dimensional structure diagram of a support mechanism in a support structure for stope recovery under weak rock conditions in an embodiment;

[0028] Figure 3 The figure shows a schematic diagram of the partial structure of the anchor rod main body in the support structure of the stope under weak rock conditions in the embodiment;

[0029] Figure 4 Shown is a schematic diagram of the reinforcing block structure in the support structure for stope recovery under weak rock conditions in an embodiment.

[0030] In the figure: steel mesh; 20, support mechanism; 21, anchor rod body; 211, limiting ring; 22, tray; 221, buckle groove; 23, connecting part; 24, anchor rod tip; 30, anti-slip disk; 40, positioning piece; 41, extrusion gap; 42, center through hole; 401, inclined surface; 50, reinforcement block; 51, reinforcement block body; 52, slurry hole; 53, elastic skirt; 60, slurry outlet hole. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0032] Example

[0033] like Figure 1 As shown, the support structure for mining in a stope under weak rock conditions includes a steel mesh 10 and a support mechanism 20. The support mechanism 20 includes an anchor body 21 and a tray 22. A buckle groove 221 is provided on the side of the tray 22 away from the anti-slip plate 30, and the buckle groove 221 matches the steel mesh 10. After the anchor body 21 is passed through the middle hole of the steel mesh 10 and then inserted into the rock formation, the buckle groove 221 on the tray 22 buckles the steel mesh 10 so that the steel mesh 10 is fixed to the rock surface, thereby improving the integrity of the surrounding rock and reducing the risk of surrounding rock collapse.

[0034] like Figure 2 As shown, the tail end of the anchor rod body 21 is fixedly connected to the limiting ring 211, and an anti-slip disk 30 is movably mounted on the outer periphery of the anchor rod body 21 between the limiting ring 211 and the tray 22; the inner diameter of the anti-slip disk 30 is smaller than the outer diameter of the limiting ring 211, and the inner diameter of the tray 22 is smaller than the outer diameter of the anti-slip disk 30.

[0035] In the present invention, the inner diameter of the tray 22 is set larger, thereby providing the tray 22 with a larger floating gap, making it easier for the buckle groove 221 to buckle the steel mesh 10, ensuring the stability of the fixation between the support mechanism 20 and the steel mesh 10; by setting an anti-fall-off plate 30 for supporting the tray 22, the larger inner diameter of the tray 22 is prevented from passing through the limiting ring 211 and then falling off from the tail end of the anchor rod body 21.

[0036] like Figure 3 、 Figure 4 As shown, the support structure also includes:

[0037] Multiple groups of positioning members 40 are fixedly connected to the inner wall of the anchor body 21 at equal intervals along the axial direction of the anchor body 21; a single group of positioning members 40 includes multiple positioning members 40 coaxial with the anchor body 21 and distributed circumferentially, with an extrusion gap 41 formed between two adjacent positioning members 40 in a single group, and a central through hole 42 formed in the middle of the circumference of the multiple positioning members 40 in a single group;

[0038] In the present invention, the positioning member 40 mainly plays the role of limiting the installation of the reinforcement block 50; at the same time, the positioning member 40 also plays a certain reinforcing role on the inner wall of the anchor rod body 21. After the anchor rod body 21 enters the borehole, since the inner diameter of the borehole is smaller than the outer diameter of the anchor rod body 21, the anchor rod body 21 will undergo radial elastic deformation, thereby increasing the friction between the anchor rod body 21 and the borehole wall. The radial elastic deformation of the anchor rod body 21 reduces the extrusion gap 41, and at the same time, the central through hole 42 formed around the circumference of the central part also becomes smaller.

[0039] The reinforcement block 50 is installed between two adjacent sets of positioning parts 40. The outer diameter of the reinforcement block 50 is smaller than the diameter of the center through hole 42 before the anchor rod body 21 is supported and installed. After the anchor rod body 21 is supported and installed, the radial force is reduced, causing the center through hole 42 to shrink accordingly, and at this time, the diameter of the center through hole 42 is smaller than the outer diameter of the reinforcement block 50.

[0040] Under the limiting effect of the positioning member 40, the multiple reinforcement blocks 50 are evenly distributed in the inner cavity of the anchor rod body 21. In this way, even if a certain area of ​​the anchor rod body 21 is subjected to concentrated stress, the reinforcement blocks 50 and the positioning member 40 can still support the anchor rod body 21, thereby preventing the anchor rod body 21 from bending, breaking, or failure.

