Method for mapping of spatial morphological characteristics of folds

Abstract

The application discloses a kind of fold space form feature's annotation method, belong to digital geology annotation technical field, solve the problem of large workload and low precision of existing fold space form feature's investigation method.The application obtains the coordinate information of the two wings of fold in indoor through digital three-dimensional map model and calculates the occurrence information of the two wings of fold, and is projected and transformed by coordinate space, to realize the accurate drawing of fold form plane profile feature on any engineering profile, greatly reduce the workload of field geological annotation, reduce operation risk, realize higher precision identification and accurate calculation drawing compared with satellite remote sensing interpretation.

Description

Technical Field

[0001] This invention relates to the field of digital geological mapping technology, specifically to a method for mapping the spatial morphological features of folds. Background Technology

[0002] The accuracy of fold feature mapping is the cornerstone of geological work, determining the reliability of subsequent geological interpretation and application. Accurate investigation of fold spatial morphology plays a crucial role in analyzing regional tectonic evolution history and stress fields, mineral resource exploration and metallogenic regularity research, various engineering geological stability assessments, hydrogeological analysis and evaluation, and topographic mapping.

[0003] Currently, there are two main methods for investigating fold structures: 1. Field survey method: observing and measuring the characteristics of rock bedding, fold morphology, and fold axis orientation through rock outcrops and profiles; 2. Fold morphology feature extraction method based on satellite remote sensing imagery: using high-resolution image data to observe the morphological features of the Earth's surface, such as the linearity and deformation of folds, constructing remote sensing interpretation markers for typical fold morphologies in the region, carrying out fold identification and interpretation work, and extracting their morphological features.

[0004] However, the first method is labor-intensive, time-consuming, and risky, and is limited by terrain and landforms, making it unable to cover areas that are inaccessible to personnel, thus affecting the survey results; the second method, although it can acquire surface information over a wide area and quickly identify the location and shape of folds, is limited by its resolution, resulting in lower identification accuracy and difficulty in identifying small folds. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides a method for drawing folded spatial morphological features, which solves the problems of high workload and low accuracy in existing methods for drawing folded spatial morphological features.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for mapping the spatial morphological features of folds is provided, including the following steps:

[0008] S1. Determine the cross-sectional orientation in the digital 3D map model containing folded regions and establish the cross-sectional equations;

[0009] S2. Collect multiple coordinate points on the folded area in the digital 3D map model, and construct the folded geometric element equation based on the multiple coordinate points. Based on the folded geometric element equation, project the multiple coordinate points onto the profile equation, and obtain multiple projection points to reflect the folded geometric elements in the profile equation.

[0010] S3. Construct a profile coordinate system based on the horizontal and vertical displacement increments between multiple projection points, and connect multiple projection points along the profile path to complete the mapping of the fold spatial morphology features.

[0011] Furthermore, the equations for the geometric elements of the fold include the equations for the dipping planes of the two flanks, which in turn include the plane equations for the left and right flanks; wherein, the plane equation for the left flank is:

[0012] ;

[0013] ;

[0014] ;

[0015] ;

[0016] The equation of the right wing plane is:

[0017] ;

[0018] ;

[0019] ;

[0020] ;

[0021] in, , and These are the three axes of the coordinate system in a digital 3D map model; , and All of these are coefficients of the left-wing plane equation; For the constant term of the left-wing plane equation; , , All of these are coefficients of the right-wing plane equation; For the constant term of the right-wing plane equation; and These represent the average inclinations of the left and right wings, respectively. and These are the average tilt angles of the left and right wings, respectively.

[0022] Furthermore, and The calculations include:

[0023] Select the left wing of the digital 3D map model Group coordinates, Each set of coordinates includes three non-collinear coordinate points.

[0024] The plane equation corresponding to each set of coordinates is obtained by calculating the three non-collinear coordinate points in each set of coordinates. The plane equation corresponding to the set of coordinates is:

[0025]

[0026] in, , and All are the first The coefficients of the coordinate plane equations. For the first The plane normal vector corresponding to the set of coordinates; For the first The constant term of the coordinate plane equations;

[0027] Calculate the dip and inclination angle based on the plane normal vector of each set of coordinates. Inclination angle of the plane corresponding to the coordinate system and tendencies The expressions are as follows:

[0028]

[0029] ;

[0030] Calculate the average tendency of the left wing and mean dip angle , and The expressions are respectively and .

