A method for analyzing periodic compression using spatial information

Abstract

The present invention provides a method for analyzing periodic pressure using spatial information, which belongs to the technical field of coal mine roof monitoring. The method analyzes the relationship between the spatial pressure of the support and the footage, removes invalid data during the process of dropping and raising the support, and confirms the real pressure cycle and pressure step; based on the analysis results of the corresponding relationship between the footage and the spatial pressure of the support, the future working face pressure law is predicted, including the next pressure location and continuous distance and pressure, to provide guidance for ensuring the safety of mining work. By analyzing the relationship between the spatial pressure of the support and the footage, and removing invalid data during the process of dropping and raising the support, the real pressure data is approached, making the judgment of the pressure cycle more accurate; combined with the relationship between the footage and the spatial pressure, special situations such as the continuous increase of the support resistance caused by the long-term suspension of mining on the working face and the failure to evacuate the support can be analyzed, so that the scientific analysis of the pressure cycle is more conducive to professional and technical personnel to perform reasonable operations.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine roof monitoring, and specifically provides a method for analyzing periodic pressure using spatial information. Background Art

[0002] During the mining process of the coal mining face, as the working face advances forward, the rocks in the fault zone begin to crack under the pressure of their own weight and the overlying rocks. The rock cracks in the fault zone become larger and larger, and gradually become broken. As the old roof cantilever becomes larger and larger, when it exceeds the strength limit of the old roof, it begins to break and collapse. This pressure change caused by the periodic breaking of the old roof cantilever as the working face advances is called periodic pressure. During the periodic pressure, it is easy to cause a large roof fall accident on the working face. The continuous pressure change may cause damage to the mine support structure (such as pillars and tunnel support), reduce the stability and effectiveness of the support system, and further affect the safe production of the working face construction personnel and the coal mine. Therefore, analyzing the periodic pressure law and pressure prediction can provide strong data support for the safety management of coal mines.

[0003] At present, there are many methods for determining periodic pressure on the market. The most commonly used method is to calculate the pressure step distance through indicators such as the working resistance and time of the support. However, through the analysis of monitoring data, the pressure of the mining face is not uniform, and the periodic pressure is closely related to the advancement of the working face. Therefore, simply using the working resistance and pressure time analysis will have errors with the actual situation; in addition, the calculation method of the working face pressure criterion is mostly based on the average working resistance and the final resistance as data samples, and the average value plus the mean square error as the judgment standard. This calculation method is suitable for supports in normal working conditions, but when the support resistance is too large and the safety valve is frequently opened, the criterion obtained by adding the mean square error is too large. At this time, it is difficult to judge the periodic pressure by adding the mean square error; in addition, there will be special circumstances where the support resistance continues to rise when the working face stops mining for a long time and the support is not evacuated. It cannot be judged as periodic pressure by working resistance alone. Summary of the invention

[0004] Therefore, the present invention provides a method for analyzing periodic pressure using spatial information to solve the above problems. At the same time, based on the analysis results, the future working face pressure law is predicted to predict the next pressure location, continuous distance and pressure, providing guidance for the continued advancement of the working face.

[0005] The present invention provides a method for analyzing periodic pressure by using spatial information. The method analyzes the relationship between the spatial pressure and the footage of the support, removes invalid data during the process of lowering and raising the support, and confirms the real pressure cycle and pressure step.

[0006] Based on the analysis results of the correspondence between the footage and the support space pressure, the future working face pressure pattern is predicted, including the next pressure location, continuous distance and pressure, to provide guidance for ensuring the safety of mining work.

[0007] Furthermore, the method comprises the following steps:

[0008] S1 obtains the monitoring pressure data and data collection time of each support on the current working surface within the query time;

[0009] S2 obtains the footage data and footage entry time of the current working face within the query time;

[0010] S3 obtaining a corresponding curve diagram of footage and support space pressure using time as a medium according to the above steps;

[0011] S4 confirms each coal mining cycle and advancement footage according to the query time period. Each coal mining cycle removes the pressure data of the frame drop and the frame rise, as well as the data of the long-term suspension of mining at the working face with no increase in footage but continuous increase in space pressure;

[0012] S5: averaging the spatial pressure of each support in each working cycle to obtain the average spatial pressure in the working cycle, and then obtaining the pressure criterion of each support in the query time period;

[0013] S6 determines the spatial pressure of each coal mining cycle, and further confirms the pressure point of the current working face according to the pressure judgment criterion;

[0014] S7 calculates the mean value of the spatial pressure characteristics of each support according to the support partition information and distance weighted data, and combines the spatial pressure of all supports with the advancement footage. When the proportion of supports with pressure at the same time exceeds a certain proportion, the adjacent areas that are too close are connected and determined as one pressure area;

[0015] S8 calculates each pressure step distance and the average pressure step distance according to the pressure data and footage;

[0016] S9 predicts the next significant pressure according to the variance of pressure step, number of pressure, footage within the query time period, and dynamic load coefficient, and uses the mean value to predict the location of the next pressure, the duration distance of the pressure, and the pressure value.

