A long-span suspension bridge with replaceable main cable and main cable replacement method thereof

Abstract

The present invention provides a long-span suspension bridge with replaceable main cables, comprising a main cable, a cable tower, a stiffening beam and a sling, wherein the cable tower is located on both sides or in the middle of the bridge deck, the stiffening beam is a steel structure main beam, the main cable comprises an upper main cable and a lower main cable, the upper main cable is a single main cable, the lower main cable is two main cables with the same diameter, the sum of the cross-sectional areas of the two lower main cables is equal to the cross-sectional area of ​​the upper main cable, the upper main cable and the lower main cable have the same linear shape on the elevation, and are arranged in an isosceles triangle on the cross section, the sling comprises an upper sling and a lower sling, the upper sling connects the upper main cable and the stiffening beam, the lower sling connects the lower main cable and the stiffening beam, and the upper sling and the lower sling are arranged at equal intervals along the bridge direction. The present invention provides a long-span suspension bridge with replaceable main cables and a main cable replacement method thereof, wherein the upper main cable and the lower main cable are staggered in both the vertical and horizontal directions, so that the upper and lower main cables do not affect each other during the replacement process, and the replacement of the main cable is convenient.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction engineering, and in particular to a long-span suspension bridge with replaceable main cables and a main cable replacement method thereof. Background Art

[0002] A suspension bridge is a bridge with main cables as the main load-bearing components of the upper structure, which are suspended by cable towers and anchored to the foundations on both sides or at both ends of the main beam. A ground-anchored suspension bridge is one in which the ends of the main cables are anchored to the foundations on both sides, and a self-anchored suspension bridge is one in which the ends of the main cables are anchored to both ends of the main beam. As the lifeline of a suspension bridge, the anti-corrosion of the main cable has always been an important research topic for engineers and technicians around the world, but no satisfactory results have been achieved so far. Nowadays, the most thorough repair method for bridge cables after rust is to replace the cables. Among them, the hangers and tie rods of arch bridges, the cables of cable-stayed bridges, the suspenders of suspension bridges, and the anchoring systems of anchors have all been replaced, but the technology for replacing the main cables of suspension bridges has not yet been implemented in the world. If the anti-corrosion problem of the main cables of suspension bridges can be solved by replacing the main cables, it will play an important role in improving the safety of bridges and reducing economic losses caused by the durability of the main cables.

[0003] Application No.: 201810598712.6 discloses a method for replacing the main cable of a suspension bridge. The method is to perform transition construction through a temporary main cable, and to modify the original saddle and anchor to anchor the temporary main cable. This method requires the installation of a temporary main cable, which is difficult to construct and costly.

[0004] Application No.: 201220723770.5 discloses a new main cable arrangement structure for a suspension bridge, in which the main tower of the bridge is located in the middle of the bridge deck, and the main tower of the bridge is connected to the bridge deck by a double-layer main cable, which is arranged on two different suspension lines in the same vertical direction. The problem that the upper main cable cannot vertically pass through the lower main cable is solved by pulling the slings obliquely on both sides of the bridge deck, and a double-layer cable saddle structure is used when passing the tower. The slings of this main cable arrangement structure are pulled obliquely on both sides of the bridge deck, which will affect the clearance of the bridge deck, especially at locations where the main cable height is small, such as the middle of the main span and the end of the side span beam. The inclination angle of the slings is very small, and the bridge deck cannot meet the traffic requirements. In addition, the inclined arrangement of the slings will reduce the efficiency of the vertical force they provide, and the force is unreasonable, making it difficult to use in actual engineering.

[0005] The technical solutions of the above-mentioned disclosed technologies are all different from the present invention. With respect to more technical features, technical problems to be solved and beneficial effects of the present invention, the above-mentioned disclosed technical documents do not contain any technical inspiration. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a large-span suspension bridge with replaceable main cables and a main cable replacement method thereof, wherein the upper main cable and the lower main cable are staggered in both the vertical and horizontal directions, so that the upper and lower main cables do not affect each other during the replacement process, thereby facilitating the replacement of the main cables.

