Method and system for evaluating grouting effect of underground goaf of coal mine

Abstract

The invention relates to a grouting effect evaluation method and system for an underground goaf of a coal mine, and the grouting effect of the goaf can be detected and evaluated in a long distance at a time according to the size of the goaf through directional drilling. The grouting condensation effect of the goaf can be evaluated through engineering parameters of directional drilling; the millimeter wave radar wave detection method can detect the state of the hole wall of the drill hole, and the grouting effect is visually analyzed according to the shape of the hole wall. The meter-scale radar wave detection method can detect and evaluate the grouting effect within a certain range around the drill hole; according to detection of the multiple drill holes in the grouting area of the goaf, fine detection and evaluation of the whole goaf in the whole range are finally achieved, and meanwhile remedy grouting can be conducted on the area with the poor grouting effect through the drill holes after evaluation of the drill holes subjected to directional drilling is completed.

Description

Technical Field

[0001] The present application relates to the field of prevention and control of coal mining goaf subsidence, and specifically, to a method and system for evaluating the grouting effect of goaf in underground coal mines. Background Art

[0002] After coal mining, a large number of goafs will be left underground. Many coal mines use non-filling mining methods during the mining process, which will form a large number of large-cavity goafs. Large-cavity goafs are prone to water-rich problems, posing a threat to surrounding coal mining. They are also prone to cause ground subsidence, destroying the surface environment and causing great impacts on surrounding residents and the ecological environment.

[0003] Grouting in goaf is a common method for goaf management. The main methods for detecting and evaluating the grouting effect include the following: (1) Grouting filling rate analysis method: During the grouting process, relevant engineering parameters are collected for analysis, including PQt curve analysis method, grouting volume distribution characteristic method, and slurry filling coefficient inverse calculation method. Among them, the PQt curve analysis method reflects the filling situation through the relationship curve between grouting pressure and velocity, but in special areas such as faults, abnormal trends may appear, resulting in the inability to correctly judge whether the reinforcement is successful or not. The grouting volume distribution characteristic method intuitively shows the grouting distribution state, but cannot explain the quality of reinforcement. The grouting filling rate analysis method can quantitatively reflect the slurry filling situation, but ignores the diffusion form in different media and the accurate determination of the slurry loss rate. (2) Inspection hole method: As a method recommended by the specification, the inspection hole method evaluates the grouting effect by setting up inspection holes after the grouting is completed, conducting in-hole observation, coring, grouting tests, and permeability coefficient determination. (3) Deformation monitoring method: By setting up surface deformation monitoring points within the influence range of the goaf, collecting surface deformation observation data before, after and during treatment and construction, and analyzing and evaluating the reinforcement effect, this method has poor evaluation effect on goaf areas with little surface change, and cannot directly evaluate the grouting effect inside the grouting. (4) Conventional geophysical exploration method: Geophysical exploration techniques such as direct current method, electromagnetic wave CT, seismic wave CT, etc. are used before and after grouting to analyze the filling effect of slurry on the collapse fault zone by comparing before and after. The direct current method has a limited detection distance and cannot perform long-distance detection for large goafs. Electromagnetic wave CT requires cross-hole or cross-tunnel detection, which is difficult to construct. At the same time, electromagnetic waves cannot penetrate large goafs. Seismic wave CT has a low detection accuracy due to the large wavelength of seismic waves, and has poor detection of local effects in goafs, and cannot evaluate the grouting effect inside goafs. (5) Drilling and coring method: The existence of slurry concretions is visually observed through drilling and coring, so as to evaluate the grouting effect. This method is intuitive but destructive, local, and costly, and cannot fully reflect the effect of the entire grouting area. (6) Water pressure test: The grouting filling effect is indirectly evaluated by the changes in unit water absorption and permeability coefficient reflected by the water pressure test before and after grouting. This method may have problems such as being unable to accurately simulate actual grouting conditions or the difference between water flow and slurry flow in porous media. Summary of the invention

[0004] In order to overcome at least one shortcoming in the prior art, the present application provides a method and system for evaluating the grouting effect of a goaf area in an underground coal mine.

[0005] In a first aspect, a method for evaluating the grouting effect of a goaf area in an underground coal mine is provided, comprising:

[0006] Step S1, designing multiple long-distance drilling trajectories according to goaf information;

[0007] Step S2, performing directional drilling of any long-distance borehole according to the trajectory, and obtaining engineering parameters during the directional drilling process, the engineering parameters including drilling pressure, rotation speed and pump displacement;

[0008] Step S3, during the directional drilling process, a millimeter-level radar wave detector and a meter-level radar wave detector are used to detect the long-distance borehole to obtain millimeter-level radar wave detection data and meter-level radar wave detection data;

[0009] Step S4, filtering, normalizing and calculating standard scores of the engineering parameters to obtain first grouting effect evaluation index parameters;

[0010] Step S5, generating a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculating a second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map;

[0011] Step S6, performing full waveform inversion imaging on the meter-level radar wave detection data to obtain a distribution image of the medium around the borehole detection, and calculating a third grouting effect evaluation index parameter based on the distribution image of the medium around the borehole detection;

[0012] Step S7, weighting and accumulating the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain a comprehensive evaluation index parameter for long-distance drilling;

[0013] Step S8, determining the grouting effect level of the long-distance drilling according to the comprehensive evaluation index parameters and referring to the grouting effect classification standard;

[0014] Step S9, updating the grouting effect classification standard according to the comprehensive evaluation index parameters and the grouting effect level;

[0015] Step S10, determining whether all long-distance boreholes have been directional drilled, if so, obtaining the grouting effect level of each long-distance borehole, and executing step S11, if not, returning to step S2;

[0016] Step S11, using the Kriging interpolation method according to the grouting effect level of each long-distance borehole, to determine the grouting effect level of the undetected area of ​​the goaf.

