Working face roof water drainage method and device

Abstract

The invention relates to a working face roof water drainage method and device, and the method comprises the steps: determining the drainage amount of a working face roof water head from a natural non-drainage state to a maximum allowable drainage residual water head according to the maximum allowable residual water head, and constructing a roof water drainage model related to the number of working face drill sites according to the drainage amount. The roof water drainage model is solved to obtain the optimal number of drill sites of the working face, and the optimal drainage time and the optimal drainage residual water head are determined, so that the roof drainage amount is small and the drainage time is short under the condition that the water inflow of the pushing and mining roof of the working face is safe, economical and controllable, and meanwhile, the drainage efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of mine roof water hazard prevention and water resource protection, and specifically, to a working face roof water drainage method and device. Background Art

[0002] The Western Jurassic Coalfield is the main production area of ​​coal resources in my country and faces the threat of roof water damage. Therefore, before the working face is mined, it is generally necessary to construct roof drilling holes in the underground tunnels to drain the water from the roof aquifer to reduce the amount of roof water inflow during mining and ensure safety. The actual drainage of water on site is excessive, that is, the amount of drainage is large, the drainage project is large, the drainage time is long, and there is a lack of quantitative evaluation criteria for the rationality of drainage.

[0003] At present, the research on the optimal arrangement of roof drainage engineering before working face mining in the existing technology mainly includes: first, based on the actual drainage capacity of the working face, the roof head reserve value is calculated by numerical method. However, this method is only based on the safety of working face recovery, and does not comprehensively consider the drainage efficiency factor; second, based on the seepage-turbulence multi-flow state characteristics during drilling drainage, the water inflow of the borehole and the water inflow of the group of holes are calculated by numerical method, and the number of drilling construction in the drilling site is designed accordingly. The core of this method is to calculate the maximum water inflow per unit length of the borehole, and on this basis, determine the optimal inclination angle of the borehole and the number of boreholes in the drilling site, without considering the mutual influence between the borehole groups; third, according to the attenuation characteristics during drilling drainage, the numerical method is used to calculate the parameters such as the end hole position of the borehole and the number of boreholes. This method believes that the best time to end drainage is when the water inflow reaches dynamic stability, and determines the optimal drainage time accordingly. In fact, borehole water inflow is not only affected by the drainage of boreholes in the same drilling site, but also by the drainage of boreholes in other surrounding drilling sites. In addition, the end time of drainage should be based on the maximum water inflow discharged by the drainage system during the mining period. The roof head corresponding to this maximum water inflow is the best time to end the drainage. This maximum water inflow has no direct relationship with the stable water inflow of borehole drainage. In related technologies, it is not scientific to use the stable water inflow of borehole drainage as the basis for judging the end of drainage. Summary of the invention

[0004] In order to overcome at least one shortcoming in the prior art, the present application provides a method and device for draining water from a working surface roof.

[0005] In a first aspect, a method for draining water from a working surface roof is provided, comprising:

[0006] Calculate the maximum allowable residual water head of the top plate of the working face, and determine the drainage volume of the top plate water head of the working face from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head;

[0007] A roof water drainage model for the number of drilling sites on the working face was constructed based on the drainage volume;

[0008] Solve the roof water drainage model to obtain the optimal number of drilling sites on the working face;

[0009] Calculate the optimal drainage time based on the optimal number of drilling sites on the working face;

[0010] The optimal drainage residual head is determined based on the maximum allowable residual head.

[0011] In one embodiment, according to the maximum allowable residual water head, the drainage volume of the top plate water head of the working face from the natural non-drainage state to the maximum allowable drainage residual water head is determined by the following formula:

[0012] W 疏 =(H0-H wm )·b·a

[0013] Among them, W 疏 is the drainage volume, H0 is the initial water head of the aquifer on the top of the working face before drainage, H wm is the maximum allowable drainage residual head, b is the width of the working surface, and a is the length of the working surface.

