Method, device and equipment for estimating grouting amount of surrounding rock fissures in repeated mining tunnel

Abstract

The present invention provides a method for estimating the amount of grouting in the surrounding rock fissures of a repeated mining tunnel, including calculating the theoretical fissure damage range area according to the monitoring data of the fissure damage range; calculating the average development depth according to the monitoring data of the fissure development depth, and calculating the total actual equivalent damage area of ​​the tunnel space according to the average development depth; obtaining a correction coefficient by dividing the change in the total actual equivalent damage area before and after each mining or tunneling by the change in the theoretical damage range area, correcting the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area, and obtaining a corrected damage area change before and after each mining or tunneling according to the corrected damage area; and obtaining the grouting amount by multiplying the corrected damage area change by the tunnel length. This solution solves the problem that the change in fissure predicted by the numerical model method in the prior art is not accurate enough, which leads to low efficiency of tunnel surrounding rock support work and affects coal production safety and production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel support safety, and in particular relates to a method, a device and equipment for estimating the grouting amount of surrounding rock fissures in a repeated mining tunnel. Background Art

[0002] With the widespread application of double-tunnel excavation technology in longwall mining, in order to prevent roof collapse and water inrush accidents caused by unfavorable geological structures in coal mines, thereby ensuring the safety and efficiency of coal production, two mining tunnels are excavated at the same time when the mining tunnel of this working face is excavated. One of the tunnels serves this working face. As the mining of this working face is gradually abandoned, the other tunnel is left to serve the next working face. Therefore, the retained tunnel will be affected by repeated mining, resulting in the stress of the rock around the tunnel being re-released. Under the action of high stress, the tunnel surrounding rock is destroyed and cracks are generated inside the surrounding rock. The expansion and penetration of the cracks require the prediction of the amount of cracks in the tunnel surrounding rock.

[0003] In recent years, many scholars have conducted a lot of research and discussion on repeated mining tunnels, but there is still little research on the estimation of grouting volume in repeated mining tunnels. At present, many scholars predict the grouting volume of tunnels through theoretical calculations. This method predicts the amount of cracks in the surrounding rock of repeated mining tunnels by combining theory with numerical simulation in the early stage of mining. However, the crack change predicted by the numerical simulation method is not accurate enough. When encountering emergencies during the actual mining process, it will cause a large difference between the theoretical calculation amount and the actual crack amount, which will lead to low efficiency of tunnel surrounding rock support work and affect coal production safety and production efficiency. Summary of the invention

[0004] In order to solve the problem that the numerical model method in the prior art predicts the change amount of cracks inaccurately, when encountering emergencies during the actual mining process, it will cause a large difference between the theoretical calculation amount and the actual crack amount, thereby resulting in low efficiency of tunnel surrounding rock support work, affecting the safety and production efficiency of coal production, the present invention provides a method, device and equipment for estimating the grouting amount of surrounding rock cracks in repeated mining tunnels.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel comprises the following steps:

[0007] Construct a numerical model of the surrounding rock of the tunnel under repeated mining, obtain monitoring data of the scope of crack damage of the tunnel surrounding rock at each stage of repeated mining based on the numerical model, and obtain monitoring data of the depth of crack development based on the tunnel on-site monitoring stations;

[0008] The theoretical fracture damage range is calculated based on the monitoring data of the fracture damage range; the average fracture development depth is calculated based on the monitoring data of the fracture development depth before and after each mining or excavation, and the total actual equivalent damage area of ​​the space in the tunnel is calculated based on the average development depth;

[0009] The correction coefficient is obtained according to the ratio of the change in the total actual equivalent damage area before and after each mining or excavation to the change in the theoretical damage range area. The theoretical damage range area is corrected according to the correction coefficient to obtain the corrected damage range area. The change in the corrected damage area before and after each mining or excavation is obtained according to the difference between the corrected damage area and the corrected damage area before each mining or excavation.

[0010] The grouting volume is obtained by multiplying the corrected damage area change by the tunnel length.

[0011] Furthermore, the step of calculating the theoretical fracture damage range area according to the monitoring data of the fracture damage range includes:

[0012] A two-dimensional rectangular coordinate system is established based on the monitoring data of the crack damage range. A piecewise function curve of the boundary line is fitted according to the point data on the boundary line of the crack damage range. The crack damage range is integrated and summed according to the piecewise function curve to obtain the theoretical crack damage range area.

