Method for building main body structure model of steel box girder of steel structure bridge at cross slope change section

Abstract

The invention relates to the technical field of bridge engineering, in particular to a cross slope change section steel structure bridge steel box girder main body structure model building method, which comprises the following steps: acquiring the cross slope ratio of a mileage point at a preset position in a cross slope change section and the section size of a steel box girder at the mileage point, segmenting the cross slope change section along the length direction, determining a cross slope line at each segmentation point, and constructing a steel box girder main body structure model; and determining the section size of the steel box girder at each segment point, establishing a space reference plane, and sequentially generating solid models of a bottom plate, a web plate and a flange plate of the steel box girder through three-dimensional lofting to complete the overall three-dimensional model building of the cross slope change section box girder. According to the method, accurate lofting and size control of the steel box girder at the cross slope change section are achieved, errors caused by manual calculation and approximate processing in a traditional method are avoided, the modeling precision and effect are improved, through refined modeling of the cross slope change section, it is ensured that the line shape of a bridge structure meets the design requirement, the structure safety is improved, and the construction cost is reduced. And standardization and normalization of a steel structure bridge modeling technology are promoted.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a method for constructing a main structural model of a steel box girder for a steel structure bridge with varying cross slope. Background Technology

[0002] With the rapid development of modern bridge construction technology, steel structure bridges and steel-concrete composite structure bridges, with their outstanding advantages such as high strength, light weight, and short construction period, are increasingly widely used in various complex bridge projects. Especially in projects such as urban elevated roads, interchanges, and mountain highways, steel box girders often need to be placed in sections with continuously changing cross slopes to adapt to changes in road alignment and terrain conditions. In such sections, the web height of each box girder cell must be precisely adjusted according to the continuous changes in cross slope, which is crucial to ensuring a smooth bridge deck alignment and reasonable structural stress.

[0003] In traditional design and construction methods, the treatment of such cross slope variations mainly relies on two-dimensional plan drawings combined with partial sectional views, supplemented by a large amount of tedious manual calculations and geometric layout. This method is difficult to comprehensively and intuitively describe the true geometric shape and spatial position of the box girder in three-dimensional space, especially lacking in the description of web height, inclination angle, and spatial positioning of connection nodes between plates.

[0004] Its limitations directly lead to problems such as misunderstandings and accumulated layout errors in multiple stages, including factory material preparation, component processing, and on-site installation. This not only affects the processing accuracy and splicing quality of components, but may also cause installation difficulties, deviations from the design intent in terms of alignment, and even structural safety hazards, ultimately slowing down the overall construction progress and increasing project costs.

[0005] Therefore, in the face of increasingly complex bridge alignment design and high-standard quality control requirements, the industry urgently needs a method that can systematically, accurately and efficiently construct three-dimensional solid models of steel box girders with varying cross slopes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method for constructing a main structural model of a steel box girder for a steel structure bridge with varying cross slopes. This method enables accurate three-dimensional modeling of the steel box girder under conditions of continuous cross slope variation.

[0007] The technical solution adopted by this invention to solve its technical problem is: A method for constructing a main structural model of a steel box girder bridge with a changing cross slope, comprising the following steps: S1. Obtain the cross slope ratio at each mileage point at multiple predetermined locations within the cross slope change section, and determine the cross-sectional dimensions of the steel box girder at each mileage point. S2. Divide the cross slope change section into several segments along the length direction and determine the cross slope line at each segment point. S3. Based on the cross slope lines at each segment point determined in step S2 and the parameters involved in the steel box girder, determine the cross-sectional dimensions of the steel box girder at each segment point. S4. Place the cross-sectional dimension diagrams at each segment point determined in step S3 along the corresponding planar layout curve and vertical curve to establish a spatial reference plane. S5. Based on the cross-sectional dimension drawings placed in step S4, generate solid models of the bottom plate, web plate and flange plate of the steel box girder in sequence through three-dimensional lofting. S6. Integrate the various entity models to complete the overall three-dimensional model construction of the box girder of the cross slope change section.

