Stiff framework arch rib structure based on aluminum alloy web members and arch bridge

Abstract

The invention relates to the technical field of arch bridges, in particular to a stiff framework arch rib structure based on aluminum alloy web members and an arch bridge, the arch rib structure comprises an upper chord member and a lower chord member which are distributed up and down, the web members are connected between the upper chord member and the lower chord member, and the web members are made of aluminum alloy materials; the upper chord member is wrapped by an arch rib top plate, and the lower chord member is wrapped by an arch rib bottom plate. The web members made of the aluminum alloy are used for connecting the upper chord member and the lower chord member, the characteristics of high strength, low density, excellent corrosion resistance and the like of the aluminum alloy can be utilized, the dead weight of the structure is effectively reduced, and the long-term durability of the structure in a severe environment is improved; the upper chord is wrapped by the arch rib top plate, the lower chord is wrapped by the arch rib bottom plate, the bearing capacity of the upper chord and the lower chord can be improved, and therefore the size of the arch rib is optimized. According to the stiff framework arch rib structure based on the aluminum alloy web members, the requirements for the weight, durability and bearing capacity of the arch ribs can be met, and the arch bridge building requirements in different environments are met.

Description

Technical Field

[0001] The present invention relates to the technical field of arch bridges, and particularly to a rigid-frame arch rib structure and an arch bridge based on aluminum alloy web members. Background Art

[0002] Arch bridges are widely used in modern bridge construction due to their strong spanning ability, adaptability to complex terrains, and low later operation and maintenance costs. In the field of long-span arch bridges (single-span greater than 200m), rigid-frame concrete arch bridges are the fastest-developing arch bridge types in China in recent years, and the maximum span of the completed arch bridges has reached 600m. However, traditional rigid-frame concrete arch bridges use a steel tube concrete skeleton wrapped with reinforced concrete structure to form the arch rib, and the web is a reinforced concrete structure. Due to the large structural specific gravity, the overall weight of the arch rib is relatively large, which further poses a greater load requirement on the arch bridge foundation (arch seat). This not only increases the design difficulty of the arch bridge foundation but also puts forward higher requirements for the construction technology of the arch rib to ensure construction safety and economy, thus restricting the popularization and application of long-span arch bridges to a certain extent. Secondly, the construction of reinforced concrete webs is complex, the construction period is long, and the pouring quality of mass concrete is greatly affected by human and environmental factors and is difficult to stably control. At the same time, due to the large self-weight of the reinforced concrete structure, in long-span arch bridges, the self-weight effect of the structure has become the main control factor affecting bridge design, restricting the further increase of the arch bridge span. Summary of the Invention

[0003] The purpose of the present invention is to overcome the problem in the background art that the self-weight of traditional rigid-frame concrete arch bridges is large and restricts the further increase of the arch bridge span, and to provide a rigid-frame arch rib structure and an arch bridge based on aluminum alloy web members.

[0004] In the first aspect, the present invention provides a rigid-frame arch rib structure based on aluminum alloy web members, including an upper chord and a lower chord distributed up and down. Web members are connected between the upper chord and the lower chord, and the web members are made of aluminum alloy material; the upper chord is wrapped with an arch rib top plate, and the lower chord is wrapped with an arch rib bottom plate.

[0005] For the rigid-frame arch rib structure based on aluminum alloy web members of the present invention, by using web members made of aluminum alloy material to connect the upper chord and the lower chord, the characteristics of high strength, low density, and excellent corrosion resistance of aluminum alloy can be utilized to effectively reduce the structural self-weight and improve the long-term durability of the structure in harsh environments; by covering the upper chord with the arch rib top plate and the lower chord with the arch rib bottom plate, it is beneficial to solve the force problem of large axial forces at the upper chord and the lower chord, thereby optimizing the arch rib size. The rigid-frame arch rib structure based on aluminum alloy web members of the present invention can take into account the requirements of arch rib weight, durability, and bearing capacity, and meet the construction needs of arch bridges in different environments.

[0006] Preferably, mounting gusset plates are provided on both the upper chord and the lower chord. The end of the mounting gusset plate is connected to the outer wall of the upper chord or the lower chord. The two mounting gusset plates face each other and enclose an installation space. The end of the web member is coated with a composite plate. The end of the web member extends into the installation space, and the composite plate is connected to the mounting gusset plate.

[0007] Preferably, the composite plate is an aluminum-steel explosion welding composite plate. The composite plate includes an aluminum side and a steel side. The aluminum side is connected to the web member, and the steel side is connected to the inner wall of the mounting gusset plate.

[0008] Preferably, two symmetrically arranged composite plates are coated on the outer side of the web member, and the composite plates are connected to the web member by welding.

