Centroid axle distance optimization method of steel-concrete composite structure bridge and computer program product

Abstract

The invention relates to the technical field of steel-concrete double-layer swivel bridges, in particular to a centroid axle distance optimization method of a steel-concrete composite structure bridge and a computer program product. The method comprises the following steps: constructing a first constraint condition based on a centroid axis of a cross section of an upper chord, a centroid axis of a cross section of a longitudinal concrete beam and a centroid axis of a combined cross section of the cross section of the upper chord and the cross section of the longitudinal concrete beam; constructing a second constraint condition based on the flexural rigidity of the upper chord and the flexural rigidity of the longitudinal concrete beam; on the basis of the area of the cross section of the upper chord, the area of the cross section of the longitudinal concrete beam and the steel consumption of the truss, constructing a characterization model between the centroid shaft distance between the centroid shaft of the cross section of the upper chord and the centroid shaft of the cross section of the longitudinal concrete beam and the steel consumption of the truss per unit length in the longitudinal direction; and obtaining the optimal centroid axle distance. According to the method, the economical-efficiency-based structural optimization of the upper-layer steel structure bridge body and the lower-layer concrete structure bridge body can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of steel-concrete double-deck rotating bridges, and in particular to a centroidal wheelbase optimization method and a computer program product for a steel-concrete composite structure bridge. Background Art

[0002] Compared with the traditional double-layer steel truss, the lower concrete structure of the steel-concrete double-layer rotating bridge replaces the steel lower chord and the orthotropic steel bridge deck. First, it meets the stress state during the rotation construction process, giving full play to the advantages of the good compressive performance of concrete, avoiding the increase of the plate thickness of the lower steel structure near the support point, saving steel; second, the maintenance workload of the lower concrete beam is small, meeting the requirements for good structural durability and less maintenance and repair workload in the later period. The technical difficulties of the steel-concrete double-layer rotating bridge are reflected in: strong spatiality and complex stress; many system conversions, the structure is a T-structure during the rotation, and it is a continuous beam system after the bridge is completed; the stress of the steel-concrete node is complex, the positioning accuracy of the steel structure is strict, and the quality of concrete pouring is high.

[0003] For steel-concrete double-deck rotating bridges, it is necessary to analyze and study their overall bending stiffness, but there is no relevant research in the prior art. Summary of the invention

[0004] In order to analyze and study the flexural stiffness of the upper steel structure bridge body and the lower concrete structure bridge body in a steel-concrete double-deck rotating bridge, the present invention provides a centroidal wheelbase optimization method and a computer program product for a steel-concrete composite structure bridge, which can use the minimum amount of steel as an optimization condition and use the flexural stiffness as a constraint to achieve economic structural optimization of the upper steel structure bridge body and the lower concrete structure bridge body.

[0005] One of the purposes of the present invention is to provide a centroidal wheelbase optimization method for a steel-concrete composite structure bridge based on bending stiffness matching, wherein the steel-concrete composite structure bridge comprises a steel structure bridge body located at an upper layer and a concrete structure bridge body located at a lower layer, and the steel structure bridge body and the concrete structure bridge body are connected by a truss; the truss comprises an upper chord, a web member and a lower chord, and the lower chord is located at a longitudinal concrete beam of the concrete structure bridge body; It includes: Based on the centroidal axis of the cross section of the upper chord, the centroidal axis of the cross section of the longitudinal concrete beam, and the centroidal axis of the combined cross section of the cross section of the upper chord and the cross section of the longitudinal concrete beam, a first constraint condition is constructed; wherein the first constraint condition is used to constrain the centroidal axis of the combined cross section to be located within the concrete beam; Based on the bending stiffness of the upper chord and the bending stiffness of the longitudinal concrete beam, a second constraint condition is constructed; wherein the second constraint condition is used to constrain the ratio of the bending stiffness of the upper chord to the bending stiffness of the longitudinal concrete beam to be not less than a set threshold; Based on the cross-sectional area of ​​the upper chord, the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption of the truss, a characterization model is constructed between the centroidal axis distance between the centroidal axis of the cross-sectional area of ​​the upper chord and the centroidal axis of the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption per unit length of the truss in the longitudinal direction; The optimal centroidal wheelbase is obtained; wherein the optimal centroidal wheelbase satisfies the first constraint and the second constraint at the same time, and minimizes the steel consumption per unit length of the truss in the longitudinal direction in the characterization model.

