Method, device and equipment for predicting grouting amount of surrounding rock fissures in repeated mining tunnels

Abstract

The present invention provides a method for predicting the amount of grouting in the surrounding rock fissures of a repeated mining tunnel, including calculating the volume of tunnel space deformation at each stage according to the monitoring data of the tunnel surrounding rock movement, thereby obtaining the increase rate of tunnel surrounding rock grouting at each stage; calculating the change area of ​​the tunnel surrounding rock damage range at each stage according to the monitoring data of the damage range, thereby obtaining the extension rate of the tunnel surrounding rock damage range at each stage; obtaining the grouting amount prediction coefficient at each stage by the ratio of the grouting amount increase rate to the damage range extension rate, and predicting the grouting amount of the surrounding rock fissures of the same tunnel outside the current monitoring range by the grouting amount prediction coefficient at each stage within the current monitoring range and the change area of ​​the tunnel surrounding rock damage range at each stage of the same tunnel outside the current monitoring range. This solution solves the problem that the prediction of the amount of tunnel surrounding rock fissures in the prior art is not accurate enough, resulting in excessive or insufficient preparation of grouting materials, thereby causing waste of resources or delays in construction period.

Description

Technical Field

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

[0002] With the increasing demand for coal production, most mines in my country today have the characteristics of high mining intensity, long mining tunnels, and shallow burial depth. In order to ensure the safety of excavation, mining ventilation and system, a double-tunnel layout is usually adopted for the working face. The reserved tunnels arranged in this way have a long service life and are affected by repeated mining on both sides of the working face. Although coal pillars are retained to protect the tunnels, with the increase of mining intensity and mining depth, the asymmetric destruction and stability control problems of the tunnel surrounding rock due to repeated mining are becoming more and more serious. For the double-tunnel layout working face, the reserved tunnels are affected by repeated mining on the overlying coal seam working face and the working faces on both sides of the coal seam. The problem of large deformation and damage of the tunnel surrounding rock due to superimposed stress is a major problem restricting the efficient production of coal in this area.

[0003] During the excavation of underground coal mining tunnels, the impact of mining in the mine field causes the stress of the rocks around the tunnel to be redistributed. Under the action of high stress, the tunnel surrounding rock is damaged and cracks are generated inside the surrounding rock. The generation of cracks causes the tunnel surrounding rock to become unstable and damaged, making it difficult to support the tunnel. In severe cases, it will cause various accidents. For the double-tunnel tunnel layout, the expansion range of the cracks in the tunnel is larger and the crack volume is larger under the influence of repeated mining, making it more difficult to support and more likely to cause various accidents.

[0004] At present, in order to solve the problem of difficult support caused by large expansion of cracks in the surrounding rock of the tunnel and large deformation of the surrounding rock, most of the methods used are surrounding rock grouting. However, in the grouting process, since the slurry needs to be prepared in advance, the problem of the amount of slurry to be prepared is difficult to solve. Excessive slurry preparation causes waste of resources, and too little preparation causes the grouting strength to be insufficient. Therefore, it is necessary to make a relatively accurate prediction of the amount of cracks in the surrounding rock of the tunnel to avoid waste of grouting materials and work delays, and to timely grout the surrounding rock to enhance the stability of the surrounding rock, avoid accidents, and ensure safe and efficient production of coal mines. Summary of the invention

[0005] In order to solve the problems in the prior art of inaccurate prediction of the amount of cracks in the tunnel surrounding rock, which leads to excessive or insufficient grouting material, thus causing waste of resources or delay in construction period, the present invention provides a method, device and equipment for predicting the grouting amount of cracks in the surrounding rock of a repeated mining tunnel.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel comprises the following steps:

[0008] In the range of the tunnels not affected by mining, obtain the monitoring data of the tunnel surrounding rock movement and the monitoring data of the tunnel surrounding rock damage range after excavation and mining impact of the same repeated mining tunnel within the current monitoring range;

[0009] The volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, is calculated based on the monitoring data of the tunnel surrounding rock movement, and then the tunnel surrounding rock grouting volume increase rate within the current monitoring range is obtained; the change area of ​​the current tunnel surrounding rock damage range is calculated based on the monitoring data of the damage range, and the tunnel surrounding rock damage range extension rate within the current monitoring range is obtained;

[0010] The grouting volume prediction coefficient after excavation and mining is obtained by the ratio of the increase rate of surrounding rock grouting volume and the corresponding extension rate of surrounding rock damage range. The grouting volume prediction coefficient within the current monitoring range and the change area of ​​surrounding rock damage range of the same tunnel outside the current monitoring range are used to predict the grouting volume of surrounding rock cracks in the same tunnel outside the current monitoring range.

[0011] Furthermore, the step of calculating the volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, based on the monitoring data of the tunnel surrounding rock movement, and then obtaining the tunnel surrounding rock grouting volume increase rate within the current monitoring range includes:

[0012] The monitoring of the amount of surrounding rock movement in the tunnel is carried out in the tunnel with the cross section of the tunnel as the monitoring data unit;

[0013] The section of the tunnel monitored after each excavation or mining deformation is divided into multiple single contour polygons.

