A high stress amplitude mesh hanger tie arch system

Abstract

The present invention is a high stress amplitude mesh hanger tie arch system, including arch ribs, mesh hanger system and main beam, characterized in that: the mesh hanger system adopts high stress amplitude oblique hangers to form a mesh structure, and the oblique hangers are connected by shock-absorbing cable clamps at their intersections; the oblique hangers adopt an external structural anchoring structure on the arch ribs, and an anchor plate anchoring structure on the main beam, and the beam end tensioning is operated outside the structure. Based on giving full play to the advantages of high vertical stiffness and good force-bearing performance of the mesh hanger arch bridge structure, the system combines the characteristics of the mesh hanger tie arch bridge itself, can adapt to the characteristics of large live load stress amplitude of the oblique hangers, and avoid collision between crossed hangers; the anchor end on the hanger arch is placed outside the structure to avoid the anchor structure becoming a control condition for the size of the arch rib, and adapt to the slender arch rib characteristics of the mesh hanger tie arch bridge; the anchor plate avoids opening holes in the top plate of the main beam, reduces the size of the anchor structure, and has a beautiful and durable structure.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, in particular to a high stress amplitude mesh hanger tie arch system. Background Art

[0002] The tied arch bridge originated in Europe in the late 19th century. The Austrian Langer proposed the tied arch bridge with rigid tied rods and flexible arches, emphasizing the hinged structure between the arch ribs and the hangers. This was an early form of the modern tied arch bridge. On this basis, Nelson proposed the use of oblique hangers instead of Langer's vertical hangers, which could greatly improve the structural stiffness. In 1955, the Norwegian Per Tveit proposed the concept of mesh hangers. Compared with the Nelson system arch bridge, the oblique hangers of the mesh hanger system cross at least twice, the number of hangers increases, the arch ribs and tie beams are more reasonably stressed, and the beam-arch structure is more slender.

[0003] At present, many mesh hanger arch bridges have been built at home and abroad, mostly in Japan, the United States, Germany and other countries, and there are relatively few domestic bridge examples. Foreign mesh hanger tie arch bridges generally have small spans and small bridge widths, and the constant and live loads borne by the inclined hangers are relatively small. They usually use steel bars, steel bars or galvanized metal cables, and the diameter is generally not more than 100mm. The connection structure with the arch rib and main beam generally uses node plates as intermediate components.

[0004] With the development of the domestic economy, the traffic volume has gradually increased, and the lane scale of newly built bridges has also become larger and larger. The demand for two-way eight lanes + pedestrian and non-motorized vehicle lanes to cross the river at the same time is very common. Some common rail bridges also provide rail crossings across the river. Compared with foreign mesh hanger tie arch bridges, domestic bridges bear greater live loads, greater changes in inclined hanger cable forces, larger live load stress amplitudes, and more prominent inclined hanger fatigue problems; affected by the large width of the bridge, the inclined hangers of domestic mesh hanger tie arch bridges bear large constant and live loads, and the scale of the inclined hangers is large. The node plate anchoring form of foreign mesh hanger tie arch bridges is not applicable, and the inclined hanger anchoring structure has become a factor that needs to be considered in the design. In response to these factors, a high stress amplitude mesh hanger tie arch system has been developed. Summary of the invention

[0005] The purpose of the present invention is to provide a high stress amplitude mesh hanger tie arch system to meet the construction needs of increasing bridge spans and bridge widths.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a high stress amplitude mesh hanger tie arch system, including arch ribs, a mesh hanger system and a main beam, characterized in that the mesh hanger system adopts high stress amplitude inclined hangers to form a mesh structure, and the intersections of the inclined hangers are connected by shock-absorbing cable clamps; the inclined hangers adopt an external structural anchoring structure on the arch ribs, and an anchor plate anchoring structure on the main beam, and the beam end tensioning is operated outside the structure.