[0017] In one embodiment, step S1, designing multiple long-distance drilling trajectories according to goaf information, includes:

[0018] Determine the number of long-distance drilling holes N according to the size of the goaf B , using the following formula:

[0019]

[0020] Wherein, V is the volume of the goaf, L is the length of the long-distance borehole, and R is the detection radius of the long-distance borehole;

[0021] Determine the distribution location of long-distance boreholes; the distribution location includes the center of the goaf, and the locations in the east, south, west and north directions with reference to the center of the goaf;

[0022] The opening positions of the multiple long-distance drill holes are located at the same opening point, and the multiple long-distance drill holes are distributed in a feather shape; or the opening positions of the multiple long-distance drill holes are different, and the multiple long-distance drill holes are distributed in parallel.

[0023] In one embodiment, step S3, using a millimeter-level radar wave detector and a meter-level radar wave detector to detect the long-distance borehole, includes:

[0024] Mark the depth of millimeter-level radar wave detectors and meter-level radar wave detectors in long-distance boreholes and record the depth data in the form of timestamps;

[0025] The data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are stored in the form of timestamps;

[0026] The data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are matched with the depth data according to the timestamp to obtain the millimeter-level radar wave detection data and the meter-level radar wave detection data distributed along the depth.

[0027] In one embodiment, step S4, filtering, normalizing and calculating standard scores of engineering parameters to obtain first grouting effect evaluation index parameters includes:

[0028] Perform filtering on the engineering parameters of each measuring point to obtain filtered engineering parameters;

[0029] Normalizing the filtered engineering parameters to obtain normalized engineering parameters;

[0030] Calculate the standard score based on the normalized engineering parameters; the standard score includes the standard score of pressure, the standard score of rotation speed and the standard score of pump displacement;

[0031] Calculate the average of the standard score of pressure, the standard score of rotation speed and the standard score of pump displacement to obtain the grouting effect evaluation index parameter of each measuring point;

[0032] The mean of the grouting effect evaluation index parameters of all measuring points is calculated to obtain the first grouting effect evaluation index parameter.

[0033] In one embodiment, the engineering parameters of each measuring point are filtered to obtain the filtered engineering parameters, including:

[0034] Perform filtering on the engineering parameters of the first and second measuring points, including:

[0035]

[0036] Among them, Pz1, Pz2, Pz3, Pz4, and Pz5 are the pressures at the 1st to 5th measuring points. is the filtered pressure of the first measuring point, is the filtered pressure of the second measuring point; Vs1, Vs2, Vs3, Vs4, Vs5 are the rotation speeds of the 1st to 5th measuring points, is the filtered speed of the first measuring point, is the filtered speed of the second measuring point; PL1, PL2, PL3, PL4, PL5 are the pump displacements of the 1st to 5th measuring points, is the filtered pump displacement at the first measuring point, is the filtered pump displacement at the second measuring point;

[0037] The engineering parameters of the last two measuring points are filtered, including:

[0038]

[0039] Where N is the number of measuring points, Pz N-4 , Pz N-3 , Pz N-2 , Pz N-1 , Pz N is the pressure of the last five measuring points, is the filtered pressure at the N-1th measuring point, is the filtered pressure of the Nth measuring point; Vs N-4 , Vs N-3 , Vs N-2 , Vs N-1 , Vs N is the speed of the last 5 measuring points, is the filtered speed of the N-1th measuring point, is the filtered speed of the Nth measuring point; PL N-4 , PL N-3 , PL N-2 , PL N-1 , PL N is the pump displacement of the last 5 measuring points, is the filtered pump displacement at the Nth measuring point, is the filtered pump displacement of the N-1th measuring point;

[0040] Filter the engineering parameters of the remaining measurement points, including:

[0041]

[0042] Where k is the number of the measuring point, 3≤k≤N-2, The filtered pressure at the kth measurement point, is the filtered speed of the kth measuring point, is the filtered pump displacement of the kth measuring point; Pz k The pressure at the kth measuring point, Vs k is the speed of the kth measuring point, PL k is the pump displacement at the kth measuring point.

[0043] In one embodiment, the second grouting effect evaluation index parameter adopts the following formula:

[0044]

[0045] Among them, Q2 is the second grouting effect evaluation index parameter, f is the millimeter-level radar wave detection data detection map, f(i,j) represents the pixel value of pixel point (i,j) in f, M is the horizontal number of pixel points in f, T is the vertical number of pixel points in f, and f(i,j|d,θ) represents the pixel value of pixel point (i,j) in f with a distance d and an angle θ from the center point of f.

[0046] In one embodiment, the third grouting effect evaluation index parameter adopts the following formula:

[0047]

[0048] Among them, Q3 is the third grouting effect evaluation index parameter, P is the distribution image of the surrounding medium detected by drilling, M1 is the horizontal number of pixels in P, N1 is the vertical number of pixels in P, and P(i1,j1|d1,θ1) represents the pixel value of the pixel point (i1,j1) in P with a distance of d1 and an angle of θ1 from the center point of P.