[0014]

[0015] In the formula, is the jth single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; p a is one of the vertices, x a, y a ,z a is the coordinate of the vertex; i is the monitoring section number, and R is a real number;

[0016] The area formula of the coordinate analysis method is used to calculate the areas of multiple segmented single contour polygons separately, and the sum of all is used to obtain the monitoring section area. The calculation formula is as follows:

[0017]

[0018] for The area of ​​the enclosed region, A, is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the laneway;

[0019] The calculation formula for the total volume of the tunnel after deformation within the monitoring range is as follows:

[0020]

[0021] V 变 is the space volume per meter of the tunnel within the monitoring range after deformation, h is the monitoring section interval, which is 20 cm, n is the number of sections divided into the space volume per meter after the tunnel is deformed, and A 变_i is the cross-sectional area of ​​the i-th tunnel after deformation;

[0022] According to the volume of the tunnel space before and after repeated mining per meter, the volume strain of the tunnel affected by each excavation or mining is obtained, that is, the increase rate of tunnel surrounding rock grouting. The formula is as follows:

[0023]

[0024] Among them, C is the increase rate of surrounding rock grouting volume after each excavation or mining impact, V 原 V is the volume of each meter of tunnel space before each excavation or mining operation causes changes; 变 It is the volume of the tunnel space per meter after each excavation or mining impact, and V0 is the volume of the tunnel space per meter under the designed cross-sectional size of the tunnel.

[0025] Furthermore, the step of calculating the change area of ​​the current tunnel surrounding rock damage range according to the monitoring data of the damage range and obtaining the extension rate of the tunnel surrounding rock damage range within the current monitoring range includes:

[0026] The monitoring of the damage range of the surrounding rock of the tunnel is carried out in the tunnel with the cross section of the loosening zone of the surrounding rock outside the tunnel as the monitoring data unit;

[0027] The area of ​​the tunnel surrounding rock damage after each excavation or mining deformation is divided into multiple single contour polygons

[0028]

[0029] In the formula, is the single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; d a is one of the vertices, x a, y a ,z a are the coordinates of the vertices;

[0030] The area formula of the single contour polygons separated by the coordinate analysis method is calculated separately. The calculation formula is as follows:

[0031]

[0032] in, for Area of ​​the enclosed area, S i It is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the tunnel;

[0033] The calculated damage range change area is:

[0034] S 扩展 =S 变 -S 原

[0035] Among them, S 变 S is the area of ​​the surrounding rock crack expansion caused by each tunnel excavation or mining. 原 S is the area of ​​fracture damage in the surrounding rock before each tunnel excavation or mining operation. 扩展 The area of ​​damage change is finally obtained through measurement and calculation;

[0036] Then the extension rate of surrounding rock damage range after each excavation or mining impact is: S0 is the design cross-sectional dimension of the repeated mining tunnel.

[0037] Furthermore, the expression of the grouting volume prediction coefficient is:

[0038]

[0039] Among them, J is the prediction coefficient of grouting volume after each excavation or mining impact, C is the increase rate of surrounding rock grouting after each excavation or mining impact, and K is the extension rate of tunnel surrounding rock damage range after each excavation or mining impact.

[0040] Furthermore, the expression of the grouting amount of the tunnel surrounding rock is:

[0041]

[0042] Among them, J is the prediction coefficient of grouting volume after each excavation or mining impact within the current monitoring range, S 扩展 The change area of ​​the surrounding rock damage range of the tunnel after each excavation or mining outside the current monitoring range, V0 is the tunnel space volume per meter under the designed cross-sectional dimensions of the tunnel, and S0 is the designed cross-sectional dimensions of the tunnel with repeated mining.

[0043] A device for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel, comprising:

[0044] The data acquisition module is used to obtain the monitoring data of the displacement of the surrounding rock and the monitoring data of the damage range of the surrounding rock of the same repeated mining tunnel within the current monitoring range after excavation and mining impact within the tunnel range not affected by mining;

[0045] A calculation processing module is used to calculate the volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, based on the monitoring data of the tunnel surrounding rock movement, and then obtain the tunnel surrounding rock grouting volume increase rate within the current monitoring range; calculate the change area of ​​the current tunnel surrounding rock damage range based on the monitoring data of the damage range, and obtain the tunnel surrounding rock damage range extension rate within the current monitoring range;

[0046] The result acquisition module is used to obtain the grouting volume prediction coefficient after each excavation and after the impact of mining through the ratio of the surrounding rock grouting volume increase rate to the corresponding surrounding rock damage range extension rate. The grouting volume prediction coefficient within the current monitoring range and the change area of ​​the surrounding rock damage range of the same tunnel outside the current monitoring range are used to predict the grouting volume of the surrounding rock cracks in the same tunnel outside the current monitoring range.

[0047] 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 predicting the grouting amount of surrounding rock fissures in a repeated mining tunnel as described above.

[0048] The method for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel provided by the present invention has the following beneficial effects:

[0049] The scheme of the present invention is to obtain the monitoring data of the movement of the surrounding rock within the monitoring range of the current tunnel through real-time monitoring during the entire process of coal mining production, and obtain the change of the tunnel space volume within the monitoring range of the current tunnel at each period before and after the excavation or mining impact when the tunnel is repeatedly mined, and measure the expansion range of the surrounding rock cracks of the repeated mining tunnel to obtain the extension rate of the surrounding rock damage range within the monitoring range of the current tunnel, establish a relationship between the tunnel space volume strain of the repeated mining tunnel and the expansion range of the surrounding rock cracks, and obtain the grouting amount prediction coefficient for each excavation and mining within the monitoring range of the current tunnel, and obtain the grouting amount prediction coefficient for each excavation and mining within the monitoring range of the current tunnel through this measurement, and predict the grouting amount of the surrounding rock cracks of the same tunnel outside the monitoring range of the current tunnel based on the change area of ​​the tunnel surrounding rock damage range after each excavation and mining impact of the same tunnel outside the monitoring range of the current tunnel. The present invention does not need to repeatedly monitor and calculate the grouting volume prediction coefficient of the entire section of the current monitored tunnel after each excavation and mining impact, but the grouting volume prediction coefficient is obtained after real-time monitoring and calculation of the tunnels within the fixed monitoring range of the same tunnel. The present invention uses the grouting volume prediction coefficient within the current tunnel monitoring range to predict the grouting volume of the tunnel outside the current monitoring range of the same tunnel. Therefore, the prediction method of the present invention has low calculation complexity, can save prediction time, improve work efficiency, save budget costs, can quickly predict the grouting volume of the tunnel surrounding rock, and grouting can be carried out in time to avoid unsafe accidents caused by large crack range and large crack volume of the tunnel surrounding rock as soon as possible. In addition, the method is simple, convenient, intuitive, and highly accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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.

[0051] Figure 1 A flowchart of a prediction method according to an embodiment of the present invention;

[0052] Figure 2 A schematic diagram of arranging measuring stations in a repeatedly mined tunnel according to an embodiment of the method of the present invention;

[0053] Figure 3 A coordinate schematic diagram of dividing the surrounding rock displacement monitoring section in an embodiment of the method of the present invention;

[0054] Figure 4 A schematic diagram of the arrangement of a monitoring station for the damage range of surrounding rock in a tunnel according to an embodiment of the method of the present invention;

[0055] Figure 5A schematic diagram of a single contour polygon of a tunnel cross section of an embodiment of the method of the present invention;

[0056] Figure 6 A schematic diagram of a tunnel section and surrounding rock damage range after tunnel excavation deformation in an embodiment of the method of the present invention;

[0057] Figure 7 A schematic diagram of a tunnel section and surrounding rock damage range after a mining event in an embodiment of the method of the present invention;

[0058] Figure 8 A schematic diagram of the tunnel section and surrounding rock damage range after secondary mining is affected by an embodiment of the method of the present invention;

[0059] Fig. 9 This is a comparison chart of the predicted grouting volume per meter of the repeated mining tunnel and the actual grouting volume results of the embodiment of the method of the present invention. DETAILED DESCRIPTION

[0060] 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.

[0061] In the present invention, during the whole process of coal mining production, from the completion of tunnel excavation, a monitoring station of the movement of surrounding rock is arranged in the repeated mining tunnel, and the change of the spatial volume of the current repeated mining tunnel in each period after the repeated mining tunnel excavation, after the impact of the first mining, and after the impact of the second mining is obtained, and the expansion range of the surrounding rock cracks in the current repeated mining tunnel is measured, and the relationship between the tunnel space volume strain of the current repeated mining tunnel and the expansion range of the surrounding rock cracks is established to obtain the repeated mining tunnel excavation, after the impact of the first mining, and after the impact of the second mining in each period within the monitoring range. The prediction coefficient of the amount of grouting injected during the period is used, and the grouting amount outside the monitoring range of the same tunnel is predicted by the prediction coefficient of the grouting amount obtained within the monitoring range and the expansion range of the surrounding rock cracks of the same repeated mining tunnel inside and outside the monitoring range; the rock movement of the tunnel surrounding rock is caused by the generation of crack space inside the surrounding rock. The purpose of surrounding rock grouting is to fill the cracks in the surrounding rock with slurry, so the crack volume of the surrounding rock is equal to the grouting volume. This monitoring method can quickly predict the grouting volume of the tunnel surrounding rock and grout in time to avoid unsafe accidents caused by large crack range and large crack volume of the tunnel surrounding rock as soon as possible. This method uses geological radar to measure the damage range of the tunnel surrounding rock, which provides convenient help for anchor rod and anchor cable support. In addition, this method is simple, convenient, intuitive and highly accurate.

[0062] Method Embodiment

[0063] The present invention provides a method for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel, specifically, Figure 1 As shown, specifically including the following:

[0064] Before the adjacent working face served by the repeated mining tunnel is about to start coal mining activities, the measuring station is arranged in the repeated mining tunnel (including the return air level tunnel of the 02 working face) outside the influence range of the advanced support pressure of the opening eye, such as Figure 2 As shown, the arrangement of measuring stations includes a monitoring station for the approach of the tunnel surrounding rock and a monitoring station for the damage range of the tunnel surrounding rock. The monitoring stations intercept 5 to 7 m of the tunnel for measurement.

[0065] Obtain the front end of the same repeated mining tunnel in the tunnel range not affected by mining, monitor the monitoring data of the tunnel surrounding rock movement before and after each repeated mining tunnel excavation and mining impact, and the monitoring data of the tunnel surrounding rock damage range.

[0066] The movement of the tunnel surrounding rock is caused by the cracks inside the tunnel surrounding rock. Only when the tunnel surrounding rock moves out a space equal to the size of the crack space, the surrounding rock will have enough space for cracks to form. The grouting amount is to fill the crack space with slurry. Therefore, the movement amount of the tunnel surrounding rock is the grouting amount of the tunnel surrounding rock.

[0067] like Figure 3 As shown, the monitoring stations for the movement of tunnel surrounding rock are arranged on the top and bottom plates and both sides of the tunnel in units of sections within the tunnel using multi-point displacement meters. The monitoring stations monitor the movement of tunnel surrounding rock in three periods: after excavation, the first mining, and the second mining. The volume of the tunnel space per meter is obtained based on the spacing between monitoring sections, and the current tunnel space volume strain in each period is obtained.

