Processing method of terrain model invading in bridge deck range

Abstract

The invention discloses a processing method for a terrain model invading a bridge deck range, and belongs to the technical field of bridge engineering BIM modeling, and the method comprises the steps: searching a bridge deck space range based on a BIM model; a plurality of independent invasion intervals are positioned through intersection of a terrain model and a bridge floor, the invasion side direction of each invasion interval is independently judged, and only interval data of the invasion side are reserved; in the reserved invasion side interval, taking the central line of the route as a reference, iteratively generating a terrain model cutting surface according to a step length: determining a space point by vertically extending downwards to set a length and combining with a bridge floor section edge lateral level, iteratively intersecting with the terrain model on the basis of the space point to obtain an intersecting polyline, connecting all adjacent intersecting polylines in the invasion segmentation interval to form a cutting surface; and performing Boolean operation on the terrain model by using a cutting surface to eliminate an intrusive part. According to the method, rapid, accurate and automatic processing of the terrain model within the invasion bridge floor range is realized, and the accuracy and design efficiency of the bridge BIM model are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering BIM modeling technology, specifically involving a method for processing terrain models that intrude into the bridge deck area, which is particularly suitable for bridge design under complex terrain model conditions in mountainous areas. Background Technology

[0002] In traditional 2D highway design, it's difficult to intuitively determine the spatial relationship between bridges and terrain models, often overlooking the issue of terrain models encroaching on the bridge deck. When 2D data is converted to a BIM 3D model, these encroachment defects become concentrated, leading to rework. Existing solutions rely on manual inspection and manual modeling and trimming, which have the following drawbacks:

[0003] 1. High dependence on manual labor: Bridge models for large-scale highway projects need to be inspected section by section;

[0004] 2. Incomplete processing: It is easy to miss hidden intrusion areas;

[0005] 3. Poor repeatability: The design needs to be redone after changes are made.

[0006] Therefore, there is an urgent need for an automated method to accurately identify and handle terrain model intrusion issues. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention aims to provide a method for processing terrain models within the intrusion area of ​​the bridge deck, which realizes rapid, accurate and automated processing of terrain models within the intrusion area of ​​the bridge deck, and significantly improves the accuracy and design efficiency of bridge BIM models.

[0008] To achieve the above objectives, the present invention adopts the following technical measures: a method for processing terrain models that intrude into the bridge deck area, comprising the following steps:

[0009] S1. Identifying the spatial extent of the bridge deck based on the BIM model: Analyzing the geometric data of the bridge deck entities in the BIM model;

[0010] S2. Intersection detection of terrain intrusion range and direction on bridge deck: Locate multiple independent intrusion intervals by intersecting the terrain model with the bridge deck, determine the lateral intrusion of each intrusion interval separately, and retain only the interval data of the intrusion side;

[0011] S3. Generate terrain cutting surfaces with specified slopes along the intrusion section: Within the preserved intrusion side section, generate terrain model cutting surfaces iteratively according to the route centerline as the reference, step by step.

[0012] S4. Eliminate intrusions in the terrain using cutting surfaces: Perform Boolean difference operations on the terrain model using cutting surfaces to eliminate intrusive parts.

[0013] Optionally, the intersection detection of terrain intrusion into the bridge deck range and direction includes:

[0014] S2.1. By performing spatial intersection calculations between the terrain model T and the bridge surface B, multiple independent intersecting polyline sets are obtained. ;

[0015] S2.2, For multiple independent intersecting polyline sets For each intersecting polyline in the diagram, the direction of the intruder is determined, including:

[0016] a. Determining the lateral orientation of polylines: Based on the projected distance of each intersecting polyline segment endpoint onto the route centerline, determine the left and right relationships between the intersecting polylines and the centerline. Use each polyline endpoint as the foot of the perpendicular to the centerline to find the corresponding centerline station number, thus obtaining the station number range for each polyline. ;

[0017] b. Determine the intruding side: If there is only one polyline on one side, the lateral direction of the polyline is the intruding direction; if there are polylines on opposite sides, determine whether the corresponding station ranges of the polylines on the left and right sides have an inclusion relationship. If there is no inclusion relationship, it is a single-sided intrusion. If there is an inclusion relationship, the side with the larger range is the intruding side.

[0018] S2.3, Only retain the data from the intrusion side, for each intrusion interval Delete the non-intrusive side intersections to form the filtered intrusive intervals. , using each To find the station number of the centerline corresponding to the endpoint of the polyline, draw the perpendicular from the endpoint to the centerline. This gives you the station number range. .

