Tunnel support and surrounding rock filling synergistic method for local anti-rock burst in mines

Abstract

The present invention discloses a tunnel support-surrounding rock filling coordination method for local anti-impact ground pressure in mines, and relates to the technical field of coal mine tunnel support. The method comprises: firstly, a pressure relief borehole is drilled in the middle of the two sides of the tunnel, a borehole stress gauge is arranged at the end of the pressure relief borehole, and the borehole stress gauge is used to monitor whether there is a rock burst hazard in the tunnel section, and if there is a rock burst hazard, a pressure relief borehole is arranged above it; then, the tunnel surrounding rock is initially supported by anchor rods; non-Newtonian fluid is injected into the cavity through the injection hole until it is full, and the non-Newtonian fluid that continues to be injected flows into the pressure relief borehole around the tunnel surrounding rock, and after the pressure relief borehole is filled with non-Newtonian fluid, the cavity and the non-Newtonian fluid in the pressure relief borehole form an integral structure, and when the tunnel is deformed, the pressure relief borehole and the non-Newtonian fluid in the cavity jointly play a role in allowing pressure to deform. The method of the present invention can support tunnels or areas with rock burst.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel support, and in particular to a tunnel and surrounding rock filling integration method suitable for a local mine or an original stress concentration structural area. Background Art

[0002] With the increase in the intensity and depth of coal mining, the number of rock burst mines and the degree of rock burst danger have increased significantly, so its safety has received much attention. Rock burst can cause the following hazards: First, it can seriously damage the tunnel, instantly shrink the tunnel section, damage the support, and even close the tunnel in severe cases; Second, it can seriously damage the tunnel, instantly shrink the tunnel section, damage the support, and even close the tunnel in severe cases; Third, it can destroy ventilation facilities, with powerful shock waves destroying the air doors and wind tubes of the excavation working face; Fourth, it can cause casualties, with most of the personnel being injured by impact, shock waves, etc.; Fifth, it can cause secondary disasters such as gas outbursts.

[0003] At present, the existing technology mainly adopts local pressure relief to deal with rock burst. The local pressure relief method reduces the stress concentration of coal and rock mass by creating deformation space, releasing elastic energy and changing the physical and mechanical properties of coal and rock mass. However, the pressure relief range is limited and it is impossible to fundamentally eliminate stress concentration. Therefore, the pressure relief area often forms stress concentration again in a short period of time due to stress transfer, resulting in reduced timeliness and effect of pressure relief.

[0004] In addition, the support in the prior art usually adopts the method of primary support and secondary lining support, such as shotcrete support. Although this support method can support the tunnel, the dust generated during the spraying process poses a threat to the health of construction workers, and the construction period is long. Therefore, the support method in the above-mentioned prior art and the method of local pressure relief to resist impact ground pressure need to be further improved. Summary of the invention

[0005] The purpose of the present invention is to provide a tunnel support-surrounding rock filling collaborative method for local resistance to impact ground pressure in mines, by injecting non-Newtonian fluid into the cavity and the pressure relief boreholes around the tunnel to form an integral structure. When the tunnel is deformed, the non-Newtonian fluid in the pressure relief borehole and the non-Newtonian fluid in the cavity can jointly play a role in allowing pressure deformation.

[0006] A tunnel support-surrounding rock filling coordination method for local anti-impact rock pressure in a mine, comprising the following steps in sequence:

[0007] a. Drill a pressure relief hole in the middle of the two sides of the tunnel, and set a borehole stress gauge at the end of the pressure relief hole;

[0008] b. Use the borehole stress meter in step a to monitor whether there is rock burst hazard in the tunnel. If rock burst hazard is detected in the tunnel, drill pressure relief holes on the upper sides of both sides of the tunnel;

[0009] c. Initial support is provided to the tunnel surrounding rock by driving anchor rods into the tunnel surrounding rock, forming an integral and stable rock belt around the tunnel;

[0010] d. Construct tunnel support area

[0011] The invention comprises a cavity and a non-Newtonian fluid in the cavity, a fluid pressure gauge is arranged on the inner wall of the cavity, a liquid injection hole is arranged on the cavity, a liquid injection pipe is connected to the liquid injection hole, the liquid injection pipe is connected to the liquid injection pump, and the liquid injection pump is connected to the liquid storage tank; the periphery of the cavity is reinforced by wire mesh, and a steel bracket is arranged under the cavity to further fix it;

[0012] e. Inject non-Newtonian fluid into the cavity through the injection hole until it is full, and continue to inject non-Newtonian fluid into the pressure relief borehole around the surrounding rock of the tunnel. After the pressure relief borehole is filled with non-Newtonian fluid, the cavity and the non-Newtonian fluid in the pressure relief borehole form an integral structure. When the tunnel is deformed, the pressure relief borehole and the non-Newtonian fluid in the cavity jointly play a role in allowing pressure to deform;

[0013] f. When the fluid pressure gauge indicates that the pressure is equal to ρgh, the injection pump is turned off to stop injecting the non-Newtonian fluid. When the fluid pressure gauge indicates that the pressure is less than ρgh, the injection pump is turned on to inject the non-Newtonian fluid into the cavity.