[0031] Furthermore, the interwing angle between the left and right wings The expression is:

[0032] ;

[0033] Left-wing approach and the right wing The expressions are respectively and .

[0034] Furthermore, the equations for the geometric elements of the folds also include the equations for the pivot lines, which are expressed as follows:

[0035]

[0036] in, , and Let be any point on the equation of the pivot line, which is obtained by solving the equations of the left and right wings simultaneously.

[0037] Furthermore, the equation for the geometric elements of the fold also includes the equation for the fold cutting plane, which is expressed as follows:

[0038]

[0039]

[0040]

[0041]

[0042]

[0043] in, and All of these are coefficients of the equation of the fold cutting plane; For the constant term of the equation of the fold cutting plane; and The X-axis and Y-axis coordinates of any point in the digital 3D map model; This represents the average orientation of the left and right wings.

[0044] Furthermore, the equations for the geometric elements of the folds also include the equations for the axial plane, which are expressed as follows:

[0045]

[0046]

[0047]

[0048]

[0049] in, and These are the coordinate points on two axes in the digital 3D map model. and The coordinates; and These are all coefficients of the equation of the axial plane; For the constant term of the equation of the axial plane; The coordinates of any point on the folded axis surface in the digital 3D map model.

[0050] Furthermore, step S1 specifically includes: obtaining the starting point coordinates along the cutting direction in the digital 3D map model. and endpoint coordinates The profile equation is calculated and expressed as follows:

[0051]

[0052]

[0053]

[0054] in, and These are all coefficients of the profile equation. is the set non-zero assumption value; D is the constant term of the profile equation.

[0055] Furthermore, the first coordinate points Coordinates of the projection point on the profile equation The expression is:

[0056]

[0057]

[0058]

[0059]

[0060] in, For natural number variables, and , The number of coordinate points; For the corresponding number The proportional parameter of a linear parametric equation, the line of the linear parametric equation. coordinate point Coordinates of the corresponding projection point The connection.

[0061] Furthermore, step S3 further includes the following steps:

[0062] S31. Transform the three-dimensional coordinates of each projection point into two-dimensional coordinates; where, the first... Coordinates of each projection point After conversion to two-dimensional coordinates , Let x be the x-coordinate in a two-dimensional coordinate system, and hour, ;

[0063] S32. Obtain the horizontal and vertical displacement increments between multiple projection points; where, the first... Projection points Horizontal displacement increment in the profile equation and vertical displacement increment The expressions are as follows:

[0064]

[0065] ;

[0066] S33. Determine the cumulative direction between multiple projection points. If:

[0067] ,but , ;otherwise , ;

[0068] S34. Connect the two-dimensional coordinates sequentially. , , , ..., Complete the mapping of the fold profile morphology; among which, , , and Corresponding to , , and Two-dimensional coordinates at time.

[0069] This invention discloses a method for mapping the spatial morphological features of folds, the beneficial effects of which are:

[0070] 1. This invention obtains the coordinate information of the two limbs of a fold through a digital three-dimensional map model indoors and calculates the attitude information of the two limbs of the fold. Through coordinate space projection transformation, it realizes the accurate drawing of the planar profile features of the fold morphology on any engineering profile, which greatly reduces the workload of field geological survey, reduces the operational risks, and achieves higher accuracy identification and precise calculation drawing compared with satellite remote sensing interpretation.

[0071] 2. This invention performs statistical averaging on multiple sets of coordinate points, generating a plane equation independently for each set of coordinate points. This suppresses local rock strata undulation noise, significantly improves the measurement accuracy of the dip and dip angle of the fold limbs, and effectively eliminates the influence of single-point measurement errors on the overall geometric model.

[0072] 3. This solution achieves a precise mathematical expression of the three-dimensional geometric elements of folds through equations, and can accurately project the geometric elements of folds (wings, core, hub, etc.) onto a user-defined engineering cutting plane to generate two-dimensional cross-sectional views for geological analysis and visualization.

