Concrete-filled steel tube arch bridge based on steel corrugated pipe cross brace system

Abstract

The utility model relates to a concrete-filled steel tube arch bridge based on a steel corrugated pipe transverse supporting system. The concrete-filled steel tube arch bridge comprises a plurality of multi-rib concrete-filled steel tube main arches arranged in parallel, a transverse supporting system, a bridge deck system, vertical suspenders or stand columns for supporting the bridge deck system, and arch feet for connecting the multi-rib concrete-filled steel tube main arches and a bridge abutment, the transverse supporting systems are arranged at equal intervals in the longitudinal direction of the arch bridge, each row of transverse supporting systems comprises two sets of K-shaped transverse supporting units and a plurality of *-shaped transverse supporting units, the K-shaped transverse supporting units and the *-shaped transverse supporting units each comprise a vertical pipe and an inclined pipe, the inclined pipes are annular corrugated steel pipes, and the vertical pipes are connected with the *-shaped transverse supporting units. And the two ends of the inclined pipe are respectively connected with the vertical pipe and the cross beam through welding or bolts. The annular rigidity and the buckling bearing capacity of a transverse supporting system are remarkably improved through the wave crest-wave trough pinch effect, the out-of-plane stability of the arch bridge is enhanced on the premise that the wall thickness is not increased, the steel amount of the transverse supporting system is reduced, and rapid assembly and later maintenance are facilitated.

Description

A steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system Technical Field

[0001] This utility model relates to the field of steel-concrete composite arch bridge technology, specifically to a steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system. Background Technology

[0002] Concrete-steel tubular (CFST) arch bridges, combining the high strength of steel with the excellent compressive strength of concrete, are widely used in medium- and long-span valley and river crossings both domestically and internationally. Overhead multi-ribbed CFST arch bridges are particularly common, with their main arch ribs arranged in circular or parabolic arcs, forming a spatial load-bearing system through crossbeams, braces, and the bridge deck system. These bridges offer advantages such as light weight, convenient construction, and simple design. However, arch ribs are compression members, and their out-of-plane stiffness is much lower than their in-plane stiffness. Lateral tilting or torsional instability of the arch ribs often becomes a controlling problem, necessitating the use of the cross bracing system in the design to improve lateral stability margin. Existing research has shown that increasing the stiffness of the cross braces and their web members can significantly increase the safety factor of arch bridge stability, having a crucial impact on lateral vibration modes and structural torsion.

[0003] Current engineering projects typically use smooth-walled circular steel pipes as diagonal braces between adjacent arch ribs. This method is mature and simplifies joint welding. However, as bridge spans increase and the width-to-span ratio decreases, the circumferential compressive and buckling stiffness of smooth-walled circular pipes becomes significantly insufficient. To meet the specifications for lateral stability and dynamic performance, designs often rely on thickening the pipe wall or adding stiffening ribs, leading to the following shortcomings: First, a significant increase in self-weight raises the load-bearing requirements of the main arch and foundation; second, variations in wall thickness or rib welding increase the difficulty of factory-rolling the pipe fittings, resulting in longer welds and stress concentration on-site, affecting fatigue life; third, structural stiffness cannot be precisely adjusted as needed, making it difficult to balance economy and dynamic comfort.

[0004] Corrugated steel pipes, due to the hoop effect generated by the alternating crests and troughs, exhibit significantly higher circumferential stiffness and buckling capacity than plain-walled pipes of the same specifications. Their superior compressive and deformation resistance has been verified in municipal underground pipelines and pressure pipelines. However, in the field of bridge structural bracing, related products and design methods have not yet formed a systematic framework. Current published literature focuses on corrugated steel web composite beams or corrugated steel corrugated web bridges, with few reports on their application in arch bridge bracing, and a lack of complete sets of node structures and construction techniques. How to achieve adjustable bracing stiffness and controllable weight using corrugated steel pipes without increasing wall thickness, while also considering processing feasibility, welding convenience, and corrosion resistance and durability, has become a pressing technical problem to be solved in the field of lateral stability of steel-concrete composite arch bridges. Summary of the Invention

[0005] The object of the present utility model is to provide a concrete-filled steel tube arch bridge based on a steel corrugated pipe cross brace system, so as to at least solve the problems of insufficient circumferential stiffness of the cross braces of existing concrete-filled steel tube arch bridges and large self-weight of the transverse support system.

