Rock burst early warning method based on initial support force identification of hydraulic support

Abstract

The present application belongs to the field of coal mine rock burst, and particularly relates to a rock burst early warning method based on initial support force identification of hydraulic support, comprising determining the starting point of the first working cycle of each hydraulic support; determining the initial support force of the first working cycle of each hydraulic support and the time for generating the initial support force; determining the starting point of the second working cycle of each hydraulic support; determining the initial support force of the second working cycle of each hydraulic support and the time for generating the initial support force; continuously determining the starting point, initial support force and time for generating the initial support force in the subsequent working cycle of each hydraulic support; performing rock burst early warning on the area where the specific hydraulic support is located based on the time for generating the initial support force; and performing rock burst early warning on the whole working face by calculating the initial support force qualification rate. The present application is convenient for the staff to timely master the working state of the hydraulic support of the working face, ensures that the hydraulic support is timely pulled and connected to the roof, avoids the topless mining, and avoids the rock burst danger.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of coal mine rock burst, and particularly relates to a rock burst early warning method based on initial support force identification of hydraulic support. BACKGROUND

[0002] The coal mine fully mechanized working face is a core area of mining operation, and the safety and stability of equipment thereof are crucial, wherein the hydraulic support as one of key equipment directly affects the safety production of the mine.

[0003] In the prior art, there are many difficulties in identifying the initial support force of the hydraulic support, and the manual recording mode of the site is not only highly dangerous, but also low in accuracy and efficiency. Each hydraulic support in the same working face may be in different working states at the same time, and the size of the initial support force required in the respective working cycle is not necessarily the same. Although some mine pressure software can analyze the pressure-time change curve of the hydraulic support column, it cannot identify the initial support force required by the roof in real time as the working face advances. In addition, if the time required for the hydraulic support to generate the initial support force is too long after the start of the working cycle, it indicates that the hydraulic support is slow to pull the frame, the hydraulic support roof beam does not timely contact the roof, or the roof contact is not real, which is also prone to rock burst risk. However, since the start time of the working cycle and the initial support force generation time cannot be accurately identified, the time required for the hydraulic support to generate the initial support force after the start of the working cycle cannot be accurately determined.

[0004] Therefore, the traditional monitoring has defects in accuracy and completeness, and these problems directly affect the accurate analysis of the mine pressure mechanism and the intelligent early warning of the roof impact disaster. Therefore, how to timely and accurately identify the initial support force of each hydraulic support in each working cycle and the time required for the hydraulic support to generate the initial support force after the start of the working cycle has become a key technical problem for realizing the intelligent monitoring and early warning of the roof impact disaster. SUMMARY

[0005] In view of the above technical problems, the application provides a rock burst early warning method based on initial support force identification of hydraulic support, which comprises the following steps:

[0006] S1. determining the start point of the first working cycle of each hydraulic support

[0007] The working resistance of the hydraulic support and the corresponding time are acquired in real time, and are presented in the form of a broken line with points and lines, wherein the time is the horizontal coordinate and the working resistance is the vertical coordinate; for each hydraulic support, the time when the working resistance starts to increase after the first lifting of the hydraulic support is taken as the start point of the first working cycle of the hydraulic support, and the time is recorded as T start-1 ;

[0008] S2. determining the initial support force of the first working cycle of each hydraulic support and the time required for generating the initial support force

[0009] For each hydraulic support, take three working resistance points in turn from the beginning of the first working cycle, and let the three working resistance points be A, B and C respectively, and the corresponding working resistances be P A , P B , P C respectively; when the first time the working resistance P B of B is greater than the critical value of initial support P0, and the slope K AB of line segment AB is < 0 while the slope K BC of line segment BC is > 0, or the slope K AB of line segment AB is = 0 while the slope K BC of line segment BC is > 0; take the working resistance of B as the initial support P1 of the first working cycle of the hydraulic support, and record the time as T i-1 ;

[0010] S3. Determine the starting point of the second working cycle of each hydraulic support

