Mine earthquake prevention and control method based on goaf water storage regulation and storage

Abstract

The invention discloses a mine earthquake prevention and control method based on goaf water storage regulation and storage, and the method comprises the steps: building a water storage dam body in a goaf corresponding to a mine earthquake layer of a coal mine, injecting water into the dam body, enabling the water to immerse the mine earthquake layer, enabling a coupling effect to be generated between a rock stratum of the mine earthquake layer and the water, promoting the fracture of the rock stratum, and achieving the purpose of preventing and controlling the mine earthquake. After the water storage dam body is immersed for a period of time, water in the water storage dam body is emptied, part of the unbroken mine earthquake rock stratum is slowly broken under the gravity of the rock stratum due to loss of support of the water body in the drainage process, and therefore the hidden danger of mine earthquake is eliminated. According to the method, elastic energy in the mine earthquake rock stratum can be slowly released, and shock waves and stress waves generated when the rock stratum is fractured are prevented from damaging the normal rock stratum to cause secondary damage.

Description

Technical Field

[0001] The present invention belongs to the technical field of mine safety and geological disaster prevention and control, and relates to a mine earthquake prevention and control method based on water storage and regulation in goaf areas. Background Art

[0002] With the continuous increase in the depth and intensity of coal mining, the frequency and intensity of mine tremors have also increased sharply, attracting strong attention from safety supervision departments, coal mine entities and scientific researchers. Among them, roof instability-type mine tremors are the main type of mine tremors in my country.

[0003] Traditional mine tremor prevention and control methods for roof instability often employ technologies such as pre-cracking blasting and hydraulic fracturing. However, these approaches not only present challenges such as high construction costs, long construction cycles, and insufficient effectiveness, but also involve the shock waves and stress waves generated during construction by some techniques, which can cause varying degrees of loosening and cracking of the surrounding rock mass, impacting the rock mass structure and, in severe cases, causing secondary damage. Therefore, a low-disturbance mine tremor prevention and control method is urgently needed to address the issue of roof instability. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preventing and controlling mine tremors by storing and regulating water in goaf areas, which has the characteristics of small disturbance and is not easy to cause secondary damage to induce mine tremors.

[0005] The technical solution adopted by the present invention is a mine earthquake prevention and control method based on water storage and regulation in goaf areas, which is implemented in the following manner: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0006] The present invention is also characterized in that: The method for determining the induced mining earthquake layer in step 1 includes one or more of settlement monitoring, rock movement detection, ground microseismic monitoring and underground microseismic monitoring to obtain the position, thickness and rock property information of the induced mining earthquake layer.

[0007] In step 2, the infiltration time and infiltration height are determined by physical simulation or similar simulation combined with mechanical calculation based on the physical and mechanical properties and hydraulic properties of the rock in the mine earthquake layer. The calculation method of the soaking time and soaking height is as follows: Step 2.1: Test the mechanical properties of the rock at different infiltration times and heights, and calculate its deflection by combining these mechanical properties with the thick plate theory equations. The specific equations are:

[0008] Where, w (x, y) is the deflection function; ψ(x, y) is the stress function; q (x, y) is the function of rock formation deadweight, overburden load and water level bearing capacity; h is the layer thickness; μ is Poisson's ratio, E is the elastic modulus, and the two parameters are functions of the infiltration time t and the infiltration height H, μ=μ (t, H), E=E (t, H); D is the bending stiffness. is a two-dimensional harmonic operator; Step 2.2: Substitute the solution of the above equation into the following equation to calculate the initial breaking distance L:

[0009] Where, I is the moment of inertia of the section, I=bh³ / 12, b is the overhang span of the thick overburden structure; Step 2.3: Calculate the elastic energy U released when the thick overburden structure breaks for the first time based on the initial breaking distance L w , the calculation formula is as follows:

[0010] According to elastic energy U w Calculation formula, select U w The corresponding infiltration time and infiltration height H when it is the minimum value.

[0011] The construction of the water storage dam in step 3 is carried out in the following manner: Step 3.1: Consider the aquifer recharge conditions and underground drainage conditions in the mine goaf and determine the water storage parameters that are suitable for the coal mine geology and production conditions at the treatment site; Step 3.2: Based on the water storage parameters, a water storage dam is constructed in the goaf corresponding to the area threatened by mine earthquakes.