[0009] Further preferably, the composite plate and the web member are connected by friction stir welding.

[0010] Preferably, the mounting gusset plate is provided with first bolt holes, the composite plate is provided with second bolt holes, and the web member is provided with third bolt holes. The fixing bolts sequentially pass through the first bolt holes, the second bolt holes, and the third bolt holes.

[0011] Further preferably, insulating members are provided between the fixing bolts and the mounting gusset plate, the composite plate, and the web member.

[0012] Preferably, a full circumferential fillet weld is provided between the mounting gusset plate and the composite plate.

[0013] Preferably, it includes two upper chords and two lower chords, and the corresponding upper chord and lower chord are connected by the web member.

[0014] Preferably, an upper horizontal bracing rod is connected between the two upper chords, and a lower horizontal bracing rod is connected between the two lower chords; the arch rib top plate covers the upper chord and the upper horizontal bracing rod, and the arch rib bottom plate covers the lower chord and the lower horizontal bracing rod.

[0015] Preferably, the two upper chords and the two lower chords are arranged in a rectangular distribution.

[0016] Preferably, the arch rib top plate and the arch rib bottom plate are of reinforced concrete structure.

[0017] Preferably, the upper chord, the lower chord, and the web member are all circular tubular structures, and the cavities of the upper chord and the lower chord are filled with concrete.

[0018] Preferably, the arch rib top plate is provided with first longitudinal steel bars and first arc erection steel bars. At least four of the first arc erection steel bars enclose the upper chord, and the two ends of the first arc erection steel bars are connected to the first longitudinal steel bars.

[0019] Preferably, second longitudinal steel bars and second arc erection steel bars are arranged in the bottom plate of the arch rib. At least four of the second arc erection steel bars enclose the lower chord, and two ends of the second arc erection steel bars are connected to the second longitudinal steel bars.

[0020] Preferably, the thickness of the bottom plate of the arch rib is H, and the thickness of the top plate of the arch rib is h, where H≥h.

[0021] More preferably, along the direction from the arch foot to the arch top, the thickness of the bottom plate of the arch rib gradually decreases until H = h.

[0022] Preferably, the arch rib structure includes an arch foot section and an intermediate section, and the intermediate section is located between the two arch foot sections; the cavity of the web member of the arch foot section is filled with concrete, and the web member of the intermediate section is a hollow tube.

[0023] Preferably, the web member includes a horizontal web member and an inclined web member. Two ends of the horizontal web member are respectively connected to the upper chord and the lower chord, two ends of the inclined web member are respectively connected to the upper chord and the lower chord, the horizontal web member and the inclined web member are arranged alternately, and the horizontal web member and the inclined web member form an N-shaped structure.

[0024] Preferably, the web member includes a horizontal web member and an inclined web member. Two ends of the horizontal web member are respectively connected to the upper chord and the lower chord, one end of the inclined web member is connected to the body of the horizontal web member, and the other end is connected to the upper chord or the lower chord, and the horizontal web member and the inclined web member form a K-shaped structure.

[0025] In a second aspect, the present invention provides an arch bridge, including the rigid frame arch rib structure based on an aluminum alloy web member as described above.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: For the rigid frame arch rib structure based on an aluminum alloy web member of the present invention, by using web members made of aluminum alloy material to connect the upper chord and the lower chord, the characteristics of high strength, low density, and excellent corrosion resistance of aluminum alloy can be utilized to effectively reduce the self-weight of the structure and improve the long-term durability of the structure in a harsh environment; by covering the upper chord with the top plate of the arch rib and covering the lower chord with the bottom plate of the arch rib, it is beneficial to solve the problem of large axial forces at the upper chord and the lower chord, thereby optimizing the size of the arch rib. The rigid frame arch rib structure based on an aluminum alloy web member of the present invention can take into account the requirements of the weight, durability, and bearing capacity of the arch rib, so as to meet the construction needs of arch bridges in different environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view of the arch rib structure of the present invention (the top plate and the bottom plate of the arch rib are omitted); Figure 2Cross-sectional schematic diagram of the arch rib structure described in the present invention; Figure 3 Arrangement schematic diagram of the web members in Embodiment 1 of the present invention; Figure 4 Structural schematic diagram of the installation gusset plate described in the present invention; Figure 5 is Figure 4 Cross-sectional view along line I-I in Figure 6 is Figure 4 Cross-sectional view along line II-II in Figure 7 Side schematic diagram of the arch foot of the arch rib structure described in the present invention.