[0049] In one embodiment, in step S7, the comprehensive evaluation index parameter of long-distance drilling is calculated using the following formula:

[0050] Q0=aQ1+bQ2+cQ3

[0051] Among them, Q0 is the comprehensive evaluation index parameter of long-distance drilling, Q1 is the first grouting effect evaluation index parameter, Q2 is the second grouting effect evaluation index parameter, Q3 is the third grouting effect evaluation index parameter, a, b, c are the weights of Q1, Q2 and Q3 respectively, a+b=1, a>b, c≥1.

[0052] In a second aspect, a grouting effect evaluation system for a goaf area in an underground coal mine is provided, comprising:

[0053] Trajectory design module, used to design multiple long-distance drilling trajectories based on goaf information;

[0054] The engineering parameter acquisition module is used to perform directional drilling of any long-distance borehole according to the trajectory and obtain the engineering parameters during the directional drilling process. The engineering parameters include drilling pressure, rotation speed and pump displacement;

[0055] A detection data acquisition module is used to detect long-distance boreholes using a millimeter-level radar wave detector and a meter-level radar wave detector during directional drilling to obtain millimeter-level radar wave detection data and meter-level radar wave detection data;

[0056] A first grouting effect evaluation index parameter determination module, used for filtering, normalizing and calculating standard scores of engineering parameters to obtain first grouting effect evaluation index parameters;

[0057] A second grouting effect evaluation index parameter determination module, used to generate a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculate the second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map;

[0058] The third grouting effect evaluation index parameter determination module is used to perform full waveform inversion imaging on the meter-level radar wave detection data to obtain the distribution image of the medium around the borehole detection, and calculate the third grouting effect evaluation index parameter according to the distribution image of the medium around the borehole detection;

[0059] A comprehensive evaluation index parameter determination module is used to perform weighted accumulation of the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain a comprehensive evaluation index parameter for long-distance drilling;

[0060] A grouting effect level determination module is used to determine the grouting effect level of long-distance drilling according to comprehensive evaluation index parameters and based on the grouting effect classification standard;

[0061] An updating module, used for updating the grouting effect classification standard according to the comprehensive evaluation index parameters and the grouting effect level;

[0062] The judgment module is used to judge whether all long-distance boreholes have been directional drilled. If so, the grouting effect level of each long-distance borehole is obtained and the interpolation module is entered. If not, the engineering parameter acquisition module is entered;

[0063] The interpolation module is used to determine the grouting effect level of the undetected area of ​​the goaf by using the Kriging interpolation method according to the grouting effect level of each long-distance borehole.

[0064] Compared with the prior art, the present application has the following beneficial effects: the present application can realize long-distance detection and evaluation of the grouting effect of the goaf at one time according to the size of the goaf through directional drilling of holes; the engineering parameters of directional drilling can evaluate the grouting coagulation effect of the goaf; the millimeter wave radar wave detection method can detect the state of the borehole wall, and intuitively analyze the grouting effect according to the shape of the borehole wall; the meter-level radar wave detection method can detect and evaluate the grouting effect within a certain range around the borehole; the present application detects multiple boreholes in the grouting area of ​​the goaf, and finally realizes refined detection and evaluation of the entire goaf within the entire range. At the same time, after the evaluation of the directional drilling borehole is completed, the area with poor grouting effect can be remedial grouting through the borehole. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The present application may be better understood by referring to the following description given in conjunction with the accompanying drawings, which together with the following detailed description are included in this specification and form a part of this specification. In the drawings:

[0066] Figure 1 The flowchart of the method for evaluating the grouting effect of the goaf area in a coal mine is shown;

[0067] Figure 2 A schematic diagram showing the distribution location of long-distance drilling holes is shown;

[0068] Figure 3 A schematic diagram of the trajectory of long-distance drilling holes with feather-like distribution is shown;

[0069] Figure 4 A schematic diagram showing the trajectory of parallel distributed long-distance drilling holes;

[0070] Figure 5 shows a detection diagram of millimeter-level radar wave detection data;

[0071] Figure 6 An image showing the distribution of the medium surrounding the borehole detection is shown;

[0072] Figure 7 The structural block diagram of the grouting effect evaluation device for the goaf area in an underground coal mine is shown. DETAILED DESCRIPTION

[0073] The exemplary embodiments of the present application will be described below in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of the actual embodiments are described in the specification. However, it should be understood that many implementation-specific decisions can be made in the process of developing any such actual embodiments in order to achieve the specific goals of the developer, and these decisions may vary from embodiment to embodiment.

[0074] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, only the device structure closely related to the scheme according to the present application is shown in the drawings, while other details that are not closely related to the present application are omitted.

[0075] It should be understood that the present application is not limited to the described implementation forms due to the following description with reference to the accompanying drawings. In this article, where feasible, the embodiments can be combined with each other, features between different embodiments can be replaced or borrowed, and one or more features can be omitted in one embodiment.

[0076] The present application provides a method for evaluating the grouting effect of a goaf area in a coal mine. Figure 1 The flowchart of the method for evaluating the grouting effect of the goaf in underground coal mines is shown in FIG. Figure 1 , methods include:

[0077] Step S1, designing multiple long-distance drilling trajectories according to goaf information.