[0012] In step 3.2, select a goaf with a rock layer thickness of not less than 20m, a strength of not less than 40Mpa, and a water-proof coal pillar width of not less than 40m as the site for building the water storage dam.

[0013] When water is injected into the water storage dam body in step 4, water is injected into the water storage dam body through the water injection and discharge pipeline or the water storage dam body is closed and the water is naturally replenished through the aquifer.

[0014] In step 5, when the energy density of the microseismic event is greater than 10 4 J / m 3 When the drainage is stopped, the energy density is 10 3 J / m³~10 4 In the J / m³ range, maintain a baseline drainage rate of no more than 5cm / d for drainage, and the energy density is less than 10 3 J / m³, the water in the water storage dam can be drained.

[0015] The beneficial effects of the present invention are: The mine tremor prevention method provided by the present invention uses water to infiltrate the rock strata, reducing its compressive strength and providing uniform support for the rock strata. Once the rock strata weaken, water is gradually drained, causing the rock strata to lose support and slowly fracture, releasing energy, thereby preventing mine tremors. This method releases energy slowly when the rock strata fracture, and the water acts as a buffer during this energy release, reducing the energy generated when the rock strata fracture, thereby achieving the purpose of preventing mine tremors. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of the mine earthquake prevention and control method based on water storage and regulation in goaf areas of the present invention. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Example 1: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0019] In this application, after determining the location of the mine tremor, a water storage dam is built within the goaf. Water is injected into the mine tremor layer to infiltrate the rock in that layer, causing the rock in that layer to couple with the water. Under the influence of water seepage, pressure changes, and chemical composition, the rock deforms and fractures, thereby destroying the integrity of the rock layer and its energy storage structure, thereby avoiding mine tremors. Furthermore, because the mine tremor layer is immersed in water, the water can absorb the impact force of the rock stratum rupture, preventing the rock rupture in the mine tremor layer from affecting the surrounding normal rock and causing secondary damage.

[0020] Example 2: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0021] The method for determining the induced mining earthquake layer in step 1 includes one or more of settlement monitoring, rock movement detection, ground microseismic monitoring and underground microseismic monitoring to obtain the position, thickness and rock property information of the induced mining earthquake layer.

[0022] In the actual production process, the mine-seismic strata of different mines are not the same. Their specific location, rock thickness, rock type and other information may affect the coupling between water and rock. In order to ensure that the rock strata at the mine-seismic strata are fully fractured, it is necessary to obtain detailed information about the rock strata.

[0023] Example 3: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0024] In step 2, the infiltration time and infiltration height are determined based on the physical and mechanical properties and hydraulic properties of the rock in the mine earthquake layer through physical simulation or similar simulation combined with mechanical calculation.

[0025] The calculation method of the soaking time and soaking height is as follows: Step 2.1: Test the mechanical properties of the rock at different infiltration times and heights, and calculate its deflection by combining these mechanical properties with the thick plate theory equations. The specific equations are:

[0026] Where, w (x, y) is the deflection function; ψ(x, y) is the stress function; q (x, y) is the function of rock formation deadweight, overburden load and water level bearing capacity; h is the layer thickness; μ is Poisson's ratio, which is a function of the infiltration time t and the infiltration height H; E is the elastic modulus, also a function of the infiltration time t, E=E (t, H); D is the bending stiffness. is a two-dimensional harmonic operator; Step 2.2: Substitute the solution of the above equation into the following equation to calculate the initial breaking distance L:

[0027] Where, I is the moment of inertia of the section, I=bh³ / 12, b is the overhang span of the thick overburden structure; Step 2.3: Calculate the elastic energy U released when the thick overburden structure breaks for the first time based on the initial breaking distance L w , the calculation formula is as follows:

[0028] According to elastic energy U w Calculation formula, select U w The corresponding infiltration time t and infiltration height H when it is the minimum value.

[0029] This application uses the relevant data of the rock layer at the mine earthquake level and combines the simulation results to establish the elastic energy U of the rock layer at the initial fracture under water infiltration. wThe equation for the infiltration time t and infiltration height h. In actual construction, the infiltration time corresponding to the minimum elastic energy is selected to minimize the impact of the rock strata in the mining earthquake layer on the surrounding rock strata when the rock strata are broken, avoiding the impact force causing secondary damage to other rock strata.