[0073] 4. This invention constructs a profile coordinate system with cumulative distance as the horizontal axis and height as the vertical axis, thereby accurately and continuously drawing the spatial morphological features of folds, such as the core, flanks, and turning points, and supports the quantitative analysis of geological parameters (such as width and angle), reducing the amount of fieldwork and improving the drawing accuracy. Attached Figure Description

[0074] Figure 1 A flowchart illustrating the method for mapping the spatial morphological features of folds;

[0075] Figure 2 It is a fold structure at the exit of the Qiganshan Tunnel of the Xi'an-Chongqing High-speed Railway. Detailed Implementation

[0076] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0077] Example 1

[0078] This embodiment provides a method for drawing folded spatial morphological features, which solves the problems of high workload and low accuracy in existing methods for drawing folded spatial morphological features. The following is a detailed demonstration.

[0079] refer to Figure 1 A method for mapping the spatial morphological features of folds, comprising the following steps:

[0080] S1. Determine the cross-sectional orientation in the digital 3D map model containing the folded region and establish the cross-sectional equation.

[0081] S2. Collect multiple coordinate points on the folded area in the digital 3D map model, and construct the folded geometric element equation based on the multiple coordinate points; project the multiple coordinate points onto the profile equation based on the folded geometric element equation, and obtain multiple projection points to reflect the folded geometric elements in the profile equation.

[0082] S3. Construct a profile coordinate system based on the horizontal and vertical displacement increments between multiple projection points, and connect multiple projection points along the profile path to complete the mapping of the fold spatial morphology features.

[0083] Specifically, the equations of the fold geometry include the equations of the dipping planes of the two flanks, which in turn include the plane equations of the left and right flanks. The equation of the left flank plane is as follows:

[0084] ;

[0085] ;

[0086] ;

[0087] ;

[0088] The equation of the right wing plane is:

[0089] ;

[0090] ;

[0091] ;

[0092] ;

[0093] in, , and These are the three axes of the coordinate system in a digital 3D map model; , and All of these are coefficients of the left-wing plane equation; For the constant term of the left-wing plane equation; , , All of these are coefficients of the right-wing plane equation; For the constant term of the right-wing plane equation; and These represent the average inclinations of the left and right wings, respectively. and These are the average tilt angles of the left and right wings, respectively.

[0094] in, and The calculation methods include:

[0095] Select the left wing of the digital 3D map model Group coordinates, Each set of coordinates includes three non-collinear coordinate points.

[0096] The plane equation corresponding to each set of coordinates is calculated by using three non-collinear coordinate points in each set of coordinates; where, the first... The plane equation corresponding to the set of coordinates is:

[0097]

[0098] in, , and All are the first The coefficients of the coordinate plane equations. For the first The plane normal vector corresponding to the set of coordinates; For the first The constant term of the coordinate plane equation.

[0099] Calculate the dip and inclination angle based on the plane normal vector of each set of coordinates. Inclination angle of the plane corresponding to the coordinate system and tendencies The expressions are as follows.

[0100]

[0101]

[0102] Calculate the average tendency of the left wing and mean dip angle , and The expressions are respectively and .

[0103] As a further embodiment, the interwing angle between the left and right wings... The expression is:

[0104] ;

[0105] Left-wing approach and the right wing The expressions are respectively and .

[0106] As a further embodiment, the equation of the fold geometry element also includes the equation of the pivot line, the expression of which is:

[0107]

[0108] in, , and Let be any point on the equation of the pivot line, which is obtained by solving the equations of the left and right wings simultaneously.

[0109] Furthermore, the equation for the geometric elements of the fold also includes the equation for the fold cutting plane, which is expressed as follows:

[0110]

[0111]

[0112]

[0113]

[0114]

[0115] in, and All are coefficients of the equation of the fold cutting plane; For the constant term of the equation of the fold cutting plane; and The X-axis and Y-axis coordinates of any point in the digital 3D map model; This represents the average orientation of the left and right wings.