[0028] Markings in the figure: 1 - upper chord; 11 - upper horizontal bracing; 12 - arch rib top plate; 13 - first longitudinal reinforcement; 14 - first arc erection reinforcement; 15 - first vertical erection reinforcement; 16 - first stirrup; 2 - lower chord; 21 - lower horizontal bracing; 22 - arch rib bottom plate; 23 - second longitudinal reinforcement; 24 - second arc erection reinforcement; 25 - second vertical erection reinforcement; 26 - second stirrup; 3 - web member; 31 - transverse web member; 32 - diagonal web member; 33 - longitudinal stiffening plate; 4 - installation gusset plate; 41 - fixing bolt; 42 - full - circumference fillet weld; 5 - composite plate. Detailed implementation manners

[0029] The present invention will be further described in detail below in conjunction with specific embodiments. However, this should not be construed as limiting the scope of the above - mentioned subject matter of the present invention to the following embodiments. Any technology implemented based on the content of the present invention belongs to the scope of the present invention.

[0030] In the description of the specific embodiments of the present invention, without special explanation, the terms expressing the orientation or positional relationship such as "upper", "lower", "left", "right", "center", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the invention product / device / equipment is usually placed. These terms of orientation or positional relationship are only for the convenience of describing the solution of the present invention or simplifying the description in the specific embodiments, so as to facilitate technicians to quickly understand the solution, rather than indicating or implying that a specific device / component / element must have a specific orientation or be constructed and operated in a specific positional relationship. Therefore, it should not be construed as a limitation to the present invention.

[0031] In addition, when terms such as "horizontal", "vertical", "hanging", "parallel" appear, it does not mean that the corresponding device / component / element is required to be absolutely horizontal or vertical or hanging or parallel. Instead, it can be slightly inclined or deviated. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined. Or, it can be simply understood that the corresponding device / component / element is arranged in directions such as "horizontal", "vertical", "hanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0032] In addition, when expressions such as "first", "second", "third", etc. appear in the terms, they are only used to distinguish the description of the same or similar components, and should not be understood as emphasizing or implying the relative importance of specific components.

[0033] In addition, in the description of the embodiments of the present invention, "several", "multiple", "a number of" represent at least 2. It can be any situation such as 2, 3, 4, 5, 6, 7, 8, 9, etc., and even can be a situation exceeding 9.

[0034] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / limited, where terms such as "set", "installed", "connected", "connected", "provided with", "laid", "arranged" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be connection means commonly used in the art such as welding, riveting, bolting, threaded connection, etc. Such a connection can be a mechanical connection, an electrical connection or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components.

[0035] Embodiment 1 The concrete-filled steel tubular arch bridge with a stiffening skeleton is an arch bridge form that combines a steel structure skeleton and an outer concrete coating. The steel skeleton is used as the support structure during the construction stage, and after forming, the outer concrete is coated to form the final composite stress-bearing system. In this type of arch bridge structure, the web is a reinforced concrete structure, resulting in a relatively large overall weight of the arch rib, and thus a greater load requirement for the arch bridge foundation. The truss-type concrete-filled steel tubular arch rib structure is a space truss structure composed of concrete-filled steel tubular chords and steel web members, which combines the high-strength compressive performance of concrete-filled steel tubes and the lightweight and efficient characteristics of the truss structure. However, the chords and steel web members are exposed for a long time and are extremely vulnerable to environmental factors, increasing the operation and maintenance costs and reducing the durability and service life of the arch bridge.

[0036] To balance weight and service life and meet the needs of arch bridge construction, such as Figure 1 and Figure 2 shown, this embodiment provides a stiffening skeleton arch rib structure based on aluminum alloy web members, including an upper chord 1, a lower chord 2, and web members 3. The web members 3 are made of aluminum alloy material, and the web members 3 are connected between the upper chord 1 and the lower chord 2.

[0037] The upper chord 1 and the lower chord 2 are usually arranged along the arch axis, and the bending moment caused by the weight of the arch bridge and the upper load can be transformed into the pressure along the arch axis, thereby improving the bearing capacity of the arch bridge. The upper chord 1 is located at the upper part of the arch rib, and the lower chord 2 is located at the lower part of the arch rib. The two are connected by web members 3 to form an integral structure; the web members 3 are made of aluminum alloy material, and aluminum alloy has a small specific gravity and excellent corrosion resistance, which can not only improve the durability and service life of the arch bridge, but also reduce the weight of the arch rib to reduce the design difficulty of the arch bridge foundation.

[0038] The upper chord 1 and the lower chord 2 can be tubular structures. Preferably, the cavities of the upper chord 1 and the lower chord 2 are filled with concrete to improve the bearing capacity; further preferably, the materials of the upper chord 1 and the lower chord 2 are preferably steel. The upper chord 1, the lower chord 2 and the concrete in the cavity together form a concrete-filled steel tube structure, which can reduce the material cost under the condition of meeting the bearing capacity requirements; further preferably, the upper chord 1 and the lower chord 2 are circular tubular structures, which can reduce local stress concentration.

