Method and device for generating longitudinal section of bridge
By using a bridge longitudinal profile generation method based on mean sea level, the problem of uneven connection between longitudinal profile and bridge hierarchy in traditional design is solved, realizing the flexibility and adaptability of bridge longitudinal profile and generating a three-dimensional road network model that conforms to the specifications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-13
- Publication Date
- 2026-04-07
AI Technical Summary
Traditional bridge longitudinal profile design, due to its fixed slope coefficient and elevation calculation logic, cannot accommodate combinations of different lengths and bridge levels, resulting in an uneven and shaky connection between the longitudinal profile and the bridge level, which fails to meet road design specifications.
Using mean sea level as the unified elevation benchmark, the key parameters of the longitudinal profile are dynamically calculated through coordinate unification and geometric preprocessing. Then, the three-dimensional longitudinal profile is generated and the endpoints are corrected to produce a three-dimensional road network model that meets the requirements.
It achieves flexibility and adaptability of bridge longitudinal profiles, ensures smoothness and geometric simplicity at connection points, and outputs a continuous three-dimensional road network model that conforms to engineering specifications.
Smart Images
Figure CN121808911A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of road design technology, and in particular to a method and apparatus for generating a bridge longitudinal profile. Background Technology
[0002] Traditional bridge longitudinal profile design is based on 2D (Two-Dimensional) vector roads and pre-assigned real elevations as its core logic. It directly assigns elevation values based on the original coordinates and uses the method of "bridge level × fixed coefficient + original elevation value" to initially set the bridge height, and directly generates slopes at the connection sections of different bridge levels.
[0003] Because the calculation logic uses a fixed slope coefficient and elevation, it cannot be compatible with road sections of different lengths and different combinations of bridge levels. In practical applications, this can easily lead to problems such as the bridge longitudinal profile not connecting smoothly with different bridge levels, vibration, and non-compliance with road design specifications. Therefore, the current design method for bridge longitudinal profiles is not flexible. Summary of the Invention
[0004] To overcome the problems existing in related technologies, this disclosure provides a method and apparatus for generating the longitudinal profile of a bridge.
[0005] According to a first aspect of the present disclosure, a method for generating a bridge longitudinal profile is provided. The method includes: unifying an input two-dimensional vector road segment to a target coordinate system and performing geometric preprocessing on the road segment after unifying the coordinate system; using mean sea level as a unified elevation datum, calculating the theoretical control elevation of the bridge deck based on the bridge layer and layer height parameters in the road longitudinal profile, and obtaining or setting the ground elevation of the road surface connecting the starting and ending points of the road segment; calculating key parameters of the longitudinal profile and the final control elevation of the bridge deck based on the theoretical control elevation of the bridge deck, the ground elevation, the maximum allowable longitudinal slope, and the horizontal alignment length of the road segment; collecting feature points on the horizontal alignment of the road segment and interpolating the elevations according to the key parameters of the longitudinal profile and the final control elevation of the bridge deck, performing geometric cleaning and endpoint elevation adjustment to generate a three-dimensional longitudinal profile; combining the three-dimensional longitudinal profiles of each road segment into a three-dimensional road network model according to the planar topological relationship, and verifying the longitudinal slope and alignment.
[0006] According to a second aspect of the present disclosure, a bridge longitudinal profile generation apparatus is provided. The apparatus includes: a preprocessing module, a parameter calculation module, a profile generation module, a road network model generation module, and a verification module. The preprocessing module is used to unify the input two-dimensional vector road segments to a target coordinate system and perform geometric preprocessing on the road segments after unification. The parameter calculation module is used to calculate the theoretical control elevation of the bridge deck based on the bridge layer and layer height parameters in the road longitudinal profile, using mean sea level as a unified elevation datum, and to obtain or set the start and end points of the road segments. The system includes: ground elevation at the point of intersection; calculation of key parameters of the longitudinal profile and the final control elevation of the bridge deck based on the theoretical control elevation of the bridge deck, ground elevation, maximum allowable longitudinal slope, and horizontal alignment length of the road segment; a profile generation module, used to collect feature points on the horizontal alignment of the road segment and interpolate elevations according to the key parameters of the longitudinal profile and the final control elevation of the bridge deck, perform geometric cleanup and endpoint elevation adjustment, and generate a three-dimensional longitudinal profile; a road network model generation module, used to combine the three-dimensional longitudinal profiles of each road segment into a three-dimensional road network model according to the planar topological relationship; and a verification module, used to verify the longitudinal slope and alignment.
[0007] According to a third aspect of the present disclosure, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer-readable instructions, when executed by the processor, implement the steps of the method for generating a bridge longitudinal section as described in the first aspect.
[0008] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method for generating a bridge longitudinal section as described in the first aspect. The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: In this embodiment, firstly, by establishing a processing framework based on sea level as a unified reference and prioritizing coordinate unification followed by geometric preprocessing, jitter caused by coordinate system differences and geometric noise is avoided from the outset. Then, by dynamically calculating key parameters of the longitudinal profile, precise matching of slope and road segment length is achieved. Finally, by performing forced endpoint correction and geometric cleanup on the generated 3D longitudinal profile, smoothness and geometric simplicity at connection points are ensured. Ultimately, through integration and verification, a compliant and continuous 3D road network model can be output, improving the flexibility of bridge longitudinal profile generation and achieving highly adaptable bridge longitudinal profile design for different bridge levels and road segments of different lengths.