[0017] Furthermore, in step S3, the calculation process of the corresponding relationship between the footage and the support space pressure is:

[0018] From the formula F=F(t), X=X(t), we get t=t(X), and finally we get the relationship between space pressure and footage: F=F(t(X));

[0019] Among them, F = F(t) is the relationship between the spatial pressure of the support and the data acquisition time, and X = X(t) is the relationship between the footage data of the current working face and the footage input time. Solving for the time as a function of the footage, the relationship between the footage and the spatial pressure is obtained, as Figure 1 shown.

[0020] Furthermore, in the step S4, the method of removing the pressure data during the lowering and raising of the support is as follows:

[0021] Obtain the maximum spatial pressure value in each working cycle and set it as F. The first pressure data of the spatial pressure obtained after one cycle is the initial support force, set as K;

[0022] In the spatial pressure dataset in the F - K interval, screen and remove the data of <F;

[0023] Obtain the current footage data and set it as L. If L does not change for consecutive days, continues to grow, remove the data after L; Remove.

[0024] Among them, the values of F and K are not fixed and depend on the size of the spatial pressure data in each working cycle. is the spatial pressure value at the i-th moment of the working cycle. The purpose of setting the thresholds F and K is to remove the abnormal roof pressure monitoring data generated by the artificial reduction of resistance during the coal mining and support moving process;

[0025] Generally, the footage data is updated daily. If there is no change for a long time continuously and the spatial pressure continues to rise, it is regarded as abnormal monitoring data.

[0026] Furthermore, in the step S5, the calculation formula of the weighting criterion is:

[0027] = * q + ) * M;

[0028] Among them, represents the mean square deviation of the spatial pressure within the query time period. is the acquisition pressure at the t -th sampling point. represents the average value of the spatial pressure; M represents the criterion ratio, which can be adjusted according to the actual situation, with a default of 100%; q is the mean square deviation coefficient;

[0029] The calculation method of q: the ratio of the data length less than the average value of the spatial pressure to the data length greater than the average value of the spatial pressure;

[0030] The calculation formula based on: = ;

[0031] p The calculation is based on the formula: p =( + + +…… ) / n;

[0032] in, It indicates the spatial pressure of the 1st to nth sampling points after removing the data of the lifting and lowering process in each working cycle;

[0033] q is calculated as: L( ) / L( ),

[0034] That is, the ratio of the length of data less than the average value of the spatial pressure to the length of data greater than the average value of the spatial pressure, where For the i The pressure collected at each sampling point.

[0035] Furthermore, in step S6, the method for confirming the pressure point is as follows:

[0036] The advancement footage in the query time period is taken as the horizontal coordinate, and the support space pressure is taken as the vertical coordinate. When the space pressure in the working cycle is greater than the pressure judgment criterion, it is recorded as the periodic pressure point.

[0037] In addition, when the periodic pressure points are not obvious, the proportion of the pressure criterion can be adjusted in the system to recalculate the distribution of the periodic pressure points.

[0038] Furthermore, in step S7, the process of determining the pressure area includes:

[0039] 1) First, the stents in the same area were grouped together;

[0040] 2) Determine the start and end positions of each bracket’s single pressure;

[0041] 3) Calculate the ratio of the number of support brackets in the footage interval to the total number of support brackets in the area. If the ratio is greater than the set value (the default is 33%, which can be adjusted dynamically), it is an area pressure.

[0042] Among them, the determination process within the same footage distance of different supports in the area within the pressure cycle is:

[0043] a. Obtain the intersection of pressure data between all brackets and all periodic brackets in the area;

[0044] The intersection is determined as follows:

[0045] li Indicates the range of 1 to i footages, f m Indicates the pressure data of 1 to m supports in each footage range, and calculates f m Whether the same position in the range of 1 to i is greater than 0, if it is greater than 0, it is an intersection:

[0046] b. If the incoming pressure is too long and belongs to n intersections at the same time, it will be divided into n parts accordingly;

[0047] c. The excessively long pressure is cut and evenly distributed into each pressure that meets the footage interval;

[0048] Furthermore, in step S8, the pressure step distance is determined according to the starting distance and ending distance of each pressure obtained in step S7, wherein:

[0049] The value of the pressure step distance is the distance from the end of the next pressure to the end of this pressure.