[0014] In the above ρgh, ρ is the density of the non-Newtonian fluid, g is the acceleration due to gravity, and h is the height difference between the position of the fluid pressure gauge on the tunnel wall and the top of the tunnel.

[0015] The beneficial technical effects directly brought about by the above technical solution are:

[0016] The above technical solution forms a support structure by injecting a non-Newtonian fluid into the cavity, and the support structure is used to support the tunnel with rock burst. By arranging pressure relief boreholes around the tunnel, the non-Newtonian fluid enters the pressure relief boreholes and forms an integral structure with the non-Newtonian fluid entering the cavity. When the tunnel is deformed, the non-Newtonian fluid in the pressure relief borehole and the non-Newtonian fluid in the cavity can work together to prevent deformation due to pressure. In addition, the pressure relief borehole and a borehole stress gauge are set at the end of the pressure relief borehole. The borehole stress gauge can more accurately monitor whether there is rock burst hazard in this section of the tunnel. The non-Newtonian fluid enters the pressure relief borehole, and the integral structure formed by the non-Newtonian fluid and the non-Newtonian fluid in the cavity has a better support effect on the tunnel.

[0017] As a preferred embodiment of the present invention, the length of the pressure relief drill hole in step a and step b is 15 m, and the vertical distance between the pressure relief drill hole in step a and the pressure relief drill hole in step b is 50 cm.

[0018] In the above technical solution, in order to ensure the accuracy of monitoring the rock burst pressure around the tunnel, the length of the pressure relief borehole is designed to be 15m.

[0019] As another preferred embodiment of the present invention, in step d, the cavity is made of injection-molded cloth, the non-Newtonian fluid is loaded into the injection-molded cloth, and at least one layer of strong canvas is wrapped outside the injection-molded cloth.

[0020] In the above technical solution, the cavity is made of injection molded cloth, which is more stable, strong and durable. Strong canvas is wrapped outside the injection molded cloth. The strong canvas not only has good waterproof performance, but is also stronger and more durable.

[0021] Further preferably, in step d, several groups of steel supports are provided, which are made according to the shape and cross-section of the tunnel, and the spacing between adjacent steel supports is 30 to 50 cm.

[0022] Further preferably, in step d, a control platform is arranged near the liquid storage tank, and the control platform is respectively connected to the fluid pressure gauge, the injection pump and the liquid storage tank.

[0023] Preferably, the non-Newtonian fluid contains cement.

[0024] Preferably, the shape of the tunnel is circular, rectangular, irregular trapezoidal, saddle-shaped or straight-walled semicircular arch.

[0025] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0026] (1) The present invention proposes a tunnel support-surrounding rock filling collaborative method for local resistance to rock burst in mines, which applies non-Newtonian fluid to mine tunnel support and surrounding rock filling. The non-Newtonian fluid is filled into the cavity and the pressure relief borehole to form an integral structure. Under normal conditions, the non-Newtonian fluid is in a soft state. When the tunnel is instantly pressurized, the non-Newtonian fluid instantly becomes a hard support structure that can resist rock burst. The non-Newtonian fluid used to support the tunnel and the non-Newtonian fluid entering the surrounding rock pressure relief borehole form an integral structure with better rock burst resistance.

[0027] (2) The tunnel support-surrounding rock filling coordinated method for local mine rock burst resistance proposed in the present invention can support tunnels or areas with rock burst without the need for full support.

[0028] (3) When cracks or joints occur in the surrounding rock, the cement in the non-Newtonian fluid can fill the plastic zone of the tunnel surrounding rock and the joints and cracks;

[0029] (4) When the tunnel is deformed, the pressure relief borehole and the non-Newtonian fluid in the inner cavity can play a role in allowing the tunnel to deform under pressure; automatic fluid replenishment can be achieved by cooperating with the control platform, fluid pressure gauge, injection pump, fluid storage tank, and injection pipe.