[0013] Furthermore, the step of calculating the total actual equivalent damage area of ​​the space in the tunnel according to the average development depth includes:

[0014] The fissure development depth includes the fissure development depth on the roof, floor, coal pillar and coal wall of the roadway;

[0015] The relationship expression of the average development depth of the fissure is:

[0016]

[0017] Where, j = {top, bottom, column, wall}, i is the number of the borehole at the monitoring point, L j ' i is the maximum depth of the fissure development in the i-th borehole on the roof, floor, coal pillar or coal wall, X j It is the displacement of the inner surface of the roof, floor, coal pillar or coal wall, that is, the deformation;

[0018] The relevant formula for calculating the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth is as follows:

[0019]

[0020] in, is the total actual equivalent damage area, It is the actual equivalent damage area on the roof, floor, coal pillar or coal wall, n is the maximum number of holes allowed, r is the hole radius, and R is half of the minimum distance between two holes with the same radius without affecting each other.

[0021] Furthermore, the correction coefficient calculation formula is as follows:

[0022]

[0023] in, is the total equivalent damage area in the current mining impact stage, It is the total equivalent damage area of ​​the last mining impact stage, S3 is the theoretical damage range area of ​​the current mining impact stage, and S2 is the theoretical damage range area of ​​the last mining impact stage.

[0024] Furthermore, the step of correcting the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area includes:

[0025] If the correction coefficient σ≤1, there is no need to correct the theoretical damage range area of ​​the crack. If the correction coefficient σ>1, the theoretical damage range area of ​​the crack is corrected according to the correction coefficient σ. The specific correction formula is as follows:

[0026] S'2=S2*σ

[0027] Among them, S2 is the theoretical damage range area of ​​the cracks in the current mining impact stage, and S'2 is the corrected damage range area in the current mining impact stage.

[0028] Furthermore, the grouting amount calculation formula is as follows:

[0029] δ1=ΔS*c

[0030] ΔS=S'2-S1

[0031] Among them, δ1 is the grouting volume of the fissure in the current mining impact stage, c represents the tunnel length, ΔS is the change in the corrected damage area, S'2 is the corrected damage range area in the current mining impact stage, and S1 is the corrected damage range area in the previous mining impact stage.

[0032] A device for estimating grouting amount of surrounding rock fissures in a repeated mining tunnel, comprising:

[0033] The data acquisition module is used to construct a numerical model of the surrounding rock of the roadway under repeated mining, obtain monitoring data of the scope of crack damage of the surrounding rock of the roadway at each stage of repeated mining according to the numerical model, and obtain monitoring data of the depth of crack development according to the on-site monitoring station of the roadway;

[0034] The area calculation module is used to calculate the theoretical fracture damage range area based on the monitoring data of the fracture damage range; calculate the average fracture development depth based on the monitoring data of the fracture development depth before and after each mining or excavation, and calculate the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth;

[0035] A correction module is used to obtain a correction coefficient according to the ratio of the change in the total actual equivalent damage area before and after each mining or excavation to the change in the theoretical damage range area, correct the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area, and obtain the change in the corrected damage area before and after each mining or excavation according to the difference between the corrected damage area and the corrected damage area before each mining or excavation;

[0036] The result acquisition module is used to obtain the grouting amount by multiplying the corrected damage area change by the tunnel length.

[0037] A computer device includes a memory and a processor, wherein the memory stores computer execution instructions, and the processor executes the computer execution instructions stored in the memory to implement a method for estimating the grouting amount of surrounding rock fissures in a repeated mining tunnel as described above.

[0038] The method for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel provided by the present invention has the following beneficial effects:

[0039] The method of the present invention constructs a numerical model of the surrounding rock of a repeatedly mined tunnel, obtains monitoring data of the fissure damage range of the tunnel surrounding rock at each stage of repeated mining according to the numerical model, and obtains monitoring data of the fissure development depth according to a tunnel on-site monitoring station; calculates the theoretical fissure damage range area according to the monitoring data of the fissure damage range; calculates the average development depth of the fissure according to the monitoring data of the fissure development depth before and after each mining or tunneling, and calculates the total actual equivalent damage area of ​​the tunnel space according to the average development depth; obtains a correction coefficient by dividing the change of the total actual equivalent damage area before and after each mining or tunneling by the change of the theoretical damage range area, corrects the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area, obtains a corrected damage area change before and after each mining or tunneling according to the corrected damage area, and obtains a grouting amount by multiplying the corrected damage area change by the tunnel length.