[0007] To achieve this object, the present invention provides a large-span suspension bridge with replaceable main cables, comprising a main cable, a cable tower, a stiffening beam and a sling, wherein the cable tower is located on both sides or in the middle of the bridge deck, the stiffening beam is a steel structure main beam, the main cable comprises an upper main cable and a lower main cable, the upper main cable is a single main cable, the lower main cable is two main cables with the same diameter, the sum of the cross-sectional areas of the two lower main cables is equal to the cross-sectional area of ​​the upper main cable, the upper main cable and the lower main cable have the same linear shape on the facade, and the upper main cable and the lower main cable are arranged in an isosceles triangle in cross section, the sling comprises an upper sling and a lower sling, the upper sling connects the upper main cable and the stiffening beam, the lower sling connects the lower main cable and the stiffening beam, and the upper sling and the lower sling are arranged at equal intervals along the bridge direction.

[0008] As a further improvement of the structure of the present invention, a main cable saddle is provided on the top of the cable tower to support the main cable. The main cable saddle is provided with three cable receiving grooves arranged in a herringbone shape. The upper cable receiving groove is used to install the upper main cable, and the lower two cable receiving grooves are used to install the lower main cables.

[0009] As a further improvement of the structure of the present invention, a cable clamp is provided between the main cable and the sling for connection, and the cable clamp comprises an upper main cable clamp and a lower main cable clamp, and the upper main cable clamp and the lower main cable clamp are both in the form of two upper and lower separated halves of the cable clamp connected by screws, and the upper main cable clamp and the lower main cable clamp are both provided with ear plates and pin holes are provided on the ear plates, and the ear plates of the upper main cable clamp are directly pinned to the fork-shaped ear plates of the upper sling, and a transverse ear plate with a pin shaft on the top is connected between the two lower main cable clamps, and both ends of the pin shaft of the transverse ear plate are inserted into the pin holes of the ear plate of the lower main cable clamp and fixed by nuts, and the transverse ear plate is provided with pin holes, and the transverse ear plate is pinned to the fork-shaped ear plate of the lower sling.

[0010] As a further improvement of the structure of the present invention, the lateral clearance between the two main cables of the lower main cable is greater than the width of the upper main cable clamp to facilitate the replacement of the lower main cable.

[0011] As a further improvement of the structure of the present invention, spare pin holes for installing temporary slings are also provided on the ear plates of the upper main cable clamp and the lower main cable clamp.

[0012] As a further improvement of the structure of the present invention, the main beam is provided with ear plates on the bridge deck below the upper main cable clamp and the lower main cable clamp, and the ear plates are provided with spare pin holes for installing temporary slings.

[0013] As a further improvement of the structure of the present invention, the stiffening beam can be a steel structure main beam such as a steel box beam, a steel truss beam, or a steel plate beam to reduce its own weight.

[0014] As a further improvement of the structure of the present invention, the long-span suspension bridge is a ground-anchored suspension bridge or a self-anchored suspension bridge. Both the ground-anchored suspension bridge and the self-anchored suspension bridge can be used in the present application.

[0015] As a further improvement of the structure of the present invention, the large-span suspension bridge adopts a single-span, double-span or multi-span layout. The present application can use a single-span, double-span or multi-span layout.

[0016] As a further improvement of the structure of the present invention, the long-span suspension bridge structure adopts a simply supported structure or a continuous structure. In the present application, both the simply supported structure and the continuous structure can be used.

[0017] The present invention provides a method for replacing a main cable of a large-span suspension bridge, comprising replacing an upper main cable and replacing a lower main cable, and the specific steps are as follows:

[0018] The specific steps of replacing the upper main cable are as follows:

[0019] a. Closure of bridge deck traffic;

[0020] b. Install temporary slings between the upper main cable clamp and the stiffening beam;

[0021] c. Tension the temporary sling to unload the force of the upper sling, and then remove the upper sling;

[0022] d. Gradually loosen the temporary sling to return the upper main cable to the empty cable state;

[0023] e. Release the anchorage of both ends of the upper main cable and the tower top, and remove the upper main cable and the upper main cable clamp;

[0024] f. Install new upper main cable;

[0025] g. Install the main cable clamp;

[0026] h. Install temporary slings between the upper main cable clamp and the stiffening beam;

