A multi-coal seam and multi-mining face modeling method for FLAC3D

Abstract

A multi-coal-seam and multi-working-face modeling method for FLAC3D includes the following steps: determining the model size, drawing a cross-sectional schematic diagram along the dip of the working face, then adjusting and arranging the cross-sectional schematic diagram in Rhino software, and establishing the curved surfaces of the coal seam and working face, roof and floor plates, and surrounding curved surfaces based on the cross-sectional schematic diagram. After the model is meshed, the output is a "FLAC3D" format file and imported into FLAC3D software, finally generating a three-dimensional, detailed, and complex model of multiple coal seams and multiple working faces. This method improves the accuracy of simulation results under specific geological conditions or complex mining conditions, and provides a strong guarantee for safe coal mine production.

Description

Technical Field

[0001] This invention relates to a multi-coal-seam and multi-working-face modeling method for FLAC3D, belonging to the field of coal mine safety mining and simulation technology. Background Technology

[0002] FLAC3D is a software developed by ITASC, Inc. in the United States, specifically for geotechnical engineering. It is used to handle soil, rock, groundwater, geothermal energy, and stratum support. Currently, it is widely used in various fields such as civil engineering, transportation, petroleum, and mining engineering, and is the internationally recognized general-purpose analysis software in the geotechnical engineering community. However, its preprocessing and self-modeling capabilities are relatively low, and it cannot directly construct detailed 3D complex models. This results in poor accuracy of simulation results under specific geological conditions or complex mining conditions, failing to meet the modeling requirements of multiple coal seams and multiple working faces, ultimately failing to provide a guarantee for safe coal mine production. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-coal-seam and multi-working-face modeling method for FLAC3D. This method can construct a detailed and complex three-dimensional model of multiple coal seams and multiple working faces, improve the accuracy of simulation results under specific geological conditions or complex mining conditions, and provide strong support for safe coal mine production.

[0004] To achieve the above objectives, the present invention provides a multi-coal-seam, multi-working-face modeling method for FLAC3D, comprising the following steps:

[0005] (1) Determine the model dimensions:

[0006] The scope of the numerical model is defined based on the coal seam mining situation and research objectives. The model size is consistent with the actual stratum size, and the cut-off point of the working face under study is used as the reference position.

[0007] (2) Draw a cross-sectional diagram along the working face:

[0008] Based on the traverse point information near the roadway in the mining engineering plan, multiple cross-sectional schematic diagrams along the working face dip at a set distance from the cutting eye are drawn in AutoCAD software. The smaller the set interval distance between the traverse point information and the cutting eye, the more cross-sectional schematic diagrams are drawn, and the more detailed the model is built later.

[0009] (3) Adjust the arrangement of the cross-sectional diagram in Rhino software:

[0010] Open the Rhino software, set the model unit to m, and the absolute tolerance to 0.1 units; import the multiple cross-sectional schematic diagrams drawn in step (2) into the Rhino software, and use the BoxEdit command to modify the coordinates of each cross-sectional schematic diagram so that each cross-sectional schematic diagram is consistent in position in dip, arranged from near to far in strike according to distance from the cut eye, and adjusted in height according to the contour data of the coal seam floor.

[0011] (4) Establish the curved surfaces of the coal seam and working face based on the cross-sectional schematic diagram:

[0012] Select all the curves in the cross-sectional diagrams at the same position, use the loft command to loft them, and create the surfaces of the coal seam and working face based on the selected curves;

[0013] (5) Create the top and bottom plates and the surrounding curved surfaces:

[0014] The lithological structure and thickness of the roof and floor strata are determined based on the borehole columnar section. The roof strata of the uppermost coal seam are used as a reference, and the copy and move commands are used to construct the roof strata of the model. The floor strata of the lowermost coal seam are used as a reference, and the plane command is used to create surfaces at the top, bottom and around the model.

[0015] (6) Model meshing:

[0016] Select all surfaces created in steps (4) and (5), and combine them into a multi-surface using the join command; mesh the multi-surface using mesh; enter the “SetWorkingFolder” command and select the file save path; select the meshed model, optimize the mesh using the Gsuf function of the Griddle plugin in Rhino, and set the shape and size of the mesh;

[0017] (7) Output "FLAC3D" format file:

[0018] Select the optimized mesh model and use the Gvol function of the Griddle plugin in Rhino to output a numerical model in FLAC3D format.