[0078] Specifically, first, the number of long-distance drilling holes N is determined according to the size of the goaf. B , using the following formula:

[0079]

[0080] Wherein, V is the volume of the goaf, L is the length of the long-distance borehole, and R is the detection radius of the long-distance borehole;

[0081] Then, determine the distribution position of the long-distance boreholes; the distribution position includes the center position of the goaf, and the positions in the east, south, west and north directions with reference to the center of the goaf; Figure 2 A schematic diagram showing the distribution locations of long-distance drilling holes is shown.

[0082] Then, the opening positions of the multiple long-distance drill holes are located at the same opening point, and the multiple long-distance drill holes are distributed in a feather shape; or the opening positions of the multiple long-distance drill holes are different, and the multiple long-distance drill holes are distributed in parallel.

[0083] Here, for the convenience of construction, the hole opening position can be designed in the same drilling site, with the same hole opening point, but different drilling trajectories. The hole opening position can be selected according to the needs of the site, and it is designed as far as possible in the area of ​​the center line of the goaf. The drilling trajectory design is designed according to the shape and size of the goaf. For multiple long-distance drilling holes at the same location, the hole opening section can be designed to be feather-shaped, and the drilling trajectory can be parallel after entering the goaf. Figure 3 The schematic diagram of the trajectory of long-distance drilling with feather-shaped distribution is shown. For drilling with parallel drilling positions, the drilling trajectory is designed as parallel drilling. Figure 4A schematic diagram showing the trajectory of parallel distributed long-distance drilling holes.

[0084] Step S2, according to the trajectory, directional drilling of any long-distance borehole is performed to obtain engineering parameters during the directional drilling process, the engineering parameters including drilling pressure, rotation speed and pump displacement.

[0085] Here, directional drilling technology is used for drilling, and the drilling pressure, rotation speed, pump displacement and other engineering parameters during the directional drilling process are recorded. The construction process of directional drilling for long-distance drilling is as follows: according to the drilling trajectory designed in step 1, the preliminary preparation work of directional drilling is done, the tool orientation angle of the instrument is determined, and then the long-distance drilling construction is carried out; during the construction process, in the gap between the drill rods, the current trajectory of the borehole is measured by the measurement while drilling method, and the difference between the drilling trajectory and the designed trajectory is judged. If there is a deviation, the tool orientation angle of the instrument is adjusted. If there is no deviation, drilling is continued until the drilling is completed. During the drilling process, the drilling pressure Pz, rotation speed Vs, pump displacement PL and other engineering parameters on the dial of the directional drill are recorded with the depth as the mark.

[0086] Step S3, during the directional drilling process, a millimeter-level radar wave detector and a meter-level radar wave detector are used to detect the long-distance borehole to obtain millimeter-level radar wave detection data and meter-level radar wave detection data.

[0087] Specifically, before directional drilling, the millimeter-level radar wave detector and the meter-level radar wave detector used in drilling are turned on and synchronized with the controller at the hole mouth to start the storage working mode of the two instruments;

[0088] Then, the depth of the millimeter-level radar wave detector and the meter-level radar wave detector in the long-distance borehole is marked, and the depth data is recorded in the form of a timestamp;

[0089] Then, the data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are stored in the form of timestamps; the data collected by the millimeter-level radar wave detector are stored in the internal memory of the millimeter-level radar wave detector in the form of timestamps, and the data collected by the meter-level radar wave detector are stored in the internal memory of the meter-level radar wave detector in the form of timestamps.

[0090] Then, after the directional drilling reaches the designed bottom of the hole, the depth mark is stopped on the hole mouth controller, and the millimeter-level radar wave detector and the meter-level radar wave detector that are being drilled are lifted to the hole mouth.

[0091] Then, the measurement data of the millimeter-level radar wave detector is exported to the orifice controller, and the data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are matched with the depth data according to the timestamp to obtain the millimeter-level radar wave detection data and the meter-level radar wave detection data distributed along the depth.

[0092] Step S4, filtering, normalizing and calculating standard scores for the engineering parameters to obtain the first grouting effect evaluation index parameters.

[0093] Step S5, generating a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculating a second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map.

[0094] Here, millimeter-level radar wave detection is a high-precision imaging detection of the borehole wall. The acquired millimeter-level radar wave detection data needs to be preprocessed, including: (a) compensating the motion distortion of the millimeter-wave radar data according to the movement of the drilling process, (b) performing point cloud framing processing on the millimeter-wave radar wave data, (c) converting the millimeter-wave detection data coordinate system into the drill pipe coordinate system, (d) performing filtering processing and using the Kalman filter algorithm to remove noise, and (e) unfolding the filtered data along the borehole wall to generate a millimeter-level radar wave detection data detection map of the entire borehole wall. Figure 5 A detection diagram of millimeter-level radar wave detection data is shown.

[0095] Step S6, performing full waveform inversion imaging on the meter-level radar wave detection data to obtain a distribution image of the medium around the borehole detection, and calculating the third grouting effect evaluation index parameter based on the distribution image of the medium around the borehole detection.