[0039] To further improve the bearing capacity of the arch rib structure, in this embodiment, the upper chord 1 is wrapped with an arch rib top plate 12, and the lower chord 2 is wrapped with an arch rib bottom plate 22. Both the arch rib top plate 12 and the arch rib bottom plate 22 can be concrete structures. By forming a composite structure between the arch rib top plate 12 and the upper chord 1 and a composite structure between the arch rib bottom plate 22 and the lower chord 2, not only can the bearing capacity of the arch rib structure be greatly improved, but also the chords can be isolated from the external environment by the concrete, so that the upper chord 1 and the lower chord 2 are less affected by the external environment. Erosion, especially in coastal or high humidity areas, is beneficial to improving the durability and service life of the arch rib.

[0040] The ends of the web members 3 can extend into the arch rib top plate 12 and / or the arch rib bottom plate 22, and the outer walls of the web members 3 are hermetically attached to the arch rib top plate 12 and / or the arch rib bottom plate 22.

[0041] Preferably, since the arch rib top plate 12 covers the upper chord 1 and the arch rib bottom plate 22 covers the lower chord 2, the corrosion resistance requirements for the upper chord 1 and the lower chord 2 are reduced, and the upper chord 1 and the lower chord 2 can use lower-cost carbon steel materials.

[0042] In summary, for the stiffening skeleton arch rib structure based on aluminum alloy web members described in this embodiment, by using the web members 3 made of aluminum alloy to connect the upper chord 1 and the lower chord 2, the characteristics of high strength, low density, and excellent corrosion resistance of aluminum alloy can be utilized to effectively reduce the self-weight of the structure and improve the long-term durability of the structure in harsh environments; by covering the upper chord 1 with the arch rib top plate 12 and covering the lower chord 2 with the arch rib bottom plate 22, it is beneficial to solve the problem of large axial forces at the upper chord 1 and the lower chord 2, thereby optimizing the dimensions of the arch rib. The stiffening skeleton arch rib structure based on aluminum alloy web members of the present invention can take into account the requirements of the arch rib weight, durability, and bearing capacity, so as to meet the construction needs of arch bridges in different environments.

[0043] Compared with the reinforced concrete web of the arch rib structure of the traditional long-span stiffening skeleton concrete-filled steel tube arch bridge, the self-weight of the stiffening skeleton arch rib structure based on aluminum alloy web members described in this embodiment can be reduced by more than 30%. This can not only effectively improve the bridge spanning ability under the condition of the same material strength, but also reduce the construction difficulty, simplify the construction process, and reduce the construction cost.

[0044] To solve the connection problem between the steel chord and the aluminum alloy web member 3, as Figures 3 to 6 shown, in some embodiments, mounting node plates 4 are provided on both the upper chord 1 and the lower chord 2. The end of the mounting node plate 4 is connected to the outer wall of the upper chord 1 or the lower chord 2. The two mounting node plates 4 face each other and enclose an installation space. The end of the web member 3 is covered with a composite plate 5. The end of the web member 3 extends into the installation space, and the composite plate 5 is connected to the mounting node plate 4.

[0045] The mounting node plate 4 can be a steel plate. The end of the mounting node plate 4 can be welded to the outer wall of the upper chord 1 or the lower chord 2. The mounting node plate 4 extends out of the outer wall of the upper chord 1 or the lower chord 2. At a connection position on the upper chord 1 or the lower chord 2, the two mounting node plates 4 face each other and enclose an installation space. The shape of the installation space can be adapted to the shape of the end of the web member 3. For example, Figure 6 as shown in the circular space, the end of the web member 3 extends into the installation space and is fixedly connected to the mounting node plate 4. A composite plate 5 is provided between the end of the web member 3 and the mounting node plate 4.

[0046] It can be understood that the thermophysical properties of aluminum alloy (melting point about 660 °C) and steel (melting point about 1500 °C) are quite different. Direct welding will generate brittle intermetallic compounds such as FeAl3, resulting in a decrease in joint strength. In addition, direct contact between aluminum alloy and steel will form a potential difference, which is likely to cause electrochemical corrosion.

[0047] To solve the above problems, preferably, the composite plate 5 is an aluminum-steel explosion-welded composite plate. The aluminum-steel explosion-welded composite plate is a metallurgical combination of aluminum and steel. Its essence is to form a bimetallic composite plate with atomic-level metallurgical bonding between the aluminum alloy layer and the carbon steel layer at the interface through the explosion welding process. This technology already has mature industrial production capacity and can be directly purchased or customized.