[0006] In order to achieve the above object, the technical solution adopted by the present utility model is as follows:

[0007] A concrete-filled steel tube arch bridge based on a steel corrugated pipe cross brace system includes a plurality of parallel multi-ribbed concrete-filled steel tube main arches, a transverse support system located between two adjacent multi-ribbed concrete-filled steel tube main arches, a bridge deck system, vertical suspenders or columns supporting the bridge deck system, and arch feet connecting the multi-ribbed concrete-filled steel tube main arches and the abutments.

[0008] The transverse support system is arranged at equal intervals along the longitudinal direction of the arch bridge. Each row of the transverse support system includes two groups of "K"-shaped cross brace units and a plurality of "rice"-shaped cross brace units. Both the "K"-shaped cross brace units and the "rice"-shaped cross brace units include vertical pipes and diagonal pipes. The vertical pipes are smooth pipes, and the vertical pipes are vertically and rigidly connected to the cross beams of the multi-ribbed concrete-filled steel tube main arches; the diagonal pipes are annular corrugated steel pipes, and both ends of the diagonal pipes are respectively connected to the vertical pipes and the cross beams by welding or bolts.

[0009] Further, the wave height h and wave pitch p of the annular corrugated steel pipe satisfy 0.3 ≤ h / p ≤ 0.6, and the outer diameter D and wall thickness t of the annular corrugated steel pipe satisfy D / t ≥ 20.

[0010] Further, the corrugated cross section of the annular corrugated steel pipe is a sine wave.

[0011] Further, the two groups of "K"-shaped cross brace units in each row of the transverse support system are arranged at the arch feet at both ends of the arch bridge; a plurality of "rice"-shaped cross brace units in each row of the transverse support system are arranged between the two groups of "K"-shaped cross brace units.

[0012] Further, positioning sleeves are arranged at both ends of the annular corrugated steel pipe, and the outer wall of the positioning sleeve is connected to the annular reinforcing plate pre-welded to the vertical pipe or the cross beam by high-strength bolts.

[0013] Further, the multi-ribbed concrete-filled steel tube main arch has a four-member truss section, and the members are connected by horizontal dumbbell tubes and diagonal web members to form a closed truss.

[0014] Further, the included angle between the two diagonal pipes and the vertical pipe in the "K"-shaped cross brace unit is 45° - 60°.

[0015] Further, the acute angle γ at the intersection of the two mutually crossed diagonal pipes in the "rice"-shaped cross brace unit is 28° - 32°.

[0016] Furthermore, the vertical hanger is made of 40CrNiMo high-strength steel tie rod and is connected to the bridge deck system through a ball joint anchor head.

[0017] Furthermore, the column is a square box-shaped steel-concrete composite component, and the column is rigidly connected to the crossbeam.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] Compared with existing technologies, this utility model uses annular corrugated steel pipes instead of smooth-walled circular pipes as the inclined pipes for "K"-shaped and "M"-shaped cross braces. By utilizing the crest-trough constriction effect, it significantly improves the circumferential stiffness and buckling capacity of the cross braces, and can meet the lateral stability requirements of large-span, low-width-to-span ratio arch bridges without increasing the wall thickness. By limiting the ratio range of wave height h to wave pitch p and the ratio of outer diameter D to wall thickness t, the stiffness of the cross braces can be designed in stages as needed, achieving a balance between structural performance and economy. Positioning sleeves are set at both ends of the corrugated steel pipes and high-strength bolts or welding are used for quick connection, which facilitates factory prefabrication and on-site assembly, reducing weld length and construction time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0021] Figure 1 is a schematic diagram of the overall structure of a steel-concrete composite arch bridge based on a steel corrugated pipe cross bracing system according to an embodiment of this utility model;

[0022] Figure 2 is a schematic diagram of the connection between the two multi-ribbed steel-concrete main arches and the transverse support system in an embodiment of this utility model.

[0023] Figure 3 is a structural schematic diagram of the "K"-shaped cross brace unit in an embodiment of this utility model;

[0024] Figure 4 is a structural schematic diagram of the "rice" shaped cross brace unit of this utility model embodiment.

[0025] The diagram is labeled as follows:

[0026] 1-Multi-ribbed steel-concrete composite main arch, 2-Bridge deck system, 3-Column, 4-Abutment, 5-“K”-shaped cross bracing unit, 6-“M”-shaped cross bracing unit, 7-Vertical tube, 8-Inclined tube, 9-Crossbeam. Detailed Implementation

[0027] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0028] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0030] Example:

[0031] This embodiment uses a six-ribbed, upper-bearing steel-concrete composite arch bridge with a span of 240m and a rise-to-span ratio of 1 / 5 as a prototype to illustrate the overall structure, working mechanism, and construction process of a steel corrugated pipe cross bracing system. For relevant component reference numerals, please refer to Figures 1 to 4.