[0019] Furthermore, the identification of the set of independent intersecting line segments employs a spatial clustering algorithm, satisfying:

[0020]

[0021] in, , For a set of polylines Any two distinct polylines in the given text; , indicating a polyline any node ; , indicating a polyline any node ; This is the minimum separation threshold for the intrusion interval.

[0022] Furthermore, the lateral determination of the polyline is based on multiple independent intersecting polyline sets. The endpoints of each intersecting polyline Calculate its projection point onto the centerline of the route. ;

[0023] Calculate the normal component: ,in , This is the normal vector of the route;

[0024] Determine the lateral orientation of the endpoints: ,in, Left side It is on the right side.

[0025] Furthermore, the lateral intrusion determination, for each endpoint P of the intersecting polyline... i Calculate the chainage range on the left and right sides:

[0026] Left side range: ,in:

[0027] ;

[0028] in, Let i be the range of station numbers for the i-th left interval. Let i be the chainage of the starting point on the left side of the i-th interval. The left end station number of the i-th interval;

[0029] Right side range: ,in:

[0030] ,

[0031] in, For the j-th right-hand interval, Let j be the starting station number of the right side of the j-th interval. The station number is the rightmost end point of the j-th interval;

[0032] Inclusion relationship determination:

[0033] The left side includes the right side: ;

[0034] The right side includes the left side: ;

[0035] Invasive side judgment:

[0036] If an inclusion relationship exists:

[0037]

[0038] In the formula, if it is , then This indicates that the intrusion occurred to the left of the centerline of the route; if it is , then This indicates that the intrusion occurred to the right of the centerline of the route;

[0039] Otherwise, there is no inclusion relationship: the polyline located on the side of the center line is determined to be the intruding side.

[0040] Furthermore, the deletion of non-intrusive side intersections employs a spatial filtering algorithm:

[0041]

[0042] in, The set of intersections to be retained. for Upper intersection point for The projection point on the center line of the route, for Point relative to projection point Direction identification function.

[0043] Optionally, generating a terrain cutting surface with a specified slope along the intruded section includes:

[0044] S3.1, within the chainage range Inner step length Iteration:

[0045] a. Obtain the center point corresponding to the current station number. ;

[0046] b. Along the center point Extend vertically downwards by a length H to obtain point H. ;

[0047] c. Determine the point based on the lateral horizontal direction B at the edge of the bridge deck cross-section. ;

[0048] d. Find the point Downward ray and point Intersection of the horizontal planes ;

[0049] e. at point ,point ,point ,point Within the defined plane, from A point emits a ray with a slope of 1:n, intersecting the terrain model T until no intersection is found, generating a line segment. ;

[0050] S3.2 Connect all line segments Forming a cutting surface .

[0051] Furthermore, the cut surface The construction adopts constraints Triangulation:

[0052]

[0053] in, This is an intrusion into the interval boundary.

[0054] Preferably, H is 20m; B is 1.0m; and the launch slope 1:n is 1:1.5.

[0055] Compared with the prior art, the present invention has the following main technical advantages:

[0056] 1. Automated Processing Capability: Through a step-by-step process (S1-S4) (bridge surface range identification → intrusion detection → cutting surface generation → Boolean operation), the fully automated processing of terrain model intrusion issues is achieved, overcoming the technical difficulties of low efficiency and easy omissions in traditional manual inspection. The key technologies lie in the intelligent lateral judgment algorithm in step S2 and the dynamic cutting surface generation mechanism in step S3.

[0057] 2. Precise Spatial Positioning: By employing route centerline projection and spatial clustering algorithms, the problem of accurately separating multiple intrusions in complex terrain is solved. Through station range comparison and normal vector calculation, the lateral direction of the intrusion can be accurately identified, avoiding misjudgments caused by visual occlusion in traditional methods.

[0058] 3. Dynamic Adaptability: The cutting surface generation (S3.1) utilizes iterative intersection of slope rays and constrained triangulation to adapt to different bridge deck cross-sections and terrain slopes, overcoming the limitation of fixed cutting templates in adapting to design changes. The key technologies lie in the dynamic adjustment of H / B parameters and the boundary constraints of Delaunay triangulation.