[0009] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description
[0010] The accompanying drawings, which are incorporated in and form part of this disclosure, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.
[0011] Figure 1 This is a schematic diagram of a system architecture for generating a bridge longitudinal profile, provided in an embodiment of this disclosure.
[0012] Figure 2 A flowchart illustrating a method for generating a bridge longitudinal profile according to an embodiment of this disclosure.
[0013] Figure 3 This is a schematic diagram of a longitudinal section structure of a bridge provided in an embodiment of this disclosure.
[0014] Figure 4 This is a hardware structure diagram of a computer device provided in an embodiment of the present disclosure.
[0015] Figure 5 This is a schematic diagram of a device for generating a longitudinal section of a bridge, provided in an embodiment of this disclosure. Detailed Implementation
[0016] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.
[0017] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.
[0018] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."
[0019] The embodiments of this disclosure will now be described in detail.
[0020] Figure 1 This is a schematic diagram of a system architecture for generating a bridge longitudinal profile, as provided in an embodiment of this disclosure. Figure 1 As shown, the bridge longitudinal profile generation system 100 includes: a vector road segment preprocessing unit 101, a reference height setting unit 102, a connection elevation determination unit 103, a longitudinal profile parameter calculation unit 104, a longitudinal profile generation unit 105, and a 3D (Three-Dimensional) road network integration unit 106. The vector road segment preprocessing unit 101 includes a unified preprocessing framework and a differentiated preprocessing framework. The unified preprocessing framework is used to unify accuracy standards, pruning rules, and vertex cleanup rules. The differentiated preprocessing framework is used to select different execution processes based on road segment characteristics. The reference height setting unit 102 is used to set the peak height (ground elevation) of ground roads and the peak height (theoretical control elevation of the bridge deck) of bridges respectively, using mean sea level as a unified elevation reference without superimposing the actual elevation. The connection elevation determination unit 103 is used to obtain the ground elevation of the connecting road surfaces at the start and end points of the road segment. The longitudinal profile parameter calculation unit 104 is used to determine the slope, ramp length, and peak height. The longitudinal profile generation unit 105 is used to sample key points, remove duplicates, calculate the elevation values of uphill, horizontal, and downhill sections, and perform geometric cleanup. The 3D road network integration unit 106 is used to integrate the generated 3D longitudinal profiles into a complete 3D road network according to topological relationships and verify the slope and smoothness.
[0021] Figure 2 A flowchart illustrating a method for generating a bridge longitudinal section according to an embodiment of this disclosure is shown below. Figure 2 As shown, the method includes the following steps S201 to S206.
[0022] S201. Unify the input two-dimensional vector road segments to the target coordinate system, and perform geometric preprocessing on the road segments after unifying the coordinate system.
[0023] The target coordinate system is a projected coordinate system. Geometric preprocessing includes: accuracy normalization and redundant geometry cleanup. Accuracy normalization indicates the standardization of accuracy, and redundant geometry cleanup indicates the uniform cleaning and trimming of vertices.
[0024] Specifically, the coordinate systems of two-dimensional vector road segments from different sources may be different. Therefore, the data of two-dimensional vector road segments from different sources are uniformly transformed into a common target coordinate system. Under the unified coordinate framework, the road segments are then geometrically preprocessed to unify accuracy, clean up redundant vertices, and prune excessively long road segments.
[0025] It should be noted that by unifying the coordinate system and performing geometric preprocessing, a stable and reliable planar foundation can be provided for all subsequent calculations involving elevation and geometry.
[0026] S202. Using the mean sea level as the unified elevation benchmark, calculate the theoretical control elevation of the bridge deck based on the bridge layer and layer height parameters in the road longitudinal section, and obtain or set the ground elevation of the road surface connecting the start and end points of the road section.
[0027] The start and end points of each road segment indicate the beginning and end of that segment.
[0028] Elevation is usually represented by the Z-axis (elevation axis). Therefore, the ground elevation of the road surface connecting the start and end points of a road segment is often referred to as the connection Z-value in actual engineering, which is the true elevation of the connection point.
[0029] It should be noted that when calculating the theoretical control elevation of the bridge deck (which can also be called the peak height of the bridge in engineering), all theoretical control elevations of the bridge deck are based on the mean sea level and are calculated by multiplying the bridge level by a preset level height parameter. The actual terrain elevation is not superimposed in advance during this process.
[0030] Specifically, the theoretical control height of the bridge deck is determined based on formula (1).
[0031] Theoretical control height of bridge deck = bridge level × HEIGHT Formula (1) Here, HEIGHT represents the fixed height coefficient for each floor.
[0032] It should be noted that the theoretical control elevation of the bridge deck calculated based on formula (1) is the theoretical design target value. The actual final control elevation of the bridge deck will be dynamically determined according to the actual length of the road section.
[0033] For example, the default value for HEIGHT can be set to 7 meters.
[0034] It should be noted that in this embodiment of the disclosure, the peak height of the ground road is fixed at 0, which is level with the sea level.
[0035] It is understandable that by using the above method, an absolute elevation benchmark for the longitudinal profile design can be established, and the ground elevation can be used as a mandatory boundary constraint for the generation of the bridge longitudinal profile, so as to ensure the connection between the generated bridge longitudinal profile and the surrounding environment at the endpoints.
[0036] S203. Based on the theoretical control elevation of the bridge deck, the ground elevation, the maximum allowable longitudinal slope, and the horizontal alignment length of the road section, calculate the key parameters of the longitudinal profile and the final control elevation of the bridge deck.