[0006] Preferably, the expression of the first constraint condition is: ; in, is the centroidal distance between the centroidal axis of the cross section of the upper chord and the centroidal axis of the cross section of the longitudinal concrete beam; It is the vertical distance between the centroid axis of the combined cross section and the lower edge of the longitudinal concrete beam; is the ratio of the elastic modulus of the material of the upper chord to that of the longitudinal concrete beam; It is the ratio of the cross-sectional area of ​​the upper chord to the cross-sectional area of ​​the longitudinal concrete beam.

[0007] Preferably, the expression of the second constraint condition is: ; Where h is the equivalent height of the longitudinal concrete beam.

[0008] As a preferred method, based on the matching of bending stiffness, a corresponding relationship between the centroidal wheelbase and the cross-sectional ratio is constructed; Based on the truss structure, the corresponding relationship between the cross-section ratio and the amount of steel used in the truss is obtained.

[0009] Preferably, the corresponding relationship between the centroidal wheelbase and the cross-sectional ratio is constructed based on the bending stiffness matching, including: Based on the theoretical stress value of the upper edge of the longitudinal concrete beam, the allowable compressive stress value of the material of the longitudinal concrete beam, the theoretical stress value of the upper chord and the allowable compressive stress value of the material of the upper chord, the stress ratio relationship between the longitudinal concrete beam and the upper chord is constructed; Based on the stress ratio relationship, the centroidal axis distance, and the distance between the centroidal axis of the upper chord cross section and the centroidal axis of the combined cross section, the corresponding relationship between the centroidal axis distance and the section ratio is obtained.

[0010] Preferably, the theoretical stress value of the upper edge of the longitudinal concrete beam and the theoretical stress value of the upper chord are determined based on their respective cross-sectional axial forces and cross-sectional bending moments.

[0011] Preferably, based on the sectional axial force, sectional bending moment and sectional shear force at the combined cross-section, the sectional axial force and sectional bending moment at the combined cross-section are distributed according to the ratio of the bending stiffness of the upper chord and the bending stiffness of the longitudinal concrete beam to obtain the sectional axial force and sectional bending moment of the longitudinal concrete beam and the upper chord respectively.

[0012] Preferably, the sectional axial force and the sectional bending moment at the combined cross section are determined based on the sectional axial force, the sectional bending moment and the sectional shear force at the combined cross section.

[0013] As a preferred embodiment, the expression of the corresponding relationship between the centroidal wheelbase and the cross-sectional ratio is: ; in, ; ; ; in, N is the axial force of the combined cross section, M is the bending moment of the combined cross section, T is the shear force of the combined cross section, α is the angle between the web and the horizontal direction, is the distance in height between the centroid axis of the combined cross section and the upper edge of the longitudinal concrete beam, and h is the equivalent beam height when the longitudinal concrete beam is equivalent to a rectangular cross section.

[0014] Another object of the present invention is a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned centroidal wheelbase optimization methods for steel-concrete composite structure bridges based on bending stiffness matching.