[0040] This scheme combines the actual data obtained from the tunnel on-site monitoring station with the theoretical data of numerical model simulation to predict the change area of ​​the crack volume of the tunnel surrounding rock under repeated mining. The grouting volume is calculated after correcting the theoretical damage range area of ​​the cracks by the total actual equivalent damage area. The change in the damage range area after correction will be more accurate, and the calculation process only involves simple addition, subtraction, multiplication and division operations, without complex theoretical calculations, which improves the calculation efficiency, can provide a theoretical basis for the prediction of the grouting volume in time, and grout the cracks in the surrounding rock in time, thereby improving the stability of the surrounding rock, thereby improving the work efficiency of the tunnel surrounding rock support and the coal production efficiency, and providing safety guarantees for coal production safety; and improving the anchoring performance of anchor rods and cables, providing an accurate range for tunnel surrounding rock support, which is of great significance to tunnel support safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A flowchart of a prediction method according to an embodiment of the present invention;

[0043] Figure 2 A schematic diagram of a crack development curve of surrounding rock in a tunnel during a mining phase in an embodiment of the method of the present invention;

[0044] Figure 3 Schematic diagram of the development curve of the surrounding rock cracks in the tunnel during the primary and secondary mining stages of the method embodiment of the present invention;

[0045] Figure 4 A schematic diagram of the scope of crack damage in the surrounding rock of a tunnel during the tunneling stage of a numerical simulation of an embodiment of the method of the present invention;

[0046] Figure 5 A schematic diagram of the scope of fracture damage of surrounding rock in a tunnel during a mining phase of numerical simulation of an embodiment of the method of the present invention;

[0047] Figure 6 A schematic diagram of the scope of fracture damage of surrounding rock in a tunnel during secondary mining in numerical simulation of an embodiment of the method of the present invention;

[0048] Figure 7 A schematic diagram of a two-dimensional rectangular coordinate system of the surrounding rock of a tunnel during the tunneling stage of an embodiment of the method of the present invention;

[0049] Figure 8 A schematic diagram of a two-dimensional rectangular coordinate system of surrounding rock in a tunnel during a mining phase of an embodiment of the method of the present invention;

[0050] Fig. 9 A schematic diagram of a two-dimensional rectangular coordinate system of surrounding rock in a tunnel during the secondary mining phase of an embodiment of the method of the present invention;

[0051] Fig.10 A schematic diagram of a casing deformation monitoring system according to an embodiment of the method of the present invention;

[0052] Fig.11 A schematic diagram of the judgment logic of the casing deformation monitoring system of the method embodiment of the present invention;

[0053] In the figure: 1. casing; 2. strain collector; 3. data receiver; 4. data processing center; 5. monitoring and dispatching center; 6. wire. DETAILED DESCRIPTION

[0054] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0055] Method Embodiment

[0056] The present invention provides a method for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel, specifically, Figure 1 As shown, it includes the following steps:

[0057] S1: Construct a numerical model of the surrounding rock of the tunnel subjected to repeated mining, obtain the monitoring data of the crack damage range of the tunnel surrounding rock at each stage of repeated mining according to the data model, and the monitoring data of the crack development depth; after establishing the numerical model of the surrounding rock of the tunnel subjected to repeated mining, simulate the whole process of mining impact, record the damage range of the tunnel surrounding rock at each stage of repeated mining, establish a mathematical formula, and use area to express the damage range.

[0058] A numerical model of the surrounding rock of the tunnel in repeated mining was established to simulate the entire process of primary and secondary mining, and to record the damage range of the tunnel surrounding rock at each stage of repeated mining.

[0059] A mathematical formula is established to define the damage range of each stage of repeated mining by area, and the change in area of ​​each stage of repeated mining is the change in cracks.

[0060] A two-dimensional rectangular coordinate system is established based on the monitoring data of the fracture damage range. A piecewise function curve of the boundary line is fitted according to the point data on the boundary line of the fracture damage range. The fracture damage range is integrated and summed according to the piecewise function curve to obtain the fracture damage area. The fracture damage area is subtracted before and after each mining or excavation to obtain the change in the fracture damage area.

[0061] S2: Establish on-site monitoring stations in the tunnels to observe and record the maximum depth of surrounding rock fissure development during the entire mining process.