[0014] In one embodiment, the roof water drainage model for the number of working face drilling sites is:

[0015]

[0016] The constraints are:

[0017]

[0018] Where n is the number of drilling sites on the working face, i is the number of the borehole in each drilling site, L is the horizontal projection length of the borehole perpendicular to the groundwater flow direction, α i is the inclination angle of borehole i, θ i is the azimuth of borehole i, W 疏 is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, and R is the drainage influence radius.

[0019] In one embodiment, the optimal number of drilling sites on the working face is:

[0020]

[0021] Among them, n * is the optimal number of drilling sites on the working face, W 疏is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, R is the drainage influence radius, and int means rounding.

[0022] In one embodiment, the optimal drainage time is:

[0023]

[0024] Among them, t * is the optimal drainage time, n * is the optimal number of drilling sites on the working face, W 疏 is the amount of water discharged, and Q0 represents the initial efficiency of water discharge.

[0025] In one embodiment, the optimal residual head of drainage water is:

[0026]

[0027] in, is the optimal residual water head of drainage water, η is the safety factor constraining the peak flow rate after mining at the working face, H wm The maximum allowable discharge residual head.

[0028] In a second aspect, a working face roof water drainage device is provided, comprising:

[0029] The drainage water volume calculation module is used to calculate the maximum allowable residual water head of the top plate of the working face, and determine the drainage water volume between the water head of the top plate of the working face from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head;

[0030] A roof water drainage model building module is used to build a roof water drainage model for the number of drilling sites on the working face based on the drainage volume;

[0031] Model solving module, used to solve the roof water drainage model and obtain the optimal number of drilling sites on the working face;

[0032] The optimal drainage time calculation module is used to calculate the optimal drainage time based on the optimal number of drilling sites on the working face;

[0033] The optimal drainage water residual head determination module is used to determine the optimal drainage water residual head according to the maximum allowable residual head.

[0034] In a third aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned working face roof water drainage method is implemented.

[0035] In a fourth aspect, a computer program product is provided, including a computer program / instruction, which, when executed by a processor, implements the above-mentioned working face roof water drainage method.

[0036] Compared with the prior art, the present application has the following beneficial effects: the working face roof water drainage method and device of the present application determines the drainage amount of the working face roof water head from the natural non-drainage state to the maximum allowable drainage residual head according to the maximum allowable residual head, and constructs a roof water drainage model related to the number of working face drilling sites according to the drainage amount, solves the roof water drainage model to obtain the optimal number of working face drilling sites, and determines the optimal drainage time and the optimal drainage residual head, thereby achieving a small amount of roof drainage and a short drainage time under the conditions of safe, economical and controllable roof water inflow of the working face, and at the same time, improves the drainage efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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:

[0038] Figure 1 A flowchart of a method for draining water from a working surface roof according to an embodiment of the present application is shown;

[0039] Figure 2 The optimized layout diagram of the drainage project on the top plate of the test working face is shown;

[0040] Figure 3 The schematic diagram of the structure of the water inflow model of the working face under the roof head condition is shown;

[0041] Figure 4 A graph showing the relationship between water inflow and the location of peak water flow is shown;

[0042] Figure 5 A structural block diagram of a working face top plate water drainage device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The present application provides a method for draining water from a working surface roof. Figure 1 A flowchart of a method for draining water from a working surface roof according to an embodiment of the present application is shown. Figure 1 , methods include:

[0047] Step S1, calculate the maximum allowable residual water head of the working face top plate, and determine the drainage volume of the working face top plate water head from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head.

[0048] Here, the maximum allowable residual water head H of the top plate of the working face is calculated wn , which is a conventional method in this field, can be expressed by the following formula:

[0049]

[0050] Among them, α1, α2, β1, β2, γ1, and γ2 are the correlation coefficients of the parameters in the multiple linear regression. f is the maximum height of the water-conducting fracture zone, V is the mining speed of the working face, k1 is the static water release attenuation coefficient (m 3 / h·1), k2 is the lateral dynamic replenishment growth coefficient (m 3 / h·1), C is the dynamic stable water inflow, Q wm is the maximum water inflow, x m The maximum water inflow Q wm The corresponding pushing distance.