[0048] Specifically, the composite plate 5 includes an aluminum side and a steel side. The aluminum side is connected to the web member 3, and the steel side is connected to the inner wall of the mounting gusset plate 4. Through the aluminum-steel explosion-welded composite plate, the generation of brittle phases in the direct welding of dissimilar metals is avoided, effectively solving the metallurgical compatibility problem in the welding of dissimilar metals. The aluminum-steel explosion-welded composite plate can also be used as an isolation layer to block the galvanic corrosion path and can also be used as a rigid transition layer to disperse local stress and reduce stress concentration around the bolt holes.

[0049] Further preferably, two symmetrically arranged composite plates 5 are wrapped around the outside of the end of the web member 3 to form a connection structure. The plate edge of the composite plate 5 is welded to the outer wall of the web member 3, for example, by friction stir welding. The web member 3 and the composite plate 5 can be pre-connected in the factory and then transported to the construction site, thereby reducing the on-site welding volume.

[0050] In some embodiments, the fixing bolt 41 passes through the mounting gusset plate 4, the composite plate 5, and the web member 3. The end of the fixing bolt 41 is located inside the web member 3. The fixing bolt 41 can be a high-strength bolt. Through the fixing bolt 41, the rapid connection between the mounting gusset plate 4 and the web member 3 can be achieved, and the connection strength can be improved. The tensile strength of the fixing bolt 41 is preferably greater than or equal to 1000 MPa.

[0051] Specifically, the mounting gusset plate 4 is provided with a first bolt hole, the composite plate 5 is provided with a second bolt hole, and the web member 3 is provided with a third bolt hole. The fixing bolt 41 sequentially passes through the first bolt hole, the second bolt hole, and the third bolt hole. The pre-tightening force of the fixing bolt 41 is controlled within the range of ±10% of the design value, and the torque-rotation method is used for construction to ensure the connection stiffness.

[0052] To prevent electrolyte penetration, insulating sleeves are preset in the first bolt hole, the second bolt hole, and the third bolt hole. The insulating sleeves are made of insulating materials, such as rubber, etc. The fixing bolt 41 passes through the insulating sleeves. A rubber washer is provided between the nut of the fixing bolt 41 and the mounting gusset plate 4. The rubber washer is preferably fluororubber to improve the corrosion resistance and sealing performance.

[0053] Further, within the range of the end of the web member 3, the area of the composite plate 5 is larger than that of the installation gusset plate 4. A full-perimeter fillet weld 42 is provided between the edge of the installation gusset plate 4 and the steel side surface of the composite plate 5. The full-perimeter fillet weld 42 refers to a fillet weld form in which the entire contact perimeter is continuously welded, which can form a permanent force transmission path, improving the connection strength and sealing performance between the installation gusset plate 4 and the composite plate 5. Preferably, the full-perimeter fillet weld 42 is set after the bolt connection. After welding, ultrasonic flaw detection is used to ensure the weld quality, ensuring that there are no defects such as cracks and lack of fusion in the weld, and an anti-corrosion coating is applied to the weld area, with the coating thickness ≥ 200μm.

[0054] In some embodiments, the arch rib structure includes two upper chord members 1 and two lower chord members 2, and web members 3 are connected between the corresponding upper chord member 1 and lower chord member 2.

[0055] Preferably, an upper horizontal bracing member 11 is connected between the two upper chord members 1, and a lower horizontal bracing member 21 is connected between the two lower chord members 2; the arch rib top plate 12 covers the upper chord member 1 and the upper horizontal bracing member 11, and the arch rib bottom plate 22 covers the lower chord member 2 and the lower horizontal bracing member 21.

[0056] The upper horizontal bracing member 11 and the lower horizontal bracing member 21 can be made of steel. Two spaced upper chord members 1 are connected by the upper horizontal bracing member 11, and two spaced lower chord members 2 are connected by the lower horizontal bracing member 21. The upper chord member 1, the lower chord member 2, the web member 3, the upper horizontal bracing member 11 and the lower horizontal bracing member 21 form an integral truss structure to bear the force together.

[0057] Further preferably, the two upper chord members 1 and the two lower chord members 2 are arranged in a rectangular distribution. The rectangle has high symmetry, which is beneficial to improving the self-stability of the arch rib structure and optimizing the stress distribution of the arch rib structure.