[0050] The average pressing step length is the average of the pressing step lengths of all pressing times.

[0051] Furthermore, in step S9, the prediction method of the next pressure is to judge whether it is obvious pressure by the discrete situation of the number of pressure and the length of the pressure step. If the number of times is small and the distance difference is large, it is not obvious; wherein:

[0052] a: The pressure step variance of each area must be less than the specified value (the default is 10);

[0053] b: The number of pressures in each area must be greater than the specified value (default 2);

[0054] c: If the variance of the number of pressures in each area is greater than the specified value (the default value is 2), it is determined that the number of pressures varies greatly, and only the area with the largest number of pressures is predicted;

[0055] d: If the variance of the footage within the query is greater than the specified value (the default is 2), it is determined that the footage change is large and a footage prompt is required;

[0056] The calculation formula of the pressure step variance is:

[0057] in is the value of each pressure step, is the average step length of pressure, N is the total number of pressures;

[0058] The calculation formula is: = .

[0059] Furthermore, the method calculates the average pressure intensity, that is, the sum of the spatial pressure of each pressure in the area / total number of times, and predicts the position of the next pressure as the current footage plus the average pressure step length, the pressure intensity as the average pressure intensity, and the pressure duration distance as the average pressure step length.

[0060] Compared with the prior art, the method of using spatial information to analyze the cycle has the following outstanding beneficial effects:

[0061] By analyzing the relationship between the support space pressure and footage, and removing the invalid data during the process of lowering and raising the support, the real pressure data can be obtained, making the judgment of the pressure cycle more accurate.

[0062] Combined with the relationship between footage and spatial pressure, special situations such as the continuous increase in support resistance caused by long-term suspension of mining at the working face and failure to remove the support can be analyzed, so that scientific analysis of the pressure cycle can be made more conducive to reasonable operations by professional and technical personnel.

[0063] The pressure criterion can automatically adjust the proportion up and down according to the distribution of the support space pressure, so as to solve the problems such as excessive judgment criteria and failure to analyze the pressure cycle caused by frequent opening of the safety valve when the working resistance exceeds the limit, so that the judgment criterion can be more in line with the actual value.

[0064] Based on the analysis results, the future working face pressure law is predicted to predict the next pressure location, continuous distance and pressure, providing guidance for safe production in coal mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a graph of footage and space pressure of the present invention;

[0066] Figure 2 It is an invalid data analysis diagram of the process of lifting and lowering the frame of the present invention;

[0067] Figure 3 It is a schematic diagram of the pressure point position and pressure judgment criteria of the present invention;

[0068] Figure 4 It is a schematic diagram of the pressure area of ​​the present invention. DETAILED DESCRIPTION

[0069] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0070] A method for analyzing periodicity using spatial information comprises the following steps:

[0071] S1 obtains the monitoring pressure data and data collection time of each support on the current working surface within the query time;

[0072] S2 obtains the footage data and footage entry time of the current working face within the query time;

[0073] S3 Obtain the corresponding relationship between the footage and the support space pressure through the above steps with time as the medium;

[0074] Among them, the calculation method of the corresponding relationship between the footage and the support space pressure is:

[0075] From the formulas F = F(t) and X = X(t), we get t = t(X), and finally obtain the relationship between the space pressure and the footage F = F(t(X))

[0076] Among them, F = F(t) is the relationship between the support space pressure and the data acquisition time, and X = X(t) is the relationship between the footage data of the current working face and the footage input time. Solve the time as a function curve graph of the footage;

[0077] S4 Confirm each coal mining working cycle and the advancing footage according to the query time period. For each coal mining working cycle, exclude the pressure data during the falling and rising of the support, as well as the data where the space pressure continues to rise while the footage of the working face stops advancing for a long time without growth;

[0078] The method of excluding the data during the rising and falling of the support is as follows:

[0079] Obtain the maximum space pressure value in each working cycle and set it as F. The first pressure data of the space pressure obtained after a cycle is the initial support force, set as K;

[0080] In the set of space pressure data in the F~K interval, screen out and remove the data of F i < data of F;

[0081] Obtain the current footage data and set it as L. If L does not change for several consecutive days and F i continues to grow, for the F after L i Remove it.