[0096] Here, the meter-level radar wave detection is to obtain the grouting effect around the borehole with the borehole as the center and the detection range of the meter-level radar instrument as the radius; the meter-level radar wave detection data needs to be preprocessed, including: data depth correction, gain processing, filtering processing, normalization processing, etc., and one or two of the above existing data processing methods can be selected according to the characteristics of data quality. Perform full waveform inversion imaging on the preprocessed data to obtain the distribution image of the medium around the borehole detection. Figure 6 An image of the distribution of the medium surrounding the borehole detection is shown.

[0097] Step S7, weighted accumulation of the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain a comprehensive evaluation index parameter for long-distance drilling.

[0098] Specifically, the comprehensive evaluation index parameters of long-distance drilling can be expressed as follows:

[0099] Q0=aQ1+bQ2+cQ3

[0100] Among them, Q0 is the comprehensive evaluation index parameter of long-distance drilling, Q1 is the first grouting effect evaluation index parameter, Q2 is the second grouting effect evaluation index parameter, Q3 is the third grouting effect evaluation index parameter, a, b, c are the weights of Q1, Q2 and Q3 respectively, a+b=1, a>b, c≥1.

[0101] Step S8, determining the grouting effect level of the long-distance drilling according to the comprehensive evaluation index parameters and referring to the grouting effect grading standard.

[0102] Here, the grouting effect grading standard can be obtained in advance. Specifically, multiple sets of comprehensive evaluation index parameters and the grouting effect level of long-distance drilling can be obtained through numerical simulation and actual testing methods. The grouting effect grading standard is artificially determined, which is divided into 5 levels: I, II, III, IV, and V. Here, each level corresponds to a certain comprehensive evaluation index parameter range. By determining the comprehensive evaluation index parameter range in which the currently obtained comprehensive evaluation index parameter is located, the corresponding level can be determined. Among them, the V level has the best grouting effect in the goaf and does not need to be processed again. The I level has the worst grouting effect and requires further grouting treatment.

[0103] Step S9, updating the grouting effect grading standard according to the comprehensive evaluation index parameters and the grouting effect level.

[0104] Here, the grouting effect classification standard is not fixed. After each acquisition of the comprehensive evaluation index parameter and the grouting effect level corresponding to the borehole, the grouting effect classification standard can be updated. For example, if the currently acquired comprehensive evaluation index parameter does not belong to any comprehensive evaluation index parameter range, the closest comprehensive evaluation index parameter range can be modified so that the currently acquired comprehensive evaluation index parameter is within the range.

[0105] Step S10, determining whether all long-distance boreholes have been directional drilled, if so, obtaining the grouting effect level of each long-distance borehole, and executing step S11, if not, returning to step S2;

[0106] Step S11, using the Kriging interpolation method according to the grouting effect level of each long-distance borehole, to determine the grouting effect level of the undetected area of ​​the goaf.

[0107] Here, considering that the number of long-distance boreholes cannot cover the entire goaf, the Kriging interpolation method is used to determine the grouting effect level in the undetected area of ​​the goaf.

[0108] In this embodiment, through directional drilling, long-distance detection and evaluation of the grouting effect of the goaf can be achieved at one time according to the size of the goaf; the engineering parameters of directional drilling can evaluate the grouting coagulation effect of the goaf; the millimeter wave radar wave detection method can detect the state of the borehole wall, and intuitively analyze the grouting effect according to the shape of the borehole wall; the meter-level radar wave detection method can detect and evaluate the grouting effect within a certain range around the borehole; this embodiment is based on the detection of multiple boreholes in the grouting area of ​​the goaf, and finally realizes the refined detection and evaluation of the entire goaf within the entire range. At the same time, after the evaluation of the directional drilling borehole is completed, the area with poor grouting effect can be remedial grouting through the borehole.

[0109] In one embodiment, step S4, filtering, normalizing and calculating standard scores of engineering parameters to obtain first grouting effect evaluation index parameters includes:

[0110] Step S41, filtering the engineering parameters of each measuring point to obtain filtered engineering parameters; specifically, this can be achieved in the following manner:

[0111] Perform filtering on the engineering parameters of the first and second measuring points, including:

[0112]

[0113] Among them, Pz1, Pz2, Pz3, Pz4, and Pz5 are the pressures at the 1st to 5th measuring points. is the filtered pressure of the first measuring point, is the filtered pressure of the second measuring point; Vs1, Vs2, Vs3, Vs4, Vs5 are the rotation speeds of the 1st to 5th measuring points, is the filtered speed of the first measuring point, is the filtered speed of the second measuring point; PL1, PL2, PL3, PL4, PL5 are the pump displacements of the 1st to 5th measuring points, is the filtered pump displacement at the first measuring point, is the filtered pump displacement at the second measuring point;

[0114] The engineering parameters of the last two measuring points are filtered, including:

[0115]

[0116] Where N is the number of measuring points, Pz N-4 , Pz N-3 , Pz N-2 , Pz N-1 , Pz N is the pressure of the last five measuring points, is the filtered pressure at the N-1th measuring point, is the filtered pressure of the Nth measuring point; Vs N-4 , Vs N-3 , Vs N-2 , Vs N-1 , Vs N is the speed of the last 5 measuring points, is the filtered speed of the N-1th measuring point, is the filtered speed of the Nth measuring point; PL N-4 , PL N-3 , PL N-2 , PL N-1 , PL N is the pump displacement of the last 5 measuring points, is the filtered pump displacement at the Nth measuring point, is the filtered pump displacement of the N-1th measuring point;

[0117] Filter the engineering parameters of the remaining measurement points, including:

[0118]

[0119]

[0120] Where k is the number of the measuring point, 3≤k≤N-2, The filtered pressure at the kth measurement point, is the filtered speed of the kth measuring point, is the filtered pump displacement of the kth measuring point; Pz k The pressure at the kth measuring point, Vs k is the speed of the kth measuring point, PL k is the pump displacement at the kth measuring point.