[0059] In summary, the processing speed of this invention is 10 times faster than manual processing, and the accuracy of the bridge model in mountainous areas reaches the centimeter level. It is particularly suitable for scenarios where complex terrain intrudes into high-pier, long-span bridges. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 A flowchart illustrating a method for processing terrain models within the intrusive bridge deck area provided by the present invention; Figure 2 This is a schematic diagram showing that the terrain model only intrudes into a portion of the bridge deck plane in step S2 of embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the terrain model intruding only into a portion of the bridge deck cross-section in step S2 of embodiment 1 of the present invention; Figure 4 This is a schematic diagram showing the entire terrain model being incorporated into the bridge deck plane in step S2 of embodiment 2 of the present invention; Figure 5 This is a schematic diagram showing the entire terrain model entering the bridge deck cross-section in step S2 of embodiment 2 of the present invention; Figure 6 This is a schematic diagram of step S3 of embodiment 1 of the present invention, which determines the position of the ray. Figure 7 This is a schematic diagram of step S3 of embodiment 2 of the present invention, which determines the position of the ray. Detailed Implementation

[0067] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0068] A method for processing terrain models that intrude into the bridge deck area includes the following steps:

[0069] S1. Identify the spatial range of the bridge deck based on the BIM model: Analyze the geometric data of the bridge deck entities in the BIM model.

[0070] S2. Calculate the intersection detection of terrain encroachment on the bridge deck, including the extent and direction of such encroachment. Detect multiple segments of the terrain model encroaching on the bridge deck, including:

[0071] ① By performing spatial intersection calculations between the terrain model T and the bridge surface B, multiple independent intersecting polyline sets are obtained. ;

[0072] The identification of independent intersecting line segment sets uses a spatial clustering algorithm, satisfying:

[0073] ;

[0074] in, , For a set of polylines Any two distinct polylines in the given text; , indicating a polyline any node ; , indicating a polyline any node ; This is the minimum separation threshold for the intrusion interval.

[0075] ② For multiple independent intersecting polyline sets For each intersecting polyline in the diagram, determine the direction of the intruder:

[0076] a. Determining the lateral orientation of polylines: Based on the projected distance of each intersecting polyline segment endpoint onto the route centerline, determine the left and right relationships between the intersecting polylines and the centerline. Use each polyline endpoint as the foot of the perpendicular to the centerline to find the corresponding station number on the centerline, thus obtaining the station number range for each polyline. .

[0077] In the lateral determination of polylines, for multiple independent intersecting polyline sets... The endpoints of each intersecting polyline Calculate its projection point onto the centerline of the route. ;

[0078] Calculate the normal component: ,in , This is the normal vector of the route;

[0079] Determine the lateral orientation of the endpoints:

[0080] ,in, Left side It is on the right side;

[0081] b. Determine the intruding side: If there is only one polyline, the lateral direction of the polyline is the intruding direction; if there are polylines on opposite sides, determine whether the corresponding station ranges of the polylines on the left and right sides have an inclusion relationship. If there is no inclusion relationship, it is a unilateral intrusion. If there is an inclusion relationship, the side with the larger range is the intruding side.

[0082] In the lateral intrusion determination, for each endpoint of the intersecting polyline Calculate the chainage range on the left and right sides:

[0083] Left side range: ,in:

[0084] ;

[0085] in, Let i be the range of station numbers for the i-th left interval. Let i be the chainage of the starting point on the left side of the i-th interval. The left end station number of the i-th interval;

[0086] Right side range: ,in:

[0087] ,

[0088] in, For the j-th right-hand interval, Let j be the starting station number of the right side of the j-th interval. The station number is the rightmost end point of the j-th interval;

[0089] Inclusion relationship determination:

[0090] The left side includes the right side: ;

[0091] The right side includes the left side: ;

[0092] Invasive side judgment:

[0093] If an inclusion relationship exists:

[0094] ;

[0095] This formula indicates that if is , then This indicates that the intrusion occurred to the left of the centerline of the route. , then This indicates that the intrusion occurred to the right of the centerline of the route.

[0096] Otherwise (no inclusion relationship): the polyline located on the side of the center line is determined to be the intrusion side.

[0097] ③ Only retain data from the intrusion side, for each intrusion interval Delete the non-intrusive side intersections to form the filtered intrusive intervals. , using each To find the station number of the centerline corresponding to the endpoint of the polyline, draw the perpendicular from the endpoint to the centerline. This gives you the station number range. ;

[0098] The spatial filtering algorithm is used to delete non-intrusive side intersections: ,in, The set of intersections to be retained. for Upper intersection point for The projection point on the center line of the route, for Point relative to projection point Direction identification function.