[0030] Example 4: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0031] The construction of the water storage dam in step 3 is carried out in the following manner: Step 3.1: Consider the aquifer recharge conditions and underground drainage conditions in the mine goaf and determine the water storage parameters that are suitable for the coal mine geology and production conditions at the treatment site; Step 3.2: Based on the water storage parameters, a water storage dam is constructed in the goaf corresponding to the area threatened by mine earthquakes.

[0032] In step 3.2, select a goaf with a rock layer thickness of not less than 20m, a strength of not less than 40Mpa, and a water-proof coal pillar width of not less than 40m as the site for building the water storage dam.

[0033] In the actual prevention and control process, in order to make water submerge the rock strata in the mine earthquake layer, it is necessary to increase the water pressure, and the high-pressure water will also produce pressure on the corresponding water storage dam body. In order to prevent the water storage dam body from rupturing, it is necessary to ensure the strength and thickness of the water storage dam body rock strata and other parameter requirements. Therefore, the thickness, strength and width of the anti-waterproof coal pillar of the goaf are limited.

[0034] Embodiment 5: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0035] When water is injected into the water storage dam body in step 4, water is injected into the water storage dam body through the water injection and discharge pipeline or the water storage dam body is closed and the water is naturally replenished through the aquifer.

[0036] Example 6: like Figure 1 As shown in the figure, the mine earthquake prevention and control method based on water storage and regulation in the goaf is implemented in the following way: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time microseismic energy density until all the water in the goaf is drained.

[0037] In step 5, when the energy density of the microseismic event is greater than 10 4 J / m 3 When the energy density of the microseismic event is less than 10 4 J / m 3 Continue to drain; Energy density is 10 3 J / m³~10 4 If the pressure is within the J / m³ range, it indicates that there may be insufficiently fractured rock layers due to mining earthquakes at this location. Therefore, drainage should be carried out at a baseline drainage rate of no more than 5 cm / d, so that the unfractured rock layers will break under the influence of gravity after losing the support of the water body. At the same time, a lower drainage rate can also stop drainage in time to restore the infiltration state. Energy density is less than 10 3J / m³, it proves that the rock stratum at that location is fully fractured, the energy in the rock stratum from the mine earthquake is fully released, the hidden danger of the mine earthquake is eliminated, and the water in the water storage dam can be drained.

[0038] Working principle: Step 1: First, obtain the location, thickness, and rock property information of the induced mining earthquake layer through one or more of settlement monitoring, rock movement detection, surface microseismic monitoring, and underground microseismic monitoring; Step 2: Combine the data obtained in step 1 to obtain the elastic energy U of the rock structure at the initial fracture through simulation and mechanical calculation w The relationship between the infiltration time t and the infiltration height H is as follows:

[0039] Select elastic energy U w The infiltration time t and infiltration height H corresponding to the minimum are used as the actual construction standards; Step 3: Comprehensively consider the aquifer recharge conditions and underground drainage conditions in the mine goaf, determine the water storage parameters that are suitable for the coal mine geology and production conditions of the treatment site, and build a water storage dam in the goaf corresponding to the mine-seismic layer based on the water storage parameters; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time detected microseismic energy density to drain the water storage dam.

[0040] In step 5, when the energy density of the microseismic event is greater than 10 4 J / m 3 When the energy density of the microseismic event is less than 10 4 J / m 3 Continue to drain; Energy density is 10 3 J / m³~10 4 If the pressure is within the J / m³ range, it indicates that there may be insufficiently fractured rock layers due to mining earthquakes at this location. Therefore, drainage should be carried out at a baseline drainage rate of no more than 5 cm / d, so that the unfractured rock layers will break under the influence of gravity after losing the support of the water body. At the same time, a lower drainage rate can also stop drainage in time to restore the infiltration state. Energy density is less than 10 3 J / m³, it proves that the rock stratum at that location is fully fractured, the energy in the rock stratum from the mine earthquake is fully released, and the hidden danger of the mine earthquake is eliminated.