[0068] like Figure 4 As shown in the figure, the tunnel surrounding rock damage range monitoring station uses geological radar to detect the range of the current tunnel surrounding rock loosening circle in three periods after the tunneling, the first mining, and the second mining according to the survey line. According to the monitored data, the surrounding rock damage area of ​​each monitoring section after the tunneling, the first mining, and the second mining are calculated, and the extension rate of the surrounding rock damage range is obtained according to the tunnel section design area.

[0069] like Figure 5 As shown in the figure, the tunnel section after each excavation or deformation caused by mining is divided into multiple single contour polygons.

[0070]

[0071] In the formula, is the jth single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; pa is one of the vertices, x a, y a ,z a is the coordinate of the vertex; i is the monitoring section number.

[0072] The area formula of the coordinate analysis method is used to calculate the areas of multiple segmented single contour polygons separately, and the sum of all is used to obtain the monitoring section area. The calculation formula is as follows:

[0073]

[0074] for The area of ​​the enclosed area, A i It is the sum of the areas of all segmented single contour polygons, that is, the approximate value of the monitoring cross-sectional area of ​​the tunnel.

[0075] like Figure 6 As shown in (b), the cross-sectional area of ​​the currently monitored tunnel after tunnel excavation deformation; Figure 7 As shown in (b), a mining event affects the cross-sectional area of ​​the currently monitored tunnel after deformation; Figure 8 As shown in (b), the cross-sectional area of ​​the current monitored tunnel after the impact of secondary mining.

[0076] The cross-sectional area of ​​the tunnel before each tunneling or mining operation affects the tunnel deformation is A. 原 The cross-sectional area of ​​the roadway after each tunneling or mining operation is A. 变 The total volume of the tunnel after deformation within the monitoring range is calculated as follows:

[0077]

[0078] V 变 is the space volume per meter of the tunnel within the monitoring range after deformation, h is the monitoring section interval, n is the number of sections divided into the space volume per meter after the tunnel is deformed, and A 变_i is the cross-sectional area of ​​the i-th tunnel after deformation; in this embodiment, h is set to 20 cm.

[0079] The movement of the surrounding rock of the tunnel is caused by the cracks in the tunnel surrounding rock. The tunnel surrounding rock will only have cracks when it moves a space equal to the size of the crack space. Grouting is to fill the crack space of the tunnel surrounding rock. The amount of grouting required for the tunnel surrounding rock is equal to the volume of the cracks in the tunnel surrounding rock. The volume strain of the currently monitored repeated mining tunnel is obtained according to the volume before and after the spatial change of each meter of repeated mining tunnel, that is, the increase rate of tunnel surrounding rock grouting. The formula is as follows:

[0080]

[0081] Among them, V 原V is the space volume per meter of the lane currently monitored before changes occur in each stage; 变 It is the volume of space per meter of the aisle currently monitored after the aisle changes at each stage.

[0082] After repeated mining tunnel excavation, the increase rate of grouting of surrounding rock cracks per meter in the current monitored tunnel is:

[0083]

[0084] Among them, V0 is the space volume per meter of the tunnel under the designed cross-sectional size of the tunnel; V1 is the space volume per meter of the tunnel currently monitored after the tunnel excavation deformation.

[0085] After the impact of mining, the increase rate of grouting in surrounding rock cracks per meter in the current monitored tunnel is:

[0086]

[0087] Among them, V2 is the space volume per meter of the current monitored tunnel after a mining impact.

[0088] After the impact of secondary mining, the increase rate of grouting in surrounding rock cracks per meter in the current monitored tunnel is:

[0089]

[0090] Among them, V3 is the space volume per meter of the current monitored tunnel after the impact of secondary mining.

[0091] Use geological radar to monitor the loose circle range, and take the intersection of the measured section bottom plate and the tunnel centerline as the base point to obtain the coordinates of the farthest damage point on each measuring point. The calculation method of the damage range area is consistent with the calculation method of the tunnel monitoring section area, as follows:

[0092] like Figure 5 As shown in the figure, the surrounding rock damage area of ​​the current monitored tunnel after excavation or mining is divided into multiple single contour polygons.

[0093]

[0094] In the formula, is the single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; d a is one of the vertices, x a, y a ,z a are the coordinates of the vertices;

[0095] The area formula of the single contour polygons separated by the coordinate analysis method is calculated separately. The calculation formula is as follows:

[0096]

[0097] in, for Area of ​​the enclosed area, S i It is the sum of the areas of all segmented single contour polygons, that is, the approximate value of the monitoring cross-sectional area of ​​the tunnel.

[0098] The calculated damage range change area is:

[0099] S 扩展 =S 变 -S 原

[0100] Among them, S 变 S is the area of ​​the expansion of surrounding rock cracks caused by each stage of tunnel excavation, primary mining, and secondary mining on the current monitored tunnel. 原 The area of ​​the damage range of the surrounding rock fissures that affect each stage of the current monitored tunnel. After measurement and calculation, the damage range change area S is finally obtained. 扩展 .

[0101] The extension rate of the damage range of the surrounding rock of the current monitored roadway caused by repeated mining is:

[0102]

[0103] After repeated mining tunnel excavation, the extension rate of the surrounding rock damage range of the current monitored tunnel is:

[0104]

[0105] Among them, the design section size S0 of the repeated mining tunnel is as follows: Figure 6 As shown in (a), after repeated mining tunnel excavation, the surrounding rock damage range of the current monitored tunnel is area S1.