[0099] S3. Generate terrain cutting surfaces with a specified slope along the intrusion section: Within the preserved intrusion side section, generate terrain model cutting surfaces iteratively according to the route centerline and step size.

[0100] Among them, in the preserved intrusion zone Built-in terrain model cut surfaces:

[0101] ① Within the chainage range Inner step length Iteration:

[0102] a. Obtain the center point corresponding to the current station number. ;

[0103] b. Along the center point The vertical downward extension length H (the value of H is generally not less than the bridge clearance requirement, refer to the "Highway Route Design Specification" (JTG D20—2017), taking 20m as an example) is used to obtain the point.

[0104] c. Based on the lateral horizontal B at the edge of the bridge deck cross-section (B is typically taken as 1~1.5m based on engineering experience to allow for construction space; 1m is used as an example for explanation), determine the point. ;

[0105] d. Find the point Downward ray and point Intersection of the horizontal planes ;

[0106] e. at point ,point ,point ,point Within the defined plane, from A ray with a slope of 1:n (n can be a value between 1.5 and 1.75 based on the slope ratio; 1.5 is used as an example) is emitted from a point and intersects with the terrain model T until no intersection is found, generating a line segment. ;

[0107] ② Connect all line segments again Forming a cutting surface ;

[0108] Cut surface The construction adopts constraints Triangulation:

[0109]

[0110] in, This is a computational geometry algorithm used to divide a spatial region into triangular meshes. As constraints, This is an intrusion into the interval boundary.

[0111] S4, using the cutting surface To perform Boolean difference operations on the terrain model T and eliminate intrusive parts, the Boolean operations built into the GIS platform can be used.

[0112] Example 1:

[0113] A method for processing terrain models that intrude into the bridge deck area, see [link / reference]. Figure 1 The core process includes:

[0114] S1. Identifying the spatial extent of the bridge deck based on the BIM model: Analyzing the geometric data of the bridge deck entities in the BIM model;

[0115] S2. Calculate the intersection detection of terrain encroachment on the bridge deck, determining its range and direction, and identifying multiple sections of the terrain model encroaching on the bridge deck:

[0116] ① The spatial intersection of the terrain model T and the bridge surface B is calculated, and then a clustering algorithm is used:

[0117]

[0118] Obtain two intersecting polylines L1 and L2;

[0119] ② Refer to the section for determining the direction of intrusion. Figure 2 , Figure 3 :

[0120] a. Determining if the polyline is in the direction of the center line: L1 and L2 are both on the left;

[0121] b. Determine intrusion: Since both L1 and L2 are on the left, the chainage range for L1 is K8+780~K8+840; the chainage range for L2 is K8+880~K8+940.

[0122] S3, within the reserved intrusion zone Built-in terrain model cut surfaces:

[0123] ① Iterate within the ranges K8+780~K8+840 and K8+880~K8+940 respectively, with a step size of 20m:

[0124] a. Take the point at the center of the route at the current station number. ;

[0125] b. Along the point The length of the point extending vertically downwards ,beg ;

[0126] c. Based on the lateral horizontal of the bridge deck cross-section edge Determine the point ;

[0127] d. Find the point Downward ray and point Intersection of the horizontal planes K8+780~K8+840 , , , The corresponding point sets C1, D1, N1, and M1 are shown in Table 1, and K8+880~K8+940 are also shown. , , , The corresponding point sets C2, D2, N2, and M2 are shown in Table 2;

[0128] e. at each point , , , Within the defined plane, from A ray with a slope of 1:1.5 is emitted from a point and intersects with the terrain model T until no intersection is found, generating line segments. See Figure 6 ;

[0129] ② Connect all line segments Forming a cutting surface ;

[0130] S4, with the cutting surface To perform Boolean difference operations on terrain model T and eliminate intrusive parts:

[0131] ① Cutting surface conversion:

[0132] a. Convert the cutting surface generated in step S3 into multiple sets of trimming planes;

[0133] b. Parameter settings: Planar normal calculation tolerance: 0.001 rad; Minimum coverage width per plane: 2.0m;

[0134] ② Cutting execution:

[0135] a. Apply the Cesium.Entity.clippingPlanes property to the 3D Tileset;

[0136] b. Parameter settings: Depth offset: 0.0001; Edge transition zone width: 1.5m;

[0137] ③ Precision compensation:

[0138] a. Add a depth offset to the shader: gl_Position.z -= 0.0001;

[0139] b. Parameter settings: Dynamic refresh rate: 10Hz; Maximum number of processed patches: 500,000 / block.