[0037] Among them, the key parameters of the longitudinal profile are data used to define the vertical shape of the final longitudinal profile of the bridge, including: slope, slope length, structure type and key point elevation.
[0038] Among them, the horizontal alignment of a road segment is the projection shape of the centerline of a road or bridge onto a horizontal plane, expressing the direction and curvature in the horizontal direction.
[0039] It should be noted that in the calculation of key parameters of the longitudinal profile and the final control elevation of the bridge deck, design objectives, connection conditions, specification restrictions and physical space constraints can be comprehensively considered. By analyzing whether the horizontal line length of the road segment is sufficient to accommodate all the ramps required to reach the initial design elevation, the appropriate key parameters of the longitudinal profile can be dynamically calculated. Based on the specific constraints corresponding to the key parameters of the longitudinal profile of the current road segment, the achievable theoretical control elevation of the bridge deck can be dynamically determined, thereby obtaining the most suitable longitudinal profile shape of the bridge.
[0040] The maximum allowable slope for the design used in the calculation can be a fixed value that complies with industry standards, such as a uniform 10 degrees.
[0041] S204. Based on the key parameters of the longitudinal profile and the final control elevation of the bridge deck, feature points are collected on the horizontal alignment of the road section and the elevation is interpolated. Geometric cleanup and endpoint elevation adjustment are performed to generate a three-dimensional longitudinal profile.
[0042] It should be noted that elevation interpolation is performed between feature points, that is, each two-dimensional plane point is assigned a precise elevation value, generating a preliminary road profile model composed of a sequence of three-dimensional coordinate points. This process, based on the aforementioned dynamic calculation results, achieves the conversion from two-dimensional to three-dimensional.
[0043] Next, geometric cleaning and endpoint elevation correction are performed on the generated 3D point sequence. Geometric cleaning simplifies the geometry. Specifically, duplicate points with excessively close planar projection distances between adjacent points in the 3D point sequence are removed to eliminate minor visual jitter. Endpoint elevation correction corrects any minor endpoint errors that may arise from interpolation calculations. By adjusting endpoint elevations to cover and eliminate floating-point errors that may arise from linear interpolation calculations, data quality can be improved and endpoint connection accuracy can be ensured. The final 3D longitudinal profile is the 3D road longitudinal profile model obtained after the above two optimization steps.
[0044] S205. Combine the three-dimensional longitudinal profiles of each road segment into a three-dimensional road network model according to the planar topological relationship, and verify the longitudinal slope and alignment.
[0045] The verification includes: whether the longitudinal slope of all road sections does not exceed the maximum allowable longitudinal slope (e.g., 10 degrees), and whether the elevation change between adjacent three-dimensional vertices is continuous, smooth, and without sudden fluctuations, such as whether the angle of the elevation change rate conversion between adjacent points is less than 10°.
[0046] Specifically, after obtaining the three-dimensional longitudinal profiles of all independently processed road segments, they are batch-integrated according to their original planar connection (topology) relationships to form a continuous and complete three-dimensional road network model.
[0047] After obtaining the 3D road network model, the system automatically verifies its compliance. By checking the longitudinal slope and alignment, it can be determined whether the output results meet the engineering specifications, thereby achieving the integration and quality assurance from a single road segment to the complete road network, ensuring the reliability and engineering usability of the final output data.
[0048] This disclosure provides a method for generating bridge longitudinal profiles. First, by establishing a processing framework based on sea level as a unified reference, and prioritizing coordinate unification followed by geometric preprocessing, it avoids jitter caused by coordinate system differences and geometric noise from the outset. Then, by dynamically calculating key parameters of the longitudinal profile, precise matching of slope and road segment length can be achieved. Finally, by performing forced endpoint correction and geometric cleanup on the generated three-dimensional longitudinal profile, the smoothness and geometric simplicity of the longitudinal profile at connection points are ensured. Ultimately, through integration and verification, a compliant and continuous three-dimensional road network model can be output, improving the flexibility of bridge longitudinal profile generation and achieving highly adaptable bridge longitudinal profile design for different bridge levels and road segments of different lengths.
[0049] Optionally, in a method for generating a bridge longitudinal section provided in this embodiment of the present disclosure, the above-mentioned S201 may specifically include at least one of S201a to S201c.
[0050] S201a. Transform the two-dimensional vector road segment to the target projection coordinate system and normalize the accuracy of the plane coordinates.
[0051] Specifically, by transforming the two-dimensional vectors of each road segment into the same projected coordinate system, ensuring that all data are under the same plane reference system, a unified mathematical foundation can be established for geometric preprocessing.
[0052] For example, the two-dimensional vector data of all road sections are converted to the UTM3 (Universal Transverse Mercator Projection, 3-Degree Zone) coordinate system to which the bridge area belongs. The code for the Northern Hemisphere is EPSG (European Petroleum Survey Group): 326XX, and the code for the Southern Hemisphere is EPSG: 327XX, where XX represents the UTM3 degree zone number. For example, in eastern China, EPSG: 32650 is typically used, based on the WGS84 (World Geodetic System 1984) datum (EPSG: 4326), with a coordinate accuracy ≤0.01m.