[0011] For each hydraulic support, continue to take three working resistance points in turn, and let the three working resistance points be A, B and C respectively, and the corresponding working resistances be P A , P B , P C respectively; when the condition is met: the working resistance P B of B is less than the initial support P1 of the first working cycle, and the slope K AB of line segment AB is < 0 while the slope K BC of line segment BC is > 0, or the slope K AB of line segment AB is = 0 while the slope K BC of line segment BC is > 0; take the time of B as the starting point of the second working cycle of the hydraulic support, and record the time as T start-2 ;

[0012] S4. Determine the initial support of the second working cycle of each hydraulic support and the time for generating the initial support according to step S2

[0013] For each hydraulic support, take three working resistance points in turn from the beginning of the second working cycle, and let the three working resistance points be A, B and C respectively, and the corresponding working resistances be P A , P B , P C respectively; when the first time the working resistance P B of B is greater than the critical value of initial support P0, and the slope K AB of line segment AB is < 0 while the slope K BC of line segment BC is > 0, or the slope K AB= 0 and the slope of line segment BC is K BC >0; the working resistance corresponding to point B is used as the initial support force P2 of the second working cycle of the hydraulic support, and the time is recorded as T i-2 ;

[0014] S5. Loop steps S3-S4 to determine the starting point of the nth working cycle of each hydraulic support and the initial support force P n And the time D for generating the initial support force in the nth working cycle m-n ; Among them, when determining the starting point of the nth working cycle, the working resistance P at point B is B Less than the initial support force P of the previous working cycle n-1 ;

[0015] S6. Provide rock burst warning for specific hydraulic support areas based on the time it takes to generate initial support force

[0016] Set a critical time D0 for generating initial support force. If a hydraulic support fails to generate initial support force after the critical time D0 for generating initial support force has passed since the start of a certain working cycle, a rock burst warning will be issued for the hydraulic support.

[0017] S7. Calculate the initial support force qualification rate to provide early warning of rock burst pressure on the entire working face

[0018] Obtain the working resistance of each hydraulic support at a certain moment, compare the working resistance of each hydraulic support at that moment with the initial support force in its working cycle at that moment, and calculate the ratio of the sum of the number of hydraulic supports with a working resistance greater than or equal to the initial support force to the total number of hydraulic supports as the initial support force qualification rate p;

[0019] If 0≤p≤70%, a strong rock burst warning is issued and timely manual intervention should be made to increase the working resistance of the hydraulic support;

[0020] If 70% < p ≤ 85%, a moderate rock burst warning is issued and manual intervention is required to increase the working resistance of the hydraulic support;

[0021] If 85%<p≤100%, no rock burst warning will be issued.

[0022] Preferably, in step S6, manual intervention should be performed in time to pull the support and inspect and repair the hydraulic support.

[0023] Preferably, in step S2, the time D for the hydraulic support to generate the initial support force in the first working cycle is recorded. m-1 =T i-1 -T start-1 In step S4, the time D of the hydraulic support generating the initial support force in the second working cycle is recorded. m-2 =T i-2 -T start-2 .

[0024] Preferably, in step S6, if the time for generating the initial support force of a certain hydraulic support in a certain working cycle is greater than the critical time for generating the initial support force, the impact ground pressure early warning is sent to the hydraulic support, and the hydraulic support is maintained.

[0025] The present application has the following advantages: the present application can accurately identify the initial support force of each hydraulic support in each working cycle, the time for generating the initial support force after the start of the working cycle, and the impact ground pressure early warning is sent to the area where the specific hydraulic support is located based on the time for generating the initial support force, and the impact ground pressure early warning is sent to the entire working face based on the initial support force qualified rate. The present application enables the staff to timely grasp the working state of the hydraulic support of the working face, ensures that the hydraulic support is timely pulled and connected to the roof, avoids empty roof mining, and avoids the danger of impact ground pressure. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 FIG. 1 is a schematic diagram of the initial support force and the start and end points of the working cycle of the hydraulic support of the embodiment of the present application;

[0027] Fig. 2 FIG. 4 is a schematic diagram of the working resistance qualified condition of the hydraulic support at a certain time (only the hydraulic supports numbered by the integer multiples of 5 are shown). DETAILED DESCRIPTION

[0028] For the purpose, technical solutions and advantages of the present application, the present application will be further described below with reference to the drawings.