[0116] As a further embodiment, the equation of the fold geometry element also includes the equation of the axial plane, and the expression of the equation of the axial plane is:

[0117]

[0118]

[0119]

[0120]

[0121] in, and These are the coordinate points on two axes in the digital 3D map model. and The coordinates; and These are all coefficients of the equation of the axial plane; For the constant term of the equation of the axial plane; The coordinates of any point on the fold axis in the digital 3D map model are preferably... .

[0122] Specifically, step S1 includes: obtaining the starting point coordinates along the cutting direction in the digital 3D map model. and endpoint coordinates The profile equation is calculated and expressed as follows:

[0123]

[0124]

[0125]

[0126] in, and These are all coefficients of the profile equation. is the set non-zero assumption value; D is the constant term of the profile equation.

[0127] Furthermore, the first coordinate points Coordinates of the projection point on the profile equation The expression is:

[0128]

[0129]

[0130]

[0131]

[0132] in, For natural number variables, and , The number of coordinate points; For the corresponding number The proportional parameter of a linear parametric equation, the line of the linear parametric equation. Coordinates Coordinates of the corresponding projection point The connection.

[0133] Furthermore, step S3 further includes the following steps:

[0134] S31. Transform the three-dimensional coordinates of each projection point into two-dimensional coordinates; where, the first... Coordinates of each projection point After conversion to two-dimensional coordinates , Let x be the x-coordinate in a two-dimensional coordinate system, and hour, ;

[0135] S32. Obtain the horizontal and vertical displacement increments between multiple projection points; where, the first... Projection points Horizontal displacement increment in the profile equation and vertical displacement increment The expressions are as follows:

[0136]

[0137] ;

[0138] S33. Determine the cumulative direction between multiple projection points. If:

[0139] ,but , ;otherwise , By using the pivot direction instead of the traditional normal projection, the geometric form of the fold structure is ensured to maintain geological rationality on any cross section, such as the continuity of the pivot.

[0140] S34. Connect the two-dimensional coordinates sequentially. , , , ..., Complete the mapping of the fold profile morphology; among which, , , and Corresponding to , , and Two-dimensional coordinates at time.

[0141] Among them, the starting point It is the user-defined starting point of the section line. The projection point on the cutting plane, and used as the origin of the two-dimensional coordinate system of the section. The reference points for constructing the fold profile are used, and the positions of all subsequent points are determined by relative... The horizontal and vertical increments are determined to ensure that the cross-sectional view can accurately reflect the geometric features of the three-dimensional folds, such as any point on the fold's wings, axial plane, core, pivot, or turning point.

[0142] Specifically, taking the drawing of the core and two wings of the fold as an example, in the digital 3D map model, spatial coordinates are obtained sequentially along the boundary between the core and the two wings. , Obtained through step S3 By sequentially connecting multiple two-dimensional coordinates, the shape of the junction between the core and the two flanks in the fold cross-section plane, the curve at the turning point of the fold from one flank to the other, and the actual width of the fold core can be measured in the fold cross-section diagram. Similarly, by collecting the three-dimensional coordinates of the two flanks in the digital three-dimensional map model, and obtaining multiple corresponding two-dimensional coordinates through step S3, and sequentially connecting the two-dimensional coordinates, the shape of the two flanks of the fold or one flank of a monoclinic structure can be drawn.

[0143] In summary, the beneficial effects of this solution are as follows:

[0144] This invention obtains the coordinate information of the two limbs of a fold through a digital three-dimensional map model indoors and calculates the attitude information of the two limbs of the fold. Through coordinate space projection transformation, it can accurately draw the planar profile features of the fold morphology on any engineering profile, which greatly reduces the workload of field geological survey, reduces the operational risks, and achieves higher accuracy identification and precise calculation drawing compared with satellite remote sensing interpretation.

[0145] Example 2

[0146] Taking the fold structure at the exit of the Qiganshan Tunnel on the Xi'an-Chongqing High-speed Railway as an example, this plan will be implemented in detail.