[0032] As shown in Figure 1, the entire arch bridge consists of six multi-ribbed steel-concrete composite main arches 1, forming a spatial main load-bearing system. The main arches are arranged parallel to the bridge axis, and each main arch adopts a four-limb truss section: the outer diameter of each limb is 800mm, the wall thickness is 18mm, and it is filled with C55 fine stone concrete. The trusses are welded together to form a closed truss by horizontal dumbbell tubes with an outer diameter of 508mm and diagonal web members of 355mm. Each truss has pre-set segmented flanges at the top of the arch and at L / 4 and L / 2, which facilitates segmented roll forming in the factory and assembly on site with high-strength bolts. The bridge deck system 2 is set on the top surface of the main arches and consists of 14mm orthotropic steel bridge deck panels and upper and lower 6mm combined epoxy asphalt layers. The bridge deck load is transferred to the horizontal beams 9 through the vertical columns 3, and then distributed to each main arch by the horizontal beams and the horizontal bracing system. The abutments 4 at both ends are reinforced concrete anchorage structures. The arch feet are anchored to the abutments by shear keys and prestressed anchor rods to achieve horizontal thrust closure.

[0033] As shown in Figure 2, a transverse support system arranged at equal longitudinal intervals between adjacent main arches 1 can be seen; each column of the support system includes two groups of "K"-shaped cross-brace units 5 located in the arch springing area and nine groups of "rice"-shaped cross-brace units 6 located in the middle, and the two are arranged alternately longitudinally with a spacing of 5 m; the vertical pipe 7 of the "K"-shaped unit 5 forms an angle of 45° to 60° with the inclined bellows 8, which can preferentially inhibit the lateral inclination of the arch springing; the "rice"-shaped unit 6 uses four inclined bellows to cross at the central vertical main pipe, and the acute angle γ of the intersection point is controlled at 28° to 32°, which can effectively improve the torsional stiffness at the mid-span.

[0034] Figure 3 shows the structure of the "K"-shaped cross-brace unit 5: the vertical pipe 7 is selected as a Φ700 mm × 20 mm smooth-walled round pipe, and its upper and lower ends are welded to the cross beam 9 by full penetration with a groove; the two inclined pipes 8 are selected as sinusoidal annular corrugated steel pipes with an outer diameter D = 560 mm and a wall thickness t = 14 mm, a wave pitch p = 60 mm, and a wave height h = 20 mm, so that h / p ≈ 0.33, meeting the requirements of 0.3 ≤ h / p ≤ 0.6 and D / t ≥ 20; the corrugated structure significantly increases the circumferential moment of inertia and improves the compressive and torsional resistance of the inclined pipe without increasing the self-weight.

[0035] Figure 4 shows the details of the "rice"-shaped cross-brace unit 6: the four corrugated inclined pipes 8 cross each other in pairs and are welded to the vertical main pipe at the center to form a diamond-shaped stress network; the upper and lower ends of the central main pipe are rigidly connected to the cross beam 9, which can weaken the torsional vibration mode in the mid-span area; all bellows ends are rolled with a 300 mm smooth closing section and welded with a 20 mm thick annular flange, and the flange is evenly distributed with 16 × M24 high-strength bolt holes, which can be quickly assembled with the pre-welded flange of the vertical pipe or the cross beam, and the flange-sleeve-bolt joint is convenient for later single-piece replacement and maintenance; for anti-corrosion and monitoring, the outer wall of the bellows is first hot-dip galvanized and then sprayed with fluorocarbon topcoat, and the inner cavity is injected with C40 slightly expanded grout and embedded with fiber Bragg grating sensing grooves.

[0036] The lateral stability of the ribbed arch bridge is mainly controlled by the stiffness of the cross braces; the traditional smooth-walled round pipe cross braces are difficult to balance weight and stiffness. In this embodiment, the smooth pipe is replaced by an annular corrugated steel pipe with alternating wave crests and wave troughs, and the hoop stiffness and buckling bearing capacity of the inclined pipe are significantly improved by the constriction effect; and the stiffness grading of the cross braces is achieved by adjusting the h / p and D / t ratios, which can optimize the out-of-plane stability and lateral vibration performance of the arch bridge for different span-width ratios; the "K"-type cross-brace unit focuses on restricting the opening angle of the arch springing, and the "rice"-type cross-brace unit enhances the torsional stiffness at the mid-span. The combination of rigidity and flexibility of the two keeps the whole bridge stable under the action of wind-vehicle coupling or unbalanced vehicle loads; the quick-assembly joints reduce high-altitude welding, reduce stress concentration, and are convenient for disassembly and assembly, and are also convenient for the later upgrade or maintenance of the cross braces.