[0029] As shown in FIG. 1, the present application proposes an impact ground pressure early warning method based on the initial support force identification of the hydraulic support, which comprises the following steps: Figs. 1-2 S1. determining the start point of the first working cycle of each hydraulic support

[0030] The hydraulic support working resistance monitoring device acquires the working resistance of the hydraulic support in real time. The real time here is relative, and the working resistance of the hydraulic support can be read every 1, 2 or 3 minutes, and then the working resistance and the corresponding time of each hydraulic support are recorded. The working resistance data of each hydraulic support is presented in the form of a broken line with points connected, and the time is the horizontal coordinate and the working resistance is the vertical coordinate.

[0031] For each hydraulic support, the time when the working resistance starts to increase after the first lifting is taken as the start point of the first working cycle of the hydraulic support, and the time is recorded as T start-1 .

[0032] S2. determining the initial support force of the first working cycle of each hydraulic support and the time for generating the initial support force

[0033]

[0034] ​Taking 0.8 times of the rated working pressure of the hydraulic support pump station as the critical value of the initial support force P0; the rated working pressure of the hydraulic support pump station is generally not less than 30 MPa, and according to the requirements of the coal mine safety standardization system, the initial support force of the hydraulic support should be not less than 80% of the rated working pressure of the hydraulic support pump station, i.e. P0=24 MPa;

[0035] For each hydraulic support, three adjacent working resistance points are taken from the starting point of the first working cycle, and the three working resistance points are A, B and C, and the corresponding working resistances are P A , P B , P C ; when the working resistance P B of the B point is greater than the critical value of the initial support force P0, and the slope K AB of the line segment AB is less than 0 and the slope K BC of the line segment BC is greater than 0, or the slope K AB of the line segment AB is equal to 0 and the slope K BC of the line segment BC is greater than 0, the working resistance corresponding to the B point is taken as the initial support force P1 of the first working cycle of the hydraulic support, i.e. the hydraulic support reaches the initial support force of the first working cycle at this time; the time at this time is recorded as T i-1 , and the time D m-1 taken by the hydraulic support to generate the initial support force after the start of the first working cycle is T i-1 -T start-1 ;

[0036] S3. Determining the starting point of the second working cycle of each hydraulic support

[0037] For each hydraulic support, the starting point of the next working cycle is the end point of the previous working cycle, i.e. the starting point of the second working cycle is the end point of the first working cycle;

[0038] For each hydraulic support, three adjacent working resistance points are taken, and the three working resistance points are A, B and C, and the corresponding working resistances are P A , P B , P C ; when the working resistance P B of the B point is less than the initial support force P1 of the first working cycle, and the slope K AB of the line segment AB is less than 0 and the slope K BC of the line segment BC is greater than 0, or the slope K AB of the line segment AB is equal to 0 and the slope K BC of the line segment BC is greater than 0, the time corresponding to the B point is taken as the end point of the first working cycle of the hydraulic support, and the end point of the first working cycle is also the starting point of the second working cycle, and the time is recorded as T start-2 ;

[0039] The time of the first working cycle is T start-2 -T start-1 ;

[0040] S4. Determine the initial support force of each hydraulic support in the second working cycle and the time for generating the initial support force according to step S2

[0041] For each hydraulic support, take three working resistance points successively adjacent from the starting point of the second working cycle, and assume that the three working resistance points are A, B and C, and the corresponding working resistances are P A , P B , and P C ; when the first time that the working resistance P B of the point B is greater than the critical value P0 of the initial support force, and the slope K AB of the line segment AB is less than 0 and the slope K BC of the line segment BC is greater than 0, or the slope K AB of the line segment AB is equal to 0 and the slope K BC of the line segment BC is greater than 0; the working resistance corresponding to the point B is taken as the initial support force P2 of the second working cycle of the hydraulic support, that is, the hydraulic support reaches the initial support force of the second working cycle at this time; the time at this time is recorded as T i-2 , and the time for the hydraulic support to generate the initial support force after the start of the second working cycle is D m-2 = T i-2 -T start-2 ;

