A method for dividing height of filling mining stage of near-vertical medium-thick and thick coal seam
By constructing an artificial isolation layer and anchor bolt support in near-vertical coal seams and optimizing the stage height design, the problem of balancing safety and economy in the backfilling mining of near-vertical medium-thick coal seams was solved, achieving efficient and safe mining results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AKSU COAL RESEARCH INSTITUTE
- Filing Date
- 2026-04-07
- Publication Date
- 2026-06-02
AI Technical Summary
In existing technologies, there is a lack of scientific and reasonable methods for dividing the stage height of backfilling mining in near-vertical medium-thick and thick coal seams. This makes it difficult to balance safety and economy in the mining system. Excessive stage height may lead to roof structure damage and high support costs, while insufficient height increases process complexity and cost.
By constructing an artificial isolation layer, the nearly vertical coal seam is divided into multiple stages. The full mining and full filling method is adopted, a mechanical model is established to calculate the stage height, and artificial false roof and false bottom are constructed using anchor bolts and high-strength filling materials. Combined with anchor bolt support, normal and shear resistance are provided, and the stage height design is optimized.
It significantly reduces mining process costs, improves work efficiency, enhances the stability of the roof and surrounding rock, reduces the exposed area of the roof and the risk of accidents, optimizes support costs and process complexity, and achieves a balance between safety and economy.
Smart Images
Figure CN122129309A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of near-vertical medium-thick and thick coal seam backfilling mining and strata control, and is a method for dividing the stage height of near-vertical medium-thick and thick coal seam backfilling mining. Background Technology
[0002] Due to their complex occurrence conditions, the safe and efficient mining of near-vertical coal seams has always been a key focus and challenge in the field of mining engineering. With the continuous development of backfilling mining technology, new approaches have been provided for the safe and efficient mining of this type of coal seam. Dividing near-vertical coal seams into stages for layered mining has become the main technical approach for this type of coal seam. Therefore, the scientific division of mining stage heights directly affects the overall economic benefits of the mining system: if the stage height is designed too large, resulting in excessive roof overhang and excessive load on the artificial false roof, excessive bending stress can easily lead to tensile failure of the structure, potentially inducing a series of chain disasters such as roof collapse and even overall system instability; if the stage height is too conservative, although it can improve local safety, it will lead to an increase in the frequency of arranging production systems and constructing artificial false roofs, significantly increasing support costs and process complexity, severely restricting mining efficiency and economic feasibility. Therefore, for near-vertical medium-thick and thick coal seams, establishing a reasonable mechanical model and developing a more scientific and reasonable stage height design and optimization method is the core issue for achieving a balance between safety and economy in near-vertical coal seam backfilling mining. There is currently no corresponding technical record in the existing technology. Summary of the Invention
[0003] Technical problem: To address the shortcomings of existing technologies, a method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages is provided. The calculation is simple, provides clear guidance for practical work, and can significantly reduce the cost of the corresponding mining process and improve work efficiency.
[0004] The purpose of this invention is to address the lack of existing technology for the rational division of the height of near-vertical medium-thick and thick coal seam filling mining stages, and to provide a method for dividing the height of near-vertical medium-thick and thick coal seam filling mining stages.
[0005] Technical Solution: To achieve the above technical objectives, this invention discloses a method for dividing the filling stage height of near-vertical medium-thick and thick coal seams. The method is characterized by constructing an artificial isolation layer to divide the near-vertical coal seam into multiple stages from top to bottom, and employing full mining and filling to complete each stage. The stage height division steps are as follows: S1. Establish a mechanical model for a single stage based on the geological information of the vertical coal seam; S2, Bending deflection of the top plate during the analysis phase; S3. Calculate the maximum unsupported roof height theoretically for each stage division using the coal seam dip angle and stage height, and use the maximum unsupported roof height to determine the safe stage height when full mining is completed.
