A method for predicting lateral fracture of overburden strata in fully mechanized caving mining and optimizing roadway layout

Abstract

This invention discloses a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining, belonging to the field of surrounding rock control technology in coal mining. First, a mechanical model considering the influence of fractures in the underlying rock beams is constructed. Then, based on the elastic foundation beam theory and strength theory, the deflection and bending moment of each rock beam are calculated to predict its lateral fracture location. Combining borehole observation data, the spatial morphology of the overburden lateral fracture surface is determined to be F-shaped, inverted F-shaped, C-shaped, or inverted C-shaped according to the spatial relationship of each fracture surface. Finally, based on the fracture location and spatial morphology determination results, the lateral support pressure distribution is determined, and the roadway along the goaf is optimized and arranged in the stress reduction zone with a reasonable coal pillar width designed. This invention achieves accurate prediction and scientific identification of the lateral fracture behavior of complex overburden structures, providing a reliable theoretical basis and technical means for the safe and efficient layout of roadways along the goaf, effectively ensuring the stability of the surrounding rock and mining safety.

Description

Technical Field

[0001] This invention relates to the field of coal mine surrounding rock stability control technology, specifically to a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining. Background Technology

[0002] In fully mechanized longwall mining, the rational layout of roadways along the goaf and the effective control of mine pressure manifestation at the working face are core prerequisites for ensuring mining safety and efficiency. Achieving this goal highly depends on a deep understanding of the laws governing overburden movement and load transfer mechanisms. In overburden structures that are not single-layered (i.e., composed of multiple layers of hard rock), the lateral bending deformation, rotational subsidence, and instability fracture processes of the overburden beam group trigger the reconstruction of the overburden stress field and energy transfer, directly altering the distribution characteristics of the lateral support pressure at the working face, and thus decisively affecting the stability of the roadways along the goaf.

[0003] Existing research has clearly shown that the basic roof beam group exhibits a bottom-up, layer-by-layer fracture characteristic in the lateral direction, and its fracture structure directly determines the peak distribution and morphology of the overburden load on the lateral coal seam in the goaf, making it a key controlling factor affecting the scientific layout of roadways along the goaf. However, current technologies mostly focus on the fracture analysis of single basic roof structures, lacking systematic research on the lateral fracture mechanism and spatial morphology of non-single basic roofs composed of multiple rock beams. This makes it difficult to accurately calculate the location of the lateral fracture surface of each rock beam layer, and also makes it impossible to effectively determine the overall spatial morphology of the overburden lateral fracture surface. Consequently, the determination of the coal pillar width and the location of roadways along the goaf lacks a reliable theoretical basis, easily leading to safety hazards such as large deformation of the surrounding rock, coal pillar instability, and abnormal mine pressure manifestation, thus hindering the safe and efficient advancement of fully mechanized longwall mining.

[0004] Therefore, there is an urgent need to propose a technical method that can accurately predict the lateral fracture locations of rock beams in each layer under non-single basic roof conditions and scientifically determine their overall spatial morphology, so as to provide reliable theoretical guidance and technical tools for the optimized layout of roadways along the goaf and active control of mining pressure in fully mechanized longwall mining. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This application provides a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining, including: Construct a mining overburden lateral mechanics model containing at least three basic roof rock beams, where the coal seam and immediate roof are generalized as an elastic foundation; Based on the mechanical model, the deflection response function of each basic top rock beam under the progressive bearing mechanism is solved. Based on the deflection response functions described above, the bending moment distribution of each rock beam is determined, and its lateral fracture location is predicted through bending moment extreme value analysis. Based on downhole borehole inspection data, the actual fracture locations of each rock layer in the overburden were identified and extracted; Based on the spatial relationship between the predicted and measured fracture locations, the spatial morphology type of the overburden lateral fracture structure is determined. Based on the spatial morphology and fracture location, the lateral support pressure distribution is determined, and the layout of the goaf roadway is optimized accordingly.

[0007] Furthermore, constructing the mechanical model specifically includes: Establish the first sub-model of the first rock beam located on the original elastic foundation; A second sub-model is established on a composite elastic foundation containing the fractured first rock beam; and A third sub-model is established on a composite elastic foundation containing the first and second rock beams after their fracture.