[0030] In summary, the present invention does not need to adopt hard support structures such as concrete support in the prior art, and introduces non-Newtonian fluid into the surrounding rock support and surrounding rock filling of coal mine tunnels, so the overall structural impact pressure resistance performance is better; and the method of the present invention is simple to operate and the construction time is short. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings:

[0032] Figure 1 It is a schematic diagram of tunnel support-surrounding rock filling for local anti-impact rock pressure in a mine according to the present invention;

[0033] Figure 2 This is a schematic diagram of the control platform and liquid storage tank structure of the present invention;

[0034] In the figure:

[0035] 1. Liquid injection hole, 2. Liquid injection pipe, 3. Liquid injection pump, 4. Control platform, 5. Liquid storage tank, 6. Non-Newtonian fluid, 7. Pressure relief borehole, 8. Borehole stress gauge, 9. Fluid pressure gauge, 10. Cavity, 11. Steel support, 12. Anchor rod. DETAILED DESCRIPTION

[0036] The present invention proposes a tunnel support-surrounding rock filling collaborative method for local anti-impact ground pressure in mines. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is described in detail below in conjunction with specific embodiments.

[0037] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “comprising” and the like will be understood to include stated elements or components but not to exclude other elements or components.

[0038] In this document, for the convenience of description, spatial relative terms such as "below", "beneath", "below", "above", "above", etc. may be used to describe the relationship of one component or feature to another component or feature in the accompanying drawings. It should be understood that the spatial relative terms are intended to include different orientations of the object in use or operation in addition to the orientation depicted in the figure. For example, if the object in the figure is turned over, the component described as being "below" or "below" other components or features will be oriented "above" the component or feature. Therefore, the exemplary term "below" can include both below and above. The components may also have other orientations (rotated 90 degrees or other orientations) and the spatial relative terms used in this document should be interpreted accordingly.

[0039] The non-Newtonian fluid used in the present invention refers to a fluid that does not satisfy Newton's experimental law of viscosity, that is, a fluid whose shear stress and shear strain rate are not in a linear relationship.

[0040] The non-Newtonian fluid used in the present invention contains cement.

[0041] In the process of supporting the surrounding rock of a mine, usually hard structures such as shotcrete are used to support it, or the surrounding rock is supported by a combination of primary support and secondary lining support. The present invention supports the surrounding rock of the tunnel by introducing non-Newtonian fluid, especially for tunnels with impact ground pressure. For impact ground pressure, the specific point of its damage range is difficult to determine. The existing technology usually supports the entire tunnel. However, although this overall support method can resist impact ground pressure, it undoubtedly increases the workload.

[0042] Based on the support of the tunnel surrounding rock by non-Newtonian fluid, the present invention injects pressure relief holes in the surrounding rock around the tunnel and installs borehole stress gauges, so as to monitor whether there is rock burst disaster in the tunnel by means of borehole stress gauges, thereby further determining the specific area of ​​rock burst, and then focusing on supporting the surrounding rock in this area. This is equivalent to the present invention first determining the potential area where rock burst may occur, and then supporting the surrounding rock in this potential area by means of local support, and then injecting non-Newtonian fluid into the pressure relief holes to form an integral structure with the non-Newtonian fluid in the local support area to jointly resist rock burst.

[0043] The following is a specific combination Figure 1 and Figure 2 The present invention is described in detail.

[0044] A tunnel support-surrounding rock filling coordination method for local anti-impact rock pressure in a mine, comprising the following steps in sequence:

[0045] a. Drill a pressure relief hole in the middle of the two sides of the tunnel, and set a borehole stress gauge 8 at the end of the pressure relief hole. The specific number of the pressure relief holes 7 is 2, which are respectively located in the middle of the two sides of the tunnel. The borehole stress gauge is mainly used to monitor the rock burst pressure in the tunnel. The specific structure can be realized by referring to the prior art;

[0046] b. Use the borehole stress meter in step a to monitor whether there is rock burst hazard in the tunnel. If rock burst hazard is detected in the tunnel, drill pressure relief holes on the upper sides of both sides of the tunnel. The pressure relief holes in this step are located above the pressure relief holes in step a, and the specific number is 2.