[0006] Furthermore, in a single stage, the upper artificial isolation layer serves as an artificial false roof, and the lower artificial isolation layer serves as an artificial false floor. Simultaneously, the artificial false floor of the previous stage is used as the artificial false roof of the next stage. The geological information of the vertical coal seam includes geological and mining conditions information, roof lithology information of the stage, artificial isolation layer strength information, strength information of the filling body formed by full mining and filling, and anchor bolt strength information for support. The artificial isolation layer is constructed by anchor bolts and high-strength filling materials. The strength information of the artificial isolation layer, the strength information of the filling body, and the strength information of the anchor bolts for support are obtained through laboratory testing.
[0007] Furthermore, the mechanical model for a single stage is established as follows: The mechanical model of a single stage includes a backfill body, with an artificial false roof above the backfill body and an artificial false floor below it. There are roof and floor plates with the same mechanical conditions on both sides of the backfill body. The roof plate is represented as a coal seam roof fixed beam mechanical model using a fixed beam mechanical model, and the artificial false floor is represented as an artificial isolation layer fixed beam mechanical model. The safe stage height is determined by the lithology and strength of the roof plate in the stage and the self-weight of the backfill body constructed in the goaf of this stage. In the mechanical model of the coal seam roof support beam, the connection point between the roof and the artificial false roof is denoted as point O, and the connection point between the roof and the artificial false bottom is denoted as point A. The normal load on the roof is the component of the horizontal ground stress. The normal load gradually increases with the burial depth and is linearly distributed. The anchor bolts that construct the artificial false roof and artificial false bottom provide tensile force, including normal pressure and shear resistance.
[0008] Furthermore, based on Kinnick's modification of the Heim stress hypothesis, the normal loads q1 and q2 at points O and A of the coal seam roof during a single stage of horizontal stress are expressed as follows: , In the formula: γ is the unit weight of the rock stratum, in N / m³. 3 λ is the lateral pressure coefficient; α is the dip angle of the near-vertical coal seam, in degrees; h O h A q represents the burial depth of the corresponding locations of the artificial false roof and artificial false bottom during the mining stage. O q A The horizontal geostress load at the corresponding locations of the artificial false roof and artificial false bottom during the mining stage; Horizontal ground stress acting on the linear load in the normal direction of the goaf roof : , In the formula: H is the span of the stage top plate, in meters; x represents the distance between a point on the mechanical model and the origin of the coordinate system. The differential equation of the bending deflection of the top plate and the linear normal load on the top plate are used to determine the angle of change. The bending deflection of the roof of the goaf in a single stage is obtained by simultaneously integrating the expressions. : , In the formula: E is the elastic modulus of the top plate, in GPa; I is the moment of inertia of the beam, in m. 4 ; C1, C2, C3, and C4 are undetermined constants determined by boundary conditions; x represents the distance between a point on the analogous mechanical model and the origin of the coordinate system. Based on the mechanical model of a fixed beam in the coal seam roof, the maximum span H of the equivalent beam from point O to point A in the coal seam roof is derived; by the strength criterion, the maximum bending stress is set to not exceed the allowable tensile stress of the roof. The following relation is obtained: , In the formula: M(x) is the bending moment of the beam, in N·m; the section from point O to point A of the coal seam roof is equivalent to a rectangular cross-section beam, b is the width of the rectangular cross-section, taken as 1m, and h1 is the beam thickness, in m; The maximum bending stress of the beam; Let H be the maximum span from point O to point A of the coal seam roof. Therefore, the equivalent mechanical model of the fixed-supported beam of the coal seam roof can obtain the maximum bending moment of the beam by using the span H: take the maximum value of the absolute values of the bending moment M(0) at the fixed end of the roof, the bending moment M(H) at the roof point A, and the mid-span bending moment M(H / 2) of OA; through the maximum span H, the roof beam span H1=Hsina obtained from the mechanical properties of the coal seam roof can be obtained, where a represents the dip angle of the coal seam.
[0009] Furthermore, in the mechanical model of the coal seam roof support beam, the undetermined constants C1, C2, C3, and C4 in the calculation formula for the bending deflection of the roof in a single stage of the goaf are derived from the boundary conditions w1(0)=0, w1′(0)=0, w1(H)=0, and w1′(H)=0, and their specific expressions are as follows: .