[0082] Among them, the values of F and K are not fixed and depend on the size of the space pressure data in each working cycle. F i is the space pressure value at the i-th moment of the working cycle. The purpose of setting the thresholds F and K is to remove the abnormal roof pressure monitoring data generated by the artificial reduction of resistance during the coal mining and support moving process. Generally, the footage data is updated daily. If it does not change for a long time continuously and the space pressure continues to rise, it is regarded as abnormal monitoring data.

[0083] S5 Calculate the average of the space pressures of each support in each working cycle to obtain the average space pressure within the working cycle, and then obtain the weighting criterion of each support during the query time period;

[0084] The calculation formula of the weighting criterion is:

[0085] = *q + )*M;

[0086] in, represents the mean square error of spatial pressure during the query period, For the t The sampling pressure at each sampling point is It represents the average value of space pressure; M represents the criterion ratio, which can be adjusted according to actual conditions and is 100% by default; q represents the mean square error coefficient;

[0087] q is the ratio of the length of data less than the average value of the spatial pressure to the length of data greater than the average value of the spatial pressure;

[0088] The calculation is based on the formula: =

[0089] p The calculation is based on the formula: p =( + + + … ) / n

[0090] in, It indicates the spatial pressure of the 1st to nth sampling points after removing the data of the lifting and lowering process in each working cycle;

[0091] q is calculated as: L( ) / L( ),

[0092] That is, the ratio of the length of data less than the average value of the spatial pressure to the length of data greater than the average value of the spatial pressure, where For the i The pressure collected at each sampling point.

[0093] S6 determines the spatial pressure of each coal mining cycle, and further confirms the pressure point of the current working face according to the pressure judgment criterion;

[0094] The method for confirming the pressure point is as follows:

[0095] The advancement footage in the query time period is taken as the horizontal coordinate, and the support space pressure is taken as the vertical coordinate. When the space pressure in the working cycle is greater than the pressure judgment criterion, it is recorded as the cycle pressure point, such as Figure 3 As shown;

[0096] In addition, when the periodic pressure points are not obvious, the proportion of the pressure criterion can be adjusted in the system to recalculate the distribution of the periodic pressure points.

[0097] S7 calculates the mean value of the spatial pressure characteristics of each support according to the support partition information and distance weighted data, and combines the spatial pressure of all supports with the advancement footage. When the proportion of supports with pressure at the same time exceeds a certain proportion, the adjacent areas that are too close are connected and determined as one pressure area;

[0098] The determination process is as follows:

[0099] 1. First, the stents in the same area are grouped together;

[0100] 2. Determine the start and end positions of each bracket's single pressure.

[0101] 3. Calculate the ratio of the number of pressure brackets in the footage interval to the total number of brackets in the area. If the ratio is greater than the set value (the default is 33%, which can be adjusted dynamically), it is an area pressure.

[0102] S8 calculates each pressure step distance and the average pressure step distance according to the pressure data and footage;

[0103] The pressure step distance is obtained from the starting distance and ending distance of each pressure in step S7, where:

[0104] The value of the pressure step distance is the end distance of the next pressure - the end distance of this pressure.

[0105] The average pressing step length is the average of the pressing step lengths of all pressing times.

[0106] Table 1 Calculation process of pressure step distance

[0107]

[0108] S9 predicts the next significant pressure according to the variance of pressure step, number of pressure, footage within the query time period, and dynamic load coefficient, and uses the mean value to predict the location of the next pressure, the duration distance of the pressure, and the pressure value.

[0109] in:

[0110] a: The pressure step variance of each area must be less than the specified value (the default is 10);

[0111] b: The number of pressures in each area must be greater than the specified value (default 2);

[0112] c: If the variance of the number of pressures in each area is greater than the specified value (the default value is 2), it is determined that the number of pressures varies greatly. In this case, only the area with the largest number of pressures is predicted;

[0113] d: If the variance of the footage within the query is greater than the specified value (the default is 2), it is determined that the footage change is large and a footage prompt is required;

[0114] Among them: The formula for the variance of the pressure step distance is: ,

[0115] is the value of each pressure step, is the average step length of pressure, N is the total number of pressures;

[0116] The calculation formula is: = ,

[0117] Whether the pressure is obvious is determined by the discrete conditions of the number of pressures and the length of the pressure steps. If the number of pressures is small and the distance difference is large, it is not obvious.

[0118] Calculate the average pressure intensity, that is, the sum of the spatial pressure of each pressure in the area / total number of times. Based on steps S8 and S9, predict the location of the next pressure as the current footage plus the average pressure step length, the pressure intensity as the average pressure intensity, and the average pressure step length.

