An arched steel tube central buckle structure for a super-long span suspension bridge

Abstract

The arched steel tube central buckle includes cable fasteners, connecting steel plates and arched steel tubes. The cable fasteners tightly hold the main cable. The connecting steel plates are welded directly below the cable fasteners. The left and right arched steel tubes are located on both sides of the connecting steel plates. The top of the arched steel tube is welded to the cable fasteners and the connecting steel plates. The bottom of the arched steel tube is anchored on the stiffening beam. The upper end of the sling is suspended under the connecting steel plate, and the lower end of the sling suspends the stiffening beam. The arched steel tube central buckle is set up in the super-large span suspension bridge to ensure the coordinated work of the bridge deck stiffening beam and the main cable of the suspension bridge, strengthen the longitudinal stiffness of the suspension bridge, reduce the longitudinal seismic displacement of the suspension bridge, greatly increase the antisymmetric torsion frequency of the super-large span suspension bridge, and significantly reduce the seismic dynamic response of the suspension bridge tower. The arched steel tube central buckle structure is both rigid and flexible, with the advantages of beautiful shape, convenient construction, reliable force, good seismic ductility and low cost. It can be used as the central buckle structure of the super-large span suspension bridge.

Description

Technical Field

[0001] The invention belongs to the field of bridge engineering, and relates to a central buckle structure of a suspension bridge, and in particular to an arched steel pipe central buckle structure of a super-large span suspension bridge. Background Art

[0002] As the span of suspension bridges continues to increase, the longitudinal seismic displacement of suspension bridge structures continues to increase, and the problem of longitudinal drift of suspension bridge structures becomes increasingly prominent.

[0003] At present, there are two main forms of central buckle structures. One is the rigid central buckle, which uses a rigid triangular truss to connect the main cable and the stiffening beam; the other is the flexible central buckle, which uses a pair or three teams of inclined cables to establish longitudinal constraints between the cable and the stiffening beam. Relatively speaking, the flexible central buckle is more favored by designers due to its convenience in construction.

[0004] The rigid central buckle is reliable in bearing force, but its construction is difficult, and in the rare event of a strong earthquake, the stress fatigue damage problem of the main cables and main beams of the rigid central buckle suspension bridge is more prominent.

[0005] The flexible central buckle is easy to construct. However, due to the characteristic that the central buckle cable is only subjected to tension but not compression, in the event of a rare strong earthquake, the longitudinal seismic displacement is large, which will cause the flexible central buckle cable to break and fail.

[0006] In high-intensity earthquake zones, it is not appropriate to use rigid central buckles or flexible central buckles for super-large span suspension bridges, which will cause a significant increase in stress or even damage to the main beam and the central buckle component itself. Therefore, the central buckle structure of super-large span suspension bridges requires technical improvements.

[0007] In high-intensity earthquake zones, the central buckle structure of a super-large span suspension bridge should adopt a rigid and flexible central buckle structure, which can use an arched steel pipe structure with excellent seismic performance. The arched steel pipe structure and the cable fastener are connected to form an arched steel pipe central buckle structure of a super-large span suspension bridge. The cable fastener tightly grips the main cable, and the connecting steel plate is welded directly below the cable fastener. The left and right arched steel pipes are located on both sides of the connecting steel plate. The top of the arched steel pipe is welded to the cable fastener and the connecting steel plate, and the bottom of the arched steel pipe is anchored on the stiffening beam. The arched steel pipe central buckle structure has the advantages of beautiful shape, convenient construction, reliable force, strong seismic energy dissipation capacity and low price. Summary of the invention

[0008] Purpose of the invention: The present invention provides an arched steel tube central buckle structure for an ultra-large span suspension bridge which has beautiful shape, convenient construction, reliable force bearing, strong earthquake resistance and energy absorption capacity and low price. The bottom of the arched steel tube central buckle structure is fixed on the bridge deck stiffening beam, and the arched steel tube structure is connected to the cable fastener. The arched steel tube central buckle structure can greatly improve the longitudinal force bearing performance of the ultra-large span suspension bridge structure.

[0009] Technical solution: In order to solve the above technical problems, the present invention provides an arched steel pipe central buckle structure for an ultra-large span suspension bridge, including a cable fastener, a connecting steel plate and an arched steel pipe, characterized in that: the cable fastener tightly grips the main cable, the connecting steel plate is welded directly below the cable fastener, the left and right arched steel pipes are located on both sides of the connecting steel plate, the top of the arched steel pipe is welded to the cable fastener and the connecting steel plate, the bottom of the arched steel pipe is anchored on the stiffening beam, the upper end of the sling is suspended under the connecting steel plate, and the lower end of the sling suspends the stiffening beam.