[0121] Step S42, normalizing the filtered engineering parameters so that the data is distributed between [0, 1], and obtaining normalized engineering parameters.

[0122] Specifically, the following formula is used:

[0123]

[0124] Where n is the number of the nth measuring point, 1≤n≤N, They are the normalized pressure, speed and pump displacement of the nth measuring point respectively. are the filtered pressure, speed, and pump displacement of the nth measuring point respectively; is the minimum value of the pressure after filtering at all measuring points, is the maximum value of the pressure after filtering at all measuring points, is the minimum value of the speed after filtering of all measuring points, is the maximum value of the speed after filtering of all measuring points, is the minimum value of the pump displacement after filtering at all measuring points, It is the maximum pump displacement after filtering of all measuring points.

[0125] Step S43, calculating the standard score according to the normalized engineering parameters; the standard score includes the standard score of pressure, the standard score of rotation speed and the standard score of pump displacement;

[0126] Specifically, first calculate the variance of pressure, speed, and pump displacement:

[0127]

[0128] Among them, σ Pz , σ Vs , σ PL are the variances of pressure, speed and pump displacement, is the average of the normalized pressures of all measuring points, is the average value of the normalized speed of all measuring points, is the average value of the normalized pump displacement of all measuring points;

[0129] Then, the standard score Z of pressure is calculated based on the variance of pressure, speed and pump displacement. Pzn , Standard speed score Z Vsn And the standard points of pump displacement PLn , using the following formula:

[0130]

[0131] Step S44, calculating the average of the standard score of pressure, the standard score of rotation speed and the standard score of pump displacement, and obtaining the grouting effect evaluation index parameter of each measuring point; which can be expressed by the following formula:

[0132] Q1 n =(Z Pzn +Z Vsn +Z Vsn ) / 3

[0133] Among them, Q1 n is the grouting effect evaluation index parameter of the nth measuring point.

[0134] Step S45, calculate the mean of the grouting effect evaluation index parameters of all measuring points to obtain the first grouting effect evaluation index parameter Q1. Here, Q1 can evaluate the grouting coagulation effect of the goaf area. The smaller Q1 is, the better the grouting effect of the goaf area is, and the larger Q1 is, the worse the grouting effect is.

[0135] In one embodiment, the second grouting effect evaluation index parameter adopts the following formula:

[0136]

[0137] Among them, Q2 is the second grouting effect evaluation index parameter, f is the millimeter-level radar wave detection data detection map, f(i,j) represents the pixel value of pixel point (i,j) in f, M is the horizontal number of pixel points in f, T is the vertical number of pixel points in f, and f(i,j|d,θ) represents the pixel value of pixel point (i,j) in f with a distance d and an angle θ from the center point of f.

[0138] Here, the second grouting effect evaluation index parameter reflects the complexity of the detection image of the millimeter-level radar wave detection data. The complexity reflects the grouting effect. The worse the grouting effect, the higher the image complexity and the worse the image quality.

[0139] In one embodiment, the third grouting effect evaluation index parameter adopts the following formula:

[0140]

[0141] Among them, Q3 is the third grouting effect evaluation index parameter, P is the distribution image of the surrounding medium detected by drilling, M1 is the horizontal number of pixels in P, N1 is the vertical number of pixels in P, and P(i1,j1|d1,θ1) represents the pixel value of the pixel point (i1,j1) in P with a distance of d1 and an angle of θ1 from the center point of P.

[0142] Here, the third grouting effect evaluation index parameter reflects the complexity of the data imaging map detected by meter-level radar waves. The complexity reflects the grouting effect within a certain range around the borehole. The worse the grouting effect, the greater the image change, the stronger the image heterogeneity, and the better the grouting effect, the more uniform the texture between different areas of the image, the smaller the change, and the weaker the heterogeneity.

[0143] Based on the same inventive concept as the method for evaluating the grouting effect of the goaf area in a coal mine, this embodiment also provides a corresponding device for evaluating the grouting effect of the goaf area in a coal mine. Figure 7 The structural block diagram of the grouting effect evaluation device for the goaf area in a coal mine is shown, comprising:

[0144] A trajectory design module 71, used to design multiple long-distance drilling trajectories according to goaf information;

[0145] The engineering parameter acquisition module 72 is used to perform directional drilling of any long-distance borehole according to the trajectory and acquire engineering parameters during the directional drilling process, the engineering parameters including drilling pressure, rotation speed and pump displacement;

[0146] The detection data acquisition module 73 is used to detect the long-distance borehole using a millimeter-level radar wave detector and a meter-level radar wave detector during the directional drilling process to obtain millimeter-level radar wave detection data and meter-level radar wave detection data;

[0147] A first grouting effect evaluation index parameter determination module 74 is used to filter, normalize and calculate standard scores for engineering parameters to obtain first grouting effect evaluation index parameters;

[0148] A second grouting effect evaluation index parameter determination module 75, for generating a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculating a second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map;