[0062] Select a monitoring station for cracks in the tunnel surrounding rock, and drill peep holes into the top and bottom plates and both sides of the tunnel at the monitoring station. After the peep holes are formed, insert high-strength casing into the holes to protect the shape of the holes. Determine whether the casing needs to be removed for maintenance based on the casing monitoring system.

[0063] At each stage of primary and secondary mining, the casing 1 in the borehole at the monitoring point is taken out to observe and record the maximum depth of surrounding rock fracture development in each borehole. After each observation, the casing 1 is lowered into the borehole again to maintain the shape of the borehole for repeated observation, and finally the casing 1 is recovered.

[0064] At the monitoring site, drill peep holes into the top and bottom plates and both sides of the tunnel. The peep holes are perpendicular to the tunnel surface. The number of holes is designed according to the geometric dimensions of the tunnel. To ensure that the observation holes do not affect each other, according to the influence range of the bidirectional isobaric hole:

[0065]

[0066] Where r is the borehole radius, and the minimum distance between two boreholes with the same radius without affecting each other is 2R. If the tunnel width is a, the boreholes are symmetrically distributed in the tunnel, and the distance between the starting borehole and the tunnel boundary is m.

[0067] The maximum number of holes allowed is It should be noted that when calculating the number of holes drilled on both sides, a represents the height of the tunnel.

[0068] The relationship expression of the average development depth of the cracks is:

[0069]

[0070] Where, j = {top, bottom, column, wall}, i is the number of the borehole at the monitoring point, L j ' i is the maximum depth of the fissure development in the i-th borehole on the roof, floor, coal pillar or coal wall, X j It is the displacement of the inner surface of the roof, floor, coal pillar or coal wall in the tunnel, that is, the deformation.

[0071] During the first mining impact phase, the casing 1 is taken out, the maximum value of the development depth of the surrounding rock fractures in each borehole is observed and recorded, and the casing 1 is lowered into the borehole again.

[0072] The first mining impact stage: the minimum development depth of roof cracks S 顶min =L 顶min +X 顶 , maximum development depth S 顶max=L 顶max +X 顶 , average development depth The calculation formula for the crack development depth of the floor, coal pillar and coal wall is the same as the calculation formula for the average crack development depth of the roof. Figure 2 shown.

[0073] During the secondary mining impact stage, the casing is removed, the maximum depth of surrounding rock fracture development in each borehole is observed and recorded, and the casing is lowered into the borehole again.

[0074] Secondary mining impact stage: minimum development depth of roof cracks S′ 顶min =L′ 顶min +X′ 顶 , maximum development depth S′ 顶max =L′ 顶max +X′ 顶 Its average development depth The calculation formula for the crack development depth of the floor, coal pillar and coal wall is the same as the calculation formula for the average crack development depth of the roof. Draw a schematic diagram of the crack development of the tunnel surrounding rock, such as Figure 3 shown.

[0075] S3: The damage area in the numerical simulation is corrected according to the actual measured values ​​on site, and the change in area is used to define the change in the cracks, which is the grouting amount.

[0076] The fracture damage areas of the three stages of tunneling, primary mining and secondary mining are corrected according to the monitored development depth. The change in area defines the change in fractures, and the change in fractures is the grouting volume.

[0077] The following is a further explanation of the method for predicting the amount of grouting in surrounding rock fissures of the present invention by taking a specific project as an example.

[0078] This embodiment takes the return air roadway of the 22205 working face as the engineering background, which is affected by the mining of the 22204 working face and the mining of the 22205 working face. The return air roadway of the 22205 working face of the Buertai Coal Mine is located in the 2-2 coal second plate area, with a length of 4865m. The roadway is excavated along the 2-2 coal seam, with an average burial depth of 300m. The cross-sectional shape of the roadway is rectangular, with width × height = 5000mm × 3500mm. The return roadway adopts a double roadway layout, and the width of the coal pillar between the double roadways is 20m. When the 22204 working face is mined, the remaining roadway (the return air roadway of the 22205 working face) serves as the auxiliary transportation roadway of its working face. When the 22205 working face is mined, the remaining roadway (the return air roadway of the 22205 working face) serves as the return air roadway. This remaining roadway is affected by two mining operations, and the modeling parameters are obtained to establish a numerical simulation model.

[0079] Simulate the whole process of tunneling, primary mining and secondary mining, and record the scope of fracture damage of tunnel surrounding rock at each stage of repeated mining, such as Figure 4-Figure 6 shown.