[0051] Specifically, the amount of water discharged W 疏 It can be calculated using the following formula:

[0052] W 疏 =(H0-H wm )·b·a

[0053] Among them, H0 is the initial water head of the aquifer on the top of the working face before drainage, H wm is the maximum allowable drainage residual head, b is the width of the working surface, and a is the length of the working surface.

[0054] Step S2, constructing a roof water drainage model for the number of drilling sites on the working face based on the drainage volume.

[0055] Specifically, the roof water drainage model for the number of drilling sites on the working face is:

[0056]

[0057] The constraints are:

[0058]

[0059] Where n is the number of drilling sites on the working face, i is the number of the borehole in each drilling site, L is the horizontal projection length of the borehole perpendicular to the groundwater flow direction, α i is the inclination angle of borehole i, θ i is the azimuth of borehole i, W 疏 is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, and R is the drainage influence radius.

[0060] Step S3, solving the roof water drainage model to obtain the optimal number of working face drilling sites.

[0061] Here, the roof water drainage model can be converted into a double-hook function optimal solution calculation problem, and the optimal solution can be obtained by using the first-order Taylor expansion. Alternatively, other model solving methods can be used, such as genetic algorithms.

[0062] Specifically, the optimal number of drilling sites on the working face is:

[0063]

[0064] Among them, n * is the optimal number of drilling sites on the working face, W 疏 is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, R is the drainage influence radius, and int means rounding.

[0065] Step S4, calculating the optimal drainage time based on the optimal number of working face drilling sites.

[0066] Specifically, the optimal drainage time is:

[0067]

[0068] Among them, t *is the optimal drainage time, n * is the optimal number of drilling sites on the working face, W 疏 is the amount of water discharged, and Q0 represents the initial efficiency of water discharge.

[0069] Step S5, determining the optimal residual water head of drainage water according to the maximum allowable residual water head.

[0070] Specifically, the optimal residual head of drainage water is:

[0071]

[0072] in, is the optimal residual water head of drainage water, η is the safety factor constraining the peak flow rate after mining at the working face, H wm The maximum allowable discharge residual head.

[0073] In this embodiment, the drainage volume of the working face roof water head from the natural non-drainage state to the maximum allowable drainage residual head is determined based on the maximum allowable drainage head, a roof water drainage model for the number of working face drilling sites is constructed based on the drainage volume, the roof water drainage model is solved to obtain the optimal number of working face drilling sites, and the optimal drainage time and the optimal drainage residual head are determined, thereby achieving a small amount of roof drainage and a short drainage time under the conditions of safe, economical and controllable roof water inflow from the working face, and at the same time, improving the drainage efficiency.

[0074] An exemplary verification of the embodiments of the present application in an actual application scenario. Figure 2 The optimized layout diagram of the top plate drainage project of the test working face is shown.

[0075] (1) Determination of the length of the drilling project along the working face

[0076] According to the principle of drilling project length arrangement, the total length of the design project arrangement of the I020204 Hongliu Coal Mine working face is 1.5 times the strike length of the location where the peak water inflow occurs. The location where the peak water inflow occurs in the working face is calculated as the pushing distance / mining width. The strike length of the peak water inflow is converted to 131.70m, and the calculated length of the pre-drainage drilling project arrangement for the working face is 197.55m.