[0019] (8) Import into FLAC3D software:

[0020] Open the FLAC3D software, click the "File-Grid-import from FLAC3D grid file" command in the menu bar, import the "FLAC3D" format file output in the previous step, and generate a detailed and complex three-dimensional model of multiple coal seams and working faces.

[0021] Furthermore, the steps for drawing the cross-sectional schematic diagram along the working surface in step (2) are as follows:

[0022] a. Rotate the working surface of the defined area so that it tends along the X-axis and moves along the Y-axis;

[0023] b. Use the ID command to obtain the x and y coordinates of the intersection point of the profile line and the working face roadway, and obtain the z coordinate of the intersection point based on the traverse point information, thereby obtaining the specific coordinates of the outer side of the roadway floor;

[0024] c. Draw the cross-sectional lines of the upper coal seam roof and the lower coal seam floor based on the measured data;

[0025] d. Connect the coordinates of the outer sides of the floor plates of the two roadways in the same working face, and at the same time, draw vertical rays upward from the outer side of the floor plates of each roadway to the line connecting the two roadways in the next working face or the profile line of the roof of the next coal seam, starting from the position of the outer side of the floor plates of each roadway.

[0026] e. Complete the coal pillars on both sides according to the actual situation, and complete the drawing of the cross-sectional schematic diagram.

[0027] Furthermore, in step b, if there is no traverse point information at the section to be drawn, it is approximated using the difference method, and the calculation formula is as follows:

[0028]

[0029] In the formula, z0 is the z-coordinate of the intersection of the profile line and the working face roadway; z1 is the z-coordinate of the guide point below the intersection of the profile line and the working face roadway; z2 is the z-coordinate of the guide point above the intersection of the profile line and the working face roadway; y0 is the y-coordinate of the intersection of the profile line and the working face roadway; y1 is the y-coordinate of the guide point below the intersection of the profile line and the working face roadway; and y2 is the y-coordinate of the guide point above the intersection of the profile line and the working face roadway.

[0030] Furthermore, in step (6), the shape of the mesh is set using Gsuf, including quadrilateral mesh, triangular mesh, and hybrid mesh composed of triangular mesh and quadrilateral mesh.

[0031] This invention determines the model dimensions, draws a cross-sectional schematic diagram along the working face, then adjusts and arranges the cross-sectional schematic diagram in Rhino software, and establishes the curved surfaces of the coal seam and working face, roof and floor plates, and surrounding curved surfaces based on the cross-sectional schematic diagram. After the model is meshed, it is output as a "FLAC3D" format file and imported into FLAC3D software, ultimately generating a complex three-dimensional model of multiple coal seams and multiple working faces. This improves the accuracy of simulation results under specific geological conditions or complex mining conditions, and provides a strong guarantee for safe coal mine production. Attached Figure Description

[0032] Figure 1 This is a flowchart of the present invention;

[0033] Figure 2 This is a schematic diagram of the differential solution for the z-coordinate of a traverse according to the present invention;

[0034] Figure 3 This is a schematic diagram of the model establishment area defined in the mining engineering plan in an embodiment of the present invention;

[0035] Figure 4 This is a cross-sectional schematic diagram of the cutting position in the inclined direction of the 250101-2 working face in an embodiment of the present invention;

[0036] Figure 5 This is a cross-sectional schematic diagram drawn at a distance of 300m from the cut eye position in an embodiment of the present invention;

[0037] Figure 6 This is a cross-sectional schematic diagram drawn at a distance of 600m from the cut eye position in an embodiment of the present invention;

[0038] Figure 7 This is a rendering of the first face after lofting in an embodiment of the present invention;

[0039] Figure 8 This is a diagram showing the effect of laying out all the faces of the coal seam in an embodiment of the present invention;

[0040] Figure 9 This is a model diagram created in Rhino in an embodiment of the present invention;

[0041] Figure 10 This is a meshed model diagram in an embodiment of the present invention;

[0042] Figure 11 This is a model diagram with mesh optimization in an embodiment of the present invention;

[0043] Figure 12 This is a model diagram presented in FLAC3D in an embodiment of the present invention;

[0044] Figure 13 This is a slice of the model at Y=0 in an embodiment of the present invention;

[0045] Figure 14 This is a slice of the model at Y=300 in an embodiment of the present invention;

[0046] Figure 15 This is a slice of the model at Y=600 in an embodiment of the present invention. Detailed Implementation

[0047] The invention will now be further described with reference to the accompanying drawings.