[0008] Furthermore, the deflection response function of the first rock beam is solved. This includes solving its governing differential equations: ; in, For the first rock beam bending stiffness, This is the foundation stiffness coefficient. For a uniformly distributed load in the far field, For incremental load peak value, The range of load influence; This is the incremental load function for the inner side of the coal wall.

[0009] Furthermore, the deflection response function of the second rock beam is solved. At that time, the distributed load it experiences Original rock load Additional load on the fracture of the first rock beam The sum of, where:

[0010]

[0011] For a uniformly distributed load in the far field, For the load influence range, This represents the peak value of the incremental load. The values ​​are the unit weight, thickness, and predicted fracture location of the first rock beam. The span is affected by the fracture. This is the attenuation coefficient.

[0012] Furthermore, the deflection response function of the third rock beam is solved. At that time, the distributed load it receives Original rock load Additional load on the fracture of the second rock beam The sum of, where:

[0013]

[0014] For a uniformly distributed load in the far field, For the load influence range, For incremental load peak value, , , The values ​​are the unit weight, thickness, and predicted fracture location of the second rock beam. The span is affected by the fracture. This is the attenuation coefficient.

[0015] Furthermore, the prediction of fracture location through bending moment extreme value analysis includes: for the first... Layered rock beam, by its deflection function Calculate the bending moment: ), and solve The obtained root is the predicted fracture location. .

[0016] Furthermore, the rules for determining the type of spatial form are as follows: If three predicted fracture locations satisfy Then it is determined to be type; If satisfied Then it is determined to be reversed. type; If satisfied and Then it is determined to be type; If satisfied and Then it is determined to be reversed. type.

[0017] Furthermore, the actual fracture location is extracted based on downhole borehole inspection data, including: comparing inspection images of the same lithological strata in different boreholes, and spatially connecting the locations of delamination or borehole collapse to determine the actual orientation of the fracture surface of the stratum.

[0018] Furthermore, optimizing the layout of the roadways along the tunnel includes: placing the roadways within the lateral support pressure reduction zone defined by the spatial morphology type and fracture location.

[0019] Secondly, this application provides an electronic device, comprising: processor; Memory, used to store computer programs; When the computer program is executed by the processor, the above method is implemented.

[0020] Compared with the prior art, this application has the following beneficial effects: This invention presents a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining. Instead of focusing on layered structures with non-single basic roofs, it is the first to construct a mechanical model of multi-beam layer-by-layer fracture, considering the additional load impact of lower-layer beam fractures on upper-layer beams. This overcomes the limitations of existing single-beam fracture analyses and better reflects actual engineering conditions. By establishing the elastic foundation beam-deflection curve equations for each beam and combining boundary conditions and bending moment extreme conditions, the location of the lateral fracture surface of each beam is calculated. The calculation results provide a quantitative basis for roadway layout along the goaf. Based on the numerical relationships of the fracture surface locations of each beam and field measurement results, a comprehensive judgment method for four spatial morphologies—F-type, inverted F-type, C-type, and inverted C-type—is proposed, clarifying the overall characteristics of lateral fractures in overburden and providing a new perspective for predicting mine pressure manifestation patterns. The method is logically clear and the calculation process is rigorous. It can be directly applied to the optimization of roadway layout and mine pressure control in fully mechanized longwall mining under non-single basic roof conditions, effectively reducing the risks of roadway surrounding rock deformation and coal pillar instability, and improving the safety and efficiency of mining operations. Attached Figure Description

[0021] Figure 1 This is a flowchart of a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining.

[0022] Figure 2 This is a diagram showing the measured location and spatial morphology of the lateral fracture surface of the overlying rock.

[0023] Figure 3 This is a schematic diagram of a device for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining.

[0024] Figure 4 This is a schematic diagram of the components of an electronic device.