[0008] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves precise layout and dimensional control of steel box girders with varying cross slopes through a systematic segmented modeling method. It avoids errors caused by manual calculation and approximation in traditional methods, improving the accuracy and effectiveness of modeling. It facilitates designers in refining construction drawings and allows for accurate calculation of steel plate usage for each segment, which is beneficial for material procurement and cost control. Through refined modeling of the cross slope variation segments, it ensures that the bridge structure alignment meets design requirements, improves structural safety, and promotes the standardization and normalization of steel structure bridge modeling technology.

[0009] As a preferred embodiment, a further technical solution of the present invention is: Preferably, the cross-sectional dimensions of the steel box girder in step S1 include the flange width, flange thickness, web height, web thickness, bottom plate thickness, and net height inside the box.

[0010] Preferably, in step S2, the changing segment is linearly divided into equal parts, and the cross slope line is determined by connecting the points of division with the corresponding points of the center lines of the left and right chamber flanges.

[0011] Preferably, the spatial reference plane is determined by the perpendicular point of the segment point on the planar layout curve, the corresponding point on the vertical curve, and the reference point in the cross-sectional dimension drawing. Attached Figure Description

[0012] Figure 1 This is a plan view of the cross slope variation section in this invention; Figure 2 This is a schematic diagram of the cross slope change section in this invention; Figure 3 This is a cross-sectional view at EK0+397.540 in an embodiment of the present invention; Figure 4 This is a cross-sectional view at EK0+417.540 in an embodiment of the present invention; Figure 5This is a cross-sectional view at EK0+447.540 in an embodiment of the present invention; Figure 6 This is a schematic diagram showing the distribution of equally divided points between mileage EK0+397.540 and EK0+417.540 in an embodiment of the present invention; Figure 7 This is a schematic diagram of the cross slope lines of the steel beam formed at each equally divided point between mileage EK0+397.540 and EK0+417.540 in an embodiment of the present invention. Figure 8 This is a schematic diagram showing the distribution of equally divided points between mileage EK0+417.540 and EK0+447.540 in an embodiment of the present invention; Figure 9 This is a schematic diagram of the cross slope lines of the steel beam formed at each equally divided point between mileage EK0+417.540 and EK0+447.540 in an embodiment of the present invention. Figure 10 N is extracted in the embodiments of this invention. Z9 N9, N Y9 A schematic diagram of the cross slope line of the formed steel box girder; Figure 11 According to N in the embodiments of the present invention Z9 N9, N Y9 The cross-sectional dimensions of the steel box girder at EK0+406.504 obtained from the cross slope line of the formed steel box girder; Figure 12 This is a distribution diagram of the planar layout curve in the planar layout diagram of the embodiment of the present invention, with perpendicular lines drawn from each of the equally divided points; Figure 13 This is a distribution diagram of the intersection points of each equally divided point on the planar arrangement curve and the vertical line in an embodiment of the present invention; Figure 14 This is a schematic diagram of establishing a reference plane by the perpendicular foot of the segment point on the planar layout curve, the corresponding point on the vertical curve, and the reference point in the cross-sectional dimension diagram in an embodiment of the present invention. Figure 15 This is a schematic diagram of placing the cross-sectional dimension diagram at the corresponding mileage location in an embodiment of the present invention; Figure 16 This is a schematic diagram of placing all cross-sectional dimension diagrams at their respective corresponding mileage locations in an embodiment of the present invention; Figure 17 These are the solid model diagrams of the left and right chamber floor plates generated by the layout in this embodiment of the invention; Figure 18 These are the solid model diagrams of the left and right chamber webs generated by the layout in this embodiment of the invention; Figure 19 These are the solid model diagrams of the left and right chamber flanges generated by the layout in this embodiment of the invention; Detailed Implementation

[0013] The present invention will be further illustrated below with reference to specific embodiments. The purpose of this illustration is solely to provide a better understanding of the invention. Therefore, the examples given do not limit the scope of protection of the present invention.