[0106] After a repeated mining tunnel has experienced one mining, the extension rate of the surrounding rock damage range of the current monitored tunnel is:

[0107]

[0108] Among them, Figure 6 As shown in (a), after repeated mining tunnel excavation, the surrounding rock damage range of the current monitored tunnel is S1; Figure 7 As shown in (a), S2 is the area of ​​surrounding rock damage in the currently monitored tunnel after a mining operation.

[0109] The extension rate of the surrounding rock damage range of the current monitored tunnel after the secondary mining of the repeated mining tunnel is:

[0110]

[0111] Among them, Figure 8 As shown in (a), S3 refers to the area of ​​surrounding rock damage in the current monitored tunnel after secondary mining.

[0112] The grouting volume prediction coefficient is established based on the extension rate of the surrounding rock damage range of the repeated mining roadway and the increase rate of grouting in the surrounding rock cracks of the roadway:

[0113]

[0114] Among them, J i is the prediction coefficient of the grouting volume of the current monitored tunnel after each excavation or mining impact, C i is the grouting increase rate of the surrounding rock of the current monitored tunnel after each excavation or mining impact, K i It is the extension rate of the damage range of the surrounding rock of the current monitored tunnel after each excavation or mining impact.

[0115] The prediction coefficient of the grouting volume of the current monitoring tunnel and the surrounding rock fissure grouting volume of the current monitoring tunnel after repeated mining tunnel excavation is:

[0116]

[0117] The prediction coefficient of the grouting volume of the current monitoring tunnel and the grouting volume of the surrounding rock cracks of the current monitoring tunnel during a mining operation is:

[0118]

[0119] The prediction coefficient of the grouting volume of the current monitoring tunnel and the grouting volume of the surrounding rock cracks of the current monitoring tunnel during secondary mining is:

[0120]

[0121] After obtaining the grouting volume of the surrounding rock fissures of the current monitoring tunnel after repeated mining, primary mining, and secondary mining, and the prediction coefficient of the grouting volume of the surrounding rock fissures, the damage range is measured by the geological radar, thereby predicting the grouting volume required for the tunnel surrounding rock after repeated mining, primary mining, and secondary mining outside the monitoring station of the current monitoring tunnel. Specifically, after the tunnel excavation of the adjacent working face is completed, the prediction coefficient of the grouting volume of the surrounding rock fissures of the current monitoring tunnel within the monitoring range is obtained in real time through the monitoring station arranged in the repeated mining tunnel, and then combined with the damage range of the surrounding rock of the current monitoring tunnel outside the monitoring range after the excavation is completed measured by the geological radar, thereby predicting the grouting volume of the surrounding rock fissures of the current monitoring tunnel after repeated mining tunnel excavation outside the monitoring station of the current monitoring tunnel; after the influence of the primary mining tunnel, the prediction coefficient of the grouting volume of the surrounding rock fissures of the current monitoring tunnel within the monitoring range is obtained in real time through the monitoring station arranged in the repeated mining tunnel, and then combined with the damage range of the surrounding rock of the current monitoring tunnel outside the monitoring range after the excavation is completed measured by the geological radar. After the impact of the primary mining roadway, the surrounding rock damage range of the current monitoring roadway outside the monitoring range is determined, so as to predict the grouting volume of the surrounding rock cracks of the current monitoring roadway after the impact of the primary mining roadway outside the monitoring station of the current monitoring roadway; after the impact of the secondary mining roadway, the prediction coefficient of the grouting volume of the surrounding rock cracks of the current monitoring roadway within the monitoring range is obtained in real time through the monitoring stations arranged in the repeated mining roadway, and then combined with the surrounding rock damage range of the current monitoring roadway outside the monitoring range after the impact of the secondary mining roadway measured by the geological radar, so as to predict the grouting volume of the surrounding rock cracks of the current monitoring roadway after the impact of the secondary mining roadway outside the monitoring station of the current monitoring roadway.

[0122] The method for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel of the present invention is further described below through a specific double tunnel arrangement and gob-side tunnel retention arrangement.

[0123] like Figure 7 As shown, in the double-tunnel layout along the gob-retaining tunnel, when the working face that first carries out mining in the two adjacent working faces of the repeated mining tunnel is about to open a cut and advance, a measuring station is arranged in the repeated mining tunnel at a position in front of the cut where the coal body is not affected by the advance support pressure.

[0124] like Figure 8 As shown in the figure, the tunnel surrounding rock displacement monitoring station is arranged, a displacement monitoring section is arranged every 20cm in the section, a displacement monitoring point is arranged every 10-15cm in the monitoring section, and a monitoring station is arranged every 5-7m. After the monitoring station is arranged, the surrounding rock damage range after repeated mining tunnel excavation in the measuring station is measured by geological radar between two displacement monitoring sections and the area S1 is calculated. S1 is the weighted average of the damage range areas of multiple tunnel sections measured in each meter of the tunnel.

[0125] The waveform signal received by the geological radar is analyzed by the following formula:

[0126]

[0127] Wherein, h is the depth of the damage range (m); t is the time interval from the emission to the reception of the electromagnetic wave (s); v is the propagation speed of the electromagnetic wave in the rock and soil (m / s) (see Table 1); x is the distance between the transmitting antenna and the receiving antenna (m); c is the propagation speed of the electromagnetic wave in a vacuum (m / s); ε is the relative dielectric constant of the medium (see Table 1); the relative dielectric constant, propagation speed and attenuation coefficient corresponding to each medium are shown in Table 1 below.