[0041] The grouting hole 60 is provided on the annular wall of the anchor rod body 21 and is located between two adjacent sets of positioning members 40. In the present invention, even if the anchor rod body 21 is deformed by radial pressure after installation, its inner diameter after deformation is still larger than the outer diameter of the reinforcing block 50. Therefore, a redundant gap is formed between the reinforcing block 50 and the inner wall of the anchor rod body 21. After the support mechanism 20 is installed, chemical slurry (including cement slurry, polyurethane grouting, etc.) is injected from the tail end of the anchor rod body 21. The slurry flows outward from the grouting hole 60 along the inner cavity of the anchor rod body 21 to the cracks in the rock formation, filling the broken gaps and cooperating with the steel mesh 10 to improve the strength of the surrounding rock and enhance the integrity of the surrounding rock. At the same time, the excess slurry fills the redundant gaps, further ensuring the structural stability of the support mechanism 20.

[0042] When the chemical slurry is injected, there is a certain fluid pressure in the chemical slurry. At this time, the shrunken central through hole 42 can limit the reinforcement block 50 between two adjacent groups of positioning parts 40, thereby avoiding axial stacking of the reinforcement block 50 and affecting the uniformity of the distribution of the reinforcement block 50.

[0043] The slurry outlet hole 60 has a conical opening, and the opening diameter of the slurry outlet hole 60 located on the inner wall of the anchor rod body 21 is larger than the opening diameter of the slurry outlet hole 60 located on the outer wall of the anchor rod body 21; the opening direction of the slurry outlet hole 60 is perpendicular to the central axis of the anchor rod body 21.

[0044] The conical opening shape can not only pressurize the slurry when it is ejected outward from the anchor rod body 21, so that it can overflow into the rock formation gap better; at the same time, it can reduce the probability of broken rock particles entering the inner cavity of the anchor rod body 21 from the slurry outlet hole 60 and the slurry outlet hole 60 being blocked.

[0045] The supporting mechanism 20 further includes an anchor rod tip 24 , and a connecting portion 23 is provided between the anchor rod tip 24 and the top end of the anchor rod body 21 .

[0046] The connection portion 23 and the anchor rod tip 24 are provided to facilitate the anchor rod body 21 to better drill into the borehole.

[0047] The positioning member 40 is provided with an inclined surface 401 ; along the axial direction of the anchor rod body 21 , the lower edge of the inclined surface 401 fits in contact with the inner wall of the anchor rod body 21 , and the upper edge of the inclined surface 401 fits in contact with the upper edge of the positioning member 40 .

[0048] The inclined surface 401 is provided to guide the reinforcing block 50 into the deep inner cavity of the anchor rod body 21 , thereby preventing the positioning member 40 from being stuck in the inner cavity of the anchor rod body 21 .

[0049] The reinforcing block 50 includes a reinforcing block main body 51, a through-type slurry hole 52 is opened in the middle of the reinforcing block main body 51 along its axial direction, and a plurality of circumferentially distributed elastic skirts 53 are fixedly connected to the tail end of the reinforcing block main body 51, and the lower edge of the elastic skirt 53 is flush with the bottom of the reinforcing block main body 51.

[0050] By setting up the slurry holes 52, even if the redundant gaps are squeezed and become smaller, the slurry can flow through the inner cavity of the anchor rod body 21; the elastic and outward-stretching design of the elastic skirt 53 allows the reinforcement block 50 to pass through the obstruction of the positioning piece 40 when it is put into use, and under the obstruction of the outward-stretching lower edge of the elastic skirt 53, the reinforcement block 50 can be prevented from detaching from the anchor rod body 21.

[0051] A construction method is applied to a support structure for stope recovery under the above-mentioned weak rock conditions, and the construction method comprises the following steps:

[0052] S1. Preparation before support: Put multiple reinforcement blocks 50 into the inner cavity of the anchor body 21 from the tail end of the anchor body 21, so that there is a reinforcement block 50 between two adjacent sets of positioning members 40, and then insert the tray 22 from the top of the anchor body 21 and clamp it to the tail end of the anchor body 21;

[0053] S2. Support: First, drill a hole perpendicular to the rock surface with an inner diameter slightly smaller than the outer diameter of the anchor rod body 21. Then, insert the anchor rod body 21 into the hole until the tray 22 contacts the rock surface. The inner wall of the hole radially squeezes the anchor rod body 21. The radial force on the anchor rod body 21 decreases, causing the central through hole 42 to shrink accordingly. At this time, the diameter of the central through hole 42 is smaller than the outer diameter of the reinforcement block 50. The reinforcement block 50 is confined and fixed between two adjacent sets of positioning members 40.

[0054] S3. Grouting: Inject chemical slurry (including cement slurry, polyurethane grouting, etc.) from the tail end of the anchor body 21. The slurry flows outward from the slurry outlet 60 along the inner cavity of the anchor body 21 to the rock formation cracks, filling the broken gaps, improving the strength of the surrounding rock, and enhancing the integrity of the surrounding rock.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same.