[0080] A two-dimensional rectangular coordinate system is established based on the model, and a mathematical formula is established to calculate the fracture damage area in the three stages of tunneling, primary mining, and secondary mining.

[0081] In the tunneling stage, the crack damage area is recorded as S1, and the coordinate system is marked with R, S, T, U, V, W, X, Y, and Z respectively. is the actual correction amount after drilling, such as Figure 7 shown.

[0082] Establish the mathematical formula:

[0083]

[0084] In the first mining stage, the fracture damage area is recorded as S2, and the points A, B, C, D, E, F, G, and H are marked on the coordinate system. is the actual correction amount after drilling, such as Figure 8 shown.

[0085] Establish the mathematical formula:

[0086]

[0087] In the secondary mining stage, the fracture damage area is recorded as S3, and the coordinate system is marked with I, J, K, L, M, N, Q, and P. is the actual correction amount after drilling, such as Fig. 9 shown.

[0088] Establish the mathematical formula:

[0089]

[0090] At each stage of primary and secondary mining, the casing 1 in the borehole at the monitoring point is taken out to observe and record the maximum depth of surrounding rock fracture development in each borehole. After each observation, the casing 1 is lowered into the borehole again to maintain the shape of the borehole for repeated observation, and finally the casing 1 is recovered.

[0091] Select a tunnel monitoring station, drill holes into the top and bottom plates and both sides of the tunnel at the monitoring station, and observe the depth of crack development in the tunnel surrounding rock, including:

[0092] The location of the surrounding rock fracture monitoring station should ensure that the stress deep in the coal wall is close to the original rock stress, avoiding the stress reduction area and stress increase area in front of the working face. The surrounding rock of the roadway roof and floor and the coal bodies on both sides of the selected monitoring station should be relatively complete to facilitate drilling construction and maintenance as well as later fracture observation;

[0093] At the monitoring site, drill peep holes into the top and bottom plates and both sides of the tunnel. The peep holes are perpendicular to the tunnel surface. The number of holes is designed according to the geometric dimensions of the tunnel. To ensure that the observation holes do not affect each other, according to the influence range of the bidirectional isobaric hole:

[0094]

[0095] Where r is the borehole radius, and the minimum distance between two boreholes with the same radius without affecting each other is 2R. If the tunnel width is a, the boreholes are symmetrically distributed in the tunnel, and the distance between the starting borehole and the tunnel boundary is m.

[0096] The maximum number of holes allowed is It should be noted that when calculating the number of holes drilled on both sides, a represents the height of the tunnel.

[0097] After the peep hole is formed, a high-strength casing 1 is lowered into the hole to protect the shape of the hole. The casing monitoring and dispatching center 5 determines whether the casing 1 needs to be removed for maintenance, including:

[0098] The high-strength casing 1 can reduce or offset the damage to the borehole caused by mining stress to maintain the shape of the borehole. The top of the front end of the casing is spherical, which can evenly distribute the surrounding rock pressure. The end of the casing is sealed with a threaded cover. The sealing cover has a hole for the monitoring wire 6. A rubber ring is used to seal the hole and the wire 6 to prevent foreign matter from entering the casing 1. Each section of the casing 1 is 3.5m long, which ensures that it can be constructed in the tunnel, and reduces the number of connections of each section of the casing 1, reducing the risk of low strength of the connection being easily damaged by mining stress. The casing 1 is connected by a thread, such as Fig.10 As shown, a strain collector 2, that is, a strain gauge, is installed at the connection. The strain gauge is connected to a strain warning device to monitor the stress deformation of the casing 2. When the set threshold is exceeded, the casing 2 needs to be removed to prevent the casing from being stuck. After the casing 2 is removed, maintenance is carried out; when the working surface is not advanced, the drill bit is used to re-mill the hole to maintain the shape of the hole.

[0099] According to the distance between the mining face and the monitoring point, check whether the casing is stuck. When the distance is far, check once every other maintenance team. When the distance is close, check once for each maintenance team.

[0100] When the casing 1 is lowered, a strain collector 2 is installed in the middle and joint of each section of the casing 1, and connected to an external data receiver 3. The data receiver 3 transmits the received data to the data processing center 4 and the ground monitoring and dispatching center 5. The pre-set programs of the data processing center 4 and the ground monitoring and dispatching center 5 automatically determine the stress condition of the casing 1, and finally output the result whether the casing needs to be removed or repaired. The staff can check the real-time status of the casing 1 at the underground monitoring station and the ground monitoring and dispatching center 5. Fig.10 As shown, the judgment logic diagram is as follows Fig.11 shown.