[0058] In some embodiments, the arch rib top plate 12 and the arch rib bottom plate 22 are made of reinforced concrete structures, and steel bars are provided inside the arch rib top plate 12 and the arch rib bottom plate 22 to improve the overall strength. The upper and lower parts of the arch rib skeleton are wrapped with reinforced concrete to form the arch rib top plate 12 and the arch rib bottom plate 22, so that the load-bearing capacity of the arch rib is enhanced, which can effectively solve the problem of large axial force at the chord member, thereby achieving the purpose of optimizing the arch rib size. For long-span arch bridges with a span exceeding 200m using the arch rib of this scheme, compared with the traditional truss-type concrete-filled steel tube arch rib structure, the chord member size can be reduced by more than 25% on the basis of maintaining the same main arch force safety, thereby reducing the manufacturing and construction difficulty and cost.

[0059] Preferably, a first longitudinal steel bar 13 and a first arc erection steel bar 14 are provided inside the arch rib top plate 12. At least four first arc erection steel bars 14 surround the upper chord member 1, and both ends of the first arc erection steel bar 14 are connected to the first longitudinal steel bar 13. Specifically, as Figure 2As shown, the longitudinal steel bars extend along the length direction of the arch rib. The middle part of the arc-shaped erection bars is an arc adapted to the shape of the chord member. Four first arc-shaped erection bars 14 wind around the same upper chord member 1 from four directions. The two ends of the first arc-shaped erection bars 14 are respectively connected to different first longitudinal steel bars 13, thereby improving the connection tightness between the arch rib top plate 12 and the upper chord member 1, and making the bonding effect between the concrete and the upper chord member 1 better.

[0060] Preferably, second longitudinal steel bars 23 and second arc-shaped erection bars 24 are provided in the arch rib bottom plate 22. At least four second arc-shaped erection bars 24 enclose the lower chord member 2. The two ends of the second arc-shaped erection bars 24 are connected to the second longitudinal steel bars 23; as Figure 2 shown, four second arc-shaped erection bars 24 wind around the same lower chord member 2 from four directions. The two ends of the second arc-shaped erection bars 24 are respectively connected to different second longitudinal steel bars 23, thereby improving the connection tightness between the arch rib bottom plate 22 and the lower chord member 2, and making the bonding effect between the concrete and the lower chord member 2 better.

[0061] Furthermore, first stirrups 16 and first vertical erection bars 15 are provided in the arch rib top plate 12. The first stirrups 16 enclose the first longitudinal steel bars 13. Second stirrups 26 and second vertical erection bars 25 are provided in the arch rib bottom plate 22. The second stirrups 26 enclose the second longitudinal steel bars 23.

[0062] In a preferred embodiment, the thickness of the arch rib bottom plate 22 is H, and the thickness of the arch rib top plate 12 is h, where H≥h.

[0063] Furthermore, along the direction from the arch foot to the arch crown, the thickness of the arch rib bottom plate 22 gradually decreases until H = h.

[0064] It can be understood that the arch rib bottom plate 22 needs to resist greater compressive stress and shear stress compared with the arch rib top plate 12. By adopting the method that the thickness of the arch rib bottom plate 22 at the arch foot is greater than that of the arch rib top plate 12 and continuously decreases along the arch crown direction, the problem of large main arch axial force at the arch foot section can be effectively solved, enabling the structure to reduce its own weight and save costs while meeting the strength requirements.

[0065] It can be understood that for an arch bridge, after the vertical dead load and live load are transmitted to the main arch, they will be decomposed along the linear direction of the main arch. The mechanical characteristics of the main arch usually show that the axial force of the chord member at the arch crown position is the smallest. As it approaches the arch foot position, the main arch section needs to bear more self-weight from the upper part and the transmitted load, resulting in the largest axial force at the arch foot.

[0066] To give fuller play to the mechanical properties of the materials and reduce the self-weight of the structure, in a preferred embodiment, the arch rib structure includes arch foot sections and an intermediate section. The intermediate section is located between the two arch foot sections; the cavity of the web member 3 in the arch foot section is filled with concrete, and the web member 3 in the intermediate section is a hollow tube.

[0067] The arch springing section is the part close to the arch bridge foundation, and the middle section is located between the two arch springing sections; preferably, the sum of the horizontal projection lengths of the two arch springing sections accounts for 10% - 20% of the horizontal span of the arch bridge. The web members 3 of the arch springing section and the middle section adopt a differential design, which can significantly reduce the self-weight of the structure while ensuring the overall load-bearing performance of the arch rib, reduce the hoisting construction difficulty and the load requirement of the arch bridge foundation, effectively improve the spanning ability of the bridge under the condition of the same material strength, simplify the construction process, shorten the construction period, and reduce the construction cost.

[0068] In some embodiments, the web member 3 includes a horizontal web member 31 and an inclined web member 32. The two ends of the horizontal web member 31 are respectively connected to the upper chord member 1 and the lower chord member 2, and the two ends of the inclined web member 32 are respectively connected to the upper chord member 1 and the lower chord member 2. The horizontal web member 31 and the inclined web member 32 are arranged alternately, and the horizontal web member 31 and the inclined web member 32 form an N-shaped structure.