[0128] Table 1 Relative dielectric constant, propagation velocity and attenuation coefficient corresponding to each medium

[0129]

[0130] Before the adjacent working face is mined, the space volume V1 of each meter of the tunnel after repeated mining is calculated based on the displacement meter monitoring data, and the surrounding rock damage range S1 of the tunnel is measured by geological radar, and the grouting volume prediction coefficient J1 within the current monitoring range after repeated mining is calculated; the grouting volume of the surrounding rock fissures after repeated mining is equal to the displacement of the surrounding rock, so Q = V 原 -V 变 .

[0131] According to the grouting prediction coefficient formula

[0132]

[0133] The expression of grouting amount of tunnel surrounding rock is:

[0134]

[0135] Where J is the prediction coefficient of grouting volume for each excavation or mining operation within the current monitoring range, S 扩展 The change area of ​​surrounding rock damage range of each tunneling or mining outside the current monitoring range, V0 is the tunnel space volume per meter under the tunnel design section size, and S0 is the design section size of the repeated mining tunnel.

[0136] Then the amount of grouting required for surrounding rock after repeated mining tunnel excavation per meter is

[0137]

[0138] In order to improve the stability of repeatedly mined tunnels, it can be seen from the formula that the grouting volume of tunnels outside the monitoring station can be predicted by measuring the surrounding rock damage range S1 of the tunnel excavation through geological radar, and grouting can be carried out.

[0139] When the tunnels in the monitoring area are in the advanced support pressure stress reduction zone of the working face that produces a mining operation in the repeated mining tunnels, the volume V2 per meter of the repeated mining tunnel space within the current monitoring range after the mining operation is calculated based on the displacement meter monitoring data in the monitoring station, and the geological radar is used to measure and calculate the damage range area S2 of the tunnel surrounding rock within the current monitoring range after the mining operation. The grouting volume prediction coefficient J2 within the current monitoring range after the impact of the repeated mining tunnel is obtained by calculation; at this time, S1 is the surrounding rock damage range after the tunnel excavation of the measured section, because S1 and S2 are in the same section, and grouting has been injected in the range of S1 to ensure the stability of the tunnel before the mining activity is carried out. The tunnel damage range expands from S1 to S2 with surrounding rock cracks in between. Since the media in the two ranges are different, S1 and S2 can be obtained by the difference in the propagation speed of the geological radar sound wave.

[0140] Similarly, the amount of grouting required for surrounding rock after mining for each meter of repeated mining tunnel is

[0141]

[0142] In order to improve the stability of repeatedly mined tunnels, it can be seen from the formula that the grouting volume of tunnels outside the monitoring station can be predicted by measuring the surrounding rock damage range S2 after the impact of one mining in the tunnel through geological radar, and grouting can be carried out.

[0143] When the tunnels in the monitoring area are in the advanced support pressure stress reduction zone of the working face that produces secondary mining in the repeated mining tunnels, the volume V3 per meter of the repeated mining tunnel space in the current monitoring range after the secondary mining is calculated based on the monitoring data of the displacement meter in the monitoring station, and the geological radar is used to measure and calculate the damage range area S3 of the tunnel surrounding rock in the current monitoring range after the secondary mining. The grouting volume prediction coefficient J3 of the current monitoring range after the secondary mining of the repeated mining tunnel is obtained by calculation; at this time, S2 is the surrounding rock damage range of the measured section tunnel after the first mining, because S2 and S3 are in the same section, and grouting has been done in the S2 range to ensure the stability of the tunnel before the secondary mining activity. Similarly, when the tunnel damage range expands from S2 to S3, the difference in the expansion of the tunnel damage range is the surrounding rock crack. Since the media in the two ranges are different, S2 and S3 can be obtained by the difference in the propagation speed of the geological radar sound wave.

[0144] Then the grouting volume required for the surrounding rock after the second mining of each meter of repeated mining tunnel is

[0145]

[0146] Similarly, in order to improve the stability of repeatedly mined tunnels, it can be seen from the formula that the prediction of the grouting volume for tunnels outside the monitoring station can be achieved by measuring the surrounding rock damage range S3 after the secondary mining of the tunnel using geological radar, and grouting can be carried out.

[0147] J is the parameter obtained by the tunnel monitoring station. Since the monitoring station is located at the front end of the repeated mining tunnel that is not affected by mining stress, the prediction of grouting volume is for the tunnel outside the monitoring station. It is calculated by measuring the surrounding rock damage range S i Combined with the J measured at the measuring station, the grouting volume Q is obtained; at the same time, Q = V 原 -V 变 It is the change in volume of each meter of tunnel space after repeated mining and deformation. It is calculated by using multi-point displacement meters, which are arranged on the top and bottom plates and both sides of the tunnel, to monitor the movement of tunnel surrounding rock in three periods after the first mining and the second mining. The price of displacement meters is relatively expensive, and it also takes a lot of installation time to arrange multi-point displacement meters on the top and bottom plates and both sides of the tunnel. Therefore, the prediction method of the present invention can save prediction time, improve work efficiency and save budget costs.

