Rock burst early warning method based on hydraulic support setting force judgment

Abstract

The invention belongs to the field of coal mine rock burst, and particularly relates to a rock burst early warning method based on hydraulic support setting force identification, which comprises the following steps: determining the starting point of the first working cycle of each hydraulic support; the initial supporting force of each hydraulic support in the first working cycle and the time for generating the initial supporting force are determined; determining a starting point of a second working cycle of each hydraulic support; the initial supporting force of each hydraulic support in the second working cycle and the time for generating the initial supporting force are determined; the starting point and the initial supporting force of the subsequent working cycle of each hydraulic support and the time for generating the initial supporting force in the subsequent working cycle continue to be determined; rock burst early warning is carried out on the area where the specific hydraulic support is located based on the time for generating the initial supporting force; and calculating the percent of pass of the initial supporting force to carry out rock burst early warning on the whole working face. Working personnel can conveniently master the working state of the working face hydraulic support in time, it is guaranteed that the hydraulic support is pulled and connected with a roof in time, empty roof mining is avoided, and rock burst danger is avoided.

Description

Technical Field

[0001] The invention belongs to the field of coal mine rock burst, and in particular relates to a rock burst early warning method based on the identification of the initial support force of a hydraulic support. Background Art

[0002] The fully mechanized mining face of a coal mine is the core area of ​​mining operations, and the safety and stability of its equipment are of vital importance. Among them, the hydraulic support is one of the key equipment, and its working condition directly affects the safe production of the mine.

[0003] In the prior art, there are many difficulties in identifying the initial support force of the hydraulic support. The manual recording method on site is not only dangerous, but also inaccurate and inefficient. Each hydraulic support in the same working surface may be in a different working state at the same time, and the size of the initial support force required in their respective working cycles may not be the same. Although some mining pressure software can analyze the pressure-time variation curve of the hydraulic support column, it is impossible to identify the initial support force required for the roof in real time as the working surface advances. In addition, if the time it takes for the hydraulic support to generate the initial support force after the start of the working cycle is too long, it means that the hydraulic support is slow to pull the frame, the top beam of the hydraulic support does not contact the roof in time, or the top connection is not solid, which is also prone to the risk of impact ground pressure. However, since it is impossible to accurately identify the start time of the working cycle and the time when the initial support force is generated, it is also impossible to accurately determine the time it takes for the hydraulic support to generate the initial support force after the start of the working cycle.

[0004] Therefore, there are deficiencies in the accuracy and completeness of traditional monitoring, which directly affect the precise analysis of the mine pressure mechanism and the intelligent early warning of roof impact disasters. Therefore, how to timely and accurately identify the initial support force of each hydraulic support in each working cycle and the time it takes for the hydraulic support to generate the initial support force after the working cycle begins has become a key technical problem in realizing intelligent monitoring and early warning of roof impact disasters. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes a rock burst early warning method based on the identification of the initial support force of a hydraulic support, comprising the following steps:

[0006] S1. Determine the starting point of the first working cycle of each hydraulic support

[0007] 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 ;

[0008] S2. Determine the initial support force of each hydraulic support in the first working cycle and the time it takes to generate the initial support force

[0009] For each hydraulic support, three adjacent working resistance points are selected from the starting point of the first working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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 ;

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

[0011] For each hydraulic support, continue to select three adjacent working resistance points. 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 conditions are met: the working resistance P at point B B is smaller 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 ;

[0012] S4. Refer to step S2 to determine the initial support force of each hydraulic support in the second working cycle and the time it takes to generate the initial support force

[0013] For each hydraulic support, three adjacent working resistance points are selected from the starting point of the second working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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 P2 of the second working cycle of the hydraulic support, and the time is recorded as T i-2 ;

[0014] S5. Cycle steps S3-S4 to determine the starting point and initial support force P of each hydraulic support in the nth working cycle n And the time D required to generate 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] A critical time D0 for generating initial support force is set. If a hydraulic support fails to generate initial support force after the critical time D0 for generating initial support force from the starting point of a certain working cycle, an impact ground pressure warning is issued for the hydraulic support.