[0010] Preferably, the cable fastener is composed of an A-type cable fastener, a B-type cable fastener and connecting bolts, the Ω-shaped A-type cable fastener is at the upper part of the main cable; the inverted Ω-shaped B-type cable fastener is at the lower part of the main cable, and a double row of connecting bolts is arranged between the A-type cable fastener and the B-type cable fastener.

[0011] The invention discloses a construction method for an arched steel pipe central buckle structure of a super-long span suspension bridge, characterized in that it comprises the following steps:

[0012] Step 1: Select the site for the super-long span suspension bridge, build anchorages and bridge tower foundations, carry out bridge tower structure construction, carry out temporary catwalk construction, install the main cable of the suspension bridge, install the slings, and hoist the bridge deck stiffening beams in sections until the entire bridge deck is closed;

[0013] Step 2: Set up two temporary cable clamps on the left and right sides of the mid-span of the main cable of the suspension bridge, install two temporary slings, and remove the original slings at the mid-span position;

[0014] Step 3: firmly weld the inverted Ω-shaped B-type cable fastener in the cable fastener to the connecting steel plate to form a whole;

[0015] Step 4: At the mid-span, place the Ω-shaped A-type cable fastener on the top of the main cable, and place the inverted Ω-shaped B-type cable fastener under the main cable. Fasten the two together, tighten the double-row connecting bolts to form a cable fastener, which tightly holds the main cable.

[0016] Step 5: Assemble the arched steel pipe by welding in sections, anchor the bottoms of the left and right arched steel pipes on the stiffening beam, and weld the tops of the left and right arched steel pipes to the cable fasteners and the connecting steel plates to form a central buckle structure of the arched steel pipe;

[0017] Step 6: Install the arched steel pipe central buckle structure on the other side of the bridge deck at the mid-span, and then continue to complete the steel pipe central buckle structures on the left and right sides of the mid-span. The entire bridge forms one or three pairs of steel pipe central buckle structures, install railings, pave the asphalt concrete bridge deck, and the super-large span suspension bridge is put into operation.

[0018] The cable fasteners are connected to the arched steel tubes to form the arched steel tube central buckle of the large-span suspension bridge, which can ensure the coordinated work of the bridge deck stiffening beam and the main cable of the suspension bridge. The arched steel tube central buckle structure is beautiful in shape, simple and convenient to construct, economical and reasonable, and has both rigidity and flexibility, and has good ductility and energy dissipation capacity.

[0019] A suspension bridge is a flexible structure. An arched steel tube central buckle structure is set to couple the cables and the bridge deck stiffening beams, which enhances the integrity of the suspension bridge structure, strengthens the longitudinal stiffness of the suspension bridge structure, reduces the longitudinal seismic displacement of the suspension bridge structure, and can increase the antisymmetric torsional frequency of super-large span suspension bridges and improve the wind resistance and stability of super-large span suspension bridge structures.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0021] The existing rigid central buckle is difficult to construct. In rare strong earthquakes, the stress fatigue damage problem of the main cables and main beams of the rigid central buckle suspension bridge is more prominent.

[0022] The existing flexible central buckle is easy to construct, but due to the characteristic that the flexible central buckle cable is only subjected to tension but not compression, in rare strong earthquakes, the longitudinal seismic displacement is large, which will cause the flexible central buckle cable to break and fail.

[0023] In high-intensity earthquake zones, the longitudinal seismic displacement of ultra-large span suspension bridge structures is large, which will cause a significant increase in stress or even damage to the main beam or central buckle cable itself. Therefore, ultra-large span suspension bridge structures need to develop a rigid and flexible central buckle structure that can improve the stress performance of short cables, which is crucial to improving the service life of suspension bridges and saving bridge operation and maintenance costs.

[0024] The bottom of the arched steel tube central buckle structure is fixed on the bridge deck stiffening beam, and the cable fastener is connected to the arched steel tube. The arched steel tube central buckle is both rigid and flexible. The hysteresis curve of the arched steel tube central buckle is full under low-cycle repeated loads, and it has good ductility and energy dissipation capacity. In high-intensity earthquake zones, it will not cause stress fatigue damage to the main cables and main beams, nor will it cause fracture and failure of the arched steel tube. The arched steel tube central buckle has good seismic resistance.

[0025] The bottom of the central buckle of the arched steel pipe is fixed on the bridge deck stiffening beam. The bridge deck stiffening beam serves as the tie rod of the arched steel pipe. The central buckle of the arched steel pipe and the bridge deck stiffening beam are combined to form a tie arch structure. The tie arch structure is firm and can ensure the coordinated work of the bridge deck stiffening beam and the main cable of the suspension bridge.