[0010] Furthermore, the expressions for the fixed end bending moments M(0), M(H) and the mid-span bending moment M(H / 2) are as follows: .
[0011] Furthermore, anchor bolts are driven into the artificial roof and floor to connect the coal seam roof and floor, providing normal constraint force for the artificial roof and floor. and shear strength During the filling stage, the uniformly distributed normal compressive stress q generated by the self-weight of the filling body acts on the artificial false bottom below, causing the artificial false bottom to bend and deform, and generating shear force at the anchoring point of the anchor bolt. The artificial false top and artificial false bottom are equivalent to a mechanical model of a fixed beam with an artificial isolation layer, with span L in meters and thickness t in meters. The effective normal compressive stress acting on the artificial false bottom at this time for: , In the formula: For horizontal ground stress, The additional normal stress is provided to the anchor bolt at the artificial false bottom, as expressed below: , In the formula: The preload of a single anchor bolt is expressed in N. , The spacing between anchor bolts is in meters (m). This refers to the unit weight of the rock stratum, expressed in N / m³. 3 ; This is the lateral pressure coefficient; This refers to the burial depth of the artificial false bottom, i.e., its height above the ground, in meters (m). The shear strength of the artificial false bottom is: , In the formula: The shear strength of the artificial false bottom is expressed in Pa. The bonding strength of the filler is expressed in Pa. The friction angle within the filling material is expressed in degrees (°). Shear resistance provided for all anchor bolts in the artificial false bottom; Let the unit weight of the backfill be γ2, and the height of the backfill during the mining stage be H2. Based on the mechanical model of the artificial isolation layer fixed beam, the uniformly distributed load intensity of the backfill acting on the equivalent beam of the artificial false bottom in the current stage is expressed as: The unit is N / m 3 The artificial false-bottom equivalent beam is subjected to a uniformly distributed load, and the maximum shear force at both ends of the artificial false-bottom equivalent beam is... Based on the shear stress distribution of the equivalent beam with an artificial false bottom, the maximum horizontal shear stress that the artificial false bottom can withstand is... for: , Horizontal structural force Average shear stress caused by vertical structural stress due to shear stress equilibrium at the contact surface Represented as: , Among them, horizontal tectonic forces γ is the unit weight of the rock strata; λ is the lateral pressure coefficient; h A The depth of the artificial false ceiling at the corresponding location; The contact area is expressed by the formula. calculate, Using the formula: The total shear stress of the artificial false bottom was obtained. ; When the total shear stress on the artificial false bottom When the comprehensive shear strength is reached, shear failure occurs, causing have to: , Based on the structural shear failure condition of the beam, the maximum stage filling height H2, determined by the mechanical properties of the artificial false ceiling, is obtained. The minimum value of the roof beam span H1 and the filling height H2, obtained from the mechanical properties of the coal seam roof and the artificial false roof, is taken as the theoretical maximum unsupported roof height H for stage division. max The upper limit is expressed as: , By analyzing the stress on the roof of the coal seam at different burial depths and repeating the above calculation steps, the dynamic division of the height of the near-vertical coal seam stratified mining stage can be finally achieved.
[0012] Furthermore, the shear resistance provided by the anchor bolt The calculation method is as follows: , In the formula: S b d represents the shear bearing capacity of the anchor bolt; d is the diameter of the anchor bolt, in meters. The shear strength of the anchor bolt material is expressed in Pa, and is typically taken as 1. , L represents the yield strength. a The anchorage length is in meters (m). This represents the bond strength between the anchor bolt and the grouting body or rock mass, expressed in Pa.
[0013] A computer device includes a processor and a memory, the processor being electrically connected to the memory, the memory being used to store instructions and data, and the processor being used to execute a method for dividing the height of near-vertical medium-thick and thick coal seam filling mining stages.