[0007] Furthermore, the oblique hangers cross each other at least twice, and at the same time should meet the fatigue performance requirements of stress amplitude ≥ 400MPa and stress cycle 2 million times. The oblique hangers are made of steel strands or parallel steel wire cables.

[0008] Furthermore, the oblique hangers are connected by a shock-absorbing cable clamp, which can realize the in-plane relative displacement between the oblique hangers and only restrict the out-of-plane lateral displacement between the two.

[0009] Furthermore, the shock-absorbing cable clamp includes a first cable clamp and a second cable clamp, wherein the first side of the first cable clamp is a semicircular cable clamp body, and the second side of the first cable clamp includes a transverse cylinder; the first side of the second cable clamp is provided with a moving part that cooperates with the transverse cylinder and can rotate and slide in the transverse cylinder, and the second side of the second cable clamp is also a semicircular cable clamp body. When two crossed suspension rods are connected by the shock-absorbing cable clamp, the two suspension rods can achieve rotation and forward relative displacement to achieve the purpose of shock absorption.

[0010] Furthermore, the arch rib diaphragm extends through the arch rib bottom plate and is connected to the ear plate located below the arch rib. A hanger fork ear is provided at the upper end of the inclined hanger, and the hanger fork ear is connected to the ear plate through a pin shaft.

[0011] Furthermore, the anchoring structure of the inclined hanger beam end adopts an anchor plate, and the hanger tensioning space is outside the anchor plate. The anchor plate is directly welded to the top plate of the main longitudinal beam, and the center of the plate thickness is aligned with the center of the main beam web. The anchor plate is anchored to the main beam web. A hole is opened in the upper part of the anchor plate, and a force transmission tube is arranged in the hole. The anchor head at the lower end of the inclined hanger is connected to the force transmission tube.

[0012] Furthermore, the arch ribs are composed of steel box arch ribs and wind bracing, and the arch ribs are arranged in parallel or in a basket arrangement.

[0013] Furthermore, the main beam adopts a composite beam structure, in which the steel beam structure and the concrete bridge deck form a composite section through shear keys to jointly bear the load. The steel beam also serves as a tie beam, and no prestressed tie rod is required.

[0014] The technical effects of the present invention are:

[0015] (1) Compared with vertical hanger-tied arch bridges, the live load axial force of the inclined hangers of the mesh hanger-tied arch bridge varies greatly, with both compression and tension, and the live load stress amplitude is larger than that of the vertical hangers. Considering the characteristics of large bridge width and large live load of domestic bridges, it is proposed that the inclined hangers should use high stress amplitude steel wire or steel strand cables, and the hangers should meet the fatigue performance requirements of stress amplitude ≥ 400MPa and stress cycles of 2 million times, which can better meet the needs of domestic bridges.

[0016] (2) Shock-absorbing cable clamps are used to connect the cross positions of different inclined booms to avoid collisions caused by too small a gap between the booms.

[0017] (3) The main components of the mesh hanger-tied arch bridge are mainly used to bear axial forces. The structural materials can be fully utilized, and the arch ribs can be designed to be very slender. The hanger anchoring structure on the arch is placed outside the arch rib, avoiding the increase of the arch rib size due to the hanger anchoring structure.

[0018] (4) The anchor structure on the beam adopts the form of anchor plate, and the tensioning of the hanger is carried out outside the structure. On the one hand, the anchor structure on the beam can be made simpler and more beautiful; on the other hand, it avoids opening holes in the top plate of the anchor in the steel beam, thereby improving the durability of the structure.

[0019] This system can make full use of the characteristics of mesh tie arch bridge structure, such as high rigidity, good mechanical performance, and excellent landscape performance. In view of the current situation of large constant and live loads on domestic bridges, it is proposed that the hanger adopts high-stress-amplitude steel wire or steel strand cable with good fatigue performance, and the cross of the hanger adopts shock-absorbing cable clamp connection. The hanger is anchored outside the arch structure, and the anchor structure on the hanger beam adopts low-opening anchor plate, and the hanger is tensioned outside the structure. The hanger anchor structure is simple and beautiful, and the hanger tensioning construction is convenient. It has high promotion value in terms of economy, durability, construction convenience, bridge landscape, driving comfort, etc., and has pioneering significance for similar projects in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a general layout diagram of an embodiment of the present invention.