[0015] The present invention has the following beneficial effects: The first constraint condition can be used to limit the position of the centroidal axis of the combined cross section, and the second constraint condition can be used to limit the bending stiffness that the upper chord and the longitudinal concrete beam need to bear respectively. Based on the characterization model, the amount of steel used can be used as an optimization condition to minimize the overall steel use in the steel-concrete composite structure bridge, thereby reducing manufacturing costs and improving economic performance. In addition, the introduction of the first and second constraints can comprehensively consider the differences between actual construction parameters and theoretical parameters. By solving the characterization model based on the first and second constraints, it can better fit the actual construction situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic cross-sectional view of a steel-concrete composite structure bridge in a specific embodiment of the present invention; Figure 2 It is a schematic diagram of a characterization model in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0018] See Figure 1 This embodiment provides a centroidal wheelbase optimization method for a steel-concrete composite structure bridge based on bending stiffness matching, wherein the steel-concrete composite structure bridge includes a steel structure bridge body located at an upper layer and a concrete structure bridge body located at a lower layer, and the steel structure bridge body and the concrete structure bridge body are connected by a truss; the truss has an upper chord, a web and a lower chord, and the lower chord is located at the longitudinal concrete beam of the concrete structure bridge body; It includes: Based on the centroidal axis of the cross section of the upper chord, the centroidal axis of the cross section of the longitudinal concrete beam, and the centroidal axis of the combined cross section of the cross section of the upper chord and the cross section of the longitudinal concrete beam, a first constraint condition is constructed; wherein the first constraint condition is used to constrain the centroidal axis of the combined cross section to be located within the concrete beam; Based on the bending stiffness of the upper chord and the bending stiffness of the longitudinal concrete beam, a second constraint condition is constructed; wherein the second constraint condition is used to constrain the ratio of the bending stiffness of the upper chord to the bending stiffness of the longitudinal concrete beam to be not less than a set threshold value (for example, 4); Based on the cross-sectional area of ​​the upper chord, the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption of the truss, a characterization model is constructed between the centroidal axis distance between the centroidal axis of the cross-sectional area of ​​the upper chord and the centroidal axis of the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption per unit length of the truss in the longitudinal direction; The optimal centroidal wheelbase is obtained; wherein the optimal centroidal wheelbase satisfies the first constraint and the second constraint at the same time, and minimizes the steel consumption per unit length of the truss in the longitudinal direction in the characterization model.

[0019] Based on the above, the centroidal axis position of the combined cross section can be restricted by the first constraint condition, and the bending stiffness that the upper chord and the longitudinal concrete beam need to bear can be restricted by the second constraint condition. Based on the characterization model, the amount of steel used can be used as an optimization condition to minimize the overall steel usage in the steel-concrete composite structure bridge, thereby reducing manufacturing costs and improving economic performance.

[0020] In addition, the introduction of the first constraint condition and the second constraint condition can comprehensively consider the difference between the actual construction parameters and the theoretical parameters. By solving the characterization model based on the first constraint condition and the second constraint condition, it can better fit the actual construction situation.

[0021] exist Figure 1In the figure, the centroidal axis of the cross section of the upper chord is P1, the centroidal axis of the cross section of the longitudinal concrete beam is P3, and the centroidal axis of the combined cross section of the upper chord and the longitudinal concrete beam is P2.

[0022] Among them, the expression of the first constraint is: ; in, is the centroidal distance between the centroidal axis of the cross section of the upper chord and the centroidal axis of the cross section of the longitudinal concrete beam; It is the vertical distance between the centroid axis of the combined cross section and the lower edge of the longitudinal concrete beam; is the ratio of the elastic modulus of the material of the upper chord to that of the longitudinal concrete beam; It is the ratio of the cross-sectional area of ​​the upper chord to the cross-sectional area of ​​the longitudinal concrete beam.

[0023] By introducing the parameter combination in the first constraint condition, the vertical distance between the centroid axis of the cross section and the lower edge of the longitudinal concrete beam is , which can constrain the centroid axis of the composite section to be located inside the longitudinal concrete beam and as close to the longitudinal concrete beam as possible, thereby effectively realizing the constraints on the structural parameters in the actual construction process.

[0024] Among them, the expression of the second constraint is: ; Where h is the equivalent height of the longitudinal concrete beam.

[0025] Through the second constraint condition, the bending contribution of the upper chord can be constrained so that the proportion of the bending moment of inertia provided by the upper chord can be no less than 80%.

[0026] The construction of the representation model includes: Based on the matching of bending stiffness, the corresponding relationship between centroidal wheelbase and section ratio is constructed; Based on the truss structure, the corresponding relationship between the cross-section ratio and the amount of steel used in the truss is obtained.