[0014] A method for constructing a main structural model of a steel box girder bridge with a changing cross slope, comprising the following steps: S1. Obtain the cross slope ratio of each mileage point at multiple predetermined locations within the cross slope change section, and determine the cross-sectional dimensions of the steel box girder at each mileage point. The cross-sectional dimensions of the steel box girder include the flange width, flange thickness, web height, web thickness, bottom plate thickness, and net height inside the box.

[0015] S2. Divide the cross slope change section into several equal segments along the length direction, and determine the cross slope line at each segment point by connecting the corresponding points of the division points with the center lines of the left and right chamber flanges.

[0016] S3. Based on the cross slope lines at each segment point determined in step S2 and the parameters involved in the steel box girder, determine the cross-sectional dimensions of the steel box girder at each segment point.

[0017] S4. Place the cross-sectional dimension diagrams at each segment point determined in step S3 along the corresponding planar layout curve and vertical curve to establish a spatial reference plane. The spatial reference plane is jointly determined by the perpendicular foot point of the segment point on the planar layout curve, the corresponding point on the vertical curve, and the reference point in the cross-sectional dimension diagram.

[0018] S5. Based on the cross-sectional dimension drawings placed in step S4, generate solid models of the bottom plate, web plate and flange plate of the steel box girder in sequence through three-dimensional lofting.

[0019] S6. Integrate the various entity models to complete the overall three-dimensional model construction of the box girder of the cross slope change section.

[0020] Taking the steel structure bridge of ramp E of a certain city interchange as an example, the plan layout from mileage EK0+397.540 (point A) to EK0+447.540 (point B) is as follows. Figure 1 As shown, at station EK0+397.540 (point A), the cross slope i is -2%; at station EK0+417.540 (point P), the cross slope i is 0%, gradually changing from -2% to 0%; at station EK0+447.540 (point B), the cross slope i is +3%, gradually changing from 0% to +3%. Figure 2 As shown.

[0021] S1. Obtain the cross slope ratio at each mileage point within multiple predetermined locations within the cross slope change section, and determine the cross-sectional dimensions of the steel box girder at each mileage point: S11. The cross slope of the steel box girder at mileage EK0+397.540 (point A) is i= -2%. Draw the cross-sectional view at this mileage point, as follows: Figure 3 As shown, The left compartment flange is 700mm wide and 30mm thick. The two web plates are 2523mm and 2467mm high and 20mm thick, respectively. The bottom plate is 30mm thick. The net width of the compartment is 2800mm. The design centerline length of the steel box girder is 2500mm, and the distance from the centerline of the left and right box girders to the new design centerline of the road is 2750mm. The right compartment flange is 700mm wide and 30mm thick. The two web plates are 2413mm and 2357mm high and 20mm thick, respectively. The bottom plate is 30mm thick. The net width of the compartment is 2800mm. S12. The cross slope of the steel box girder at mileage EK0+417.540 (point P) is i=0%. Draw the cross-sectional diagram, as follows: Figure 4 As shown: The width of the left and right compartment flanges is 700mm and the thickness is 30mm, the height of the web plate is 2440mm and the thickness is 20mm, the thickness of the bottom plate is 30mm, and the net width of the compartment is 2800mm. The steel box girder is designed with a centerline length of 2500mm, and the centerlines of the left and right box girders are both 2750mm away from the design centerline of the road. S13. The cross slope of the steel box girder at mileage EK0+447.540 (point B) is i = +3%. Draw the cross-sectional diagram as follows: Figure 5 As shown: The left compartment flange is 700mm wide and 30mm thick. The two web plates are 2315mm and 2400mm high and 20mm thick, respectively. The bottom plate is 30mm thick. The net width of the compartment is 2800mm. The steel box girder is designed with a centerline length of 2500mm, and the centerlines of the left and right box girders are both 2750mm away from the design centerline of the road. The right compartment flange is 700mm wide and 30mm thick. The two web plates are 2480mm and 2565mm high and 20mm thick, respectively. The bottom plate is 30mm thick. The net width of the compartment is 2800mm.