[0014] Beneficial Effects: This invention, by scientifically defining the scale of mining units, can enhance the stability of the roof and surrounding rock, reduce the exposed range and time of the roof, and the supporting structure formed by the filling body can significantly reduce the risks of rockburst and prevent accidents such as roof collapse. While ensuring the safety of the roof structure, precise calculations can more fully tap the mining potential, demonstrate optimal stage heights, and effectively reduce the number of sections and false roof constructions, directly reducing support costs and process complexity, achieving a better balance between safety and economy. The analysis results can provide direct theoretical guidance for the optimized layout of anchor bolt support, improving the synergy and efficiency of the overall support system. Furthermore, the technology can be matched with filling processes such as paste and gangue, optimizing filling parameters to reduce material waste, while also reducing ecological restoration costs, resulting in significant comprehensive benefits. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of a near-vertical coal seam sandwiching coal body structure model in an embodiment of the present invention.
[0016] Figure 2 This is a schematic diagram of the mechanical model of the coal seam roof support beam in an embodiment of the present invention.
[0017] Figure 3 This is a schematic diagram of the mechanical model of the artificial isolation layer fixed beam in an embodiment of the present invention.
[0018] Figure 4 This is a schematic diagram illustrating the stage division in an embodiment of the present invention. Detailed Implementation
[0019] The embodiments of the present invention will be further described below with reference to the accompanying drawings.
[0020] Near-vertical medium-thick and thick coal seam backfilling mining technology divides the coal seam into several horizontal stages and arranges the production system within each stage. It uses continuous mechanized mining technology to mine the coal seam in stages downwards in layers. Artificial false roofs and artificial false floors are constructed between the uppermost and lowermost layers of each stage. After the stage is mined out, grouting is performed between the artificial false roofs and artificial false floors to form a stable isolation and support structure in the vertical direction.
[0021] This invention discloses a method for dividing the filling stage of near-vertical medium-thick and thick coal seams. By constructing an artificial isolation layer, the near-vertical coal seam is divided into multiple stages from top to bottom, such as... Figure 4 As shown, mining is carried out using a full-mining and full-filling stage; among which, as Figure 1As shown, in a single stage, the upper artificial isolation layer serves as an artificial false roof, and the lower artificial isolation layer serves as an artificial false floor. Simultaneously, the artificial false floor of the previous stage is used as the artificial false roof of the next stage. The geological information of the vertical coal seam includes geological and mining conditions information, roof lithology information of the stage, artificial isolation layer strength information, strength information of the filling body formed by full mining and filling, and anchor bolt strength information for support. The artificial isolation layer is constructed by anchor bolts and high-strength filling materials. The strength information of the artificial isolation layer, the strength information of the filling body, and the anchor bolt strength information for support are obtained through laboratory testing.
[0022] The steps for dividing the stage height are as follows: S1. Establish a mechanical model for a single stage based on the geological information of the vertical coal seam; The specific steps for establishing a mechanical model for a single stage are as follows: like Figure 1 As shown, the mechanical model of a single stage includes a filling body, with an artificial false roof above and an artificial false floor below. A roof and floor plate with identical mechanical conditions are located on either side of the filling body. The roof plate is represented using a fixed-beam mechanical model, as shown in the example. Figure 2 As shown, the artificial false bottom is represented as a mechanical model of a fixed beam with an artificial isolation layer, as follows: Figure 3 As shown, the safe stage height is determined by utilizing the lithology and strength of the roof in the stage and the self-weight of the filling body constructed in the goaf of this stage; In the mechanical model of the coal seam roof support beam, the connection point between the roof and the artificial false roof is denoted as point O, and the connection point between the roof and the artificial false bottom is denoted as point A. The normal load on the roof is the component of the horizontal ground stress. The normal load gradually increases with the burial depth and is linearly distributed. The anchor bolts that construct the artificial false roof and artificial false bottom provide tensile force, including normal pressure and shear resistance.