[0027] i. Tension the temporary slings to make the upper main cable reach the bridge line shape;

[0028] j. Install the sling;

[0029] k. Gradually loosen the temporary slings to transfer the sling force to the upper slings;

[0030] l. After the new upper main cable is treated with anti-corrosion, the replacement of the upper main cable is completed;

[0031] The specific steps of replacing the lower main cable are as follows:

[0032] a. Closure of bridge deck traffic;

[0033] b. Install temporary slings between the lower main cable clamp and the stiffening beam;

[0034] c. Tension the temporary sling to unload the force of the lower sling, and then remove the lower sling;

[0035] d. Remove the transverse lugs between the lower main cable clamps;

[0036] e. Gradually loosen the temporary sling to return the lower main cable to the empty cable state;

[0037] f. Release the anchorage at both ends of the lower main cable and the tower top, and remove the lower main cable and the lower main cable clamp;

[0038] g. Install new lower main cable;

[0039] h. Install the lower main cable clamp;

[0040] i. Install temporary slings between the lower main cable clamp and the stiffening beam;

[0041] j. Tension the temporary slings to make the lower main cable reach the completed bridge line shape;

[0042] k. Install the transverse lugs between the lower main cable clamps;

[0043] l. Install the lower sling;

[0044] m. Gradually loosen the temporary slings to transfer the sling force to the lower slings;

[0045] n. After the new lower main cable is treated with anti-corrosion, the replacement of the lower main cable is completed.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. During the replacement of the main cables of a large-span suspension bridge, when the old main cables are unloaded, their linear shape recovers from the completed bridge linear shape to the empty cable linear shape, and when the new main cables bear the load, their linear shape changes from the empty cable linear shape to the completed bridge linear shape. The height difference between the empty cable linear shape and the completed bridge linear shape is very large. The present invention staggers the upper main cables and the lower main cables in both the vertical and horizontal directions, so that the upper and lower main cables will not affect each other during the replacement process, thereby facilitating the replacement of the main cables.

[0048] 2. During the replacement of the main cable of a large-span suspension bridge, the load borne by the old main cable needs to be transferred. When the upper main cable is replaced, the load borne by the old main cable is transferred to the lower main cable, and when the lower main cable is replaced, the load borne by the old main cable is transferred to the upper main cable. During the replacement of the main cable, there is no need to set up a temporary main cable or to modify the original main cable anchoring structure, which greatly reduces the construction difficulty, cost and construction period.

[0049] 3. The present invention designs the cross-sectional areas of the upper main cable and the lower main cable to be equal and the linear shapes on the facade to be consistent, so that the upper and lower main cables can each bear half of the bridge load. During the main cable replacement process, the live load on the bridge deck is eliminated by closing the bridge deck traffic, so that the upper main cable or the lower main cable only bears the constant load of the bridge. The main beam adopts a light-weight steel structure main beam, the force of the main cable can meet the requirements of the specifications, and the design is scientific and reasonable.

[0050] 4. The diameter of a single main cable of a conventional large-span suspension bridge is very large, and the manufacturing and construction of the main cable is difficult. The present invention splits a single large-diameter main cable into three main cables, which reduces the size of the main cable and enables the equipment for manufacturing and construction of the main cable to be miniaturized, which is convenient for construction and maintenance and is also beneficial to increasing the span of the suspension bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the structural system of the long-span suspension bridge of the present invention;

[0052] Figure 2 This is a schematic diagram of the structural cross section of the main cable saddle on the tower top of the present invention;

[0053] Figure 3 It is a schematic cross-sectional view of the cable structure at the upper suspension cable of the present invention;

[0054] Figure 4 It is a schematic cross-sectional view of the cable structure at the lower suspension cable of the present invention;

[0055] Figure 5 It is a schematic diagram of the transverse arrangement of the stiffening beam and cable structure at the upper suspension cable of the double-cable plane suspension bridge of the present invention;

[0056] Figure 6 It is a schematic diagram of the transverse arrangement of the stiffening beam and cable structure at the lower suspension cable of the double-cable plane suspension bridge of the present invention;

[0057] Figure 7 It is a schematic diagram of the transverse arrangement of the stiffening beam and cable structure at the upper suspension cable of the single-cable plane suspension bridge of the present invention;

[0058] Figure 8 The figure is a schematic diagram of the transverse arrangement of the stiffening beam and cable structure at the lower suspension cable of the single-cable plane suspension bridge of the present invention.