[0025] Figure 5 This is a schematic diagram of the composition of a storage medium. Detailed Implementation

[0026] The technical solutions will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. It should be noted that the listed embodiments are only a part of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0027] Furthermore, in this invention, an element defined as fixed or disposed on another element can be directly mounted on that element, or an intermediate element may be present. When one element is connected to another element, it can be directly connected or an intermediate element may be present. The terms used herein, such as vertical, horizontal, left, right, etc., are for illustrative purposes only and are not the only embodiments.

[0028] Goaf-side roadways: As the name suggests, these are roadways laid out along the edge of a mined-out area. Their core purpose is to avoid leaving or leave very narrow coal pillars, thereby increasing coal extraction rates, reducing roadway excavation, and helping to alleviate roadway pressure.

[0029] Example 1 See Figure 1 This application provides a method for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining, comprising: steps S110-S160: Step S110. Construct a mining overburden lateral mechanics model containing at least three basic roof rock beams, wherein the coal seam and immediate roof are generalized as an elastic foundation.

[0030] Constructing a mechanical model specifically includes: Establish the first sub-model of the first rock beam located on the original elastic foundation; A second sub-model is established on a composite elastic foundation containing the fractured first rock beam; A third sub-model is established on a composite elastic foundation containing the first and second rock beams after their fracture.

[0031] Specifically: it is clarified that the non-single basic roof in fully mechanized longwall mining consists of the first rock beam, the second rock beam, the third rock beam, the immediate roof below, and the coal seam, distributed from bottom to top. The coal seam and the immediate roof are regarded as Winkler elastic foundations, and the overlying rock beam group is used as a load layer to transfer loads to the rock beams below. The overall mechanical model of the lateral fracture structure of the non-single basic roof before and after mining of the upper section working face is constructed respectively, and the stress boundary conditions of each rock beam are clarified.

[0032] Step S120. Using the mechanical model, the deflection response of the basic top rock beams of each layer under the progressive bearing mechanism can be calculated. The specific calculation can be carried out based on the deflection formulas under uniformly distributed load and concentrated load.

[0033] For the first rock beam, assuming its overlying load is linearly distributed, and neglecting the friction between the first rock beam and the upper and lower interlayers, the origin is taken as the location of the coal wall. The inner side of the coal wall is In the positive direction, establish a mechanical model of a semi-infinite elastic foundation beam; Based on the single-peak load characteristics of the first rock beam, the incremental load function on the inner side of the coal wall is determined as follows:

[0034] In the formula: The area affected by the mining activity is expressed in meters (m). This represents the peak value of the incremental load on the first rock beam.

[0035] According to Winkler's elastic foundation assumption, the foundation reaction force and the vertical displacement of the beam satisfy... ,in The first rock beam foundation stiffness coefficient; This represents the vertical displacement of the first rock beam.

[0036] Establish the differential equation for the deflection curve of the semi-infinite elastic foundation beam inside the coal wall of the first rock beam:

[0037] In the formula: where, For the first rock beam bending stiffness, This is the foundation stiffness coefficient. For a uniformly distributed load in the far field, For incremental load peak value, The range of load influence; This is the incremental load function for the inner side of the coal wall.

[0038] By solving this differential equation, combined with the boundary conditions ( (At point 0, the deflection is 0 and the rotation angle is 0), thus obtaining the deflection curve equation for the first rock beam:

[0039] In the formula: , , These are undetermined coefficients, determined by the boundary conditions.

[0040] Furthermore, regarding the second rock beam, the additional load generated after the first rock beam fractures is considered as a composite elastic foundation, taking the coal seam, immediate roof, and first rock beam as the basis. The overlying load of the second rock beam includes the original rock load and the additional load from the fracture of the first rock beam, namely:

[0041] Wherein: the original rock load is:

[0042] The additional load that caused the first rock beam to fracture was:

[0043] In the formula: The far-field uniformly distributed load is the second rock beam; The peak value of the incremental load on the second rock beam, in MPa; The range of influence of the incremental load on the second rock beam is given in meters. The unit weight of the first rock beam is kN / m³. 3 ; The thickness of the first rock beam is in meters (m). The span affected by the fracture of the first rock beam is in meters. The attenuation coefficient of the additional load on the fracture of the first rock beam is m. -1 .