[0023] S2, Bending deflection of the top plate during the analysis phase; Based on Kinnick's modification of the Heim stress hypothesis, the normal loads q1 and q2 at points O and A of the coal seam roof during a single stage of horizontal stress are expressed as follows: , In the formula: γ is the unit weight of the rock stratum, in N / m³. 3 λ is the lateral pressure coefficient; α is the dip angle of the near-vertical coal seam, in degrees; h O h A q represents the burial depth of the corresponding locations of the artificial false roof and artificial false bottom during the mining stage. O q A The horizontal geostress load at the corresponding locations of the artificial false roof and artificial false bottom during the mining stage; Horizontal ground stress acting on the linear load in the normal direction of the goaf roof : , In the formula: H is the span of the stage top plate, in meters; x represents the distance between a point on the mechanical model and the origin of the coordinate system. The differential equation of the bending deflection of the top plate and the linear normal load on the top plate are used to determine the angle of change. The bending deflection of the roof of the goaf in a single stage is obtained by simultaneously integrating the expressions. : , In the formula: E is the elastic modulus of the top plate, in GPa; I is the moment of inertia of the beam, in m. 4 ; C1, C2, C3, and C4 are undetermined constants determined by boundary conditions; x represents the distance between a point on the analogous mechanical model and the origin of the coordinate system.
[0024] Based on the mechanical model of a fixed beam in the coal seam roof, the maximum span H of the equivalent beam from point O to point A in the coal seam roof is derived; by the strength criterion, the maximum bending stress is set to not exceed the allowable tensile stress of the roof. The following relation is obtained: , In the formula: M(x) is the bending moment of the beam, in N·m; the section from point O to point A of the coal seam roof is equivalent to a rectangular cross-section beam, b is the width of the rectangular cross-section, taken as 1m, and h1 is the beam thickness, in m; This represents the maximum bending stress of the beam.
[0025] Let H be the maximum span from point O to point A of the coal seam roof. Therefore, the equivalent mechanical model of the fixed-supported beam of the coal seam roof can obtain the maximum bending moment of the beam by using the span H: take the maximum value of the absolute values of the bending moment M(0) at the fixed end of the roof, the bending moment M(H) at the roof point A, and the bending moment M(H / 2) at the mid-span. Through the maximum span H, the roof beam span H1=Hsina can be obtained from the mechanical properties of the coal seam roof, where a represents the dip angle of the coal seam.
[0026] In the mechanical model of the fixed beam of the coal seam roof, the undetermined constants C1, C2, C3, and C4 in the calculation formula of the bending deflection of the roof in a single stage of the goaf are obtained from the boundary conditions w1(0)=0, w1′(0)=0, w1(H)=0, and w1′(H)=0, and the specific expressions are as follows: ; Through the formula: Substituting the values of the two endpoints x=H, x=H and the midpoint x=H / 2, we obtain the derivative.
[0027] The expressions for the fixed end bending moments M(0), M(H) and the mid-span bending moment M(H / 2) are as follows: .
[0028] S3. Calculate the theoretical maximum unsupported roof height for stage division using the coal seam dip angle and stage height; use the maximum unsupported roof height to determine the safe stage height when full mining is completed. Artificial roofs and floors are constructed by driving anchor bolts to connect the coal seam roof and floor, providing normal constraint forces for the artificial roofs and floors. and shear strength During the filling stage, the uniformly distributed normal compressive stress q generated by the self-weight of the filling body acts on the artificial false bottom below, causing the artificial false bottom to bend and deform, and generating shear force at the anchoring point of the anchor bolt. The artificial false top and artificial false bottom are equivalent to a mechanical model of a fixed beam with an artificial isolation layer, with span L in meters and thickness t in meters, for analysis: The effective normal compressive stress acting on the artificial false bottom at this time for: , In the formula: For horizontal ground stress, The additional normal stress is provided to the anchor bolt at the artificial false bottom, as expressed below: , In the formula: The preload of a single anchor bolt is expressed in N. , The spacing between anchor bolts is in meters (m). This refers to the unit weight of the rock stratum, expressed in N / m³. 3 ; This is the lateral pressure coefficient; This refers to the burial depth of the artificial false bottom, i.e., its height above the ground, in meters (m). The shear strength of the artificial false bottom is: , In the formula: The shear strength of the artificial false bottom is expressed in Pa. The bonding strength of the filler is expressed in Pa. The friction angle within the filling material is expressed in degrees (°). Shear resistance provided for all anchor bolts in the artificial false bottom.