[0147] 1. Equations of the dipping planes of the two wings

[0148] Multiple coordinate points on the strata of both limbs of the fold were measured in the digital 3D map model. The attitude of the strata on both limbs was obtained by grouping three coordinate points together. Multiple strata attitudes were calculated. The measured attitudes of the four upper limb strata were: 30°∠64°, 42°∠67°, 23°∠67°, and 24°∠67°; the attitudes of the four lower limb strata were: 29°∠67°, 39°∠67°, 54°∠59°, and 34°∠68°. The average attitude of the upper limb strata was 30°∠66°, and the average attitude of the lower limb strata was 39°∠65°. The plane equations and direction vectors of the attitudes of the strata on both limbs are as follows: , Then the plane equation of the attitude of the rock strata on both limbs and They are respectively:

[0149] ;

[0150] ;

[0151] The interwing angle between the folds is:

[0152] ;

[0153] The strikes of the rock strata on both flanks are as follows: ; .

[0154] Then the direction vector of the rock strata on both sides They are respectively: A ylz =0.866025422、B ylz =0.499999969、C ylz =0 and A yrz =0.777145986、B yrz =-0.629320361、C yrz =0.

[0155] 2. Equation of the pivot line

[0156] Equation A of the dipping plane of the two wings yl x+B yl y+C yl z+D yl =0 and A yr x+B yr y+C yr z+D yr The straight line formed by the intersection of the lines with =0 is the equation of the pivot line, and the normal vectors of the dipping plane equations of the two wings are respectively... (0.791154, -0.352244, 0.500000) (0.704333, -0.328436, 0.62932), then the direction vector of the pivot equation is... (-0.057456463, -0.145722355, -0.01174596); Taking a point (535460.20, 3520888.00, 889.15) on the hub in the 3D reality model, the equation of the hub's straight line is: .

[0157] 3. Equation of the fold cutting plane

[0158] By calculating the average value of the dip direction of the two flanks: .

[0159] Since the equation of the fold cutting plane is perpendicular to the XOY plane, the normal vector of the equation of the fold cutting plane... Given (0.82412621, 0.56640621, 0), collect any point P (535497.77, 3520882.15, 880.92) on the folded surface in the 3D model, then we can obtain D. p =-2435567.249132. Therefore, the equation of the fold cutting plane is: 0.82412621x+0.56640621y-2435567.249132=0.

[0160] 4. Equations of the axial plane and the linear trace of the axial plane

[0161] When the axial plane is clear and can be captured, obtain the coordinates P of two points on the axial plane in the 3D model. z1 (535478.74,3520884.38,887.35), P z2 (535492.34, 3520881.52, 877.58), then the axial extension direction vector can be obtained. (13.6, -2.86, -9.77). Due to the vector of the axial plane equation. (A) z B z C z Simultaneously perpendicular to the equation vector of the fold cutting plane (0.82412621, 0.56640621, 0) and the axial extension direction vector (13.6, -2.86, -9.77), then:

[0162] ;

[0163] ;

[0164] ;

[0165] Therefore, the equation of the axial plane is: x - 1.455009y + 1.817945z - 4585827.075 = 0; when any elevation point is taken on the axial plane... Then we can obtain the equation of the straight line of the axis trace: x - 1.455009y - 4584190.925 = 0.

[0166] 5. Drawing the core and flanks

[0167] In the 3D model, spatial coordinates are obtained sequentially along the boundaries between the core and the two wings. , The projected coordinates of the junction between the core and the flanks on the fold section plane are: ,in:

[0168] ;

[0169] ;

[0170] ;

[0171] ;

[0172] but and The horizontal and vertical increments on the fold cutting plane are:

[0173] ;

[0174] ;

[0175] When the following conditions are met:

[0176]

[0177] but: , ;otherwise: , ;

[0178] Connect multiple in sequence The morphology of the junction between the core and the two wing sections in the fold section plane, the curve of the turning point of the fold from one wing to the other, and the actual width of the fold core can be measured in the fold section diagram. The calculation results are shown in Table 1.

[0179] Table 1. Calculation results of the boundary between the flanks and the core of the fold profile.