[0021] Figure 2 This is a structural diagram of a high stress amplitude cable.

[0022] Figure 3 Illustration of the shock-absorbing cable clamp connecting the cross hangers.

[0023] Figure 4 Schematic diagram of the anchoring structure on the arch.

[0024] Figure 5 for Figure 4 Side view of.

[0025] Figure 6 Schematic diagram of the anchoring structure on the beam.

[0026] Figure 7 for Figure 6 Side view of.

[0027] The figure includes: arch rib 1, main beam 2, cable 3, shock-absorbing cable clamp 4, cable and arch rib connection 5, cable and main beam connection 6, fork ear 7, anchor plate bottom steel pad 8, lower end anchor head 9, pin 10, lug plate 11, arch rib lug plate 12, arch rib bottom plate 13, anchor plate 14, main longitudinal beam top plate 15, main beam web plate 16. DETAILED DESCRIPTION

[0028] The following is a further detailed description of a high stress amplitude mesh hanger tie arch system proposed by the present invention in combination with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention; the above is only a description of the preferred embodiments of the present invention, and is not any limitation on the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the claims.

[0029] A bridge is a mesh hanger composite beam tied arch bridge (see Figure 1 ), the inclined hanger adopts high stress amplitude cable (see Figure 2 ), the booms are connected by shock-absorbing cable clamps (see Figure 3 ), the arch anchor structure adopts the form of ear plate (see Figure 4 , Figure 5 ), the anchor structure on the beam adopts the anchor plate form (attached Figure 6 , Figure 7 ).

[0030] The specific structure is as follows: ① The mesh hanger is inclined at an angle of 30° and crosses four times. A high stress amplitude cable 3 is used, and its fatigue performance meets the stress amplitude of not less than 400MPa and the stress cycle of 2 million times. The fork ear 7 at the upper end of the hanger is connected to the arch rib hanger ear plate 12 through the pin 10, and the anchor head 9 at the lower end is connected to the steel pad 8 at the bottom of the anchor plate (see attached Figure 2 ); ② The cables 3 at the intersection of the oblique hangers are connected by shock-absorbing cable clamps 4. The center distance of the shock-absorbing cable clamps 4 is 350mm. The shock-absorbing cable clamps 4 only constrain the out-of-plane lateral displacement between the cross hangers. The universal rotation and forward relative displacement between the cross hangers are not constrained (see Figure 3 ); ③ The suspender is anchored at the arch rib diaphragm 12, the arch rib diaphragm 12 extends through the arch rib bottom plate 13 and is connected to the ear plate 11. The ear plate 11 has a thickness of 120 mm. The ear plate 11 is connected to the suspender fork ear 7 through a pin 10 (see Figure 2 .、 Figure 4 , Figure 5 );④ The anchor structure of the suspender beam end adopts the form of anchor plate 14, which is directly welded to the main longitudinal beam top plate 15, and the plate thickness center is aligned with the center of the main beam web 16. The main tension plate is 50mm thick, and the force transmission tube 17 is 36mm thick and 1200mm long. The anchor plate 14 is anchored on the main beam web 16, and the opening height of the anchor plate is ≤500mm (see attached Figure 6 , Figure 7 ).