[0101] At each stage of mining impact, take out the casing 1 in the borehole at the monitoring point, observe and record the maximum depth of surrounding rock crack development in each borehole. After each observation, lower the casing 1 into the borehole again to maintain the shape of the borehole for repeated observation. Finally, recycle the casing 1. At the same time, use the top and bottom plate displacement meter and the three-dimensional laser measuring instrument on the tunnel surface to measure the deformation of the top and bottom plates and the two sides of the tunnel, including:

[0102] The maximum value of the fracture development depth is divided into the values ​​on the roof, floor, coal pillar and coal wall. The maximum value of the fracture development depth of x drill holes in the roof is recorded as L 顶1 , L 顶2 , L 顶3 …L 顶x The maximum depth of x drilled cracks in the bottom plate is recorded as L 底1 , L 底2 , L 底3 …L 底x The maximum depth of crack development in y boreholes on the coal pillar is recorded as L 柱1 , L 柱2 , L 柱3 …L 柱y The maximum depth of crack development in y boreholes on the coal wall is recorded as L 壁1 , L 壁2 , L 壁3 …L 壁y .

[0103] The displacement of the roof and floor plates and the two sides of the tunnel during the first mining impact phase was measured using a roof and floor displacement meter and a tunnel surface three-dimensional laser measuring instrument. The average roof subsidence was obtained as X. 顶 , the average bulge of the bottom plate is X 底 , the displacement of the coal pillar X 柱 , the displacement of the coal wall is X 壁 .

[0104] In the secondary mining impact stage, the casing is removed, the maximum depth of the surrounding rock fracture development in each borehole is observed and recorded, and finally the casing is recovered including:

[0105] The maximum value of the fracture development depth is divided into the values ​​on the roof, floor, coal pillar and coal wall. The maximum value of the fracture development depth of x drill holes in the roof is recorded as L′ 顶1 , L′ 顶2 , L′ 顶3 …L′ 顶x , the maximum depth of x drilled cracks in the bottom plate is recorded as L′ 底1 , L′ 底2 , L′ 底3 …L′ 底x The maximum depth of crack development in y boreholes on the coal pillar is recorded as L′ 柱1 , L′ 柱2 , L′ 柱3 …L′ 柱y The maximum depth of crack development in y boreholes on the coal wall is recorded as L′ 壁1 , L′ 壁2 , L′ 壁3 …L′ 壁y .

[0106] The displacement of the roof, bottom plate and two sides during the secondary mining impact stage, the average roof subsidence is X′ 顶 , the average bulge of the bottom plate is X′ 底 , the displacement of the coal pillar side X′ 柱 , the displacement of the coal wall is X′ 壁 .

[0107] During the first mining impact phase, the casing is removed, the maximum depth of surrounding rock crack development in each borehole is observed and recorded, the surrounding rock stress and crack distribution range are calculated, and the casing is lowered into the borehole again.

[0108] The first mining impact stage: the average development depth is calculated based on the maximum development depth of x borehole fractures in the roof. L 顶i is the maximum value of the fracture development depth of the i-th drill hole in the roof, then the fracture development depth calculation formula of the floor, coal pillar and coal wall is Average development depth of roof cracks The calculation formula is the same, and the schematic diagram of the tunnel surrounding rock crack development diagram is drawn as follows Figure 2 shown.

[0109] Calculate the equivalent damage area of ​​roof cracks: The calculation formula for the equivalent damage area of ​​the cracks in the floor, coal pillar and coal wall is: Equivalent damage area to roof cracks The calculation formula is the same, and the total equivalent damage area is

[0110] During the secondary mining impact stage, the casing is removed, the maximum depth of surrounding rock fracture development in each borehole is observed and recorded, and the casing is lowered into the borehole again.

[0111] Secondary mining impact stage: Calculate the average development depth of x drilled cracks in the roof L 顶i is the maximum value of the fracture development depth of the i-th drill hole in the roof, then the fracture development depth calculation formula of the floor, coal pillar and coal wall is Average development depth of roof cracks The calculation formula is the same, and a schematic diagram of the development of cracks in the surrounding rock of the tunnel is drawn, such as Figure 3 shown.