[0027] Wherein, the corresponding relationship between the centroidal wheelbase and the cross-sectional ratio is constructed based on the bending stiffness matching, including: Based on the theoretical stress value of the upper edge of the longitudinal concrete beam, the allowable compressive stress value of the material of the longitudinal concrete beam, the theoretical stress value of the upper chord and the allowable compressive stress value of the material of the upper chord, the stress ratio relationship between the longitudinal concrete beam and the upper chord is constructed; Based on the stress ratio relationship, the centroidal axis distance, and the distance between the centroidal axis of the upper chord cross section and the centroidal axis of the combined cross section, the corresponding relationship between the centroidal axis distance and the section ratio is obtained.

[0028] In this embodiment, taking C60 concrete and Q345qD steel as an example, the allowable compressive stress value of the material of the longitudinal concrete beam is 20 MPa, and the allowable compressive stress value of the material of the upper chord is 200 MPa.

[0029] Among them, the theoretical stress value of the upper edge of the longitudinal concrete beam and the theoretical stress value of the upper chord are determined based on their respective section axial forces and section bending moments.

[0030] Among them, based on the sectional axial force, sectional bending moment and sectional shear force at the combined cross section, the sectional axial force and sectional bending moment at the combined cross section are distributed according to the ratio of the bending stiffness of the upper chord and the bending stiffness of the longitudinal concrete beam, and the sectional axial force and sectional bending moment of the longitudinal concrete beam and the upper chord are obtained.

[0031] Among them, the section axial force and section bending moment at the combined cross section are determined based on the section axial force, section bending moment and section shear force at the combined cross section.

[0032] Combined with the structural characteristics of the steel-concrete composite bridge, the cross-sectional axial force, cross-sectional bending moment and cross-sectional shear force at the composite cross section can be N, M and T respectively; the cross-sectional axial force of the longitudinal concrete beam is and the cross-sectional axial force of the upper chord They are respectively, ; ; in, is the elastic modulus of the longitudinal concrete beam, is the elastic modulus of the upper chord, is the cross-sectional area of ​​the longitudinal concrete beam, is the cross-sectional area of ​​the upper chord, is the bending stiffness of the combined cross section, ; Section bending moment of longitudinal concrete beam and the bending moment of the upper chord They are respectively, ; ; in, is the distance between the centroidal axis of the upper chord and the centroidal axis of the composite section; where, .

[0033] Among them, the expression of the corresponding relationship between the centroid axis distance and the cross-sectional ratio is: ; in, ; ; ; in, N is the axial force of the combined cross section, M is the bending moment of the combined cross section, T is the shear force of the combined cross section, α is the angle between the web and the horizontal direction, is the distance in height between the centroid axis of the combined cross section and the upper edge of the longitudinal concrete beam, and h is the equivalent beam height when the longitudinal concrete beam is equivalent to a rectangular cross section.

[0034] See Figure 2 , which is a schematic diagram representing the model, where the solid line is the corresponding relationship between the centroid wheelbase and the cross-sectional ratio, and the dotted line is the corresponding relationship between the centroid wheelbase and the amount of steel used.

[0035] In addition, a specific embodiment of the present invention further provides an electronic device, which includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the centroidal wheelbase optimization method of the steel-concrete composite structure bridge based on bending stiffness matching of the present invention.

[0036] In addition, a specific embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, implements the centroidal wheelbase optimization method of the steel-concrete composite structure bridge based on bending stiffness matching of the present invention.