[0042] S5. Determine the starting point, the initial support force P n , and the time D m-n for generating the initial support force in the nth working cycle of each hydraulic support by repeating steps S3-S4; when determining the starting point of the nth working cycle, the working resistance P B of the point B is less than the initial support force P n-1 of the previous working cycle;

[0043] S6. Give a rock burst warning to the area where the specific hydraulic support is located based on the time for generating the initial support force

[0044] Set a critical time D0 for generating the initial support force. If a hydraulic support has not generated the initial support force after the critical time D0 for generating the initial support force from the starting point of a working cycle, a rock burst warning is given to the hydraulic support. This situation indicates that the hydraulic support responds slowly to the drawing instruction speed, the hydraulic support roof beam rises to support the roof for a long time, the roof support is not timely, the topless mining time is long, and manual intervention in drawing should be made in time, and the hydraulic support should be repaired if necessary.

[0045] Or, if a hydraulic support in its certain working cycle to generate the initial support force use time D m-n greater than the critical time D0 generated by the initial support force, the impact of the ground pressure warning is issued for the hydraulic support; this case shows that the hydraulic support responds to the drawing frame instruction speed is slow, the hydraulic support roof beam rises to support the roof time is long, the empty roof mining time is long, and the hydraulic support should be repaired in time;

[0046] S7. Calculate the initial support force qualified rate to warn the impact of the ground pressure on the whole working face

[0047] Even if the hydraulic support reaches the initial support force, the working resistance will be reduced due to the stability of the roof and the stability of the hydraulic support, so it is important to calculate the initial support force qualified rate at intervals to know the working state of the hydraulic support and prevent the impact of the ground pressure. Specifically, in this step:

[0048] Get the working resistance of each hydraulic support at a certain time, compare the working resistance of each hydraulic support at this time with the initial support force in its working cycle at this time, and take the proportion of the sum of the number of hydraulic supports whose working resistance is greater than or equal to the initial support force at this time to the total number of hydraulic supports as the initial support force qualified rate p.

[0049] If p satisfies 0≤p≤70%, a strong impact of the ground pressure warning is issued, indicating that the number of hydraulic supports whose working resistance meets the initial support force requirement is insufficient, and most areas of the working face are in the state of empty roof mining, which is prone to impact of the ground pressure, and manual intervention should be made to improve the working resistance of the hydraulic support in time.

[0050] If p satisfies 70%<p≤85%, a medium impact of the ground pressure warning is issued, indicating that most of the hydraulic supports meet the initial support force requirement, but some parts of the working face are in the state of empty roof mining, which may cause impact of the ground pressure, and manual intervention should be made to improve the working resistance of the hydraulic support.

[0051] If p satisfies 85%<p≤100%, no impact of the ground pressure warning is issued, indicating that most of the hydraulic supports meet the initial support force requirement, and the working face is in a normal mining state.

[0052] Although the present application has been described in detail by the preferred embodiments as described above, this description is intended to be exemplary rather than limiting the scope of the present application. Those skilled in the art can make various changes and modifications to the present application without departing from the basic concept and scope of the present application. Therefore, the protection boundary of the present application should be based on the content defined in the appended claims.