[0112] Calculate the equivalent damage area of ​​roof cracks: The calculation formula for the equivalent damage area of ​​the cracks in the floor, coal pillar and coal wall is: Equivalent damage area to roof cracks The calculation formula is the same, and the total equivalent damage area is

[0113] A correction coefficient is calculated based on the equivalent area of ​​the cracks obtained by the above drilling and the crack damage area obtained in the numerical simulation:

[0114] The fracture damage areas of the primary mining and secondary mining in the two stages of numerical simulation are corrected according to the required correction coefficient σ.

[0115] If the correction coefficient σ≤1, there is no need to correct the crack damage area. If the correction coefficient σ>1, the crack damage area is corrected according to the correction coefficient σ.

[0116] Corrected primary mining impact stage: S'2 = S2*σ, secondary mining impact stage: S'3 = S3*σ, after correction the crack damage areas are S'2 and S'3 respectively.

[0117] The change in the fracture damage area after the first mining is: ΔS1 = S'2-S1, and the change in the fracture damage area after the second mining is: ΔS2 = S'3-S'2.

[0118] Grouting volume of the fissure after one mining operation: δ1=ΔS1*c*10 3 , the grouting volume of the fissure after secondary mining δ2=ΔS2*c*10 3 , c represents the length of the lane.

[0119] The obtained grouting volume can effectively improve the structure and performance of the broken surrounding rock through grouting reinforcement, and improve the bearing capacity of the tunnel surrounding rock as a whole.

[0120] Device Embodiment

[0121] The present invention provides a device for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel, comprising:

[0122] The data acquisition module is used to construct a numerical model of the surrounding rock of the tunnel under repeated mining, obtain monitoring data on the scope of crack damage in the tunnel surrounding rock at each stage of repeated mining based on the numerical model, and obtain monitoring data on the depth of crack development based on the tunnel on-site monitoring stations.

[0123] The area calculation module is used to calculate the theoretical fracture damage range area based on the monitoring data of the fracture damage range; calculate the average fracture development depth based on the monitoring data of the fracture development depth before and after each mining or excavation; and calculate the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth.

[0124] The correction module is used to obtain a correction coefficient based on the ratio of the change in the total actual equivalent damage area before and after each mining or excavation to the change in the theoretical damage range area, correct the theoretical damage range area based on the correction coefficient to obtain a corrected damage range area, and obtain the change in the corrected damage area before and after each mining or excavation based on the difference between the corrected damage area and the corrected damage area before each mining or excavation.

[0125] The result acquisition module is used to obtain the grouting amount by multiplying the corrected damage area change by the tunnel length.

[0126] Device Embodiment

[0127] The present invention provides a computer device, including a memory and a processor, wherein the memory stores computer execution instructions, and the processor executes the computer execution instructions stored in the memory to implement a method for estimating the grouting amount of surrounding rock fissures in a repeated mining tunnel as described above, wherein the method has been described in detail in the method embodiment and will not be repeated here.

[0128] Storage Medium Embodiments

[0129] The present invention provides a computer-readable storage medium, which is used to store computer execution instructions. When the computer execution instructions are executed by a processor, they are used to implement a method for estimating the grouting amount of surrounding rock fissures in a repeated mining tunnel as described above, wherein the method has been described in detail in the method embodiment and will not be repeated here.

[0130] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0131] The present invention is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as a combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0132] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0134] It should be noted that the above-described specific implementation methods can enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way. Therefore, although the present specification and embodiments have described the invention in detail, those skilled in the art should understand that the invention can still be modified or replaced by equivalents; and all technical solutions and improvements that do not deviate from the spirit and scope of the invention are included in the protection scope of the patent for the invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A method for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel, characterized in that: The steps include: Construct a numerical model of the surrounding rock of the tunnel under repeated mining, obtain monitoring data of the scope of crack damage of the tunnel surrounding rock at each stage of repeated mining based on the numerical model, and obtain monitoring data of the depth of crack development based on the tunnel on-site monitoring stations; The theoretical fracture damage range is calculated based on the monitoring data of the fracture damage range; the average fracture development depth is calculated based on the monitoring data of the fracture development depth before and after each mining or excavation, and the total actual equivalent damage area of ​​the space in the tunnel is calculated based on the average development depth; The correction coefficient is obtained according to the ratio of the change in the total actual equivalent damage area before and after each mining or excavation to the change in the theoretical damage range area. The theoretical damage range area is corrected according to the correction coefficient to obtain the corrected damage range area. The change in the corrected damage area before and after each mining or excavation is obtained according to the difference between the corrected damage area and the corrected damage area before each mining or excavation. The grouting volume is obtained by multiplying the corrected damage area change by the tunnel length; The step of calculating the total actual equivalent damage area of ​​the space in the tunnel according to the average development depth includes: The fissure development depth includes the fissure development depth on the roof, floor, coal pillar and coal wall of the roadway; The relationship expression of the average development depth of the fissure is: Where, j = {top, bottom, column, wall}, i is the number of the borehole at the monitoring point, L j ' i is the maximum depth of the fissure development in the i-th borehole on the roof, floor, coal pillar or coal wall, X j It is the displacement of the inner surface of the roof, floor, coal pillar or coal wall, that is, the deformation; The relevant formula for calculating the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth is as follows: in, is the total actual equivalent damage area, It is the actual equivalent damage area on the roof, floor, coal pillar or coal wall, n is the maximum number of holes allowed, r is the hole radius, and R is half of the minimum distance between two holes with the same radius that do not affect each other.