[0029] Let the bulk density of the backfill be γ2, and the height of the backfill during the mining stage be H2, such as Figure 3 As shown, based on the mechanical model of the artificial isolation layer fixed beam, since the coal seam thickness is uniform both vertically and horizontally, let OB represent the coal seam thickness, which is also equivalent to the length of the artificial false bottom. The uniformly distributed load intensity of the filling material acting on the equivalent beam of the artificial false bottom at the current stage is expressed as... The unit is N / m 3The artificial false-bottom equivalent beam is subjected to a uniformly distributed load, and the maximum shear force at both ends of the artificial false-bottom equivalent beam is... Based on the shear stress distribution of the equivalent beam with an artificial false bottom, the maximum horizontal shear stress that the artificial false bottom can withstand is... for: , Horizontal structural force Average shear stress caused by vertical structural stress due to shear stress equilibrium at the contact surface Represented as: , Among them, horizontal tectonic forces γ is the unit weight of the rock strata; λ is the lateral pressure coefficient; h A The depth of the artificial false ceiling at the corresponding location; The contact area is expressed by the formula. calculate, Using the formula: The total shear stress of the artificial false bottom was obtained. ; When the total shear stress on the artificial false bottom When the comprehensive shear strength is reached, shear failure occurs, causing have to: , Based on the structural shear failure condition of the beam, the maximum stage filling height H2, determined by the mechanical properties of the artificial false ceiling, is obtained. The minimum value of the roof beam span H1 and the filling height H2, obtained from the mechanical properties of the coal seam roof and the artificial false roof, is taken as the theoretical maximum unsupported roof height H for stage division. max The upper limit is expressed as: , By analyzing the stress on the roof of the coal seam at different burial depths and repeating the above calculation steps, the dynamic division of the height of the near-vertical coal seam stratified mining stage can be finally achieved.
[0030] Shear resistance provided by anchor bolts The calculation method is as follows: , In the formula: S b d represents the shear bearing capacity of the anchor bolt; d is the diameter of the anchor bolt, in meters. The shear strength of the anchor bolt material is expressed in Pa, and is typically taken as 1. , L represents the yield strength. a The anchorage length is in meters (m). This represents the bond strength between the anchor bolt and the grouting body or rock mass, expressed in Pa.
[0031] Obviously, the above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it, and should not be used to limit the scope of protection of the present invention. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should be considered as part of the specification.
Claims
1. A method for dividing the height of near-vertical medium-thick and thick coal seams during the filling stage, characterized in that, By constructing artificial isolation layers, the nearly vertical coal seam is divided into multiple stages from top to bottom, and full mining and filling are adopted to complete the mining of each stage; the steps for dividing the stage height are as follows: S1. Establish a mechanical model for a single stage based on the geological information of the vertical coal seam; S2, Bending deflection of the top plate during the analysis phase; S3. Calculate the maximum unsupported roof height theoretically for each stage division using the coal seam dip angle and stage height, and use the maximum unsupported roof height to determine the safe stage height when full mining is completed.
2. The method for dividing the height of near-vertical medium-thick and thick coal seams into filling stages according to claim 1, characterized in that, In a single stage, the upper artificial isolation layer serves as an artificial false roof, and the lower artificial isolation layer serves as an artificial false bottom. At the same time, the artificial false bottom of the previous stage is used as the artificial false roof of the next stage. The geological information of vertical coal seams includes geological and mining conditions information, roof lithology information of the stage, artificial isolation layer strength information, filling strength information of the filling body formed by full mining and filling, and anchor bolt strength information for support. The artificial isolation layer is constructed using anchor bolts and high-strength filling material; The strength information of the artificial isolation layer, the strength information of the filling body, and the strength information of the anchor bolts used for support were obtained through laboratory testing.