[0148] According to the actual measurement data on site, the 5m tunnel data in the detection station in the repeated mining tunnel were intercepted, as shown in Table 2 and Table 3. 1m was intercepted in each section. Finally, the predicted and actual grouting data on site were obtained as shown in Table 4. Fig. 9 It can be observed that after the first and second mining, there is a deviation in the grouting volume of the surrounding rock of the repeated mining tunnel. During the grouting process, the grouting volume is affected by factors such as the slurry parameters and the slurry filling coefficient. However, it can be observed from the figure that the prediction method can also achieve an accuracy of more than 85%.

[0149] Table 2 The increase rate of surrounding rock grouting per meter of tunnel, the extension rate of damage range and the grouting prediction coefficient after repeated mining tunnel once

[0150]

[0151] Table 3 The increase rate of surrounding rock grouting per meter of repeated mining tunnel after secondary mining, the extension rate of damage range and the grouting prediction coefficient

[0152]

[0153]

[0154] Table 4 Predicted and actual grouting volume per meter of repeated mining tunnel

[0155]

[0156] Device Embodiment

[0157] The present invention provides a device for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel, comprising:

[0158] The data acquisition module is used to obtain monitoring data on the amount of tunnel surrounding rock movement and the scope of tunnel surrounding rock damage in the repeated mining tunnels within the current monitoring range after excavation and mining impact.

[0159] The calculation and processing module is used to calculate the volume of the tunnel space deformation before and after excavation and mining, that is, the current tunnel surrounding rock grouting volume, based on the monitoring data of the tunnel surrounding rock movement, and then obtain the increase rate of the tunnel surrounding rock grouting volume for each excavation and mining; calculate the change area of ​​the tunnel surrounding rock damage range before and after excavation and mining based on the monitoring data of the damage range, and obtain the extension rate of the tunnel surrounding rock damage range for each excavation and mining.

[0160] The result acquisition module is used to obtain the grouting volume prediction coefficient for each excavation and mining by the ratio of the surrounding rock grouting volume increase rate to the corresponding surrounding rock damage range extension rate. The surrounding rock fracture grouting volume of the same tunnel outside the current monitoring range is predicted by the grouting volume prediction coefficient for each excavation and mining within the current monitoring range and the change area of ​​the surrounding rock damage range of each excavation and mining of the same tunnel outside the current monitoring range.

[0161] Device Embodiment

[0162] 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 predicting 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.

[0163] 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.

[0164] 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 1A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0165] 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.

[0166] 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.

[0167] 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 predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel, characterized in that: The steps include: In the range of repeatedly mined tunnels not affected by mining, obtain the monitoring data of the tunnel surrounding rock movement and the monitoring data of the tunnel surrounding rock damage range after excavation and mining impact in the repeatedly mined tunnels within the current monitoring range; The volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, is calculated based on the monitoring data of the tunnel surrounding rock movement, and then the tunnel surrounding rock grouting volume increase rate within the current monitoring range is obtained; the change area of ​​the current tunnel surrounding rock damage range is calculated based on the monitoring data of the damage range, and the tunnel surrounding rock damage range extension rate within the current monitoring range is obtained; The grouting volume prediction coefficient after each excavation and mining impact is obtained by the ratio of the surrounding rock grouting volume increase rate to the corresponding surrounding rock damage range extension rate. The grouting volume prediction coefficient within the current monitoring range and the change area of ​​the surrounding rock damage range of the same tunnel outside the current monitoring range are used to predict the surrounding rock crack grouting volume of the same tunnel outside the current monitoring range. The step of calculating the volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, based on the monitoring data of the tunnel surrounding rock movement, and then obtaining the tunnel surrounding rock grouting volume increase rate within the current monitoring range includes: The monitoring of the amount of surrounding rock movement in the tunnel is carried out in the tunnel with the cross section of the tunnel as the monitoring data unit; Divide the section of the tunnel monitored after each excavation or mining deformation into multiple single contour polygons: In the formula, is the jth single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; p a is one of the vertices, {x a, y a ,z a is the coordinate of the vertex; i is the monitoring section number, and R is a real number; The area formula of the coordinate analysis method is used to calculate the areas of multiple segmented single contour polygons separately, and the sum of all is used to obtain the monitoring section area. The calculation formula is as follows: for The area of ​​the enclosed region, A, is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the laneway; The calculation formula for the total volume of the tunnel after deformation within the monitoring range is as follows: h is the interval of monitoring sections, n is the number of sections per meter of space volume after the tunnel is deformed, A 变_i is the cross-sectional area of ​​the i-th tunnel after deformation; According to the volume of the tunnel space before and after repeated mining per meter, the volume strain of the tunnel affected by each excavation or mining is obtained, that is, the increase rate of tunnel surrounding rock grouting. The formula is as follows: Among them, C is the increase rate of surrounding rock grouting volume after each excavation or mining impact, V 原 V is the volume of each meter of tunnel space before each excavation or mining operation causes changes; 变 It is the volume of each meter of tunnel space after each excavation or mining impact, and V0 is the volume of each meter of tunnel space under the designed cross-sectional size of the tunnel; The step of calculating the change area of ​​the current tunnel surrounding rock damage range according to the monitoring data of the damage range and obtaining the extension rate of the tunnel surrounding rock damage range within the current monitoring range includes: The monitoring of the damage range of the surrounding rock of the tunnel is carried out in the tunnel with the cross section of the loosening zone of the surrounding rock outside the tunnel as the monitoring data unit; The area of ​​the tunnel surrounding rock damage after each excavation or mining deformation is divided into multiple single contour polygons In the formula, is the single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; d a is one of the vertices, {x a, y a ,z a } is the coordinate of the vertex; The area formula of the single contour polygons separated by the coordinate analysis method is calculated separately. The calculation formula is as follows: in, for Area of ​​the enclosed area, S i It is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the tunnel; The calculated damage range change area is: S 扩展 =S 变 -S 原 Among them, S 变 S is the area of ​​the surrounding rock crack expansion caused by each tunnel excavation or mining. 原 S is the area of ​​fracture damage in the surrounding rock before each tunnel excavation or mining operation. 扩展 The area of ​​damage change is finally obtained through measurement and calculation; Then the extension rate of surrounding rock damage range after each excavation or mining impact is: S0 is the design cross-sectional size of the repeated mining tunnel; The expression of the grouting volume prediction coefficient J after each excavation or mining impact is: The expression for predicting the grouting amount of surrounding rock fissures in the same tunnel outside the current monitoring range is:

2. A device for predicting the amount of grouting in surrounding rock fissures of a repeated mining tunnel, characterized in that: include: The data acquisition module is used to obtain the monitoring data of the amount of tunnel surrounding rock movement and the monitoring data of the tunnel surrounding rock damage range of the same repeated mining tunnel within the current monitoring range after excavation and mining impact, within the range of repeated mining tunnels not affected by mining; A calculation processing module is used to calculate the volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, based on the monitoring data of the tunnel surrounding rock movement, and then obtain the tunnel surrounding rock grouting volume increase rate within the current monitoring range; calculate the change area of ​​the current tunnel surrounding rock damage range based on the monitoring data of the damage range, and obtain the tunnel surrounding rock damage range extension rate within the current monitoring range; The result acquisition module is used to obtain the grouting volume prediction coefficient after each excavation and mining impact through the ratio of the surrounding rock grouting volume increase rate to the corresponding surrounding rock damage range extension rate, and predict the surrounding rock fissure grouting volume of the same tunnel outside the current monitoring range through the grouting volume prediction coefficient within the current monitoring range and the change area of ​​the surrounding rock damage range of the same tunnel outside the current monitoring range; The step of calculating the volume of the current tunnel space deformation, that is, the tunnel surrounding rock grouting volume within the current monitoring range, based on the monitoring data of the tunnel surrounding rock movement, and then obtaining the tunnel surrounding rock grouting volume increase rate within the current monitoring range includes: The monitoring of the amount of surrounding rock movement in the tunnel is carried out in the tunnel with the cross section of the tunnel as the monitoring data unit; Divide the section of the tunnel monitored after each excavation or mining deformation into multiple single contour polygons: In the formula, is the jth single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; p a is one of the vertices, {x a, y a ,z a is the coordinate of the vertex; i is the monitoring section number, and R is a real number; The area formula of the coordinate analysis method is used to calculate the areas of multiple segmented single contour polygons separately, and the sum of all is used to obtain the monitoring section area. The calculation formula is as follows: for The area of ​​the enclosed region, A, is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the laneway; The calculation formula for the total volume of the tunnel after deformation within the monitoring range is as follows: h is the interval of monitoring sections, n is the number of sections per meter of space volume after the tunnel is deformed, A 变_i is the cross-sectional area of ​​the i-th tunnel after deformation; According to the volume of the tunnel space before and after repeated mining per meter, the volume strain of the tunnel affected by each excavation or mining is obtained, that is, the increase rate of tunnel surrounding rock grouting. The formula is as follows: Among them, C is the increase rate of surrounding rock grouting volume after each excavation or mining impact, V 原 V is the volume of each meter of tunnel space before each excavation or mining operation causes changes; 变 It is the volume of each meter of tunnel space after each excavation or mining impact, and V0 is the volume of each meter of tunnel space under the designed cross-sectional size of the tunnel; The step of calculating the change area of ​​the current tunnel surrounding rock damage range according to the monitoring data of the damage range and obtaining the extension rate of the tunnel surrounding rock damage range within the current monitoring range includes: The monitoring of the damage range of the surrounding rock of the tunnel is carried out in the tunnel with the cross section of the loosening zone of the surrounding rock outside the tunnel as the monitoring data unit; The area of ​​the tunnel surrounding rock damage after each excavation or mining deformation is divided into multiple single contour polygons In the formula, is the single contour boundary polygon segmented from the monitoring section, j is the polygon number; m is the segmented polygon The number of vertices; d a is one of the vertices, {x a, y a ,z a } is the coordinate of the vertex; The area formula of the single contour polygons separated by the coordinate analysis method is calculated separately. The calculation formula is as follows: in, for Area of ​​the enclosed area, S i It is the sum of the areas of all segmented single contour polygons, i.e., the approximate value of the monitoring cross-sectional area of ​​the tunnel; The calculated damage range change area is: S 扩展 =S 变 -S 原 Among them, S 变 S is the area of ​​the surrounding rock crack expansion caused by each tunnel excavation or mining. 原 S is the area of ​​fracture damage in the surrounding rock before each tunnel excavation or mining operation. 扩展 The area of ​​damage change is finally obtained through measurement and calculation; Then the extension rate of surrounding rock damage range after each excavation or mining impact is: S0 is the design cross-sectional size of the repeated mining tunnel; The expression of the grouting volume prediction coefficient J after each excavation or mining impact is: The expression for predicting the grouting amount of surrounding rock fissures in the same tunnel outside the current monitoring range is:

3. 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 predicting the grouting amount of surrounding rock fissures in a repeated mining tunnel as described in any one of claim 1.

Images