[0041] As water infiltrates the rock formations affected by mining earthquakes, it significantly reduces their compressive strength and elastic modulus, reducing the elastic energy stored in them. At the same time, water can create buoyancy on the rock formations, creating a uniform supporting force and reducing stress concentration in the rock formations.

[0042] During the gradual discharge of water, the rock strata that have lost the buoyancy support of the water will slowly and controllably deform and fracture under the action of their own gravity and overlying loads, thereby slowly and orderly releasing the deformation energy accumulated in the rock strata caused by mine earthquakes, thereby achieving the purpose of eliminating the hidden dangers of mine earthquakes.

Claims

1. A mine earthquake prevention and control method based on water storage and regulation in goaf areas, characterized in that: Implement it as follows: Step 1: Determine the horizon that induces the mine earthquake and test the physical, mechanical and hydraulic properties of the rocks in the horizon that induces the mine earthquake; Step 2: Calculate the fracture morphology, stress and energy characteristics of the overburden under different infiltration conditions based on the properties of the rock in the mine-seismic horizon, and determine the infiltration time and infiltration height of the rock layer; Step 3: Build a water storage dam in the mine goaf; Step 4: inject water into the dam body to raise the water level in the goaf to the infiltration height and maintain the infiltration time calculated in step 2; Step 5: After the infiltration is completed, the drainage rate is adjusted according to the real-time detected microseismic energy density to drain the water storage dam.

2. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 1 is characterized in that: The method for determining the induced mining earthquake layer in step 1 includes one or more of settlement monitoring, rock movement detection, ground microseismic monitoring and underground microseismic monitoring to obtain the position, thickness and rock property information of the induced mining earthquake layer.

3. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 1 is characterized in that: In step 2, the infiltration time and infiltration height are determined by physical simulation or similar simulation combined with mechanical calculation based on the physical and mechanical properties and hydraulic properties of the rock in the mine earthquake layer.

4. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 3 is characterized in that: The calculation method of the infiltration time and infiltration height is as follows: Step 2.1: Test the mechanical properties of the rock at different infiltration times and heights, and calculate its deflection by combining these mechanical properties with the thick plate theory equations. The specific equations are: Where, w (x, y) is the deflection function; ψ(x, y) is the stress function; q (x, y) is the function of rock formation deadweight, overburden load and water level bearing capacity; h is the layer thickness; μ is Poisson's ratio, which is a function of the infiltration time t and the infiltration height H; E is the elastic modulus, also a function of the infiltration time t, E=E (t, H); D is the bending stiffness, which is a two-dimensional harmonic operator; Step 2.2: Substitute the solution of the above equation into the following equation to calculate the initial breaking distance L: Where, I is the moment of inertia of the section, I=bh³ / 12, b is the overhang span of the thick overburden structure; Step 2.3: Calculate the elastic energy U released when the thick overburden structure breaks for the first time based on the initial breaking distance L w , the calculation formula is as follows: According to elastic energy U w Calculation formula, select U w The corresponding infiltration time and infiltration height H when it is the minimum value.

5. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 1 is characterized in that: The establishment of the water storage dam body in step 3 is implemented in the following manner: Step 3.1: Consider the aquifer recharge conditions and underground drainage conditions in the mine goaf and determine the water storage parameters that are suitable for the coal mine geology and production conditions at the treatment site; Step 3.2: Based on the water storage parameters, a water storage dam is constructed in the goaf corresponding to the area threatened by mine earthquakes.

6. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 5 is characterized in that: In the step 3.2, a goaf with a rock layer thickness of not less than 20m, a strength of not less than 40Mpa, and a water-proof coal pillar width of not less than 40m is selected as the site for building the water storage dam body.

7. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 1 is characterized in that: When water is injected into the water storage dam body in step 4, water is injected into the water storage dam body through the water injection and discharge pipeline or the water storage dam body is closed and water is naturally replenished through the aquifer.

8. The mine earthquake prevention and control method based on water storage and regulation in goaf according to claim 1 is characterized in that: In step 5, when the energy density of the microseismic event is greater than 10 4 J / m 3 When the drainage is stopped, the energy density is 10 3 J / m³~10 4 In the J / m³ range, maintain a baseline drainage rate of no more than 5cm / d for drainage, and the energy density is less than 10 3 J / m³, the water in the water storage dam can be drained.

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