Claims

1. A support structure for mining in a stope under weak rock conditions, comprising a steel mesh (10) and a support mechanism (20), wherein the support mechanism (20) comprises an anchor rod body (21) and a tray (22), and is characterized in that: The support structure further comprises: Multiple groups of positioning members (40), the multiple groups of positioning members (40) are fixedly connected to the inner wall of the anchor rod body (21) at equal distances along the axial direction of the anchor rod body (21); a single group of positioning members (40) includes multiple positioning members (40) coaxial with the anchor rod body (21) and distributed circumferentially, an extrusion gap (41) is formed between two adjacent positioning members (40) in a single group, and a central through hole (42) is formed in the middle of the circumference of the multiple positioning members (40) in a single group; A slurry outlet hole (60), the slurry outlet hole (60) is opened on the annular wall of the anchor rod body (21) and is located between two adjacent groups of positioning members (40); A reinforcing block (50) is installed between two adjacent groups of positioning members (40). The outer diameter of the reinforcing block (50) is smaller than the diameter of the central through hole (42) before the anchor rod body (21) is supported and installed. After the anchor rod body (21) is supported and installed, the radial force is reduced, so that the central through hole (42) is reduced accordingly, and at this time, the diameter of the central through hole (42) is smaller than the outer diameter of the reinforcing block (50).

2. The support structure for stope recovery under weak rock conditions according to claim 1, characterized in that: The supporting mechanism (20) further comprises an anchor rod tip (24), and a connecting portion (23) is provided between the anchor rod tip (24) and the top end of the anchor rod body (21).

3. The support structure for stope recovery under weak rock conditions according to claim 1, characterized in that: The positioning member (40) is provided with an inclined surface (401); Along the axial direction of the anchor rod body (21), the lower edge of the inclined surface (401) fits in contact with the inner wall of the anchor rod body (21), and the upper edge of the inclined surface (401) fits in contact with the upper edge of the positioning member (40).

4. The support structure for stope recovery under weak rock conditions according to claim 1, characterized in that: The slurry outlet hole (60) is a tapered opening, and the opening diameter of the slurry outlet hole (60) located on the inner wall of the anchor rod body (21) is larger than the opening diameter of the slurry outlet hole (60) located on the outer wall of the anchor rod body (21); The opening direction of the slurry outlet hole (60) is perpendicular to the central axis of the anchor rod body (21).

5. The support structure for stope recovery under weak rock conditions according to claim 1, characterized in that: The tail end of the anchor rod body (21) is fixedly connected to a limiting ring (211), and an anti-slip disc (30) movably sleeved on the outer periphery of the anchor rod body (21) is provided between the limiting ring (211) and the tray (22); The inner diameter of the anti-slip disc (30) is smaller than the outer diameter of the limiting ring (211), and the inner diameter of the tray (22) is smaller than the outer diameter of the anti-slip disc (30).

6. The support structure for stope recovery under weak rock conditions according to claim 5, characterized in that: A buckle groove (221) is provided on a side of the tray (22) away from the anti-slip plate (30), and the buckle groove (221) matches the steel mesh (10).

7. The support structure for stope recovery under weak rock conditions according to claim 1, characterized in that: The reinforcing block (50) comprises a reinforcing block body (51), a through-type slurry hole (52) is provided in the middle of the reinforcing block body (51) along its axial direction, and a plurality of circumferentially distributed elastic skirts (53) are fixedly connected to the tail end of the reinforcing block body (51), and the lower edge of the elastic skirt (53) is flush with the bottom of the reinforcing block body (51).

8. A construction method, characterized in that: The construction method is applied to the support structure for stope recovery under weak rock conditions as described in any one of claims 1 to 7, and the construction method comprises the following steps: S1. Preparation before support: multiple reinforcement blocks (50) are put into the inner cavity of the anchor rod body (21) from the tail end of the anchor rod body (21), so that there is a reinforcement block (50) between two adjacent sets of positioning members (40), and then the tray (22) is inserted from the top end of the anchor rod body (21) and clamped on the tail end of the anchor rod body (21); S2. Support: First, a borehole with an inner diameter slightly smaller than the outer diameter of the anchor rod body (21) is opened perpendicular to the rock surface, and then the anchor rod body (21) is put into the borehole until the tray (22) is against the rock surface, and the inner wall of the hole radially squeezes the anchor rod body (21), and the radial force on the anchor rod body (21) is reduced, so that the central through hole (42) is also reduced. At this time, the diameter of the central through hole (42) is smaller than the outer diameter of the reinforcement block (50), and the reinforcement block (50) is restricted and fixed between two adjacent sets of positioning members (40); S3. Grouting: Chemical slurry (including cement slurry, polyurethane grouting, etc.) is injected from the tail end of the anchor rod body (21). The slurry flows outward from the slurry outlet hole (60) along the inner cavity of the anchor rod body (21) to the cracks in the rock formation, filling the broken gaps, improving the strength of the surrounding rock and enhancing the integrity of the surrounding rock.

Images