[0180] Serial Number <![CDATA[X hi ]]> <![CDATA[Y hi ]]> <![CDATA[Z hi ]]> <![CDATA[t hi ]]> <![CDATA[X hi ']]> <![CDATA[Y hi ']]> <![CDATA[Z hi ']]> <![CDATA[γ i ]]> <![CDATA[△L hi+1 ]]> <![CDATA[L hi ]]> <![CDATA[Z hi ]]> 1 535527.53 3520877.81 880.29 22.06779306 535509.34 3520865.31 880.29 / 0 0.00 880.29 2 535521.66 3520877.58 887.83 17.09989878 535507.57 3520867.89 887.83 126.63 -3.135255403 -3.14 887.83 3 535516.55 3520878.52 890.6 13.42103569 535505.49 3520870.92 890.60 130.14 -3.669014351 -6.80 890.60 4 535506.92 3520880.37 894.14 6.532551771 535501.54 3520876.67 894.14 140.51 -6.979125255 -13.78 894.14 5 535504.72 3520885.02 893.27 7.353262969 535498.66 3520880.86 893.27 136.47 -5.078280529 -18.86 893.27 6 535488.48 3520888.62 901.13 -3.991484332 535491.77 3520890.88 901.13 140.35 -12.16529115 -31.03 901.13 7 535485.4 3520888.88 901.85 -6.382527444 535490.66 3520892.50 901.85 116.09 -1.95880393 -32.99 901.85 8 535482.62 3520889.74 903.73 -8.186488969 535489.37 3520894.38 903.73 119.42 -2.283357794 -35.27 903.73 9 535472.7 3520888.53 897.34 -17.04717248 535486.75 3520898.19 897.34 134.81 -4.621556853 -39.89 897.34 10 535469.43 3520888.52 893.74 -19.74772925 535485.70 3520899.71 893.74 114.83 -1.843907033 -41.73 893.74 11 535466.04 3520887.47 889.92 -23.13624361 535485.11 3520900.57 889.92 105.12 -1.05478452 -42.79 889.92 12 535464.14 3520887.28 887.33 -24.80970059 535484.59 3520901.33 887.33 103.28 -0.919587812 -43.71 887.33 13 535458.12 3520882.32 879.51 -32.58031516 535484.97 3520900.77 879.51 80.10 0.677900637 -43.03 879.51 14 535453.67 3520881.32 874.36 -36.814083 535484.01 3520902.17 874.36 113.15 -1.696381409 -44.73 874.36 15 535456.92 3520879.84 869.13 -34.973954 535485.74 3520899.65 869.13 53.92 3.060526961 -41.67 869.13 16 535463.2 3520878.5 864.93 -30.55742572 535488.38 3520895.81 864.93 45.03 4.661360097 -37.01 864.93 17 535466.75 3520879.5 858.23 -27.06537147 535489.06 3520894.83 858.23 73.14 1.186615823 -35.82 858.23 18 535469.2 3520879.31 854.49 -25.15387943 535489.93 3520893.56 854.49 68.64 1.544279185 -34.27 854.49 19 535473.8 3520878.03 850.18 -22.08789881 535492.00 3520890.54 850.18 49.92 3.660350098 -30.61 850.18 20 535477.8 3520874.78 845.58 -20.63221415 535494.80 3520886.47 845.58 43.98 4.944035007 -25.67 845.58 21 535482.85 3520871.91 843 -18.0959626 535497.76 3520882.16 843.00 43.06 5.225593563 -20.44 843 22 535492.59 3520867.91 835.98 -12.33459814 535502.76 3520874.90 835.98 38.37 8.813301289 -11.63 835.98 23 535496.78 3520866.65 832.67 -9.595181146 535504.69 3520872.08 832.67 51.47 3.411641029 -8.22 832.67 24 535500.53 3520864.87 829.82 -7.512910907 535506.72 3520869.13 829.82 50.33 3.590967927 -4.63 829.82 25 535508.95 3520860.16 826.09 -3.241541455 535511.62 3520862.00 826.09 38.40 8.650774705 4.02 826.09 26 535513.29 3520858.18 823.7 -0.786317993 535513.94 3520858.63 823.70 47.57 4.089972831 8.11 823.7

[0181] 6. Drawing the planar fold shape of any engineering section.

[0182] In the topographic map or 3D model, select the starting coordinates P0 (511874.30, 3521074.70, 1093.00) and ending coordinates P of the section line. n (511643.60, 3520748.00, 791.70), (n=1,2,3…), we can find P0 and P… n The general equation of any engineering section plane perpendicular to the X and Y axes is:

[0183] ;

[0184] The normal vector of the plane equation is: .