[0053] Furthermore, the planar coordinate values of the two-dimensional vector data for all road segments are normalized for precision. For example, the planar coordinate values (X, Y) of all two-dimensional vector road segments are rounded to two decimal places, with the unit being meters (m). That is, all coordinate values are unified to a precision of 0.01m, corresponding to a planar precision at the centimeter level. This eliminates calculation errors that may be caused by inconsistent floating-point precision, which not only meets engineering specifications but also avoids redundant floating-point storage. This provides a unified high-precision geometric benchmark for sampling and locating key points in the longitudinal profile of bridges and for interpolating and matching elevation values.
[0054] S201b: Delete redundant vertices whose distance from the start and end points of the road segment is less than or equal to the first distance threshold.
[0055] For example, the first distance threshold is 1.0 meter.
[0056] It should be noted that redundant vertices usually have a negligible impact on road alignment, but may cause unnecessary minor fluctuations during elevation interpolation.
[0057] Redundant vertices can be cleaned up by removing overly dense redundant geometric vertices near the start and end points of road segments, thus avoiding unnecessary step-like changes in elevation over short distances.
[0058] S201c. If the horizontal linear length of the road segment is less than the first length threshold, then retain the middle geometry of the road segment with the midpoint of the road segment as the center and the length as the first preset ratio of the total length of the road segment, and delete the vertices outside the retained part.
[0059] The first length threshold can be set according to the trimming requirement threshold in a conventional design. The first preset ratio can be one-third.
[0060] For example, when the road segment is too short to meet the pruning requirements in conventional design, it can be divided into segments at a ratio of 3 to the total length, retaining the geometry of the middle third of the road segment. This avoids excessive pruning that would render the geometry invalid and can provide a stable and effective geometric shape for extremely short road segments that can be used for subsequent calculations.
[0061] Based on this scheme, firstly, by unifying the coordinate system and normalizing its precision, a stable and high-precision mathematical benchmark can be provided for all subsequent calculations, eliminating geometric problems caused by coordinate system confusion or floating-point errors at the source. Secondly, by removing redundant vertices near the endpoints, high-frequency jitter in the longitudinal profile caused by micro-geometric fluctuations in the start and end regions is effectively prevented. Finally, by implementing a conservative geometry preservation strategy for extremely short road segments, both their topological existence and a stable geometric shape usable for calculation are maintained, thus ensuring the robustness and effectiveness of the method in dealing with road segments of various lengths, especially extremely short road segments.
[0062] Optionally, in the method for generating a bridge longitudinal section provided in this embodiment of the present disclosure, the above-mentioned S202 may specifically include the following S202a and S202b.
[0063] S202a. Obtain the ground elevation from the road segment topology attributes of the input data.
[0064] In the process of determining the elevation values of the adjacent road surfaces to be connected at the starting and ending points of the target road segment, if the input road topology attribute information contains the elevation values of the adjacent road surfaces, that is, when the road segment to be processed is not an isolated road segment, the road segment topology attribute includes the actual ground elevation values of the associated adjacent road segments at the connection point. In other words, under the standard data input method, the topology attribute information is the most accurate data source for the elevation of the connection point. The system prioritizes obtaining the actual ground elevation values of the adjacent road segments connected to the beginning and end points of the road segment to be processed at the connection point from the topology attribute information corresponding to the road segment, as the connection boundary condition for the longitudinal profile design.
[0065] S202b. If the ground elevation cannot be obtained from the road segment topology attributes, the road segment will be treated as an isolated road segment, and the ground elevation value will be controlled by the bridge deck theory.
[0066] Specifically, in the case of missing data, if there are no elevation values of adjacent pavements in the road segment topology attributes and the connection information cannot be obtained from the topology attributes, the road segment to be processed is determined as an isolated road segment. A default elevation value of the adjacent pavement can be set for the isolated road segment. The system sets the ground elevation at the beginning and end points of the isolated road segment to the theoretical control elevation (peak height) of the bridge deck by default, generates a horizontal longitudinal profile, and can create an internally self-consistent boundary condition for the isolated road segment.
[0067] Based on this scheme, by prioritizing extraction from road segment topology attributes and assigning default values if missing, a complete logic for ground elevation processing can be achieved. Because accurate topology attribute information is prioritized, it ensures that most road segments can accurately connect with the actual terrain environment. It also flexibly handles road networks in the planning stage or with incomplete data, generating reasonable longitudinal profiles, thus enhancing adaptability and practicality in different real-world environments. If ground elevation cannot be obtained from topology attributes, the road segment is directly identified as an isolated segment. Since a self-consistent default value is set for isolated segments, it can handle road segment data that is not yet connected to the surrounding road network in the planning stage, generating internally consistent horizontal or arched longitudinal profiles. This significantly enhances adaptability and practicality in scenarios with incomplete data or during the planning stage.
[0068] Optionally, in a method for generating a bridge longitudinal section provided in this embodiment of the present disclosure, S203 may specifically include S203a, S203b and S203c, or S203a, S203b and S203d.
[0069] S203a. Calculate the sum of the slope lengths of the ascending and descending sections required to reach the theoretical control elevation of the bridge deck.
[0070] Specifically, based on the theoretical control elevation of the bridge deck, the ground elevation of the starting and ending points, and the maximum allowable longitudinal slope, the theoretical lengths of the uphill and downhill sections are calculated separately, and then summed to obtain the required total ramp length.
[0071] S203b: Determine whether the horizontal alignment length of the road segment is greater than or equal to the sum of the slope lengths.
[0072] It is understandable that the actual physical length of a road segment can be compared with the required theoretical total length of the ramp to determine the spatial conditions of the current road segment.