[0026] The central buckle of the arched steel tube couples the cables and the bridge deck stiffening beams, strengthens the longitudinal stiffness of the suspension bridge structure, reduces the longitudinal seismic displacement of the suspension bridge structure, and avoids the longitudinal drift of the suspension bridge structure.

[0027] Setting the arched steel pipe central buckle can significantly increase the antisymmetric torsional frequency of the super-large span suspension bridge and improve the wind resistance stability of the super-large span suspension bridge structure.

[0028] Since the arched steel tube central buckle enhances the integrity of the super-large span suspension bridge structure, it can significantly reduce the seismic dynamic response of the super-large span suspension bridge tower structure during rare earthquakes, thereby improving the structural performance of the tall bridge towers of the super-large span suspension bridge.

[0029] The main cable of the suspension bridge is a concave curved component, and the arched steel pipe is a convex curved component. The positive and negative curved components are combined together, and the central buckle structure of the arched steel pipe is beautiful and elegant.

[0030] The lower parts of the two arched steel pipes are fixed on the stiffening beam of the bridge deck, and the tops are firmly welded to the cable fasteners and connecting steel plates, which ensure reliable force, economical and reasonable operation, and convenient construction.

[0031] The arched steel pipe central buckle has the advantages of beautiful shape, convenient construction, reliable force, earthquake resistance and energy consumption, and low price. It can be used as the central buckle structure of super-large span suspension bridges in high-intensity earthquake zones. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic elevation view of an arched steel tube central buckle structure;

[0033] Figure 2 yes Figure 1 A schematic cross-sectional view of a cable fastener in FIG.

[0034] Figure 3 It is a three-dimensional schematic diagram of an arched steel tube central buckle structure;

[0035] Figure 4 It is a three-dimensional schematic diagram of a super-large span suspension bridge with an arched steel pipe central buckle.

[0036] In the figure: cable fastener 1; A-type cable fastener 11; B-type cable fastener 12; double-row connecting bolts 13; connecting steel plate 2; arched steel pipe 3; main cable 4; sling 5; stiffening beam 6. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] Example 1

[0039] An arched steel pipe central buckle structure of an ultra-large span suspension bridge comprises a cable fastener 1, a connecting steel plate 2 and an arched steel pipe 3, wherein the cable fastener 1 tightly grips a main cable 4, a connecting steel plate 2 is welded directly below the cable fastener 1, left and right arched steel pipes 3 are located on both sides of the connecting steel plate 2, the top of the arched steel pipe 3 is welded to both the cable fastener 1 and the connecting steel plate 2, the bottom of the arched steel pipe 3 is anchored on a stiffening beam 6, the upper end of a sling 5 is suspended below the connecting steel plate 2, and the lower end of the sling 5 suspends the stiffening beam 6.

[0040] The cable fastener 1 is composed of an A-type cable fastener 11, a B-type cable fastener 12 and connecting bolts 13. The Ω-shaped A-type cable fastener 11 is at the upper part of the main cable 4; the inverted Ω-shaped B-type cable fastener 12 is at the lower part of the main cable 4, and a double row of connecting bolts 13 are arranged between the A-type cable fastener 11 and the B-type cable fastener 12.

[0041] Example 2

[0042] The construction method of the arched steel pipe central buckle structure of a super-long span suspension bridge of the present invention is characterized by comprising the following steps:

[0043] Step 1: Select the site of the super-long span suspension bridge, build the anchorage and bridge tower foundation, carry out the bridge tower structure construction, carry out the temporary catwalk construction, install the main cable 4 of the suspension bridge, install the sling 5, and hoist the bridge deck stiffening beam 6 in sections until the entire bridge deck is closed;

[0044] Step 2: Set two temporary cable clamps on the left and right sides of the mid-span of the main cable 4 of the suspension bridge, install two temporary slings 5, and remove the original slings 5 ​​at the mid-span position;

[0045] Step 3: firmly weld the inverted Ω-shaped B-type cable fastener 12 in the cable fastener 1 to the connecting steel plate 2 to form a whole;

[0046] Step 4: At the mid-span, place the Ω-shaped A-type cable fastener 11 on the top of the main cable 4, and place the inverted Ω-shaped B-type cable fastener 12 under the main cable 4, fasten the two together, tighten the double-row connecting bolts 13, and form the cable fastener 1, which tightly holds the main cable 4;

[0047] Step 5: Assemble the arched steel pipe 3 by welding in sections, anchor the bottoms of the left and right arched steel pipes 3 on the stiffening beam 6, and weld the tops of the left and right arched steel pipes 3 to the cable fastener 1 and the connecting steel plate 2 to form a central buckle structure of the arched steel pipe;

[0048] Step 6: Install the arched steel pipe central buckle structure on the other side of the bridge deck at the mid-span, and then continue to complete the steel pipe central buckle structures on the left and right sides of the mid-span. The entire bridge forms one or three pairs of steel pipe central buckle structures, install railings, pave the asphalt concrete bridge deck, and the super-large span suspension bridge is put into operation.