[0185] To calculate the positions of the fold limbs, axial plane, core, hinge, and inflection point on an arbitrary engineering geological profile, it is known that any point Pi(xi,yi,zi) (0≤i<n, and i=0,1,2,3…) of the fold limbs, axial plane, core, hinge, and inflection point is collected in the 3D model, and its projection point on the arbitrary engineering section plane AXn+BYn+D=0 is P. i (X) i Y i Z i ).

[0186] Connect P i (x i ,y i ,z i ) and P i (X) i Y i Z i The straight line formed by ) Parallel to the direction vector of the pivot line equation (-0.057456463, -0.145722355, -0.01174596), then (-0.057456463, -0.145722355, -0.01174596) is The direction vector of the line. Therefore, given a point on the line and the direction vector of the line, we can obtain... The parametric equations are as follows:

[0187]

[0188]

[0189]

[0190]

[0191] Substitute any engineering cutting plane ;

[0192] Then, we can obtain:

[0193]

[0194] Based on the above formula, the projection point of any point Pi(xi,yi,zi) (0≤i<n, and i=0,1,2,3…) on any cutting plane AXn+BYn+D=0 can be calculated as P. i (X) i Y i Z i ), continuously collect Pi+1(x) data in a 3D model for a specific element such as the two wings, axial plane, core, pivot, or turning point of the fold. i+1 ,y i+1 ,z i+1 ), and calculate P i+1 (X) i+1 Y i+1 Z i+1 Then, the horizontal and vertical increments on any engineering section plane are:

[0195] ;

[0196] ;

[0197] When satisfied ,but: , ;otherwise: , .

[0198] Connect P0(L0, Z0), P1(L1, Z1), P2(L2, Z2), P3(L3, Z3)...P in sequence. i(L) hi Z i ...P n (L) n Z n It can draw the morphological features of any element such as the wings, axial plane, core, pivot, and turning point of any engineering section plane fold.

[0199] Following the method described above, P was obtained sequentially along a certain rock stratum on both flanks of the fold. yli (x yli ,y yli ,z yli ) and P yrli (x yri ,y yri ,z yri According to the direction vector of the two wings of the fold (A) ylz B ylz C ylz ), (A) yrz B yrz C yrz The projected coordinates of the two flanks of the fold on the fold cutting plane can be obtained as P. yli ’ (x yli ’ ,y yli ’ ,z yli ’ ) and P yrli (x yri ’ ,y yri ’ ,z yri ’ ), and P yl0 ’ (L) yl0 Z yl0 ), P yl1 ’ (L) yl1 Z yl1 ), P yl2 ’ (L) yl2 Z yl2 ), P yl3 ’ (L) yl3 Z yl3 ...P yli ’ (L) yli Z yli ...P yln ’ (L) yln Zyln ) and P yr0 ’ (L) yr0 Z yr0 ), P yr1 ’ (L) yr1 Z yr1 ), P yr2 ’ (L) yr2 Z yr2 ), P yr3 ’ (L) yr3 Z yr3 ...P yri ’ (L) yri Z yri ...P yrn ’ (L) yrn Z yrn By connecting the coordinates sequentially, the shape of the two wings of the fold or the wing of the monoclinic structure can be drawn.

[0200] Although specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this invention. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this invention.

Claims

1. A method for mapping the spatial morphological features of folds, characterized in that, Including the following steps: S1. Determine the cross-sectional orientation in the digital 3D map model containing folded regions and establish the cross-sectional equations; S2. Collect multiple coordinate points on the folded area in the digital 3D map model, and construct the folded geometric element equation based on the multiple coordinate points; project the multiple coordinate points onto the profile equation based on the folded geometric element equation, and obtain multiple projection points to reflect the folded geometric elements in the profile equation. S3. Construct a profile coordinate system based on the horizontal and vertical displacement increments between multiple projection points, and connect multiple projection points along the profile path to complete the mapping of the fold space morphology features. The equations for the geometric elements of the folds include the equations for the dipping planes of the two flanks, which in turn include the plane equations for the left and right flanks; wherein, the plane equation for the left flank is: ； ； ； ； The equation of the right wing plane is: ； ； ； ； in, , and These are the three axes of the coordinate system in a digital 3D map model; , and All of these are coefficients of the left-wing plane equation; For the constant term of the left-wing plane equation; , , All of these are coefficients of the right-wing plane equation; For the constant term of the right-wing plane equation; and These represent the average inclinations of the left and right wings, respectively. and These are the average tilt angles of the left and right wings, respectively.