3. The method for dividing the height of near-vertical medium-thick and thick coal seams into filling stages according to claim 2, characterized in that, The specific steps for establishing a mechanical model for a single stage are as follows: The mechanical model of a single stage includes a backfill body, an artificial false roof above the backfill body and an artificial false floor below it, and a roof plate and a floor plate with similar mechanical conditions on both sides of the backfill body. The roof plate is represented as a coal seam roof fixed beam mechanical model using a fixed beam mechanical model, and the artificial false floor is represented as an artificial isolation layer fixed beam mechanical model. The safe stage height is determined by the lithology and strength of the roof plate in the stage and the self-weight of the backfill body constructed in the goaf of this stage. In the mechanical model of the coal seam roof support beam, the connection point between the roof and the artificial false roof is denoted as point O, and the connection point between the roof and the artificial false bottom is denoted as point A. The normal load on the roof is the component of the horizontal ground stress. The normal load gradually increases with the burial depth and is linearly distributed. The anchor bolts that construct the artificial false roof and artificial false bottom provide tensile force, including normal pressure and shear resistance.
4. The method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages according to claim 3, characterized in that, Based on Kinnick's modification of the Heim stress hypothesis, the normal loads q1 and q2 at points O and A of the coal seam roof during a single stage of horizontal stress are expressed as follows: ， In the formula: γ is the unit weight of the rock stratum, in N / m³. 3 λ is the lateral pressure coefficient; α is the dip angle of the near-vertical coal seam, in degrees; h O h A q represents the burial depth of the corresponding locations of the artificial false roof and artificial false bottom during the mining stage. O q A The horizontal geostress load at the corresponding locations of the artificial false roof and artificial false bottom during the mining stage; Horizontal ground stress acting on the linear load in the normal direction of the goaf roof : ， In the formula: H is the span of the stage top plate, in meters; x represents the distance between a point on the mechanical model and the origin of the coordinate system. The differential equation of the bending deflection of the top plate and the linear normal load on the top plate are used to determine the angle of change. The bending deflection of the roof of the goaf in a single stage is obtained by simultaneously integrating the expressions. : ， In the formula: E is the elastic modulus of the top plate, in GPa; I is the moment of inertia of the beam, in m. 4 ; C1, C2, C3, and C4 are undetermined constants determined by boundary conditions; x is the distance between a point on the mechanical model and the origin of the coordinate system. Based on the mechanical model of a fixed beam in the coal seam roof, the maximum span H of the equivalent beam from point O to point A in the coal seam roof is derived; by the strength criterion, the maximum bending stress is set to not exceed the allowable tensile stress of the roof. The following relation is obtained: ， In the formula: M(x) is the bending moment of the beam, in N·m; the section from point O to point A of the coal seam roof is equivalent to a rectangular cross-section beam, b is the width of the rectangular cross-section, taken as 1m, and h1 is the beam thickness, in m; The maximum bending stress of the beam; Let H be the maximum span from point O to point A of the coal seam roof. Therefore, the equivalent mechanical model of the fixed-supported beam of the coal seam roof can obtain the maximum bending moment of the beam by using the span H: take the maximum value of the absolute values of the bending moment M(0) at the fixed end of the roof, the bending moment M(H) at the roof point A, and the mid-span bending moment M(H / 2) of OA; through the maximum span H, the roof beam span H1=Hsina obtained from the mechanical properties of the coal seam roof can be obtained, where a represents the dip angle of the coal seam.