[0073] S203c. If the horizontal alignment length of a road segment is greater than or equal to the sum of the slope lengths, the final control elevation of the bridge deck shall adopt the value of the theoretical control elevation of the bridge deck, and the ascending slope segment, level slope segment and descending slope segment shall be allocated based on the final control elevation of the bridge deck.
[0074] The elevation of the level slope section is the same as the final control elevation of the bridge deck. The length of the level slope section is the remaining length after subtracting the sum of the lengths of the ascending and descending slope sections from the total length of the road section.
[0075] It should be noted that this process is applicable to road sections with sufficient length. When the horizontal alignment length of the road section is greater than or equal to the sum of the slope lengths, the initial design elevation is directly used as the final control elevation, and the profile structure allocated based on the final control elevation is obtained. Figure 3 The complete three-segment longitudinal section structure of uphill-planar-downhill shown in (a) is as follows: Figure 3 This is a schematic diagram of a longitudinal section structure of a bridge provided in an embodiment of this disclosure.
[0076] S203d. If the horizontal alignment length of the road segment is less than the sum of the slope lengths, then the maximum bridge deck elevation that can be achieved within the road segment is calculated based on the horizontal alignment length of the road segment, the ground elevation difference between the starting and ending points, and the maximum allowable longitudinal slope, and is taken as the final control elevation of the bridge deck. Based on the final control elevation of the bridge deck, a structure is constructed that includes only directly connected ascending and descending slope sections.
[0077] Among them, the slope lengths of the ascending and descending sections are adjusted proportionally, and the longitudinal slopes of the ascending and descending sections are the same as the maximum allowable longitudinal slope.
[0078] Understandably, this solution is suitable for road sections that are too short.
[0079] It should be noted that calculating the maximum achievable bridge deck elevation within a road segment requires satisfying specific mathematical constraints. In scenarios where the road segment length is insufficient, a quantitative balance must be maintained between the maximum bridge deck elevation (peak height), the ground elevation at the start and end points (height of the first and last segments), the maximum allowable longitudinal slope (grade), and the total road segment length.
[0080] For example, when the horizontal alignment length of a road segment is less than the sum of the slope lengths, the sum of the lengths of the ascending and descending slopes, calculated based on the maximum bridge deck elevation, the ground elevations at the start and end points, and the maximum allowable longitudinal slope, equals the total length of the road segment.
[0081] For example, the system solves the equation using formula (2) based on the total length of the road segment, the height difference between the first and last segments and the design slope, and then recalculates the maximum achievable height in the road segment by solving in reverse.
[0082] (Maximum elevation of bridge deck - ground elevation of starting and ending points) / maximum allowable slope = total length formula (2) That is, under the current length and slope constraints, the maximum achievable bridge deck elevation is determined, and the final control elevation is taken as the minimum value between the calculated maximum bridge deck elevation using formula (2) and the initially determined theoretical control elevation of the bridge deck (i.e., the initial peak height), thus forming a... Figure 3 The triangular arch longitudinal section structure shown in (b) is shown.
[0083] It is understandable that the part constructed by this process only includes the directly connected ascending and descending sections.
[0084] It should be noted that explicitly defining the core mathematical constraint equations that must be satisfied when back-calculating the maximum elevation of the bridge deck provides a rigorous and definite mathematical foundation for dynamic calculations. This transforms the complex engineering spatial adaptation problem of finding the maximum feasible elevation under constraints of finite length and fixed slope into a mathematical problem with a definite or unique solution. This ensures the determinism and uniqueness of the method's output results in scenarios with insufficient length, as well as its optimality under given constraints.
[0085] Based on this scheme, by introducing logical branches for two scenarios—sufficient and insufficient length—adaptive processing of road segments with different spatial conditions is achieved. For road segments with sufficient length, the use of the initial design elevation and the allocation of flat slope sections enables the generation of standard longitudinal profiles that meet conventional design expectations, ensuring driving comfort. For road segments with insufficient length, by calculating the feasible maximum elevation through reverse engineering and adjusting the slope length proportionally, the optimal longitudinal profile can still be generated within a limited space while strictly adhering to the maximum longitudinal slope specifications. This effectively avoids slope violations and stepped elevation changes, significantly improving the method's adaptability and compliance assurance for road segments of different lengths.
[0086] Optionally, in a method for generating a bridge longitudinal section provided in this embodiment of the present disclosure, the method may further include the following step S206.
[0087] S206. After obtaining or setting the ground elevation, if the road segment is identified as a ground road or the horizontal alignment length of the road segment is less than the second length threshold, a horizontal longitudinal profile with a zero longitudinal slope is directly generated.
[0088] Among them, the road segment type is identified based on the road segment bridge level attribute.
[0089] For example, the ground road level is set to 0, and the theoretical control elevation of the bridge deck is fixed at 0. The second length threshold is 3.0 meters, used to determine whether the road segment is an extremely short segment. After processing the ground elevation, the system checks whether the current road segment is a ground road (bridge level is 0), or whether its horizontal alignment length is less than 3 meters. If either condition is met, a horizontal longitudinal profile with zero slope and constant elevation is directly generated, thus skipping subsequent steps such as slope parameter calculation, key point sampling, and elevation interpolation. Through efficient condition judgment and simplified processing, compliant results are directly generated.