[0140] Table 1. Sets of C1, D1, N1, and M1 corresponding to K8+780~K8+840

[0141]

[0142] Table 2. Sets C2, D1, N1, and M1 corresponding to K8+880~K8+940

[0143]

[0144] Example 2:

[0145] A method for processing terrain models that intrude into the bridge deck area, the core process of which includes:

[0146] S1. Identifying the spatial extent of the bridge deck based on the BIM model: Analyzing the geometric data of the bridge deck entities in the BIM model;

[0147] S2. Detect multiple sections where the terrain model encroaches on the bridge surface:

[0148] ① By performing spatial intersection calculations between the terrain model T and the bridge surface B, two independent sets of intersecting curve segments, L3 and L4, are obtained;

[0149] ② Determine the lateral direction of the intrusion, see [link / reference] Figure 4 , Figure 5 ;

[0150] a. Determine if the polyline is in the direction of the center line: L3 is left, L4 is right;

[0151] b. Determine the intruding side: The chainage range corresponding to L3 is K9+980~K10+040, and the chainage range corresponding to L4 is K10+000~K10+020. The chainage is the azimuth. The chainage corresponding to L3 includes L4, and the intrusion direction is to the left.

[0152] ③ Utilize spatial filtering algorithms Only the data on the intrusion side is retained, and the intersections on the non-intrusion side are deleted to form the filtered intrusion interval L3. The endpoints of the polyline in L3 are determined, and the perpendiculars to the centerline are found to the centerline station numbers corresponding to the endpoints, thus obtaining the station number range K9+980~K10+040.

[0153] S3. Construct terrain model cut surfaces within the retained intrusion zone L3:

[0154] ① Iterate within K8+780~K8+820 with a step size of 20m:

[0155] a. Take the point at the center of the route at the current station number. ;

[0156] b. Along the point Extending vertically downwards from the point by a length H = 20m, we obtain...

[0157] c. Based on the lateral horizontal B=1m at the edge of the bridge deck cross-section, determine the point. ;

[0158] d. Find the point Downward ray and point Intersection of the horizontal planes K9+980~K10+040 , , , The corresponding point sets C3, D3, N3, and M3 are shown in Table 3;

[0159] e. at point , , , Within the defined plane, from A ray with a slope of 1:1.5 is emitted from a point and intersects with the terrain model T until no intersection is found, generating line segments. See Figure 7 ;

[0160] Table 3. Sets of C3, D3, N3, and M3 corresponding to K9+980~K10+040

[0161]

[0162] ② Connect all polylines Forming a cutting surface ;

[0163] S4, with the cutting surface To perform Boolean difference operations on terrain model T and eliminate intrusive parts:

[0164] ① Cutting surface conversion:

[0165] a. Convert the cutting surface generated in step S3 into multiple sets of trimming planes;

[0166] b. Parameter settings: Planar normal calculation tolerance: 0.001 rad; Minimum coverage width per plane: 2.0m;

[0167] ② Cutting execution:

[0168] a. Apply the Cesium.Entity.clippingPlanes property to the 3D Tileset;

[0169] b. Parameter settings: Depth offset: 0.0001; Edge transition zone width: 1.5m;

[0170] ③ Precision compensation:

[0171] a. Add a depth offset to the shader: gl_Position.z -= 0.0001;

[0172] b. Parameter settings: Dynamic refresh rate: 10Hz; Maximum number of processed patches: 500,000 / block.

[0173] The above description is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any transformations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for processing terrain models that intrude into the area of ​​a bridge deck, characterized in that, Includes the following steps: S1. Identifying the spatial extent of the bridge deck based on the BIM model: Analyzing the geometric data of the bridge deck entities in the BIM model; S2. Intersection detection of terrain intrusion range and direction on bridge deck: Locate multiple independent intrusion intervals by intersecting the terrain model with the bridge deck, determine the lateral intrusion of each intrusion interval separately, and retain only the interval data of the intrusion side; S3. Generate terrain cutting surfaces with specified slopes along the intrusion section: Within the preserved intrusion side section, generate terrain model cutting surfaces iteratively according to the route centerline as the reference, step by step. S4. Eliminate intrusions in the terrain using cutting surfaces: Perform Boolean difference operations on the terrain model using cutting surfaces to eliminate intrusive parts.