[0077] (2) Determination of the distance between drilling sites and the number of drilling sites

[0078] The mining width of the I020204 working face is 300m. The drilling site spacing is calculated to be 106.50 based on the formula for interference well flow of inclined drilling well group, and the number of drilling sites is calculated to be 3.76 (rounded to 4). The number of drilling sites is int[max(1.66,,2.53,0.59,4)]=4 according to the multi-objective nonlinear model. Considering that the drilling project is calculated from the cutting eye position, it is designed to add a drilling site each at the cutting eye and the upper and lower corners. Finally, it is determined that the water drainage drilling site for the test working face is 6.

[0079] (3) Determination of drilling construction parameters

[0080] The horizontal projection of the drilling trajectory was determined to be b / 2. The horizontal projection length of the test working face drilling was 150 m. Three boreholes were constructed in each drilling site (no boreholes were constructed behind the cutting eye position). The angle between the boreholes was 60°. The drilling workload was determined based on the inclination and strike of the working face formation (as shown in Table 1).

[0081] (4) Determination of drainage time

[0082] According to the back-calculation model of the roof pre-drainage quantity given the peak water inflow, the roof pre-drainage quantity is calculated to be 98,000 m 3 Based on this, the residual water head of the roof is calculated to be 63.6m. Based on the variation law of the drainage process of the Hongliu Mine borehole, assuming that the construction is completed and drainage begins when the borehole is drilled, the drainage time is calculated to be about 54.5 days.

[0083] Table 1 Drilling optimization construction parameters of the test working face (I020204 working face)

[0084]

[0085] (5) Analysis of engineering optimization effects

[0086] The above content is based on the method of this application to optimize the calculation of the drainage project of the top plate of the test working face, and determine the drilling construction parameters, the total amount of drainage and the drainage time (as shown in Table 2).

[0087] Table 2 Optimization effect of drilling construction on the test working face

[0088]

[0089] By comparison, the drilling volume of the test working face calculated based on this application is significantly less than the actual construction drilling volume, and the degree of optimization of the drilling project is above 60%. Under the premise of fully considering the drainage capacity of the working face, the designed top plate pre-drainage volume is reduced by nearly 40% compared with the actual amount, and the drainage time is reduced by more than 31%. The research results reflect the economy and efficiency of the drainage project under the premise of ensuring the safety and controllability of the peak water volume of the working face.

[0090] Figure 3 The schematic diagram of the structure of the water inflow model of the working face under the roof head condition is shown in Figure 3 As shown, the figure shows various water heads in the working face, including: drainage head, actual head on site, controlled drainage head and natural head, as well as observation boreholes.

[0091] Figure 4 The relationship between the water inflow and the peak water flow position is shown in the figure. Figure 4 As shown. The upper curve in the figure represents the variation trend of water inflow with mining under the condition of no drainage of the roof water head of the working face, and the lower curve represents the variation trend of water inflow with mining under the condition of given drainage water residual safety head of the roof of the working face. Peak water inflow 1 and peak water inflow 2 represent the peak water inflow during mining under the two working conditions of no drainage of the roof and controlled drainage of the roof, respectively. In addition, for the same working face, the two working conditions have the same peak water inflow position and dynamic stable water inflow position, and have the same initial value and dynamic stable value of water inflow.

[0092] Based on the same inventive concept as the working face roof water drainage method, this embodiment also provides a corresponding working face roof water drainage device. Figure 5 The structural block diagram of the working face roof water drainage device according to an embodiment of the present application is shown, comprising:

[0093] The drainage water volume calculation module 51 is used to calculate the maximum allowable residual water head of the top plate of the working face, and determine the drainage water volume between the water head of the top plate of the working face from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head;

[0094] A roof water drainage model building module 52 is used to build a roof water drainage model for the number of drilling sites on the working face based on the drainage volume;

[0095] The model solving module 53 is used to solve the roof water drainage model to obtain the optimal number of working face drilling sites;

[0096] The optimal drainage time calculation module 54 is used to calculate the optimal drainage time based on the optimal number of working face drilling sites;

[0097] The optimal drainage water residual head determination module 55 is used to determine the optimal drainage water residual head according to the maximum allowable residual head.