[0090] Based on this scheme, the efficiency of the overall processing workflow is significantly improved by introducing rapid identification and simplified processing of ground roads and extremely short road segments. Since ground roads themselves do not require longitudinal slope, and extremely short road segments do not have the space to set reasonable longitudinal slopes, meaningless complex calculations are avoided for these road segments that do not require or cannot undergo complex longitudinal slope calculations. This allows computing resources to be more concentrated on real bridge road segments that require dynamic adaptation, improving execution efficiency and practicality while ensuring the accuracy and compliance of the results.
[0091] Optionally, in the method for generating a bridge longitudinal section provided in this embodiment of the present disclosure, the above-mentioned S204 may further include the following S204a to S204d.
[0092] S204a. Collect feature points on the horizontal alignment of the road segment.
[0093] The feature points include road segment endpoints, slope change points, and original two-dimensional vertices.
[0094] Among them, the original two-dimensional vertices are the original two-dimensional vertices preserved by the projection.
[0095] S204b: Based on key parameters of the longitudinal profile, piecewise linear elevation interpolation is performed between feature points.
[0096] Specifically, based on the calculated key parameters of the longitudinal profile (such as the slope and length of each slope segment), piecewise linear elevation interpolation is performed between feature points (uphill segment, possible horizontal segment, downhill segment), thereby assigning an accurate elevation value to each two-dimensional horizontal point.
[0097] S204c: Based on the planar projection distance, traverse the interpolated 3D point sequence and delete points whose distance to adjacent points is less than or equal to the second distance threshold.
[0098] Traverse the 3D point sequence based on planar projection distance and delete duplicate points where the distance between adjacent points is less than a set threshold.
[0099] For example, the second distance threshold can be set to 0.5 meters. The system traverses the 3D point sequence, checking the projected distance between adjacent points on the 2D plane, and removes the next point among adjacent duplicate points whose distance on the XY plane (plane coordinate system) is less than or equal to 0.5 meters. These points are usually generated by interpolation sampling or calculation rounding and contribute very little to the geometric description. Removing these points can perform geometric cleanup to simplify the data with almost no impact on shape accuracy.
[0100] S204d: Adjust the elevation of the starting and ending points of the road segment to the obtained or set ground elevation value.
[0101] For example, the endpoint elevation adjustment forces the elevation values of the start and end points of the road segment to be precisely set to the ground elevation values (initial Z values) determined in S202.
[0102] Specifically, for the starting and ending points of the road segment, regardless of the elevation values of the starting and ending points obtained through linear interpolation, a mandatory endpoint elevation correction is performed, which is forcibly set to the ground elevation values obtained or set from S202 to eliminate the accumulation of floating-point calculation errors and ensure the absolute satisfaction of boundary conditions.
[0103] This step allows the Z-values of the beginning and end points of the road segment to be corrected to the initial Z-value.
[0104] Based on this scheme, targeted post-processing optimization significantly improved the quality of the final output data. By removing redundant vertices with excessively close planar distances, the model's data volume was reduced with almost no loss of geometric accuracy, alleviating the burden of data storage and rendering, and improving the efficiency of storage transfer and subsequent rendering processing. By forcibly correcting the endpoint elevations to preset boundary values, the small elevation errors that might accumulate at connection points due to numerical calculations were completely eliminated, ensuring absolute elevation consistency among multiple road segments at topological connection points. This achieved a seamless and smooth geometric connection of the 3D road network, facilitating the generation of high-quality 3D models suitable for practical engineering applications.
[0105] Corresponding to the embodiments of the foregoing methods, this disclosure also provides embodiments of the apparatus and the terminal to which it is applied.
[0106] Embodiments of the bridge longitudinal section generation apparatus disclosed herein can be applied to computer equipment, such as servers or terminal devices. The apparatus embodiments can be implemented through software, hardware, or a combination of both. Taking software implementation as an example, as a logically defined apparatus, it is formed by a processor that generates the longitudinal section of the bridge by reading the corresponding computer program instructions from non-volatile memory into memory and executing them. From a hardware perspective, such as... Figure 4 The diagram shown is a hardware structure diagram of a computer device provided in an embodiment of this disclosure, except... Figure 4 In addition to the processor 410, memory 430, network interface 420, and non-volatile memory 440 shown, the server or electronic device where the method for generating the longitudinal section of the bridge in the embodiment is located may also include other hardware depending on the actual function of the computer device, which will not be described in detail here.
[0107] Figure 5 This is a schematic diagram of a device for generating a bridge longitudinal section according to an embodiment of the present disclosure, as shown below. Figure 5As shown, the bridge longitudinal profile generation device 500 includes: a preprocessing module 501, a parameter calculation module 502, a longitudinal profile generation module 503, a road network model generation module 504, and a verification module 505. The preprocessing module 501 is used to unify the input two-dimensional vector road segments to the target coordinate system and perform geometric preprocessing on the road segments after unification. The parameter calculation module 502 is used to calculate the theoretical control elevation of the bridge deck based on the bridge layer and layer height parameters in the road longitudinal profile, using the mean sea level as the unified elevation datum, and to obtain or set the connecting roads at the start and end points of the road segments. The system calculates the ground elevation of the road surface; based on the theoretical control elevation of the bridge deck, the ground elevation, the maximum allowable longitudinal slope, and the horizontal alignment length of the road segment, it calculates the key parameters of the longitudinal profile and the final control elevation of the bridge deck; the longitudinal profile generation module 503 is used to collect feature points on the horizontal alignment of the road segment and interpolate the elevations according to the key parameters of the longitudinal profile and the final control elevation of the bridge deck, perform geometric cleaning and endpoint elevation adjustment, and generate a three-dimensional longitudinal profile; the road network model generation module 504 is used to combine the three-dimensional longitudinal profiles of each road segment into a three-dimensional road network model according to the planar topological relationship; the verification module 505 is used to verify the longitudinal slope and alignment.