[0048] like Figure 1 As shown, a multi-coal-seam, multi-working-face modeling method for FLAC3D includes the following steps:

[0049] (1) Determine the model dimensions:

[0050] The scope of the numerical model is defined based on the coal seam mining situation and research objectives. The model size is consistent with the actual stratum size, and the cut-off point of the working face under study is used as the reference position.

[0051] (2) Draw a cross-sectional diagram along the working face:

[0052] Based on the traverse point information near the roadway in the mining engineering plan, multiple cross-sectional schematic diagrams along the working face dip at a set distance from the cutting eye are drawn in AutoCAD software. The smaller the set interval distance between the traverse point information and the cutting eye, the more cross-sectional schematic diagrams are drawn, and the more detailed the model is built later.

[0053] (3) Adjust the arrangement of the cross-sectional diagram in Rhino software:

[0054] Open the Rhino software, set the model unit to m, and the absolute tolerance to 0.1 units; import the multiple cross-sectional schematic diagrams drawn in step (2) into the Rhino software, and use the BoxEdit command to modify the coordinates of each cross-sectional schematic diagram so that each cross-sectional schematic diagram is consistent in position in dip, arranged from near to far in strike according to distance from the cut eye, and adjusted in height according to the contour data of the coal seam floor.

[0055] (4) Establish the curved surfaces of the coal seam and working face based on the cross-sectional schematic diagram:

[0056] Select all the curves in the cross-sectional diagrams at the same position, use the loft command to loft them, and create the surfaces of the coal seam and working face based on the selected curves;

[0057] (5) Create the top and bottom plates and the surrounding curved surfaces:

[0058] The lithological structure and thickness of the roof and floor strata are determined based on the borehole columnar section. The roof strata of the uppermost coal seam are used as a reference, and the copy and move commands are used to construct the roof strata of the model. The floor strata of the lowermost coal seam are used as a reference, and the plane command is used to create surfaces at the top, bottom and around the model.

[0059] (6) Model meshing:

[0060] Select all surfaces created in steps (4) and (5), and combine them into a multi-surface using the join command; mesh the multi-surface using mesh; enter the “SetWorkingFolder” command and select the file save path; select the meshed model, optimize the mesh using the Gsuf function of the Griddle plugin in Rhino, and set the shape and size of the mesh;

[0061] (7) Output "FLAC3D" format file:

[0062] Select the optimized mesh model and use the Gvol function of the Griddle plugin in Rhino to output a numerical model in FLAC3D format.

[0063] (8) Import into FLAC3D software:

[0064] Open the FLAC3D software, click the "File-Grid-import from FLAC3D grid file" command in the menu bar, import the "FLAC3D" format file output in the previous step, and generate a detailed and complex three-dimensional model of multiple coal seams and working faces.

[0065] As a preferred embodiment, the step of drawing the cross-sectional schematic diagram along the working surface in step (2) is as follows:

[0066] a. Rotate the working surface of the defined area so that it tends to be horizontal along the X-axis and vertical along the Y-axis;

[0067] b. Use the ID command to obtain the x and y coordinates of the intersection point of the profile line and the working face roadway, and obtain the z coordinate of the intersection point based on the traverse point information, thereby obtaining the specific coordinates of the outer side of the roadway floor;

[0068] c. Draw the cross-sectional lines of the upper coal seam roof and the lower coal seam floor based on the measured data;

[0069] d. Connect the coordinates of the outer sides of the floor plates of the two roadways in the same working face, and at the same time, draw vertical rays upward from the outer side of the floor plates of each roadway to the line connecting the two roadways in the next working face or the profile line of the roof of the next coal seam, starting from the position of the outer side of the floor plates of each roadway.

[0070] e. Complete the coal pillars on both sides according to the actual situation, and complete the drawing of the cross-sectional schematic diagram.