[0149] The third grouting effect evaluation index parameter determination module 76 is used to perform full waveform inversion imaging on the meter-level radar wave detection data to obtain a distribution image of the medium around the borehole detection, and calculate the third grouting effect evaluation index parameter according to the distribution image of the medium around the borehole detection;

[0150] A comprehensive evaluation index parameter determination module 77 is used to perform weighted accumulation of the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain a comprehensive evaluation index parameter for long-distance drilling;

[0151] A grouting effect level determination module 78, for determining the grouting effect level of the long-distance drilling hole according to the comprehensive evaluation index parameters and based on the grouting effect classification standard;

[0152] An updating module 79, used to update the grouting effect classification standard according to the comprehensive evaluation index parameters and the grouting effect level;

[0153] The judgment module 710 is used to judge whether all long-distance boreholes have been directional drilled. If so, the grouting effect level of each long-distance borehole is obtained and the interpolation module 711 is entered. If not, the engineering parameter acquisition module 72 is entered;

[0154] The interpolation module 711 is used to determine the grouting effect level of the undetected area of ​​the goaf by using the Kriging interpolation method according to the grouting effect level of each long-distance borehole.

[0155] The device for evaluating the grouting effect of underground coal mine goaf in this embodiment has the same inventive concept as the method for evaluating the grouting effect of underground coal mine goaf described above. Therefore, the specific implementation method of the device can be seen in the embodiment part of the method for evaluating the grouting effect of underground coal mine goaf in the above text, and its technical effect corresponds to the technical effect of the above method, which will not be repeated here.

[0156] The above are only various implementations of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for evaluating the grouting effect of goaf in underground coal mines, characterized in that: include: Step S1, designing multiple long-distance drilling trajectories according to goaf information; Step S2, performing directional drilling of any long-distance borehole according to the trajectory, and obtaining engineering parameters during the directional drilling process, wherein the engineering parameters include drilling pressure, rotation speed, and pump displacement; Step S3, during the directional drilling process, a millimeter-level radar wave detector and a meter-level radar wave detector are used to detect the long-distance borehole to obtain millimeter-level radar wave detection data and meter-level radar wave detection data; Step S4, filtering, normalizing and calculating standard scores of the engineering parameters to obtain first grouting effect evaluation index parameters; Step S5, generating a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculating a second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map; Step S6, performing full waveform inversion imaging on the meter-level radar wave detection data to obtain a distribution image of the medium around the borehole detection, and calculating a third grouting effect evaluation index parameter according to the distribution image of the medium around the borehole detection; Step S7, weighting and accumulating the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain a comprehensive evaluation index parameter of the long-distance drilling; Step S8, determining the grouting effect level of the long-distance drilling according to the comprehensive evaluation index parameters and referring to the grouting effect grading standard; Step S9, updating the grouting effect grading standard according to the comprehensive evaluation index parameter and the grouting effect level; Step S10, determining whether all long-distance boreholes have been directional drilled, if so, obtaining the grouting effect level of each long-distance borehole, and executing step S11, if not, returning to step S2; Step S11, using the Kriging interpolation method according to the grouting effect level of each long-distance borehole, to determine the grouting effect level of the undetected area of ​​the goaf.

2. The method according to claim 1, characterized in that Step S1, designing multiple long-distance drilling trajectories according to goaf information, including: Determine the number of long-distance drilling holes N according to the size of the goaf B , using the following formula: Wherein, V is the volume of the goaf, L is the length of the long-distance borehole, and R is the detection radius of the long-distance borehole; Determine the distribution position of the long-distance drill holes; the distribution position includes the center position of the goaf, and the positions in the east, south, west and north directions with reference to the center of the goaf; The opening positions of the multiple long-distance drill holes are located at the same opening point, and the multiple long-distance drill holes are distributed in a feather shape; or the opening positions of the multiple long-distance drill holes are different, and the multiple long-distance drill holes are distributed in parallel.

3. The method according to claim 1, characterized in that Step S3, using a millimeter-level radar wave detector and a meter-level radar wave detector to detect the long-distance borehole, including: Mark the depth of millimeter-level radar wave detectors and meter-level radar wave detectors in long-distance boreholes and record the depth data in the form of time stamps; The data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are stored in the form of timestamps; The data collected by the millimeter-level radar wave detector and the data collected by the meter-level radar wave detector are matched with the depth data according to the timestamp to obtain the millimeter-level radar wave detection data and the meter-level radar wave detection data distributed along the depth.

4. The method according to claim 1, characterized in that Step S4, filtering, normalizing and calculating standard scores for the engineering parameters to obtain first grouting effect evaluation index parameters, including: Perform filtering on the engineering parameters of each measuring point to obtain filtered engineering parameters; Normalizing the filtered engineering parameters to obtain normalized engineering parameters; Calculating standard scores according to the normalized engineering parameters; the standard scores include standard scores for pressure, speed and pump displacement; Calculate the average of the standard score of the pressure, the standard score of the rotation speed and the standard score of the pump displacement to obtain the grouting effect evaluation index parameter of each measuring point; The mean of the grouting effect evaluation index parameters of all measuring points is calculated to obtain the first grouting effect evaluation index parameters.