[0108] Optionally, the parameter calculation module 502 is specifically used to calculate the sum of the slope lengths of the ascending and descending sections required to reach the theoretical control elevation of the bridge deck; determine whether the horizontal alignment length of the road segment is greater than or equal to the sum of the slope lengths; if the horizontal alignment length of the road segment is greater than or equal to the sum of the slope lengths, the final control elevation of the bridge deck adopts the value of the theoretical control elevation of the bridge deck, and the ascending, level, and descending sections are allocated based on the final control elevation of the bridge deck, wherein the elevation of the level section is the same as the final control elevation of the bridge deck; if the horizontal alignment length of the road segment is less than the sum of the slope lengths, the maximum bridge deck elevation that can be achieved within the road segment is calculated as the final control elevation of the bridge deck based on the horizontal alignment length of the road segment, the difference in ground elevation between the starting and ending points, and the maximum allowable longitudinal slope, and is constructed based on the final control elevation of the bridge deck, containing only directly connected ascending and descending sections; wherein the slope lengths of the ascending and descending sections are adjusted proportionally, and the longitudinal slopes of the ascending and descending sections are the same as the maximum allowable longitudinal slope.
[0109] Optionally, if the horizontal alignment length of the road segment is less than the sum of the slope lengths, the sum of the lengths of the ascending and descending slopes calculated based on the maximum bridge deck elevation, the ground elevations at the starting and ending points, and the maximum allowable longitudinal slope is equal to the total length of the road segment.
[0110] Optionally, the preprocessing module 501 is specifically used to convert the two-dimensional vector road segment to the target projection coordinate system and normalize the accuracy of the planar coordinates; delete redundant vertices whose distance from the start and end points of the road segment is less than or equal to a first distance threshold; if the planar linear length of the road segment is less than a first length threshold, retain the middle geometry of the road segment with the midpoint of the road segment as the center and the length as a first preset proportion of the total length of the road segment, and delete the vertices outside the retained part.
[0111] The parameter calculation module 502 is specifically used to: obtain the ground elevation from the input road segment topology attributes; if the ground elevation cannot be obtained from the road segment topology attributes, the road segment is treated as an isolated road segment, and the ground elevation value is controlled by the bridge deck theory.
[0112] Optionally, the longitudinal profile generation module 503 is also used to: after obtaining or setting the ground elevation, if the road segment is identified as a ground road or the horizontal alignment length of the road segment is less than the second length threshold, directly generate a horizontal longitudinal profile with a zero longitudinal slope.
[0113] Optionally, the longitudinal profile generation module 503 is specifically used for: collecting feature points on the horizontal alignment of the road segment, the feature points including road segment endpoints, slope change points, and original two-dimensional vertices; performing piecewise linear elevation interpolation between the feature points based on the key parameters of the longitudinal profile; traversing the interpolated three-dimensional point sequence based on the planar projection distance, deleting points whose distance from adjacent points is less than or equal to a second distance threshold; and adjusting the elevation of the start and end points of the road segment to the acquired or set ground elevation value.
[0114] This disclosure discloses a bridge longitudinal profile generation apparatus. First, by establishing a processing framework based on sea level as a unified reference, prioritizing coordinate unification followed by geometric preprocessing, it avoids vibrations caused by coordinate system differences and geometric noise from the outset. Then, by dynamically calculating key parameters of the longitudinal profile, precise matching of slope and road segment length can be achieved. Finally, the generated three-dimensional longitudinal profile undergoes forced endpoint correction and geometric cleanup, ensuring smoothness and geometric simplicity at connection points. Ultimately, through integration and verification, a compliant and continuous three-dimensional road network model can be output, improving the flexibility of bridge longitudinal profile generation and achieving highly adaptable bridge longitudinal profile design for different bridge levels and road segments of different lengths.
[0115] This disclosure also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in the above-described method for generating a bridge longitudinal section.
[0116] This disclosure also provides a computer device, which includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the computer-readable instructions, when executed by the processor, implement the steps in the above-described method embodiment for generating a bridge longitudinal section.
[0117] The specific implementation process of the functions and roles of each module in the above device can be found in the implementation process of the corresponding steps in the above method, and will not be repeated here.
[0118] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to in the description of the method embodiments. The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this disclosure according to actual needs. Those skilled in the art can understand and implement this without creative effort.
[0119] The foregoing has described specific embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
[0120] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention applied herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not claimed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.
[0121] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.
[0122] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.
Claims
1. A method for generating a longitudinal section of a bridge, characterized in that, The method includes: The input two-dimensional vector road segments are unified to the target coordinate system, and the road segments after the coordinate system is unified are geometrically preprocessed. Using mean sea level as a unified elevation benchmark, and based on the bridge layer and layer height parameters in the road longitudinal profile, the theoretical control elevation of the bridge deck is calculated, and the ground elevation of the road surface connecting the start and end points of the road section is obtained or set. Based on the theoretical control elevation of the bridge deck, the ground elevation, the maximum allowable longitudinal slope, and the horizontal alignment length of the road section, calculate the key parameters of the longitudinal profile and the final control elevation of the bridge deck. Based on the key parameters of the longitudinal profile and the final control elevation of the bridge deck, feature points are collected on the horizontal alignment of the road segment and the elevation is interpolated. Geometric cleaning and endpoint elevation adjustment are performed to generate a three-dimensional longitudinal profile. The three-dimensional longitudinal profiles of each road segment are combined into a three-dimensional road network model according to the planar topological relationship, and the longitudinal slope and alignment are verified.