5. The method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages according to claim 4, characterized in that, In the mechanical model of the fixed beam of the coal seam roof, the undetermined constants C1, C2, C3, and C4 in the calculation formula of the bending deflection of the roof in a single stage of the goaf are obtained from the boundary conditions w1(0)=0, w1′(0)=0, w1(H)=0, and w1′(H)=0, and the specific expressions are as follows: 。 6. The method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages according to claim 4, characterized in that, The expressions for the fixed end bending moments M(0), M(H) and the mid-span bending moment M(H / 2) are as follows: 。 7. The method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages according to claim 4, characterized in that, Artificial roofs and floors are constructed by driving anchor bolts to connect the coal seam roof and floor, providing normal constraint forces for the artificial roofs and floors. and shear strength ; The uniformly distributed normal compressive stress q generated by the self-weight of the filling body formed during the filling stage acts on the artificial false bottom below, causing the artificial false bottom to bend and deform, and generating shear force at the anchor point of the anchor bolt. The artificial false top and artificial false bottom are equivalent to a mechanical model of a fixed beam with an artificial isolation layer, with span L in meters and thickness t in meters. The effective normal compressive stress acting on the artificial false bottom at this time for: , In the formula: For horizontal ground stress, The additional normal stress is provided to the anchor bolt at the artificial false bottom, as expressed below: , In the formula: The preload of a single anchor bolt is expressed in N. , The spacing between anchor bolts is in meters (m). This refers to the unit weight of the rock stratum, expressed in N / m³. 3 ; This is the lateral pressure coefficient; This refers to the burial depth of the artificial false bottom, i.e., its height above the ground, in meters (m). The shear strength of the artificial false bottom is: , In the formula: The shear strength of the artificial false bottom is expressed in Pa. The bonding strength of the filler is expressed in Pa. The friction angle within the filling material is expressed in degrees (°). Shear resistance provided for all anchor bolts in the artificial false bottom; Let the unit weight of the backfill be γ2, and the height of the backfill during the mining stage be H2. Based on the mechanical model of the artificial isolation layer fixed beam, the uniformly distributed load intensity of the backfill acting on the equivalent beam of the artificial false bottom in the current stage is expressed as: The unit is N / m 3 The artificial false-bottom equivalent beam is subjected to a uniformly distributed load, and the maximum shear force at both ends of the artificial false-bottom equivalent beam is... Based on the shear stress distribution of the equivalent beam with an artificial false bottom, the maximum horizontal shear stress that the artificial false bottom can withstand is... for: , Horizontal structural force Average shear stress caused by vertical structural stress due to shear stress equilibrium at the contact surface Represented as: ， Among them, horizontal tectonic forces γ is the unit weight of the rock strata; λ is the lateral pressure coefficient; h A The depth of the artificial false ceiling at the corresponding location; The contact area is expressed by the formula. calculate, Using the formula: The total shear stress of the artificial false bottom was obtained. ; When the total shear stress on the artificial false bottom When the comprehensive shear strength is reached, shear failure occurs, causing have to: ， Based on the structural shear failure condition of the beam, the maximum stage filling height H2, determined by the mechanical properties of the artificial false ceiling, is obtained. The minimum value of the roof beam span H1 and the filling height H2, obtained from the mechanical properties of the coal seam roof and the artificial false roof, is taken as the theoretical maximum unsupported roof height H for stage division. max The upper limit is expressed as: ， By analyzing the stress on the roof of the coal seam at different burial depths and repeating the above calculation steps, the dynamic division of the height of the near-vertical coal seam stratified mining stage can be finally achieved.
8. The method for dividing the height of near-vertical medium-thick and thick coal seam backfilling mining stages according to claim 7, characterized in that, Shear resistance provided by anchor bolts The calculation method is as follows: ， In the formula: S b d represents the shear bearing capacity of the anchor bolt; d is the diameter of the anchor bolt, in meters. The shear strength of the anchor bolt material is expressed in Pa, and is typically taken as 1. , L represents the yield strength. a The anchorage length is in meters (m). This represents the bond strength between the anchor bolt and the grouting body or rock mass, expressed in Pa.
9. A computer device, characterized in that, It includes a processor and a memory, the processor being electrically connected to the memory, the memory being used to store instructions and data, and the processor being used to execute the height division method for near-vertical medium-thick and thick coal seam filling mining stages as described in any one of claims 1-8.