2. The method for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel according to claim 1, characterized in that: The step of calculating the theoretical fracture damage range area according to the monitoring data of the fracture damage range comprises: A two-dimensional rectangular coordinate system is established based on the monitoring data of the crack damage range. A piecewise function curve of the boundary line is fitted according to the point data on the boundary line of the crack damage range. The crack damage range is integrated and summed according to the piecewise function curve to obtain the theoretical crack damage range area.

3. The method for estimating the amount of grouting in surrounding rock fissures of repeated mining tunnels according to claim 2, characterized in that: The step of correcting the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area comprises: If the correction coefficient σ≤1, there is no need to correct the theoretical damage range area of ​​the crack. If the correction coefficient σ>1, the theoretical damage range area of ​​the crack is corrected according to the correction coefficient σ. The specific correction formula is as follows: S'2=S2*σ Among them, S2 is the theoretical damage range area of ​​the cracks in the current mining impact stage, and S'2 is the corrected damage range area of ​​the cracks in the current mining impact stage.

4. A device for estimating the amount of grouting in surrounding rock fissures of a repeated mining tunnel, characterized in that: include: The data acquisition module is used to construct a numerical model of the surrounding rock of the roadway under repeated mining, obtain monitoring data of the scope of crack damage of the surrounding rock of the roadway at each stage of repeated mining according to the numerical model, and obtain monitoring data of the depth of crack development according to the on-site monitoring stations of the roadway; The area calculation module is used to calculate the theoretical fracture damage range area based on the monitoring data of the fracture damage range; calculate the average fracture development depth based on the monitoring data of the fracture development depth before and after each mining or excavation, and calculate the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth; A correction module is used to obtain a correction coefficient according to the ratio of the change in the total actual equivalent damage area before and after each mining or excavation to the change in the theoretical damage range area, correct the theoretical damage range area according to the correction coefficient to obtain a corrected damage range area, and obtain the change in the corrected damage area before and after each mining or excavation according to the difference between the corrected damage area and the corrected damage area before each mining or excavation; A result acquisition module is used to obtain the grouting amount by multiplying the corrected damage area change by the tunnel length; The step of calculating the total actual equivalent damage area of ​​the space in the tunnel according to the average development depth includes: The fissure development depth includes the fissure development depth on the roof, floor, coal pillar and coal wall of the roadway; The relationship expression of the average development depth of the fissure is: Where, j = {top, bottom, column, wall}, i is the number of the borehole at the monitoring point, L j ' i is the maximum depth of the fissure development in the i-th borehole on the roof, floor, coal pillar or coal wall, X j It is the displacement of the inner surface of the roof, floor, coal pillar or coal wall, that is, the deformation; The relevant formula for calculating the total actual equivalent damage area of ​​the space in the tunnel based on the average development depth is as follows: in, is the total actual equivalent damage area, It is the actual equivalent damage area on the roof, floor, coal pillar or coal wall, n is the maximum number of holes allowed, r is the hole radius, and R is half of the minimum distance between two holes with the same radius that do not affect each other.

5. A computer device comprising a memory and a processor, characterized in that: The memory stores computer-executable instructions, and the processor executes the computer-executable instructions stored in the memory to implement a method for estimating the grouting amount of surrounding rock fissures in a repeated mining tunnel as described in any one of claims 1-3.

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