2. The method according to claim 1, characterized in that, The calculation of key parameters of the longitudinal profile and the final control elevation of the bridge deck includes: Calculate the sum of the slope lengths of the ascending and descending sections required to reach the theoretical control elevation of the bridge deck; Determine whether the horizontal alignment length of the road segment is greater than or equal to the sum of the slope lengths; If the horizontal alignment length of the road segment is greater than or equal to the sum of the slope lengths, then the final control elevation of the bridge deck adopts the value of the theoretical control elevation of the bridge deck, and the ascending slope section, level slope section and descending slope section are allocated based on the final control elevation of the bridge deck, wherein the elevation of the level slope section is the same as the final control elevation of the bridge deck; If the horizontal alignment length of the road segment is less than the sum of the slope lengths, then based on the horizontal alignment length of the road segment, the ground elevation difference between the starting and ending points, and the maximum allowable longitudinal slope, the maximum achievable bridge deck elevation within the road segment is calculated as the final control elevation of the bridge deck. Based on the final control elevation of the bridge deck, a structure is constructed that includes only directly connected ascending and descending slopes. The slope lengths of the ascending and descending slopes are adjusted proportionally, and the longitudinal slopes of the ascending and descending slopes are the same as the maximum allowable longitudinal slope.
3. The method according to claim 2, characterized in that, When the horizontal alignment length of the road segment is less than the sum of the slope lengths, the sum of the length of the ascending slope and the length of the descending slope, calculated based on the maximum elevation of the bridge deck, the ground elevation of the starting and ending points, and the maximum allowable longitudinal slope, is equal to the total length of the road segment.
4. The method according to claim 1, characterized in that, The process of unifying the input two-dimensional vector road segments to the target coordinate system and performing geometric preprocessing on the road segments after unification includes: The two-dimensional vector road segment is transformed into the target projection coordinate system, and the plane coordinates are normalized for accuracy. Delete redundant vertices whose distance from the start and end points of the road segment is less than or equal to a first distance threshold; If the planar linear length of the road segment is less than the first length threshold, then the middle geometry of the road segment centered on the midpoint of the road segment and with a length equal to the first preset proportion of the total length of the road segment is retained, and the vertices outside the retained portion are deleted.
5. The method according to claim 1, characterized in that, The acquisition or setting of the ground elevation of the road surface connecting the start and end points of the road segment includes: Obtain the ground elevation from the input road segment topology attributes; If the ground elevation cannot be obtained from the road segment topology attributes, the road segment will be treated as an isolated road segment, and the ground elevation value will be the value of the bridge deck theoretical control elevation.
6. The method according to claim 1, characterized in that, The method further includes: After obtaining or setting the ground elevation, if the road segment is identified as a ground road or the horizontal alignment length of the road segment is less than the second length threshold, a horizontal longitudinal profile with a zero slope is directly generated.
7. The method according to claim 1, characterized in that, The process of collecting feature points on the road segment's horizontal alignment and interpolating elevations, performing geometric cleanup and endpoint elevation adjustment, and generating a three-dimensional longitudinal profile includes: Feature points are collected on the horizontal alignment of the road segment, including road segment endpoints, slope change points, and original two-dimensional vertices; Based on the key parameters of the longitudinal profile, piecewise linear elevation interpolation is performed between feature points; Based on the planar projection distance, traverse the interpolated 3D point sequence and delete points whose distance to adjacent points is less than or equal to the second distance threshold; Adjust the elevation of the starting and ending points of the road segment to the obtained or set ground elevation value.
8. A device for generating a longitudinal section of a bridge, characterized in that, The device for generating the longitudinal profile of the bridge includes: a preprocessing module, a parameter calculation module, a longitudinal profile generation module, a road network model generation module, and a verification module; The preprocessing module is used to unify the input two-dimensional vector road segments to the target coordinate system and perform geometric preprocessing on the road segments after unifying the coordinate system. The parameter calculation module is used to calculate the theoretical control elevation of the bridge deck based on the average sea level as a unified elevation benchmark and the bridge layer and layer height parameters in the road longitudinal profile, and to obtain or set the ground elevation of the road surface connecting the start and end points of the road segment; based on the theoretical control elevation of the bridge deck, the ground elevation, the maximum allowable longitudinal slope and the horizontal alignment length of the road segment, it calculates the key parameters of the longitudinal profile and the final control elevation of the bridge deck. The longitudinal profile generation module is used to collect feature points on the road section plane alignment and interpolate elevations based on the key parameters of the longitudinal profile and the final control elevation of the bridge deck, perform geometric cleaning and endpoint elevation adjustment, and generate a three-dimensional longitudinal profile. The road network model generation module is used to combine the three-dimensional longitudinal profiles of each road segment into a three-dimensional road network model according to the planar topological relationship. The verification module is used to check the longitudinal slope and alignment.
9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer-readable instructions are executed by the processor, they implement the steps of the method for generating a bridge longitudinal section as described in any one of claims 1 to 7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method for generating the longitudinal section of a bridge as described in any one of claims 1 to 7.