[0119] Table 2 Regional pressure analysis process

[0120]

[0121] Table 3 Dynamic load coefficient process

[0122]

[0123] The results of the pressure forecast and analysis on the 1108 working face are as follows: it is predicted that pressure will occur when advancing to 219.8-223.9 meters, with an average pressure intensity of 2226.5 kN, an average dynamic load coefficient of 1.4, and a continuous pressure distance of 5.5 to 11.5 meters.

[0124] The embodiments described above are only preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for analyzing periodic pressure using spatial information, characterized in that: The method comprises the following steps: S1 obtains the monitoring pressure data and data collection time of each support on the current working surface within the query time; S2 obtains the footage data and footage entry time of the current working face within the query time; S3 obtaining a corresponding curve diagram of footage and support space pressure using time as a medium according to the above steps; S4 confirms each coal mining cycle and advancement footage according to the query time period. Each coal mining cycle removes the pressure data of the frame drop and the frame rise, as well as the data of the long-term suspension of mining at the working face with no increase in footage but continuous increase in space pressure; S5: averaging the spatial pressure of each support in each working cycle to obtain the average spatial pressure in the working cycle, and then obtaining the pressure criterion of each support in the query time period; In step S5, the calculation formula of the incoming pressure criterion is: = *q+ )*M; in, represents the mean square error of spatial pressure during the query period, is the collection pressure of the tth sampling point, represents the average value of space pressure; M represents the criterion ratio, and q represents the mean square error coefficient; q is calculated as follows: the ratio of the length of data less than the average value of the space pressure to the length of data greater than the average value of the space pressure; The calculation is based on the formula: = ; p The calculation is based on the formula: p =( + + +…… ) / n; in, It indicates the spatial pressure of the 1st to nth sampling points after removing the data of the lifting and lowering process in each working cycle; q is calculated as: L( ) / L( ) , That is, the ratio of the length of data less than the average value of the spatial pressure to the length of data greater than the average value of the spatial pressure, where is the collection pressure of the i-th sampling point; S6 determines the spatial pressure of each coal mining work cycle, and further confirms the pressure point of the current working face according to the pressure judgment criterion; the method for confirming the pressure point is as follows: the advancement footage in the query time period is used as the horizontal coordinate, and the support spatial pressure is used as the vertical coordinate. When the spatial pressure in the work cycle is greater than the pressure judgment criterion, it is recorded as the periodic pressure point; S7 determines the pressure area, including: 1) First, the stents in the same area were grouped together; 2) Determine the start and end positions of each bracket’s single pressure; 3) Calculate the ratio of the number of support brackets in the advancement interval within the query time period to the total number of support brackets in the area. If the ratio is greater than the set value, it is a regional pressure; S8 calculates each pressure step length and the average pressure step length; The pressure step distance is determined according to the starting distance and ending distance of each pressure step obtained in step S7, wherein: The value of the pressure step distance is the distance from the end of the next pressure to the end of this pressure. The average pressing step distance is the average of all pressing step distances; S9 determines whether it is obvious pressure based on the discrete conditions of the number of pressures and the length of the pressure step, where: a: The pressure step variance of each area must be less than the specified value; b: The number of pressures in each area must be greater than the specified value; c: If the variance of the number of pressures in each area is greater than the specified value, it is determined that the number of pressures varies greatly, and only the area with the largest number of pressures is predicted; d: If the variance of the footage within the query is greater than the specified value, it is determined that the footage change is large and a footage prompt is required; The calculation formula of the pressure step variance is: ; in is the value of each pressure step, is the average step length of pressure, N is the total number of pressures; The calculation formula is: = ; The method calculates the average pressure intensity, that is, the sum of the spatial pressure of each pressure in the area / the total number of times, and predicts the position of the next pressure as the current footage plus the average pressure step, the pressure intensity as the average pressure intensity, and the pressure duration distance as the average pressure step.

2. The method of using spatial information to analyze periodic pressure according to claim 1, characterized in that: In step S3, the calculation process of the corresponding relationship between the footage and the support space pressure is: From the formula F=Y(t), X=Z(t), we get t=T(X), and finally we get the relationship between space pressure and footage F=Y(T(X)); Among them, F=Y(t) is the relationship between the support space pressure and the data collection time, X=Z(t) is the relationship between the footage data of the current working face and the footage entry time, and the time is solved as a function of the footage to obtain the relationship between the footage and the space pressure.

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