[0037] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on one or several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0038] The present invention and its implementation methods are described schematically above, and the description is not restrictive. The embodiments shown in the embodiments are only part of the implementation methods of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the embodiments and designs a structure and an implementation method similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. The centroidal wheelbase optimization method of steel-concrete composite structure bridge based on bending stiffness matching, where: The steel-concrete composite structure bridge includes a steel structure bridge body located at the upper layer and a concrete structure bridge body located at the lower layer, and the steel structure bridge body and the concrete structure bridge body are connected by a truss; the truss has an upper chord, a web member and a lower chord, and the lower chord is located at the longitudinal concrete beam of the concrete structure bridge body; The invention is characterized by comprising: Based on the centroidal axis of the cross section of the upper chord, the centroidal axis of the cross section of the longitudinal concrete beam, and the centroidal axis of the combined cross section of the cross section of the upper chord and the cross section of the longitudinal concrete beam, a first constraint condition is constructed; wherein the first constraint condition is used to constrain the centroidal axis of the combined cross section to be located within the concrete beam; Based on the bending stiffness of the upper chord and the bending stiffness of the longitudinal concrete beam, a second constraint condition is constructed; wherein the second constraint condition is used to constrain the ratio of the bending stiffness of the upper chord to the bending stiffness of the longitudinal concrete beam to be not less than a set threshold; Based on the cross-sectional area of ​​the upper chord, the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption of the truss, a characterization model is constructed between the centroidal axis distance between the centroidal axis of the cross-sectional area of ​​the upper chord and the centroidal axis of the cross-sectional area of ​​the longitudinal concrete beam and the steel consumption per unit length of the truss in the longitudinal direction; The optimal centroidal wheelbase is obtained; wherein the optimal centroidal wheelbase satisfies the first constraint and the second constraint at the same time, and minimizes the steel consumption per unit length of the truss in the longitudinal direction in the characterization model.

2. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 1 is characterized in that: The expression of the first constraint is: ； in, is the centroidal distance between the centroidal axis of the cross section of the upper chord and the centroidal axis of the cross section of the longitudinal concrete beam; It is the vertical distance between the centroid axis of the combined cross section and the lower edge of the longitudinal concrete beam; is the ratio of the elastic modulus of the material of the upper chord to that of the longitudinal concrete beam; It is the ratio of the cross-sectional area of ​​the upper chord to the cross-sectional area of ​​the longitudinal concrete beam.

3. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 2 is characterized in that: The expression of the second constraint is, ； Where h is the equivalent height of the longitudinal concrete beam.

4. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 2 is characterized in that: The construction of the representation model includes: Based on the matching of bending stiffness, the corresponding relationship between centroidal wheelbase and section ratio is constructed; Based on the truss structure, the corresponding relationship between the cross-section ratio and the amount of steel used in the truss is obtained.

5. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 4 is characterized in that: The corresponding relationship between the centroidal wheelbase and the cross-sectional ratio is constructed based on the bending stiffness matching, including: Based on the theoretical stress value of the upper edge of the longitudinal concrete beam, the allowable compressive stress value of the material of the longitudinal concrete beam, the theoretical stress value of the upper chord and the allowable compressive stress value of the material of the upper chord, the stress ratio relationship between the longitudinal concrete beam and the upper chord is constructed; Based on the stress ratio relationship, the centroidal axis distance, and the distance between the centroidal axis of the upper chord cross section and the centroidal axis of the combined cross section, the corresponding relationship between the centroidal axis distance and the section ratio is obtained.

6. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 5 is characterized in that: The theoretical stress values ​​of the upper edge of the longitudinal concrete beam and the theoretical stress values ​​of the upper chord are determined based on their respective section axial forces and section bending moments.

7. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 6 is characterized in that: Based on the sectional axial force, sectional bending moment and sectional shear force at the combined cross section, the sectional axial force and sectional bending moment at the combined cross section are distributed according to the ratio of the flexural stiffness of the upper chord and the flexural stiffness of the longitudinal concrete beam, and the sectional axial force and sectional bending moment of the longitudinal concrete beam and the upper chord are obtained.

8. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 6 is characterized in that: The section axial force and section bending moment at the combined cross section are determined based on the section axial force, section bending moment and section shear force at the combined cross section.

9. The centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to claim 8 is characterized in that: The expression for the correspondence between the centroidal wheelbase and the cross-sectional ratio is: ； in, ； ； ； in, N is the axial force of the combined cross section, M is the bending moment of the combined cross section, T is the shear force of the combined cross section, α is the angle between the web and the horizontal direction, is the distance in height between the centroid axis of the combined cross section and the upper edge of the longitudinal concrete beam, and h is the equivalent beam height when the longitudinal concrete beam is equivalent to a rectangular cross section.

10. A computer program product, characterized in that It comprises a computer program, which, when executed by a processor, implements the centroidal wheelbase optimization method of a steel-concrete composite structure bridge based on bending stiffness matching according to any one of claims 1 to 9.

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