[0022] S2. Divide the cross slope change section linearly into several equal segments along its length, and determine the cross slope line at each segment point by connecting the corresponding points of the division points with the center lines of the left and right chamber flanges: S21, the section between EK0+397.540 and EK0+417.540 is 20m long. Determine the cross slope at each meter in this section, such as... Figure 6 As shown: Draw a straight line 20m long and divide it into 20 equal parts, with the division points being N0, N1, N2, ..., N.20 Point N0 corresponds to a cross slope of i = -2% at mileage EK0+397.540. 20 At the corresponding mileage EK0+417.540, the cross slope i = 0%, and the corresponding cross sections are placed perpendicularly to the straight line N0N. 20 On the facade where it is located.

[0023] like Figure 7 As shown, line segment N is obtained by connecting the center lines of the left flange plates of the left side chambers at both ends. Z0 N Z20 Divide it into 20 equal parts, with division point N. Z0 N Z1 N Z2 ..., N Z20 ; Connecting the center lines of the right flange plates of the two right-side compartments at both ends yields line segment N. Y0 N Y1 N Y2 ..., N Y20 ; Connection point N Z1 N1, N Y1 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+398.540, with connection point N. Z2 N2, N Y2 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+399.540, ..., connection point N Z19 N 19 N Y19 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+416.540.

[0024] S22. Determine the cross slope at each meter within a 30m interval between mileage EK0+417.540 and EK0+447.540, such as... Figure 8 As shown, Draw a straight line 30m long and divide it into 30 equal parts, with the division points being M0, M1, M2, ..., Mn. 30 Point M0 corresponds to a cross slope i = 0% at mileage EK0+417.540. 30 At the corresponding mileage EK0+447.540, the cross slope i = +3%, and the cross sections of both are placed perpendicularly on the straight line M0M. 30 On the facade where it is located.

[0025] like Figure 9 As shown, line segment M is obtained by connecting the center lines of the left flange plates of the left side chambers at both ends. Z0 M Z30 Divide it into 20 equal parts, with division point M. Z0 M Z1 MZ2 ... M Z30 ; Line segment M is obtained by connecting the center lines of the right flange plates of the right side compartments at both ends. Y0 M Y1 M Y2 ... M Y30 ; Connection point M Z1 M1, M Y1 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+418.540, connecting points MZ2, M2, and M. Y2 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+419.540, ..., connection point MZ 29 M 29 M Y29 The resulting line segment is the cross slope line of the steel box girder at mileage EK0+446.540.

[0026] S3. Based on the cross slope lines at each segment point determined in step S2 and the parameters related to the steel box girder, determine the cross-sectional dimensions of the steel box girder at each segment point: S31. Determine the cross-sectional dimensions of the steel box girder at mileage EK0+406.504; In step S2, such as Figure 10 As shown, connect point N Z9 N9, N Y9 The resulting cross slope segment of the steel box girder was extracted and used as the cross slope of the steel box girder at mileage EK0+406.504; like Figure 11 As shown, point O9 is obtained by drawing 2500mm downwards from point n9 as the base point. The line segment n9O9 is the design centerline height of the steel box girder. Point O9 is drawn 2750mm to the left and right to the right to obtain the left and right centerlines respectively. Based on the net width of 2800mm and thickness of 20mm in the left and right box chambers, and the flange width of 700mm and thickness of 30mm, the cross-sectional dimensions of the steel box girder at EK0+406.504 are obtained. Referencing the method for extracting the cross slope of the steel box girder at mileage EK0+406.504, determine the cross-sectional dimensions of the steel box girders at other mileages.