[0031] Specifically, Figure 3As shown, the shock-absorbing cable clamp comprises a first cable clamp and a second cable clamp, the first cable clamp consists of two parts, the first part is a semicircular cable clamp body, and connecting parts are arranged on both sides of the semicircular cable clamp body, and the second part comprises a transverse cylinder, and arc-shaped cable clamp parts are arranged on both sides of one end of the transverse cylinder, and connecting parts are arranged on the outer side of the arc-shaped cable clamp part. The connecting parts of the two parts of the first cable clamp are arranged correspondingly, and are connected to form a whole by bolts, so that the cable is fixed between the semicircular cable clamp body of the first part and the arc-shaped cable clamp part of the second part; the second cable clamp also consists of two parts The first part includes a movable part, which is located in the transverse cylinder of the first cable clamp, can rotate in the transverse cylinder, and can slide along the transverse cylinder. The two sides of the movable part are provided with arc-shaped cable clamp parts, and the outer side of the arc-shaped cable clamp parts is provided with a connecting part. The second part of the second cable clamp is also a semicircular cable clamp body, and the two sides of the semicircular cable clamp body are provided with connecting parts. The connecting parts of the two parts of the second cable clamp are correspondingly arranged, and are connected into a whole by bolts, and the cable is fixed between the semicircular cable clamp body of the second part and the arc-shaped cable clamp part of the first part. When two crossed suspension rods are connected by the shock-absorbing cable clamp, the two suspension rods can be rotated and displaced relative to each other in the forward direction to achieve the purpose of shock absorption. Furthermore, the movable part is piston-shaped, and the end of the transverse cylinder is provided with a limiter. The piston-shaped movable part is fixed in the transverse cylinder, and can rotate and slide along the transverse cylinder, but cannot escape from the transverse cylinder.

Claims

1. A high stress amplitude mesh hanger tie arch system, comprising an arch rib, a mesh hanger system and a main beam, characterized in that The mesh hanger system adopts high-stress-amplitude oblique hangers to form a mesh structure, and the intersections of the oblique hangers are connected by shock-absorbing cable clamps; the oblique hangers adopt an external structural anchoring structure on the arch ribs, and an anchor plate anchoring structure on the main beam, and the beam end tensioning is operated outside the structure; the shock-absorbing cable clamp includes a first cable clamp and a second cable clamp, the first side of the first cable clamp is a semicircular cable clamp body, and the second side of the first cable clamp includes a transverse cylinder; the first side of the second cable clamp is provided with a moving part that cooperates with the transverse cylinder and can rotate and slide in the transverse cylinder, and the second side of the second cable clamp is also a semicircular cable clamp body. When two crossed hangers are connected by the shock-absorbing cable clamp, the two hangers can achieve rotation and forward relative displacement to achieve the purpose of shock reduction; The inclined hangers cross each other at least twice and must meet the fatigue performance requirements of stress amplitude ≥400MPa and stress cycles of 2 million times. The inclined hangers are made of steel strands or parallel steel wire cables. The inclined hangers are connected by shock-absorbing cable clamps, which can achieve in-plane relative displacement between the inclined hangers and only constrain the out-of-plane lateral displacement between the two.

2. A high stress amplitude mesh hanger tie arch system according to claim 1, characterized in that The arch rib diaphragm extends through the arch rib bottom plate and is connected to the ear plate located below the arch rib. A hanger fork ear is provided at the upper end of the inclined hanger, and the hanger fork ear is connected to the ear plate through a pin shaft.

3. A high stress amplitude mesh hanger tie arch system according to claim 1, characterized in that The anchoring structure of the inclined hanger beam end adopts an anchor plate. The hanger tensioning space is outside the anchor plate. The anchor plate is directly welded to the top plate of the main longitudinal beam. The center of the plate thickness is aligned with the center of the main beam web. The anchor plate is anchored to the main beam web. A hole is opened on the upper part of the anchor plate, and a force transmission tube is arranged in the hole. The anchor head at the lower end of the inclined hanger is connected to the force transmission tube.

4. A high stress amplitude mesh hanger tie arch system according to claim 1, characterized in that The arch ribs are composed of steel box arch ribs and wind bracing, and the arch ribs are arranged in parallel or basket.

5. A high stress amplitude mesh hanger tie arch system according to claim 1, characterized in that The main beam adopts a composite beam structure. The steel beam structure and the concrete bridge deck form a composite section through shear keys to jointly bear the load. The steel beam also serves as a tie beam, and no prestressed tie rods are required.

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