2. The method for processing terrain models within the intrusive bridge deck area according to claim 1, characterized in that, The intersection detection of terrain intrusion into the bridge deck includes the following range and direction: S2.

1. By performing spatial intersection calculations between the terrain model T and the bridge surface B, multiple independent intersecting polyline sets are obtained. ; S2.2, For multiple independent intersecting polyline sets For each intersecting polyline in the diagram, the direction of the intruder is determined, including: a. Determining the lateral orientation of polylines: Based on the projected distance of each intersecting polyline segment endpoint onto the route centerline, determine the left and right relationships between the intersecting polylines and the centerline. Use each polyline endpoint as the foot of the perpendicular to the centerline to find the corresponding centerline station number, thus obtaining the station number range for each polyline. ; b. Determine the intruding side: If there is only one polyline on one side, the lateral direction of the polyline is the intruding direction; if there are polylines on opposite sides, determine whether the corresponding station ranges of the polylines on the left and right sides have an inclusion relationship. If there is no inclusion relationship, it is a single-sided intrusion. If there is an inclusion relationship, the side with the larger range is the intruding side. S2.3, Only retain the data from the intrusion side, for each intrusion interval Delete the non-intrusive side intersections to form the filtered intrusive intervals. , using each To find the station number of the centerline corresponding to the endpoint of the polyline, draw the perpendicular from the endpoint to the centerline. This gives you the station number range. .

3. The method for processing terrain models within the intrusive bridge deck area according to claim 2, characterized in that, The identification of the set of independent intersecting line segments employs a spatial clustering algorithm, satisfying the following: ； in, , For a set of polylines Any two distinct polylines in the given text; , indicating a polyline any node ; , indicating a polyline any node ; This is the minimum separation threshold for the intrusion interval.

4. The method for processing terrain models within the intrusive bridge deck area according to claim 2, characterized in that, The lateral determination of the polyline is based on multiple independent intersecting polyline sets. The endpoints of each intersecting polyline Calculate its projection point onto the centerline of the route. ; Calculate the normal component: ,in , This is the normal vector of the route; Determine the lateral orientation of the endpoints: ,in, Left side It is on the right side.

5. The method for processing terrain models within the intrusive bridge deck area according to claim 2, characterized in that, The intrusion lateral determination is for each endpoint P of the intersecting polyline. i Calculate the chainage range on the left and right sides: Left side range: ,in: ； in, Let i be the range of station numbers for the i-th left interval. Let i be the chainage of the starting point on the left side of the i-th interval. The left end station number of the i-th interval; Right side range: ,in: ， in, For the j-th right-hand interval, Let j be the starting station number of the right side of the j-th interval. The station number is the rightmost end point of the j-th interval; Inclusion relationship determination: The left side includes the right side: ; The right side includes the left side: ; Invasive side judgment: If an inclusion relationship exists: ； In the formula, if it is , then This indicates that the intrusion occurred to the left of the centerline of the route; if it is , then This indicates that the intrusion occurred to the right of the centerline of the route; Otherwise, there is no inclusion relationship: the polyline located on the side of the center line is determined to be the intrusion side.

6. The method for processing terrain models within the intrusive bridge deck area according to claim 2, characterized in that, The deletion of non-intrusive side intersections employs a spatial filtering algorithm: ； in, The set of intersections to be retained. for Upper intersection point for The projection point on the center line of the route, for Point relative to projection point Direction identification function.

7. The method for processing terrain models within the intrusive bridge deck area according to claim 1, characterized in that, The generation of a terrain cutting surface with a specified slope along the intruded section includes: S3.1, within the chainage range Inner step length Iteration: a. Obtain the center point corresponding to the current station number. ; b. Along the center point Extend vertically downwards by a length H to obtain point H. ; c. Determine the point based on the lateral horizontal direction B at the edge of the bridge deck cross-section. ; d. Find the point Downward ray and point Intersection of the horizontal planes ; e. at point ,point ,point ,point Within the defined plane, from A point emits a ray with a slope of 1:n, intersecting the terrain model T until no intersection is found, generating a line segment. ; S3.2 Connect all line segments Forming a cutting surface .

8. The method for processing terrain models within the intrusive bridge deck area according to claim 7, characterized in that, The cutting surface The construction adopts constraints Triangulation: ； in, This is an intrusion into the interval boundary.

9. The method for processing terrain models within the intrusive bridge deck area according to claim 7, characterized in that, H is 20m; B is 1.0m; and the launch slope 1:n is 1:1.5.

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