[0071] Furthermore, such as Figure 2 As shown, in step b, if there is no traverse point information at the section to be drawn, it is approximated by the difference method, and the calculation formula is as follows:

[0072]

[0073] In the formula, z0 is the z-coordinate of the intersection of the profile line and the working face roadway; z1 is the z-coordinate of the guide point below the intersection of the profile line and the working face roadway; z2 is the z-coordinate of the guide point above the intersection of the profile line and the working face roadway; y0 is the y-coordinate of the intersection of the profile line and the working face roadway; y1 is the y-coordinate of the guide point below the intersection of the profile line and the working face roadway; and y2 is the y-coordinate of the guide point above the intersection of the profile line and the working face roadway.

[0074] Furthermore, in step (6), the shape of the mesh is set using Gsuf, including quadrilateral mesh, triangular mesh, and hybrid mesh composed of triangular mesh and quadrilateral mesh.

[0075] Example:

[0076] This invention was used to establish a detailed and complex three-dimensional model of a certain area in the 2501 mining area of ​​a certain mine. The specific steps are as follows:

[0077] (1) Based on the coal seam mining situation and research objectives, the scope of the numerical model is defined, and the scope is delineated as follows: Figure 3 As shown, a model with dimensions of 450m(X)×600m(Y)×230m(Z) is established. The research target is the 250101-2 working face, with the cut eye of the working face as the reference position.

[0078] (2) Based on the traverse point information in the mining engineering plan, draw three schematic cross-sections of the working face along the dip direction in AutoCAD software. The cross-section locations are the cut-in point of the 250101-2 working face, 300m from the cut-in point, and 600m from the cut-in point, respectively. The schematic cross-sections are shown in the figure below. Figures 4-6 As shown;

[0079] (3) Set the model unit in Rhino software to m and the absolute tolerance to 0.1 units; import the three drawn cross-sectional diagrams into Rhino software and use the BoxEdit command to make the cross-sectional diagrams consistent in the dip direction; arrange them according to the distance from the cut-in point in the strike direction, that is, with the cross-sectional diagram at the cut-in point as a reference, place the second cross-sectional diagram 300m away from the cross-sectional diagram at the cut-in point along the strike direction of the working face, and place the third cross-sectional diagram 600m away from the cross-sectional diagram at the cut-in point along the strike direction of the working face; adjust the height according to the contour information of the coal seam floor, the height coordinate of the first cross-sectional diagram is 987m, the height coordinate of the second cross-sectional diagram is 954m, and the height coordinate of the third cross-sectional diagram is 933m;

[0080] (4) Select all lines in the same position in the cross-sectional view, and use the loft command to loft them. Create a surface based on the selected curves. After lofting the first surface, as shown... Figure 7 As shown, after the entire coal seam is laid out, it is as follows: Figure 8 As shown;

[0081] (5) Determine the lithological structure and thickness of the top and bottom strata based on the borehole columnar section; using the top surface of the uppermost coal seam as a reference, construct the model's top strata using the copy and move commands; using the bottom surface of the lowermost coal seam as a reference, construct the model's bottom strata; using the plane command, create planes at the top, bottom, and around the model; the constructed model is as follows. Figure 9 As shown;

[0082] (6) Select all the created faces and use the join command to combine them into a multifaceted surface; use mesh to mesh the multifaceted surface. The meshed model is as follows: Figure 10 As shown; enter the "SetWorkingFolder" command and select the file save path; select the meshed model, use the Gsuf command of the Griddle plugin in Rhino to optimize the mesh, and set the mesh shape to a quadrilateral mesh, using the default mesh size. The optimized mesh model is shown below. Figure 11 As shown;

[0083] (7) Select the meshed model and use the Gvol command of the Griddle plugin in Rhino to output a numerical model in "FLAC3D" format.

[0084] (8) Open the FLAC3D software, click the "File-Grid-import from FLAC3D grid file" command in the menu bar, import the "FLAC3D" format file output in the previous step, and you can generate a detailed and complex three-dimensional model of multiple coal seams and working faces, such as... Figure 12 As shown, the cross-sectional views along the working face at the cut-in position, at a distance of 300m from the cut-in position, and at a distance of 600m from the cut-in position are as follows. Figures 13-15 As shown.