[0044] Establish the differential equation for the deflection curve of the second rock beam on the elastic foundation, and solve for the deflection curve equation:

[0045] In the formula: The second rock beam foundation stiffness coefficient, in Pa; Let N be the bending stiffness of the second rock beam; ; , For undetermined coefficients, through The boundary conditions at the given location are obtained by solving.

[0046] Furthermore, considering the additional load generated after the fracture of the second rock beam, the coal seam, immediate roof, first rock beam, and second rock beam are regarded as a composite elastic foundation; the overlying load of the third rock beam includes the original rock load and the additional load from the fracture of the second rock beam, namely:

[0047] The original rock load is:

[0048] The additional load that caused the second rock beam to fracture was:

[0049] In the formula: The far-field uniformly distributed load of the third rock beam is MPa; The peak value of the incremental load on the third rock beam, in MPa; The range of influence of the incremental load on the third rock beam is given in meters. The unit weight of the second rock beam is kN / m³. 3 ; The thickness of the second rock beam is in meters. The span affected by the fracture of the second rock beam is in meters. The additional load attenuation coefficient for the second rock beam is m. -1 .

[0050] Establish the differential equation for the deflection curve of the third rock beam on the elastic foundation, and solve for the equation of the deflection curve:

[0051] In the formula: The third rock beam foundation stiffness coefficient, in Pa; Let N be the bending stiffness of the third rock beam; ; , For undetermined coefficients, through The boundary conditions at the given location are obtained by solving.

[0052] Step S130. Determine the bending moment distribution of each rock beam according to the deflection response function, and predict its lateral fracture location through bending moment extreme value analysis.

[0053] Predicting fracture location through bending moment extreme value analysis, including: for the first Layered rock beam, by its deflection function Calculate the bending moment: ), and solve The obtained root is the predicted fracture location. .

[0054] Specifically: Based on the deflection curve equations of each rock beam obtained in step S120, the bending moment expressions of each rock beam are derived respectively: The expression for the bending moment of the first rock beam is: .

[0055] The bending moment expression for the second rock beam is: .

[0056] The expression for the bending moment of the third rock beam is: .

[0057] According to the maximum tensile stress strength theory, when the maximum tensile stress in the cross-section of the rock beam exceeds the tensile strength of the rock, the rock beam will fracture laterally. The corresponding cross-section is the location of the fracture surface. By finding the extreme value of the bending moment expression for each rock beam, the location of the cross-section with the maximum bending moment for each rock beam can be obtained, which is the location of the lateral fracture surface. Location of the lateral fracture surface of the first rock beam Satisfying the extreme value condition of bending moment Solving for the problem yields:

[0058] Location of the lateral fracture surface of the second rock beam Satisfying the extreme value condition of bending moment After ignoring higher-order minor quantities, the solution is obtained as follows:

[0059] Location of the lateral fracture surface of the third rock beam Satisfying the extreme value condition of bending moment After ignoring higher-order minor quantities, the solution is obtained as follows:

[0060] Step S140. Using mine drilling data analysis, through techniques such as borehole profile segmentation, deviation rate method, and stress difference method, identify and extract the actual fracture locations of each rock layer in the overburden.

[0061] Extracting the actual fracture location based on downhole borehole inspection data includes: comparing inspection images of the same lithological strata in different boreholes, and spatially connecting the locations of delamination or borehole collapse to determine the actual orientation of the fracture surface of the stratum.

[0062] Specifically, a borehole inspection method combined with a spatiotemporal dataset of microseismic events is used to quantitatively analyze the location and spatial morphology of lateral fracture surfaces in the overburden of a fully mechanized longwall mining face. The spatiotemporal dataset of microseismic events in the coal mine is obtained through borehole inspection, and cluster analysis is performed on the dataset to determine the optimal number of clusters and identify event clusters. Combined with the overburden lithology information from borehole columnar sections, the fracture characteristics of the overburden during the mining process and the fracture characteristics of the overburden ultimately formed in the goaf are analyzed, thereby obtaining the overburden fracture line propagation process and the distribution of fracture lines perpendicular to the direction of face advancement.