[0047] c. Initially supporting the surrounding rock of the tunnel by driving anchor rods 12 into the surrounding rock of the tunnel to form an integral and stable rock belt around the tunnel. The number of anchor rods is determined according to the actual situation of the surrounding rock of the tunnel;

[0048] d. Construct tunnel support area

[0049] It includes a cavity 10 and a non-Newtonian fluid in the cavity. A fluid pressure gauge 9 is arranged on the inner wall of the cavity. The fluid pressure gauge is used to monitor the non-Newtonian fluid 6 in the cavity. An injection hole 1 is arranged on the cavity. The injection hole 1 is located at the cavity at the top of the tunnel. The injection hole is connected to an injection pipe 2. The injection pipe is arranged on the side of the tunnel. The injection pipe located at the bottom of the tunnel is connected to an injection pump 3. The injection pump 3 is connected to a liquid storage tank 5. A control platform 4 is arranged near the liquid storage tank 5. The liquid storage tank is filled with non-Newtonian fluid. When the fluid pressure gauge detects that the cavity needs to be filled with non-Newtonian fluid, the injection pump is turned on to inject non-Newtonian fluid into the injection hole through the injection pipe. The periphery of the cavity is reinforced by wire mesh, and a steel bracket is arranged under the cavity to further fix it. The structure of the steel bracket 11 is an inverted U-shape, and the cavity can be supported by multiple steel brackets. The distance between adjacent steel brackets is 30 to 50 cm.

[0050] e. Inject non-Newtonian fluid into the cavity through the injection hole until it is full, and continue to inject non-Newtonian fluid into the pressure relief borehole around the surrounding rock of the tunnel. After the pressure relief borehole is filled with non-Newtonian fluid, the cavity and the non-Newtonian fluid in the pressure relief borehole form an integral structure. When the tunnel is deformed, the pressure relief borehole and the non-Newtonian fluid in the cavity jointly play a role in allowing pressure to deform;

[0051] f. When the fluid pressure gauge indicates that the pressure is equal to ρgh, the injection pump is turned off to stop injecting the non-Newtonian fluid. When the fluid pressure gauge indicates that the pressure is less than ρgh, the injection pump is turned on to inject the non-Newtonian fluid into the cavity.

[0052] In the above ρgh, ρ is the density of the non-Newtonian fluid, g is the acceleration due to gravity, and h is the height difference between the position of the fluid pressure gauge on the tunnel wall and the top of the tunnel.

[0053] The present invention will be further described below in conjunction with specific embodiments.

[0054] Embodiment 1:

[0055] Step 1: Drill a pressure relief hole in the middle of the two sides of the tunnel. The length of the pressure relief hole is 15m, and a borehole stress meter is placed at the end of the pressure relief hole.

[0056] Step 2: When the borehole stress gauge shows that there is a rock burst hazard in this section of the tunnel, a pressure relief hole is drilled on the upper sides of both sides of the tunnel, 50 cm away from the hole in step 1, and the length of the hole is 15 m;

[0057] Step 3: Carry out anchor support to ensure that the mechanical state of the surrounding rock itself is changed and an integral and stable rock belt is formed around the tunnel;

[0058] Step 4: Make a cavity according to the length of the tunnel where the impact ground pressure will occur and the tunnel section, and use strong and durable injection molding cloth to make the cavity;

[0059] Step 5: Use sealant and steel nails to seal the injection-molded cloth. After fixing the injection-molded cloth, fix the strong canvas and wire mesh to protect the injection-molded cloth from damage.

[0060] Step 6: The cavity is fixed on the tunnel surface through an inverted U-shaped steel bracket. The inverted U-shaped steel bracket is made according to the shape and section of the tunnel, with a spacing of 30 to 50 cm;

[0061] Step 7: Inject the non-Newtonian fluid in the liquid storage tank into the cavity through the liquid injection pipe and the liquid injection pump;

[0062] Step 8. When the fluid pressure gauge indicates equal to ρgh (ρ is the density of the non-Newtonian fluid, g is the acceleration of gravity, and h is the height difference between the position of the fluid pressure gauge on the tunnel wall and the top of the tunnel), stop injecting the non-Newtonian fluid. When the fluid pressure gauge indicates less than ρgh, start replenishing the non-Newtonian fluid.

[0063] Embodiment 2:

[0064] The method of Example 1 was used to treat the 2106A working face of a certain mine.

[0065] Before treatment: microseismic event energy level ≥ 10 4 J, the energy level of some microseismic events is > 10 5 J, the working face pressure is obvious, the top and bottom plates of the tunnel move as much as possible, and the two sides move as much as possible, and the total amount of 33mm;

[0066] After governance: the energy level of microseismic events is mainly between 10 3 ~10 5 J, partly appeared 10 5For high-energy events above J, the roof and floor of the tunnel moved closer by a cumulative 22mm, and the two sides moved closer by a cumulative 15mm. The impact during the pressure on the working face was not obvious.