Claims

1. A rock burst warning method based on the identification of the initial support force of a hydraulic support, characterized in that: The steps include: S1. Determine the starting point of the first working cycle of each hydraulic support The working resistance and corresponding time of the hydraulic support are obtained in real time and presented in the form of a broken line connecting points, with time as the horizontal axis and working resistance as the vertical axis. For each hydraulic support, the time when the working resistance begins to increase after the first lifting is taken as the starting point of the first working cycle of the hydraulic support, and the time is recorded as T start-1 ; S2. Determine the initial support force and the time it takes to generate the initial support force in the first working cycle of each hydraulic support For each hydraulic support, take three adjacent working resistance points from the starting point of its first working cycle. Let these three working resistance points be A, B and C respectively. The corresponding working resistances are P A 、P B 、P C ; When the first meeting: the working resistance P of point B B Greater than the critical value of the initial support force P0, and the slope K of the line segment AB AB <0 while the slope of line segment BC is K BC > 0, or the slope of line segment AB is K AB = 0 and the slope of line segment BC is K BC >0; the working resistance corresponding to point B is taken as the initial support force P1 of the first working cycle of the hydraulic support, and the time is recorded as T i-1 ; S3. Determine the starting point of the second working cycle of each hydraulic support For each hydraulic support, continue to take three adjacent working resistance points, and let these three working resistance points be A, B and C, and the corresponding working resistances are P A 、P B 、P C ; When the conditions are met: the working resistance P at point B B Less than the initial support force P1 of the first working cycle, and the slope K of line segment AB AB <0 while the slope of line segment BC is K BC > 0, or the slope of line segment AB is K AB = 0 and the slope of line segment BC is K BC >0; the timing corresponding to point B is taken as the starting point of the second working cycle of the hydraulic support, and the time is recorded as T start-2 ; S4. Refer to step S2 to determine the initial support force and the time it takes to generate the initial support force in the second working cycle of each hydraulic support For each hydraulic support, take three adjacent working resistance points from the starting point of its second working cycle. Let these three working resistance points be A, B and C respectively. The corresponding working resistances are P A 、P B 、P C ; When the first meeting: the working resistance P of point B B Greater than the critical value of the initial support force P0, and the slope K of the line segment AB AB <0 while the slope of line segment BC is K BC > 0, or the slope of line segment AB is K AB = 0 and the slope of line segment BC is K BC >0; the working resistance corresponding to point B is used as the initial support force P2 of the second working cycle of the hydraulic support, and the time is recorded as T i-2 ; S5. Loop steps S3-S4 to determine the starting point of the nth working cycle of each hydraulic support and the initial support force P n And the time D for generating the initial support force in the nth working cycle m-n ; Among them, when determining the starting point of the nth working cycle, the working resistance P at point B is B Less than the initial support force P of the previous working cycle n-1 ; S6. Provide rock burst warning for specific hydraulic support areas based on the time it takes to generate initial support force Set a critical time D0 for generating initial support force. If a hydraulic support fails to generate initial support force after the critical time D0 for generating initial support force has passed since the start of a certain working cycle, a rock burst warning will be issued for the hydraulic support. S7. Calculate the initial support force qualification rate to provide early warning of rock burst pressure on the entire working face Obtain the working resistance of each hydraulic support at a certain moment, compare the working resistance of each hydraulic support at that moment with the initial support force in its working cycle at that moment, and calculate the ratio of the sum of the number of hydraulic supports with a working resistance greater than or equal to the initial support force to the total number of hydraulic supports as the initial support force qualification rate p; If 0≤p≤70%, a strong rock burst warning is issued and timely manual intervention should be made to increase the working resistance of the hydraulic support; If 70% < p ≤ 85%, a moderate rock burst warning is issued and manual intervention is required to increase the working resistance of the hydraulic support; If 85%<p≤100%, no rock burst warning will be issued.

2. The rock burst warning method based on the identification of the initial support force of the hydraulic support according to claim 1 is characterized in that: In step S6, manual intervention should be performed in time to pull the support and inspect and repair the hydraulic support.

3. The rock burst warning method based on the identification of the initial support force of the hydraulic support according to claim 1 is characterized in that: In step S2, the time D for the hydraulic support to generate the initial support force in the first working cycle is recorded. m-1 =T i-1 -T start-1 In step S4, the time D of the hydraulic support generating the initial support force in the second working cycle is recorded. m-2 =T i-2 -T start-2 .

4. The rock burst warning method based on the identification of the initial support force of the hydraulic support according to claim 3 is characterized in that: In step S6, or if the time taken for a hydraulic support to generate the initial supporting force in a certain working cycle is greater than the critical time taken for generating the initial supporting force, a rock burst warning is issued to the hydraulic support, and the hydraulic support is repaired.

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