[0069] Specifically, a plurality of horizontal web members 31 are arranged at intervals along the axis of the arch rib. The inclined web member 32 is located between two adjacent horizontal web members 31 and is inclined to the horizontal web member 31. One end of the inclined web member 32 is connected to the upper end of one side horizontal web member 31, and the other end is connected to the lower end of the other side horizontal web member 31, that is, the two ends of the inclined web member 32 are respectively connected to different ends of two adjacent horizontal web members 31. The web member 3 is arranged in a quasi-N-shaped structure. The quasi-N-shaped structure has a simple form, few joints, uniform distribution of web members, high construction efficiency, and can meet the force requirements in the longitudinal middle part of the main arch.

[0070] The connection of the ends of the horizontal web member 31 and the inclined web member 32 may mean that the ends of both are connected to the same mounting gusset plate 4.

[0071] Specifically, one arrangement method is that the horizontal web member 31 is perpendicular to the upper chord member 1 and the lower chord member 2, and the inclined web member 32 is inclined to the upper chord member 1 and the lower chord member 2.

[0072] Another arrangement method is that both the horizontal web member 31 and the inclined web member 32 are inclined to the upper chord member 1 and the lower chord member 2.

[0073] Embodiment 2 This embodiment provides a stiffening skeleton arch rib structure based on aluminum alloy web members. The difference from Embodiment 1 on the basis of Embodiment 1 is that the web member 3 includes a horizontal web member 31 and an inclined web member 32. The two ends of the horizontal web member 31 are respectively connected to the upper chord member 1 and the lower chord member 2. One end of the inclined web member 32 is connected to the body of the horizontal web member 31, and the other end is connected to the upper chord member 1 or the lower chord member 2. The horizontal web member 31 and the inclined web member 32 form a K-shaped structure, as Figure 7 shown.

[0074] Preferably, the transverse web member 31 is perpendicular to the upper chord member 1 and the lower chord member 2; one end of the inclined web member 32 can be connected to the middle part of the transverse web member 31. One transverse web member 31 and two inclined web members 32 form a structure similar to the shape of "K". The transverse web member 31 and the inclined web member 32 are made of the same kind of metal and can be directly welded together, which makes the connection more convenient.

[0075] Preferably, the two inclined web members 32 in the same K-shaped structure are located on the side of the transverse web member 31 away from the arch springing, as Figure 7 shown. The transverse web member 31 and the two inclined web members 32 in another K-shaped structure form a triangular structure. One end of the transverse web member 31 is connected to one end of one inclined web member 32, and the other end of the transverse web member 31 is connected to one end of the other inclined web member 32. By forming a triangular structure, the force transmission path can be made more direct, the force transmission efficiency can be higher, the axial force can be more effectively shared and transmitted, local instability or structural deformation can be avoided, and the high-intensity compressive stress and shear stress at the arch springing can be coped with.

[0076] Further preferably, in the triangular structure closest to the arch springing, the ends of the two inclined web members 32 are connected to the arch bridge foundation, and transverse stiffening plates and longitudinal stiffening plates 33 are provided between the transverse web member 31 and the inclined web member 32. The longitudinal stiffening plates 33 are arranged along the axis of the arch rib. The lower end of the longitudinal stiffening plate 33 is connected to the inclined web member 32, and the upper end is connected to the transverse web member 31. The transverse stiffening plates are arranged transversely to the arch rib. The two ends of the transverse stiffening plate are respectively connected to two transversely spaced transverse web members 31, or respectively connected to two transversely spaced inclined web members 32.

[0077] Both the transverse stiffening plates and the longitudinal stiffening plates 33 are directly exposed to the environment, so aluminum alloy materials are used, which can improve the structural durability and reduce the structural self-weight at the same time; the transverse stiffening plates and the longitudinal stiffening plates 33 can effectively improve the stiffness of the structure at the arch springing, and can effectively disperse and evenly transmit the structural load, avoid the stress concentration phenomenon, and are more conducive to sharing the main arch axial force, improving the overall mechanical stability and safety, and making the structure safer in force.

[0078] Embodiment 3 This embodiment provides an arch bridge, including the stiffening skeleton arch rib structure based on aluminum alloy web members as described in Embodiment 1 or 2.

[0079] Preferably, the arch bridge includes two spaced-apart stiffening skeleton arch rib structures based on aluminum alloy web members; the arch bridge can be a deck arch bridge, a half-through arch bridge or a through arch bridge.