[0067] This embodiment further demonstrates that the method of combining tunnel support with surrounding rock filling of the present invention can improve the tunnel impact phenomenon, the support scheme and parameters of the present invention are reasonable and effective, and the tunnel deformation is suppressed to a certain extent.

[0068] Comparative Example 1:

[0069] The following methods were used to manage the working face of a coal mine.

[0070] No pressure relief holes are drilled on both sides of the tunnel, and the remaining steps are the same as those in Example 1.

[0071] Before governance: The energy level of microseismic events was mainly between 10 3 ~10 5 J, partly appeared 10 5 For high-energy events above J, the roof and floor of the tunnel moved closer by a cumulative 22mm, and the two sides moved closer by a cumulative 15mm. The impact during the pressure on the working face was not obvious.

[0072] After governance: the energy level of microseismic events is mainly between 10 3 ~10 4 J, no 10 5 For high-energy events above J, the total movement of the tunnel roof and floor is 8mm, and the total movement of the two sides is 2mm. The impact during the pressure from the working face is not obvious and the energy is significantly reduced.

[0073] Parts not described in the present invention can be implemented by adopting or drawing on existing technologies.

[0074] It should be further noted that the specific embodiments described herein are merely examples of the spirit of the present invention. A person skilled in the art of the present invention may make various modifications or additions to the specific embodiments described or replace them in a similar manner, but this will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A tunnel support-surrounding rock filling collaborative method for local anti-impact rock pressure in mines, characterized in that: The following steps are included in sequence: a. Drill a pressure relief hole in the middle of the two sides of the tunnel, and set a borehole stress gauge at the end of the pressure relief hole; b. Use the borehole stress meter in step a to monitor whether there is rock burst hazard in the tunnel. If rock burst hazard is detected in the tunnel, drill pressure relief holes on the upper sides of both sides of the tunnel; c. Initial support is provided to the tunnel surrounding rock by driving anchor rods into the tunnel surrounding rock, forming an integral and stable rock belt around the tunnel; d. Construct tunnel support area The invention comprises a cavity and a non-Newtonian fluid in the cavity, a fluid pressure gauge is arranged on the inner wall of the cavity, a liquid injection hole is arranged on the cavity, a liquid injection pipe is connected to the liquid injection hole, the liquid injection pipe is connected to the liquid injection pump, and the liquid injection pump is connected to the liquid storage tank; the periphery of the cavity is reinforced by wire mesh, and a steel bracket is arranged under the cavity to further fix it; e. Inject non-Newtonian fluid into the cavity through the injection hole until it is full, and continue to inject non-Newtonian fluid into the pressure relief borehole around the surrounding rock of the tunnel. After the pressure relief borehole is filled with non-Newtonian fluid, the cavity and the non-Newtonian fluid in the pressure relief borehole form an integral structure. When the tunnel is deformed, the pressure relief borehole and the non-Newtonian fluid in the cavity jointly play a role in allowing pressure to deform; f. When the fluid pressure gauge indicates that the pressure is equal to ρgh, the injection pump is turned off to stop injecting the non-Newtonian fluid. When the fluid pressure gauge indicates that the pressure is less than ρgh, the injection pump is turned on to inject the non-Newtonian fluid into the cavity. In the above ρgh, ρ is the density of the non-Newtonian fluid, g is the acceleration due to gravity, and h is the height difference between the position of the fluid pressure gauge on the tunnel wall and the top of the tunnel.

2. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1 is characterized in that: The length of the pressure relief drill hole in step a and step b is 15 m, and the vertical distance between the pressure relief drill hole in step a and the pressure relief drill hole in step b is 50 cm.

3. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1 is characterized in that: In step d, the cavity is made of injection-molded cloth, the non-Newtonian fluid is loaded into the injection-molded cloth, and at least one layer of strong canvas is wrapped outside the injection-molded cloth.

4. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1 is characterized in that: In step d, several groups of steel supports are provided, which are made according to the shape and cross-section of the tunnel, and the spacing between adjacent steel supports is 30 to 50 cm.

5. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1 is characterized in that: In step d, a control platform is arranged near the liquid storage tank, and the control platform is respectively connected to the fluid pressure gauge, the injection pump and the liquid storage tank.

6. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1, characterized in that: The non-Newtonian fluid contains cement.

7. The tunnel support-surrounding rock filling coordinated method for local anti-rock burst in a mine according to claim 1, characterized in that: The shape of the lane is circular, rectangular, irregular trapezoidal, saddle-shaped or straight-walled semicircular arch.

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