[0063] Step S150. Determine the spatial morphology type of the overburden lateral fracture structure based on the spatial relationship between the predicted and measured fracture locations.

[0064] Based on the theoretical calculations in step 3 and the on-site measurements in step 4, the location of the first rock beam fracture surface was obtained. Location of the fracture surface of the second rock beam Location of the fracture surface of the third rock beam The spatial morphology of the lateral fracture surface of the overlying strata was comprehensively determined: The rules for determining the type of spatial form are as follows: If three predicted fracture locations satisfy Then it is determined to be type; If satisfied Then it is determined to be reversed. type; If satisfied and Then it is determined to be type; If satisfied and Then it is determined to be reversed. type.

[0065] Step S160. Determine the lateral support pressure distribution based on the spatial morphology type and fracture location, and optimize the layout of the goaf roadway accordingly.

[0066] Optimizing the layout of the roadways along the goaf includes: placing the roadways within the lateral support pressure reduction zone defined by the spatial morphology type and fracture location.

[0067] Based on the location of the lateral fracture surface of each rock beam obtained in step S130 and the spatial morphology determined in step S140, combined with the working face advance direction, the distribution area of ​​the peak load of the coal seam is determined, and the goaf roadway is arranged outside the influence range of the peak load or in the area where the lateral support pressure is reduced. At the same time, the width of the coal pillar in the section is optimized to achieve the stability control of the surrounding rock of the goaf roadway.

[0068] Based on the same concept as steps S110-S160 above, such as Figure 2 As shown, this application provides a device for predicting lateral fractures in overburden and optimizing roadway layout in fully mechanized longwall mining, specifically including: The building module is used to construct a mining overburden lateral mechanics model containing at least three basic roof rock beams, where the coal seam and immediate roof are generalized as an elastic foundation; The solution module is used to solve the deflection response function of each basic top rock beam under the progressive bearing mechanism based on the mechanical model. The determination module is used to determine the bending moment distribution of each rock beam based on the deflection response function, and to predict its lateral fracture location through bending moment extreme value analysis. The identification module is used to identify and extract the actual fracture locations of each rock layer in the overburden based on downhole borehole inspection data; The determination module is used to determine the spatial morphology type of the overburden lateral fracture structure based on the spatial relationship between the predicted and measured fracture locations. The optimization module is used to determine the lateral support pressure distribution based on the spatial morphology type and fracture location, and optimize the layout of the goaf roadway accordingly.

[0069] Example 2 Prediction of the location of a non-single basic top lateral fracture surface in a fully mechanized longwall mining face A coal mine's fully mechanized longwall face has a periodic pressure step of 20m, a coal seam thickness of 5.27m, and an immediate roof height of 18.76m. The non-single basic roof consists of three layers of rock beams: the first rock beam is 14m thick, with an elastic modulus of 17.3GPa, a unit weight of 22kN / m³, and a lateral fracture span of 20.00m; the second rock beam is 11.4m thick, with an elastic modulus of 18.1GPa, a unit weight of 23kN / m³, and a lateral fracture span of 20.53m; and the third rock beam is 16.2m thick, with an elastic modulus of 19.5GPa, a unit weight of 26kN / m³, and a lateral fracture span of 23.76m. The stiffness coefficient of the foundation formed by the coal seam and the immediate roof is... k 1 = 493 MPa, stiffness coefficient of the composite foundation after the first rock beam fractures. k 2 = 360 MPa, stiffness coefficient of the composite foundation after the second rock beam fractures k 3 = 299 MPa.

[0070] The method of this invention is used to predict the location and spatial morphology of the lateral fracture surface. The steps are as follows: A mechanical model of a non-single basic roof lateral fracture structure was constructed, and the stress boundary conditions of each rock beam were clarified. The structures “coal seam + immediate roof, coal seam + immediate roof + first rock beam, and coal seam + immediate roof + first rock beam + second rock beam” were respectively regarded as Winkler elastic foundations.