[0049] Example 3

[0050] A 1,600-meter-class cross-river super-large span suspension bridge has a steel truss stiffening beam structure as the main beam of the bridge deck, a main cable diameter of 900mm, and a cable spacing of 40 meters. In order to improve the longitudinal stiffness of the super-large span suspension bridge structure, an arched steel pipe central buckle structure is adopted.

[0051] The cable fastener is 10 meters long. The Ω-shaped A-type cable fastener and the inverted Ω-shaped B-type cable fastener clamp the steel wire main cable. Both Ω-shaped cable fasteners are cast. The wall thickness of the cable fastener is 40mm, the diameter of the connecting bolt is 28mm, and the spacing between the double-row connecting bolts is 330mm.

[0052] The length of the left and right arched steel pipes is 120 meters each, the rise is 20 meters, the rise-to-span ratio is 1 / 6, the diameter of the steel pipe is 1000mm, and the wall thickness of the steel pipe is 20mm.

[0053] The connecting steel plate is welded directly below the cable fastener. The length of the connecting steel plate is 10 meters. The shape of the connecting steel plate is a rectangle plus an arc. The thickness of the connecting steel plate is 40 mm.

[0054] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An arched steel pipe central buckle structure for a super-long span suspension bridge, comprising a cable buckle (1), a connecting steel plate (2) and an arched steel pipe (3), characterized in that: The cable fastener (1) tightly grips the main cable (4), a connecting steel plate (2) is welded directly below the cable fastener (1), two arched steel pipes (3) are located on both sides of the connecting steel plate (2), the top of the arched steel pipe (3) is welded to the cable fastener (1) and the connecting steel plate (2), the bottom of the arched steel pipe (3) is anchored on the stiffening beam (6), the upper end of the sling (5) is suspended below the connecting steel plate (2), and the lower end of the sling (5) suspends the stiffening beam (6).

2. The arched steel pipe central buckle structure of a super-long span suspension bridge according to claim 1, characterized in that: The cable fastener (1) is composed of an A-type cable fastener (11), a B-type cable fastener (12) and connecting bolts (13); the Ω-shaped A-type cable fastener (11) is located at the upper part of the main cable (4); the inverted Ω-shaped B-type cable fastener (12) is located at the lower part of the main cable (4); and a double row of connecting bolts (13) are arranged between the A-type cable fastener (11) and the B-type cable fastener (12).

3. A construction method for the arched steel pipe central buckle structure of a super-long span suspension bridge according to claim 1, characterized in that: The following steps are involved: Step 1: Select a site for a super-long span suspension bridge, build anchorages and bridge tower foundations, carry out bridge tower structure construction, carry out temporary catwalk construction, install the main cable (4) of the suspension bridge, install the slings (5), and hoist the bridge deck stiffening beams (6) in sections until the entire bridge deck is closed; Step 2: two temporary cable clamps are set at the left and right sides of the mid-span of the main cable (4) of the suspension bridge, two temporary slings (5) are installed, and the original slings (5) at the mid-span position are removed; Step 3: firmly welding the inverted Ω-shaped B-type cable fastener (12) in the cable fastener (1) and the connecting steel plate (2) to form a whole; Step 4: At the mid-span, place the Ω-shaped A-type cable fastener (11) on the top of the main cable (4), and place the inverted Ω-shaped B-type cable fastener (12) on the bottom of the main cable (4), fasten the two together, tighten the double-row connecting bolts (13), and form a cable fastener (1), which tightly grips the main cable (4); Step 5: Assemble the arched steel pipe (3) by welding in sections, anchor the bottoms of the left and right arched steel pipes (3) on the stiffening beam (6), and weld the tops of the left and right arched steel pipes (3) to the cable fastener (1) and the connecting steel plate (2) to form a central buckle structure of the arched steel pipe; Step 6: Install the arched steel pipe central buckle structure on the other side of the bridge deck at the mid-span, and then continue to complete the steel pipe central buckle structures on the left and right sides of the mid-span. The entire bridge forms one or three pairs of steel pipe central buckle structures, install railings, pave the asphalt concrete bridge deck, and the super-large span suspension bridge is put into operation.

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