2. The method for mapping the spatial morphological features of folds according to claim 1, characterized in that, and The calculation methods include: Select the left wing of the digital 3D map model Group coordinates, Each set of coordinates includes three non-collinear coordinate points. The plane equation corresponding to each set of coordinates is obtained by calculating the three non-collinear coordinate points in each set of coordinates. The plane equation corresponding to the set of coordinates is: in, , and All are the first The coefficients of the coordinate plane equations. For the first The plane normal vector corresponding to the set of coordinates; For the first The constant term of the coordinate plane equations; Calculate the dip and inclination angle based on the plane normal vector of each set of coordinates. Inclination angle of the plane corresponding to the coordinate system and tendencies The expressions are as follows: ； Calculate the average tendency of the left wing and mean dip angle , and The expressions are respectively and .

3. The method for mapping the spatial morphological features of folds according to claim 2, characterized in that, interwing angle between the left and right wings The expression is: ； Left-wing approach and the right wing The expressions are respectively and .

4. The method for mapping the spatial morphological features of folds according to claim 1, characterized in that, The equations for the geometric elements of the fold also include the equations for the pivot lines, which are expressed as follows: in, , and Let be any point on the equation of the pivot line, which is obtained by solving the equations of the left and right wings simultaneously.

5. The method for mapping the spatial morphological features of folds according to claim 1, characterized in that, The equations for fold geometry also include the equations for fold cutting planes, which are expressed as follows: in, and All of these are coefficients of the equation of the fold cutting plane; For the constant term of the equation of the fold cutting plane; and The X-axis and Y-axis coordinates of any point in the digital 3D map model; This represents the average orientation of the left and right wings.

6. The method for mapping the spatial morphological features of folds according to claim 5, characterized in that, The equations for the geometric elements of folds also include the equations for the axial plane, which are expressed as follows: in, and These are the coordinate points on two axes in the digital 3D map model. and The coordinates; and These are all coefficients of the equation of the axial plane; is the constant term of the equation of the axial plane; is the coordinate of any point on the folded axial plane in the digital 3D map model.

7. The method for mapping the spatial morphological features of folds according to claim 1, characterized in that, Step S1 specifically includes: obtaining the starting point coordinates along the cutting direction in the digital 3D map model. and endpoint coordinates The profile equation is calculated and expressed as follows: in, and These are all coefficients of the profile equation. is the set non-zero assumption value; D is the constant term of the profile equation.

8. The method for mapping the spatial morphological features of folds according to claim 7, characterized in that, No. coordinate points Coordinates of the projection point on the profile equation The expression is: in, Let be a natural number variable, and , The number of coordinate points; For the corresponding number The proportional parameter of a linear parametric equation, the line of the linear parametric equation. coordinate point Coordinates of the corresponding projection point The connection.

9. The method for mapping the spatial morphological features of folds according to claim 8, characterized in that, Step S3 further includes the following steps: S31. Transform the three-dimensional coordinates of each projection point into two-dimensional coordinates; where, the first... Coordinates of each projection point After conversion to two-dimensional coordinates , Let x be the x-coordinate in a two-dimensional coordinate system, and hour, ; S32. Obtain the horizontal and vertical displacement increments between multiple projection points; where, the first... Projection points Horizontal displacement increment in the profile equation and vertical displacement increment The expressions are as follows: ； S33. Determine the cumulative direction between multiple projection points. If: ,but , ;otherwise , ; S34. Connect the two-dimensional coordinates sequentially. , , ,......, Complete the mapping of the fold profile morphology; among which, , , and Corresponding to , , and Two-dimensional coordinates at time.

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