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

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

[0019] If 0≤p≤70%, a strong impact ground pressure 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 frame and inspect and repair the hydraulic support.

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

[0024] Preferably, in step S6, or if the time taken by a certain hydraulic support to generate an initial support force in a certain working cycle thereof is greater than a critical time taken to generate the initial support force, an impact ground pressure warning is issued to the hydraulic support, and the hydraulic support is inspected and repaired.

[0025] Beneficial effects of the present invention: The present invention can accurately identify the initial support force of each hydraulic support in each working cycle, the time taken for the hydraulic support to generate the initial support force after the working cycle begins, and based on the time taken for generating the initial support force, provide an early warning of rock burst pressure in the area where the specific hydraulic support is located, and based on the initial support force qualification rate, provide an early warning of rock burst pressure for the entire working face. The present invention facilitates the staff to timely grasp the working status of the hydraulic support on the working face, ensures that the hydraulic support is pulled up and connected to the top in time, avoids empty top mining, and avoids the danger of rock burst pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the initial support force and the start and end point identification of the working cycle of the hydraulic support according to the embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the qualified working resistance of a hydraulic support at a certain moment in an embodiment of the present invention (only hydraulic supports numbered as an integer multiple of 5 are shown). DETAILED DESCRIPTION

[0028] To specifically demonstrate the purpose, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings.

[0029] like Figure 1-2 As shown, the present invention proposes a rock burst early warning method based on the identification of the initial support force of a hydraulic support, comprising the following steps:

[0030] S1. Determine the starting point of the first working cycle of each hydraulic support

[0031] The hydraulic support working resistance monitoring device obtains the hydraulic support working resistance in real time. Real time here is relative. The hydraulic support working resistance can be read every 1, 2, or 3 minutes, and then the working resistance and 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 connecting points, with time as the horizontal axis and working resistance as the vertical axis.

[0032] For each hydraulic support, the time when the working resistance starts 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 ;

[0033] S2. Determine the initial support force of each hydraulic support in the first working cycle and the time it takes to generate the initial support force

[0034] Take 0.8 times 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 30MPa. According to the requirements of the coal mine safety standardization system, the initial support force of the hydraulic support should not be less than 80% of the rated working pressure of the hydraulic support pump station, that is, P0 = 24MPa;

[0035] For each hydraulic support, three adjacent working resistance points are selected from the starting point of the first working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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, that is, at this time, the hydraulic support reaches the initial support force of its first working cycle; the time at this time is recorded as T i-1 The time it takes for the hydraulic support to generate initial support force after the first working cycle begins (D) m-1 =T i-1 -T start-1 ;

[0036] S3. Determine 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, that is, the starting point of the second working cycle is the end point of the first working cycle;

[0038] For each hydraulic support, continue to select three adjacent working resistance points. 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 conditions are met: the working resistance P at point B B is smaller 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 time corresponding to point B is taken as the end point of the first working cycle of the hydraulic support. The end point of the first working cycle is also the starting point of the second working cycle. 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. Refer to step S2 to determine the initial support force of each hydraulic support in the second working cycle and the time it takes to generate the initial support force

[0041] For each hydraulic support, three adjacent working resistance points are selected from the starting point of the second working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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 P2 of the second working cycle of the hydraulic support, that is, at this time, the hydraulic support reaches the initial support force of its second working cycle; the time at this time is recorded as T i-2 After the second working cycle begins, the time it takes for the hydraulic support to generate the initial support force is D m-2 =T i-2 -T start-2 ;

[0042] S5. Cycle steps S3-S4 to determine the starting point and initial support force P of each hydraulic support in the nth working cycle n And the time D required to generate 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 ;

[0043] S6. Provide rock burst warning for specific hydraulic support areas based on the time it takes to generate initial support force

[0044] The critical time D0 for generating initial support force is set. If a hydraulic support fails to generate initial support force after the critical time D0 for generating initial support force since the starting point of a certain working cycle, an impact ground pressure warning is issued for the hydraulic support. This situation indicates that the hydraulic support responds slowly to the support pulling instruction, the time for the top beam of the hydraulic support to rise to support the roof is long, the roof support is not timely, and the empty top mining time is long. The support pulling should be manually intervened in time, and the hydraulic support should be repaired if necessary.