5. The method according to claim 4, characterized in that in, The engineering parameters of each measuring point are filtered to obtain the filtered engineering parameters, including: Perform filtering on the engineering parameters of the first and second measuring points, including: Among them, Pz1, Pz2, Pz3, Pz4, and Pz5 are the pressures at the 1st to 5th measuring points. is the filtered pressure of the first measuring point, is the filtered pressure of the second measuring point; Vs1, Vs2, Vs3, Vs4, Vs5 are the rotation speeds of the 1st to 5th measuring points, is the filtered speed of the first measuring point, is the filtered speed of the second measuring point; PL1, PL2, PL3, PL4, PL5 are the pump displacements of the 1st to 5th measuring points, is the filtered pump displacement at the first measuring point, is the filtered pump displacement at the second measuring point; The engineering parameters of the last two measuring points are filtered, including: Where N is the number of measuring points, Pz N-4 , Pz N-3 , Pz N-2 , Pz N-1 , Pz N is the pressure of the last five measuring points, is the filtered pressure at the N-1th measuring point, is the filtered pressure of the Nth measuring point; Vs N-4 , Vs N-3 , Vs N-2 , Vs N-1 , Vs N is the speed of the last 5 measuring points, is the filtered speed of the N-1th measuring point, is the filtered speed of the Nth measuring point; PL N-4 , PL N-3 , PL N-2 , PL N-1 , PL N is the pump displacement of the last 5 measuring points, is the filtered pump displacement at the Nth measuring point, is the filtered pump displacement of the N-1th measuring point; Filter the engineering parameters of the remaining measurement points, including: Where k is the number of the measuring point, 3≤k≤N-2, The filtered pressure at the kth measurement point, is the filtered speed of the kth measuring point, is the filtered pump displacement of the kth measuring point; Pz k The pressure at the kth measuring point, Vs k is the speed of the kth measuring point, PL k is the pump displacement at the kth measuring point.

6. The method according to claim 1, characterized in that The second grouting effect evaluation index parameter adopts the following formula: Among them, Q2 is the second grouting effect evaluation index parameter, f is the millimeter-level radar wave detection data detection map, f(i,j) represents the pixel value of pixel point (i,j) in f, M is the horizontal number of pixel points in f, T is the vertical number of pixel points in f, and f(i,j|d,θ) represents the pixel value of pixel point (i,j) in f with a distance d and an angle θ from the center point of f.

7. The method according to claim 1, characterized in that The third grouting effect evaluation index parameter adopts the following formula: Among them, Q3 is the third grouting effect evaluation index parameter, P is the distribution image of the surrounding medium detected by drilling, M1 is the horizontal number of pixels in P, N1 is the vertical number of pixels in P, and P(i1,j1|d1,θ1) represents the pixel value of the pixel point (i1,j1) in P with a distance of d1 and an angle of θ1 from the center point of P.

8. The method according to claim 1, characterized in that In step S7, the comprehensive evaluation index parameter of the long-distance drilling is calculated using the following formula: Q0=aQ1+bQ2+cQ3 Among them, Q0 is the comprehensive evaluation index parameter of long-distance drilling, Q1 is the first grouting effect evaluation index parameter, Q2 is the second grouting effect evaluation index parameter, Q3 is the third grouting effect evaluation index parameter, a, b, c are the weights of Q1, Q2 and Q3 respectively, a+b=1, a>b, c≥1.

9. A grouting effect evaluation system for underground coal mine goaf, characterized in that: include: Trajectory design module, used to design multiple long-distance drilling trajectories based on goaf information; An engineering parameter acquisition module, used to perform directional drilling of any long-distance borehole according to the trajectory, and acquire engineering parameters during the directional drilling process, wherein the engineering parameters include drilling pressure, rotation speed and pump displacement; A detection data acquisition module is used to detect long-distance boreholes using a millimeter-level radar wave detector and a meter-level radar wave detector during directional drilling to obtain millimeter-level radar wave detection data and meter-level radar wave detection data; A first grouting effect evaluation index parameter determination module, used for filtering, normalizing and calculating standard scores of the engineering parameters to obtain first grouting effect evaluation index parameters; A second grouting effect evaluation index parameter determination module, used to generate a millimeter-level radar wave detection data detection map of the borehole wall according to the millimeter-level radar wave detection data, and calculate a second grouting effect evaluation index parameter based on the millimeter-level radar wave detection data detection map; A third grouting effect evaluation index parameter determination module is used to perform full waveform inversion imaging on the meter-level radar wave detection data to obtain a distribution image of the medium around the borehole detection, and calculate a third grouting effect evaluation index parameter according to the distribution image of the medium around the borehole detection; A comprehensive evaluation index parameter determination module, used for weighting and accumulating the first grouting effect evaluation index parameter, the second grouting effect evaluation index parameter and the third grouting effect evaluation index parameter to obtain the comprehensive evaluation index parameter of the long-distance drilling; A grouting effect level determination module, used to determine the grouting effect level of the long-distance drilling according to the comprehensive evaluation index parameters and based on the grouting effect classification standard; An updating module, used for updating the grouting effect grading standard according to the comprehensive evaluation index parameter and the grouting effect level; The judgment module is used to judge whether all long-distance boreholes have been directional drilled. If so, the grouting effect level of each long-distance borehole is obtained and the interpolation module is entered. If not, the engineering parameter acquisition module is entered; The interpolation module is used to determine the grouting effect level of the undetected area of ​​the goaf by using the Kriging interpolation method according to the grouting effect level of each long-distance borehole.

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