[0098] The working face top water drainage device of this embodiment has the same inventive concept as the working face top water drainage method mentioned above, so the specific implementation method of the device can be seen in the implementation example part of the working face top water drainage method in the previous text, and its technical effect corresponds to the technical effect of the above method, which will not be repeated here.

[0099] An embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned working face roof water drainage method is implemented.

[0100] 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 draining water from a working surface roof, characterized in that: include: Calculate the maximum allowable residual water head of the top plate of the working face, and determine the drainage volume of the top plate water head of the working face from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head; Based on the drainage water volume, a roof water drainage model is constructed with respect to the number of drilling sites on the working face; Solving the roof water drainage model to obtain the optimal number of working face drilling sites; Calculating the optimal drainage time based on the optimal number of working face drilling sites; The optimal drainage water residual head is determined according to the maximum allowable residual head.

2. The method according to claim 1, characterized in that in, According to the maximum allowable residual water head, the drainage volume between the water head of the top plate of the working face from the natural non-drainage state to the maximum allowable drainage residual water head is determined using the following formula: <h2 style=";text-align:left;direction:ltr">W<h2 style=";text-align:left;direction:ltr"> 疏 <h2 style=";text-align:left;direction:ltr"> (H0-H)<h2 style=";text-align:left;direction:ltr"> wm <h2 style=";text-align:left;direction:ltr"> )·b·a Among them, W 疏 is the drainage volume, H0 is the initial water head of the aquifer on the top of the working face before drainage, H wm is the maximum allowable drainage residual head, b is the width of the working surface, and a is the length of the working surface.

3. The method according to claim 1, characterized in that The roof water drainage model for the number of drilling sites on the working face is: The constraints are: n≥max(W 疏 / 3Q0t e ,3x m / R) Where n is the number of drilling sites on the working face, i is the number of the borehole in each drilling site, L is the horizontal projection length of the borehole perpendicular to the groundwater flow direction, α i is the inclination angle of borehole i, θ i is the azimuth of borehole i, W 疏 is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, and R is the drainage influence radius.

4. The method according to claim 1, characterized in that The optimal number of working face drilling sites is: Among them, n * is the optimal number of drilling sites on the working face, W 疏 is the drainage volume, Q0 represents the initial drainage efficiency, β is the parameter introduced into the roof water drainage model, t e is the dynamic stabilization time of drainage water, x m is the pushing and mining distance corresponding to the maximum water inflow, R is the drainage influence radius, and int means rounding.

5. The method according to claim 1, characterized in that The optimal drainage time is: Among them, t * is the optimal drainage time, n * is the optimal number of drilling sites on the working face, W 疏 is the amount of water discharged, and Q0 represents the initial efficiency of water discharge.

6. The method according to claim 1, characterized in that The optimal residual head of drainage water is: in, is the optimal residual water head of drainage water, η is the safety factor constraining the peak flow rate after mining at the working face, H wm The maximum allowable discharge residual head.

7. A working surface roof water drainage device, characterized in that: include: A drainage water volume calculation module is used to calculate the maximum allowable residual water head of the top plate of the working face, and determine the drainage water volume between the water head of the top plate of the working face from the natural non-drainage state to the maximum allowable drainage residual water head according to the maximum allowable residual water head; A roof water drainage model building module, used to build a roof water drainage model for the number of drilling sites on the working face based on the drainage water volume; A model solving module, used to solve the roof water drainage model to obtain the optimal number of working face drilling sites; An optimal drainage time calculation module, used to calculate the optimal drainage time based on the optimal number of working face drilling sites; The optimal drainage water residual head determination module is used to determine the optimal drainage water residual head according to the maximum allowable residual head.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the working face roof water drainage method described in any one of claims 1-6.

9. A computer program product, characterized in that It includes computer programs / instructions, which, when executed by a processor, implement the working face roof water drainage method described in any one of claims 1-6.

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