[0045] Or, if the time D taken by a hydraulic support to generate initial support force in a certain working cycle is m-n If the time is greater than the critical time D0 for generating the initial support force, an impact ground pressure warning is issued for the hydraulic support; this situation indicates that the hydraulic support responds slowly to the support command, the time for the top beam of the hydraulic support to rise to support the roof is long, the roof support is not timely, and the empty top mining time is long. The hydraulic support should be repaired in time;

[0046] S7. Calculate the qualified rate of initial support force to provide early warning of rock burst pressure on the entire working surface

[0047] Even if the hydraulic support reaches the initial support force, its working resistance will be reduced in the later stage due to the stability of the roof and the stability of the hydraulic support. Therefore, calculating the initial support force qualification rate at a certain interval is of great significance to understanding the working status of the hydraulic support and preventing the danger of impact ground pressure. Specifically, in this step:

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

[0049] If p satisfies 0≤p≤70%, a strong rock burst warning is issued, indicating that the number of hydraulic supports that meet the initial support force requirements is insufficient, and most areas of the working face are in an empty top mining state, which is very prone to rock burst. Timely manual intervention should be made to increase the working resistance of the hydraulic supports;

[0050] If p satisfies 70%<p≤85%, a moderate rock burst warning is issued, indicating that the working resistance of most hydraulic supports meets the initial support force requirements, but some parts of the working face are in an empty top mining state, rock burst may occur, and manual intervention should be made to increase the working resistance of the hydraulic supports;

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

[0052] Although the present invention has been described in detail through the preferred embodiments as described above, this description is intended to illustrate rather than limit the scope of the present invention. Personnel with ordinary skills in the art can make various changes and modifications to the present invention without departing from the basic concept and scope of the present invention. Therefore, the protection boundary of the present invention shall be based on the content clearly defined in the attached claims.

Claims

1. A rock burst early 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 of each hydraulic support in the first working cycle and the time it takes to generate the initial support force For each hydraulic support, three adjacent working resistance points are selected from the starting point of the first working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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 select three adjacent working resistance points. 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 conditions are met: the working resistance P at point B B is smaller 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 of each hydraulic support in the second working cycle and the time it takes to generate the initial support force For each hydraulic support, three adjacent working resistance points are selected from the starting point of the second working cycle. Let these three working resistance points be A, B and C respectively, and the corresponding working resistances are P A , P B , P C ; When the first satisfaction: the working resistance P of point B B is 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 P2 of the second working cycle of the hydraulic support, and the time is recorded as T i-2 ; S5. Cycle steps S3-S4 to determine the starting point and initial support force P of each hydraulic support in the nth working cycle n And the time D required to generate 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 A critical time D0 for generating initial support force is set. If a hydraulic support fails to generate initial support force after the critical time D0 for generating initial support force from the starting point of a certain working cycle, an impact ground pressure warning is issued for the hydraulic support. S7. Calculate the qualified rate of initial support force to provide early warning of rock burst pressure on the entire working surface Obtain the working resistance of each hydraulic support at a certain moment, compare the working resistance of each hydraulic support at this moment with the initial support force in the working cycle at this moment, and take the ratio of the sum of the number of hydraulic supports whose working resistance is greater than or equal to the initial support force to the total number of hydraulic supports as the initial support force qualified rate p; If 0≤p≤70%, a strong impact ground pressure 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 frame 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 taken 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 for the hydraulic support to generate 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, alternatively, if the time taken for a hydraulic support to generate an initial support force in a certain working cycle is greater than a critical time taken for generating the initial support force, an impact ground pressure warning is issued to the hydraulic support, and the hydraulic support is inspected and repaired.

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