[0080] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A rigid frame arch rib structure based on an aluminum alloy web member, characterized in that, It includes an upper chord (1) and a lower chord (2) which are distributed vertically. Web members (3) are connected between the upper chord (1) and the lower chord (2), and the web members (3) are made of aluminum alloy. The upper chord (1) is externally wrapped with an arch rib top plate (12), and the lower chord (2) is externally wrapped with an arch rib bottom plate (22).

2. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 1, characterized in that Mounting gusset plates (4) are provided on both the upper chord (1) and the lower chord (2). The end of the mounting gusset plate (4) is connected to the outer wall of the upper chord (1) or the lower chord (2). The two mounting gusset plates (4) face each other and enclose an installation space. The end of the web member (3) is coated with a composite plate (5). The end of the web member (3) extends into the installation space, and the composite plate (5) is connected to the mounting gusset plate (4).

3. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 2, characterized in that, The composite plate (5) is an aluminum-steel explosion-bonded composite plate. The composite plate (5) includes an aluminum side and a steel side. The aluminum side is connected to the web member (3), and the steel side is connected to the inner wall of the mounting gusset plate (4).

4. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 3, characterized in that: Two symmetrically arranged composite plates (5) are coated on the outer side of the web member (3), and the composite plates (5) are welded to the web member (3); and / or, the mounting gusset plate (4) is provided with first bolt holes, the composite plate (5) is provided with second bolt holes, and the web member (3) is provided with third bolt holes. A fixing bolt (41) sequentially passes through the first bolt hole, the second bolt hole and the third bolt hole. Insulating members are provided between the fixing bolt (41) and the mounting gusset plate (4), the composite plate (5) and the web member (3); and / or, a full circumferential fillet weld (42) is provided between the mounting gusset plate (4) and the composite plate (5).

5. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to any one of claims 1-4, characterized in that, It includes two upper chords (1) and two lower chords (2). The web members (3) are connected between the corresponding upper chord (1) and the lower chord (2); An upper horizontal bracing rod (11) is connected between the two upper chords (1), and a lower horizontal bracing rod (21) is connected between the two lower chords (2). The arch rib top plate (12) covers the upper chord (1) and the upper horizontal bracing rod (11), and the arch rib bottom plate (22) covers the lower chord (2) and the lower horizontal bracing rod (21).

6. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 5, characterized in that: The two upper chords (1) and the two lower chords (2) are arranged in a rectangular distribution; and / or, the arch rib top plate (12) and the arch rib bottom plate (22) are of reinforced concrete structure; and / or, the upper chord (1), the lower chord (2) and the web member (3) are all circular tubular structures, and the cavities of the upper chord (1) and the lower chord (2) are filled with concrete.

7. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 5, characterized in that: The arch rib top plate (12) is provided with a first longitudinal steel bar (13) and a first arc erection steel bar (14). At least four of the first arc erection steel bars (14) enclose the upper chord rod (1), and two ends of the first arc erection steel bar (14) are connected to the first longitudinal steel bar (13). And / or, the arch rib bottom plate (22) is provided with a second longitudinal steel bar (23) and a second arc erection steel bar (24). At least four of the second arc erection steel bars (24) enclose the lower chord rod (2), and two ends of the second arc erection steel bar (24) are connected to the second longitudinal steel bar (23).

8. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to claim 5, wherein: The stiffening skeleton arch rib structure based on an aluminum alloy web member comprises an arch foot section and an intermediate section, and the intermediate section is located between the two arch foot sections; the lumen of the web member (3) of the arch foot section is filled with concrete, and the web member (3) of the intermediate section is a hollow pipe; And / or, the thickness of the arch rib bottom plate (22) is H, the thickness of the arch rib top plate (12) is h, and H≥h; along the direction from the arch foot to the arch top, the thickness of the arch rib bottom plate (22) gradually decreases until H = h.

9. The stiffening skeleton arch rib structure based on an aluminum alloy web member according to any one of claims 1-4, characterized in that: The web member (3) comprises a horizontal web member (31) and an inclined web member (32). Two ends of the horizontal web member (31) are respectively connected to the upper chord rod (1) and the lower chord rod (2), wherein: Two ends of the inclined web member (32) are respectively connected to the upper chord rod (1) and the lower chord rod (2). The horizontal web member (31) and the inclined web member (32) are arranged alternately, and the horizontal web member (31) and the inclined web member (32) form an N-shaped structure; Or, one end of the inclined web member (32) is connected to the rod body of the horizontal web member (31), and the other end is connected to the upper chord rod (1) or the lower chord rod (2), and the horizontal web member (31) and the inclined web member (32) form a K-shaped structure.

10. An arch bridge, characterized in that, It includes the stiffening skeleton arch rib structure based on an aluminum alloy web member according to any one of claims 1-9.

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