[0071] Calculate the characteristic parameters and fracture equation of the rock beam group: Characteristic parameters of the first rock beam β 1 = 0.075, the lateral fracture equation of the first rock beam is: x 1+ l 1=20

[0072] Characteristic parameters of the second rock beam β 2 = 0.080, the lateral fracture equation of the second rock beam is: x 2+ l 2 = 20.53

[0073] Characteristic parameters of the third rock beam β 3 = 0.057, the lateral fracture equation of the third rock beam is: x 3+ l 3 = 23.76

[0074] Furthermore, the locations of the lateral fracture surfaces of each rock beam are calculated: Location of the fracture surface of the first rock beam x 1 = 6.06m; Location of the fracture surface of the second rock beam x 2 = 5.29m; Location of the fracture surface of the third rock beam x 3 = 8.65m.

[0075] On-site measurements of the location and spatial morphology of the lateral fracture surfaces of each rock beam: like Figure 3 As shown, boreholes were arranged using the borehole inspection method to measure the location and spatial morphology of the lateral fracture surfaces of the overburden. Based on the lithology and thickness of the borehole columnar section, the basic top rock beam groups were identified as the first rock beam (coarse sandstone), the second rock beam (medium sandstone), and the third rock beam (fine sandstone). The locations of obvious delamination and borehole collapse within the same lithological strata of the coarse, medium, and fine sandstone in the inspection holes were analyzed by connecting the lines. The lateral fracture surfaces of the first (coarse sandstone) and third (fine sandstone) rock beams gradually move away from the upper goaf from bottom to top, while the lateral fracture surface of the second (medium sandstone) rock beam moves away from the working face of this section and tends towards the upper goaf, exhibiting an inverted C-shaped spatial morphology.

[0076] Furthermore, determine the spatial morphology of the lateral fracture surface of the overlying strata: because x 3> x 2 and x 1> x 2. The spatial morphology of the lateral fracture surface of the overlying rock is determined to be an inverted C-shape.

[0077] Furthermore, the layout of the roadway along the goaf was optimized: based on the location of the fracture surface and the inverted C-shaped spatial morphology, the coal pillar section was placed in the stress reduction zone. The distribution and variation characteristics of the supporting pressure in this area are determined by the weight and movement of the basic roof, placing the roadway in a more favorable stress environment, which is beneficial to the stability of the surrounding rock. The stress reduction zone ranges from 0 to 6 meters, and the designed width of the coal pillar section is 6 meters, effectively avoiding the peak load area. Compared with the original layout, the deformation of the surrounding rock in the roadway was reduced by 20%, and the mine pressure manifestation was stable.

[0078] Example 3 In an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described method is also provided.

[0079] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: a completely hardware implementation, a completely software implementation (including firmware, microcode, etc.), or a combination of hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0080] The following reference Figure 4To describe an electronic device 400 according to this embodiment of the present invention. Figure 4 The electronic device 400 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0081] like Figure 4 As shown, the electronic device 400 is manifested in the form of a general-purpose computing device. The components of the electronic device 400 may include, but are not limited to: at least one processing unit 410, at least one storage unit 420, and a bus 430 connecting different system components (including the storage unit 420 and the processing unit 410). The storage unit stores program code that can be executed by the processing unit 410, causing the processing unit 410 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of the present invention. For example, a lateral mechanical model of the overburden containing at least three basic roof beams is constructed, where the coal seam and immediate roof are generalized as an elastic foundation. Based on the mechanical model, the deflection response function of each basic roof beam under a progressive bearing mechanism is solved. According to the deflection response function, the bending moment distribution of each beam is determined, and its lateral fracture location is predicted through bending moment extreme value analysis. Based on downhole borehole inspection data, the actual fracture locations of each rock layer in the overburden are identified and extracted. According to the spatial relationship between the predicted and measured fracture locations, the spatial morphology type of the overburden lateral fracture structure is determined. And according to the spatial morphology type and fracture location, the lateral support pressure distribution is determined, and the layout of the goaf roadway is optimized accordingly.

[0082] Storage unit 420 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 4201 and / or cache memory 4202, and may further include a read-only memory (ROM) 4203.