Claims

1. A method for modeling multiple coal seams and multiple working faces in FLAC3D, characterized in that, The steps include the following: (1) Determine the model dimensions: The scope of the numerical model is defined based on the coal seam mining situation and research objectives. The model size is consistent with the actual stratum size, and the cut-off point of the working face under study is used as the reference position. (2) Draw a cross-sectional diagram along the working face: Based on the traverse point information near the roadway in the mining engineering plan, multiple cross-sectional schematic diagrams along the working face dip at a set distance from the cutting eye are drawn in AutoCAD software. The smaller the set interval distance between the traverse point information and the cutting eye, the more cross-sectional schematic diagrams are drawn, and the more detailed the model is built later. (3) Adjust the arrangement of the cross-sectional diagram in Rhino software: Open the Rhino software, set the model unit to m, and the absolute tolerance to 0.1 units; import the multiple cross-sectional schematic diagrams drawn in step (2) into the Rhino software, and use the BoxEdit command to modify the coordinates of each cross-sectional schematic diagram so that each cross-sectional schematic diagram is consistent in position in dip, arranged from near to far in strike according to distance from the cut eye, and adjusted in height according to the contour data of the coal seam floor. (4) Establish the curved surfaces of the coal seam and working face based on the cross-sectional diagram: Select all the curves in the cross-sectional diagrams at the same position, use the loft command to loft them, and create the surfaces of the coal seam and working face based on the selected curves; (5) Create the top and bottom plates and the surrounding curved surfaces: The lithological structure and thickness of the roof and floor strata are determined based on the borehole columnar section. The roof strata of the uppermost coal seam are used as a reference, and the copy and move commands are used to construct the roof strata of the model. The floor strata of the lowermost coal seam are used as a reference, and the plane command is used to create surfaces at the top, bottom and around the model. (6) Model meshing: Select all surfaces created in steps (4) and (5), and combine them into a multi-surface using the join command; mesh the multi-surface using mesh; enter the "SetWorkingFolder" command and select the path to save the file; select the meshed model, optimize the mesh using the Gsuf function of the Griddle plugin in Rhino, and set the shape and size of the mesh; (7) Output "FLAC3D" format file: Select the optimized mesh model and use the Gvol function of the Griddle plugin in Rhino to output a numerical model in FLAC3D format. (8) Import into FLAC3D software: Open the FLAC3D software, click the "File-Grid-import from FLAC3D grid file" command in the menu bar, import the "FLAC3D" format file output in the previous step, and generate a detailed and complex three-dimensional model of multiple coal seams and working faces.

2. The multi-coal seam and multi-working-face modeling method for FLAC3D according to claim 1, characterized in that, The steps for drawing the cross-sectional schematic diagram along the working face in step (2) are as follows: a. Rotate the working surface of the defined area so that it tends along the X-axis and moves along the Y-axis; b. Use the ID command to obtain the x and y coordinates of the intersection point of the profile line and the working face roadway, and obtain the z coordinate of the intersection point based on the traverse point information, thereby obtaining the specific coordinates of the outer side of the roadway floor. c. Draw the cross-sectional lines of the upper coal seam roof and the lower coal seam floor based on the measured data; d. Connect the coordinates of the outer sides of the floor plates of the two roadways in the same working face, and at the same time, draw vertical rays upward from the outer side of the floor plates of each roadway to the line connecting the two roadways in the next working face or the profile line of the roof of the next coal seam, starting from the position of the outer side of the floor plates of each roadway. e. Complete the coal pillars on both sides according to the actual situation, and complete the drawing of the cross-sectional schematic diagram.

3. The multi-coal seam and multi-working-face modeling method for FLAC3D according to claim 2, characterized in that, In step b, if there is no traverse point information at the section to be drawn, it is approximated by the difference method, and the calculation formula is as follows: In the formula, z0 is the z-coordinate of the intersection of the profile line and the working face roadway; z1 is the z-coordinate of the guide point below the intersection of the profile line and the working face roadway; z2 is the z-coordinate of the guide point above the intersection of the profile line and the working face roadway; y0 is the y-coordinate of the intersection of the profile line and the working face roadway; y1 is the y-coordinate of the guide point below the intersection of the profile line and the working face roadway; and y2 is the y-coordinate of the guide point above the intersection of the profile line and the working face roadway.

4. The multi-coal seam and multi-working-face modeling method for FLAC3D according to claim 1, characterized in that, In step (6), the shape of the mesh is set using Gsuf, including quadrilateral mesh, triangular mesh, and hybrid mesh composed of triangular mesh and quadrilateral mesh.

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