[0037] In terms of construction, each segment of the main arch is roll-formed once in the factory and filled with concrete internally. On-site, the bracket rotation method is used to lift the segments in sections and assemble them one by one with high-strength bolts until closure; after the cross beams are hoisted, the vertical pipes are welded or installed first, and then the pre-assembled and welded "K"-shaped and "meter"-shaped cross brace gantry frames are hoisted as a whole, and rapid positioning is achieved through flanges - bolts. Finally, anti-corrosion sealant is injected into all bellows joints and fiber Bragg grating strain sensors are installed for later health monitoring. In other embodiments, the bellows cross braces can also be transported separately by root and assembled on-site to adapt to the working conditions where the transportation channels or hoisting capabilities are insufficient.

[0038] The finite element analysis results based on the above parameters show that after assembly, the first-order lateral flexural-torsional buckling coefficient of the arch bridge is increased to 4.2, which is about 35% higher than the scheme of thickened smooth-walled circular pipe cross braces with the same span; the first-order lateral vibration mode frequency is increased by 27%, and the dynamic performance of the structure is significantly optimized. The static load test shows that the maximum strain at the flange of the "meter"-shaped cross brace is only 0.15 times the yield strain, and the total weight of the steel structure of the whole bridge is reduced by about 7% compared with the traditional scheme. These data verify the comprehensive advantages of the steel bellows cross brace system described in this embodiment in improving lateral stability, reducing structural weight, and simplifying node construction.

[0039] The above uses specific examples to elaborate on the present utility model, which is only used to help understand the present utility model and is not intended to limit the present utility model. For those skilled in the technical field to which the present utility model pertains, based on the idea of the present utility model, several simple deductions, deformations or substitutions can also be made.

Claims

1. A steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system, characterized in that, It includes several parallel multi-ribbed concrete-filled steel tube main arches, a transverse support system located between adjacent multi-ribbed concrete-filled steel tube main arches, a bridge deck system, vertical suspenders or columns supporting the bridge deck system, and arch feet connecting the multi-ribbed concrete-filled steel tube main arches and the abutments; the transverse support system is arranged at equal intervals along the longitudinal direction of the arch bridge, and each row of the transverse support system includes two groups of "K"-shaped cross brace units and several "rice"-shaped cross brace units. Both the "K"-shaped cross brace units and the "rice"-shaped cross brace units include vertical tubes and diagonal tubes. The vertical tubes are smooth tubes and are vertically and rigidly connected to the cross beams of the multi-ribbed concrete-filled steel tube main arches; the diagonal tubes are circular corrugated steel tubes, and both ends of the diagonal tubes are connected to the vertical tubes and the cross beams respectively by welding or bolts.

2. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 1, characterized in that, For the circular corrugated steel tube, the wave height h and the wave pitch p satisfy 0.3 ≤ h / p ≤ 0.6, and the outer diameter D and the wall thickness t of the circular corrugated steel tube satisfy D / t ≥ 20.

3. The steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system according to claim 2, characterized in that, The corrugated cross-section of the circular corrugated steel tube is a sine wave.

4. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 2 or 3, characterized in that, The two groups of "K"-shaped cross brace units in each row of the transverse support system are arranged at the arch feet at both ends of the arch bridge; several "rice"-shaped cross brace units in each row of the transverse support system are arranged between the two groups of "K"-shaped cross brace units.

5. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 1, characterized in that, Positioning sleeves are arranged at both ends of the circular corrugated steel tube, and the outer wall of the positioning sleeve is connected to the circular stiffening plate pre-welded to the vertical tube or the cross beam by high-strength bolts.

6. The steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system according to claim 1, characterized in that, The multi-ribbed concrete-filled steel tube main arch has a four-limb truss section, and the truss limbs are connected by horizontal dumbbell tubes and diagonal web members to form a closed truss.

7. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 1, characterized in that, The included angle between the two diagonal tubes and the vertical tube in the "K"-shaped cross brace unit is 45° - 60°.

8. The steel-concrete composite arch bridge based on a corrugated steel pipe cross bracing system according to claim 1, characterized in that, The acute angle γ at the intersection of the two intersecting diagonal tubes in the "rice"-shaped cross brace unit is 28° - 32°.

9. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 1, characterized in that, The vertical suspender uses a 40CrNiMo high-strength steel tie rod and is connected to the bridge deck system through a spherical hinge anchor head.

10. The steel-concrete composite arch bridge based on a corrugated steel cross bracing system according to claim 1, characterized in that, The column is a square box-shaped concrete-filled steel tube member, and the column is rigidly connected to the cross beam.

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