[0083] Storage unit 420 may also include a program / utility 4204 having a set (at least one) program module 4205, such program module 4205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0084] Bus 430 can represent one or more of several types of bus structures, including memory cell bus or memory cell controller, peripheral bus, graphics acceleration port, processing unit, or local bus using any of the multiple bus structures.

[0085] Electronic device 400 can also communicate with one or more external devices 300 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 400, and / or any device that enables electronic device 400 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 450. Furthermore, electronic device 400 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 460. As shown, network adapter 460 communicates with other modules of electronic device 400 via bus 430. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 400, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0086] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the method according to the embodiments of this disclosure.

[0087] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the invention described in the "Exemplary Methods" section of this specification.

[0088] refer to Figure 5 As shown, a program product 500 for implementing the above-described method according to an embodiment of the present invention is described. It may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0089] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0090] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0091] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0092] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Python and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0093] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0094] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for predicting lateral fracture of overburden strata in fully mechanized caving mining and optimizing roadway layout, characterized in that, include: Construct a mining overburden lateral mechanics model containing at least three basic roof rock beams, where the coal seam and immediate roof are generalized as an elastic foundation; Based on the mechanical model, the deflection response function of each basic top rock beam under the progressive bearing mechanism is solved. Based on the deflection response functions described above, the bending moment distribution of each rock beam is determined, and its lateral fracture location is predicted through bending moment extreme value analysis. Based on downhole borehole inspection data, the actual fracture locations of each rock layer in the overburden were identified and extracted; Based on the spatial relationship between the predicted and measured fracture locations, the spatial morphology type of the overburden lateral fracture structure is determined. Based on the spatial morphology and fracture location, the lateral support pressure distribution is determined, and the layout of the goaf roadway is optimized accordingly.

2. The method of claim 1, wherein, Constructing a mechanical model specifically includes: Establish the first sub-model of the first rock beam located on the original elastic foundation; A second sub-model is established on a composite elastic foundation containing the fractured first rock beam; and A third sub-model is established on a composite elastic foundation containing the first and second rock beams after their fracture.

3. The method according to claim 2, characterized in that, solving a deflection response function for the first rock beam including solving its governing differential equation: ； wherein, is the first rock beam bending stiffness, is the foundation stiffness coefficient, is the far field uniform load, is the peak incremental load, is the load influence range; is the coal wall inside incremental load function.

4. The method according to claim 3, characterized in that, solving the deflection response function for the second rock beam the distributed load it is subjected to is the original rock load plus the first rock beam fracture additional load wherein: ； ； is a far-field uniform load, is a load influence range, is an incremental load peak value; are the unit weight, thickness and predicted fracture location of the first rock beam, respectively, is a fracture influence span, is an attenuation coefficient.

5. The method according to claim 4, characterized in that, Solve for the deflection response function of the third rock beam. At that time, the distributed load it experiences Original rock load Additional load on the fracture of the second rock beam The sum of, where: ； ； For a uniformly distributed load in the far field, For the load influence range, For incremental load peak value, , , The values ​​are the unit weight, thickness, and predicted fracture location of the second rock beam. The span is affected by the fracture. This is the attenuation coefficient.

6. The method according to claim 1, characterized in that, The method of predicting the fracture location through bending moment extreme value analysis includes: for the first Layered rock beam, by its deflection function Calculate the bending moment: ), and solve The obtained root is the predicted fracture location. .

7. The method according to claim 1, characterized in that, The rules for determining the type of spatial form are as follows: If three predicted fracture locations satisfy Then it is determined to be type; If satisfied Then it is determined to be reversed. type; If satisfied and Then it is determined to be type; If satisfied and Then it is determined to be reversed. type.

8. The method according to claim 1, characterized in that, Extracting the actual fracture location based on downhole borehole inspection data includes: comparing inspection images of the same lithological strata in different boreholes, and spatially connecting the locations of delamination or borehole collapse to determine the actual orientation of the fracture surface of the stratum.

9. The method according to claim 1, characterized in that, Optimizing the layout of the roadways along the goaf includes: placing the roadways within the lateral support pressure reduction zone defined by the spatial morphology type and fracture location.

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