[0027] S4. Place the cross-sectional dimension diagrams at each segment point determined in step S3 along the corresponding planar layout curve and vertical curve to establish a spatial reference plane. The spatial reference plane is jointly determined by the perpendicular foot point of the segment point on the planar layout curve, the corresponding point on the vertical curve, and the reference point in the cross-sectional dimension diagram: Divide the plan layout curve AB in the plan layout drawing into 50 equal parts, with the division points being N0, N1, N2, ..., N... 50 Each equally spaced point corresponds to a distance of one meter. For example, point N0 corresponds to mileage EK0+397.450, point N9 corresponds to mileage EK0+406.450, and point N... 20 The corresponding mileage is EK0+417.450, point N. 50 The corresponding mileage is EK0+447.450; like Figure 12 As shown, draw a perpendicular line N0C0 through N0 to curve AB, a perpendicular line N1C1 through N1 to curve AB, a perpendicular line N2C2 through N2 to curve AB, ..., and so on. 50 Draw the perpendicular line N to curve AB. 50 C 50 ; like Figure 13 As shown, the points N0, N1, N2, ..., N are divided into equal parts. 50 Draw a vertical line upwards from the base point, intersecting the vertical curve ab at points n0, n1, n2, ..., n. 50 ; like Figure 14 As shown, a vertical plane is established using points n9, N9, and C9, and this vertical plane is used as the reference plane. like Figure 15 As shown, point n9 in the cross-sectional dimension diagram at mileage EK0+406.504 coincides with point n9 on the vertical curve; Apply the above method to place the cross-sectional dimension diagrams of the steel box girders at each other mileage point at the corresponding mileage point.

[0028] S5. Based on the cross-sectional dimension drawings placed in step S4, generate solid models of the bottom plate, web plate, and flange plate of the steel box girder sequentially through 3D lofting: like Figures 16 to 19 As shown, the solid models of the left and right chamber bottom plates, the solid models of the left and right chamber web plates, and the solid models of the left and right chamber flange plates are drawn in sequence. S6. Integrate the various entity models to complete the overall three-dimensional model construction of the box girder of the cross slope change section.

[0029] This invention achieves precise layout and dimensional control of steel box girders with varying cross slopes through a systematic segmented modeling method. It avoids errors caused by manual calculation and approximation in traditional methods, improving the accuracy and effectiveness of modeling. It facilitates designers in refining construction drawings and allows for accurate calculation of steel plate usage for each segment, which is beneficial for material procurement and cost control. Through refined modeling of the cross slope variation segments, it ensures that the bridge structure alignment meets design requirements, improves structural safety, and promotes the standardization and normalization of steel structure bridge modeling technology.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A method for constructing a main structural model of a steel box girder bridge with a changing cross slope, characterized in that, Follow these steps: S1. Obtain the cross slope ratio at each mileage point at multiple predetermined locations within the cross slope change section, and determine the cross-sectional dimensions of the steel box girder at each mileage point. S2. Divide the cross slope change section into several segments along the length direction and determine the cross slope line at each segment point. S3. Based on the cross slope lines at each segment point determined in step S2 and the parameters involved in the steel box girder, determine the cross-sectional dimensions of the steel box girder at each segment point. S4. Place the cross-sectional dimension diagrams at each segment point determined in step S3 along the corresponding planar layout curve and vertical curve to establish a spatial reference plane. S5. Based on the cross-sectional dimension drawings placed in step S4, generate solid models of the bottom plate, web plate and flange plate of the steel box girder in sequence through three-dimensional lofting. S6. Integrate the various entity models to complete the overall three-dimensional model construction of the box girder of the cross slope change section.

2. The method for constructing the main structural model of a steel box girder bridge with a changing cross slope according to claim 1, characterized in that: The cross-sectional dimensions of the steel box girder in step S1 include the flange width, flange thickness, web height, web thickness, bottom plate thickness, and net height inside the box.

3. The method for constructing the main structural model of a steel box girder bridge with a changing cross slope as described in claim 1, characterized in that: In step S2, the changing segment is linearly divided into equal parts, and the cross slope line is determined by connecting the points of division with the corresponding points of the center lines of the left and right chamber flanges.

4. The method for constructing the main structural model of a steel box girder bridge with a changing cross slope according to claim 1, characterized in that: The spatial reference plane is determined by the perpendicular point of the segment point on the planar layout curve, the corresponding point on the vertical curve, and the reference point in the cross-sectional dimension drawing.

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