[0059] Marked in the figure are: 1. upper main cable; 2. lower main cable; 3. cable tower; 4. stiffening beam; 5. upper sling; 6. lower sling; 7. main cable saddle; 8. upper main cable clamp; 9. lower main cable clamp; 10. transverse ear plate; 11. nut. DETAILED DESCRIPTION

[0060] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0061] The present invention provides a long-span suspension bridge with replaceable main cables and a main cable replacement method thereof, wherein an upper main cable and a lower main cable are staggered in both vertical and horizontal directions, so that the upper and lower main cables do not affect each other during replacement, thereby facilitating the replacement of the main cables.

[0062] As an embodiment of the present invention, the present invention provides Figure 1-8 A long-span suspension bridge with replaceable main cables is shown, comprising a main cable, a cable tower 3, a stiffening beam 4 and a suspender cable, wherein the main cable comprises an upper main cable 1 and a lower main cable 2, wherein the upper main cable 1 is a single main cable, and the lower main cables 2 are two main cables with the same diameter, and the sum of the cross-sectional areas of the two lower main cables 2 is equal to the cross-sectional area of ​​the upper main cable 1, and the upper main cable 1 and the lower main cable 2 have the same linear shape on the vertical plane and are arranged in an isosceles triangle on the cross section.

[0063] The cable tower 3 is located on both sides or in the middle of the bridge deck. A main cable saddle 7 is provided on the top of the cable tower 3 to support the main cable. The main cable saddle 7 is provided with three cable grooves arranged in a herringbone shape. The upper cable groove is used to install the upper main cable 1, and the lower two cable grooves are used to install the lower main cables 2.

[0064] The stiffening beam 4 is a steel structure main beam, which can be a steel box beam, a steel truss beam or a steel plate beam.

[0065] The slings include an upper sling 5 and a lower sling 6. The upper sling 5 connects the upper main cable 1 and the stiffening beam 4. The lower sling 6 connects the lower main cable 2 and the stiffening beam 4. The upper sling 5 and the lower sling 6 are arranged at equal intervals along the bridge direction.

[0066] A cable clamp is provided between the main cable and the sling for connection. The cable clamp includes an upper main cable clamp 8 and a lower main cable clamp 9, both of which are connected by screws in the form of two upper and lower separated half-clip clamps, wherein the upper main cable clamp 8 and the lower main cable clamp 9 are both provided with ear plates, and the ear plates are provided with pin holes. The ear plate of the upper main cable clamp 8 is directly pin-connected with the fork-shaped ear plate of the upper sling 5, and a transverse ear plate 10 with a pin shaft at the top is connected between the two lower main cable clamps 9, and the two ends of the pin shaft are inserted into the pin holes of the ear plate of the lower main cable clamp and fixed by nuts 11. The transverse ear plate 10 is provided with a pin hole, and the transverse ear plate 10 is pin-connected with the fork-shaped ear plate of the lower sling 6.

[0067] Furthermore, the lateral clearance between the two main cables of the lower main cable 2 is greater than the width of the upper main cable clamp 8 .

[0068] Furthermore, spare pin holes for installing temporary slings are provided on the ear plates of the upper main cable clamp 8 and the lower main cable clamp 9.

[0069] Furthermore, the main beam 4 is provided with a lug plate on the bridge deck below the upper main cable clamp 8 and the lower main cable clamp 9, and the lug plate is provided with a spare pin hole for installing a temporary sling.

[0070] Furthermore, the long-span suspension bridge may be a ground-anchored suspension bridge or a self-anchored suspension bridge.

[0071] Furthermore, the long-span suspension bridge may be arranged in single-span, double-span, multi-span or other forms, and the structural form may be simply supported, continuous or other forms.

[0072] The present invention provides a method for replacing a main cable of a long-span suspension bridge, and the specific steps of replacing the main cable are as follows:

[0073] a. Closure of bridge traffic;

[0074] b. Install a temporary sling between the upper main cable clamp 8 and the stiffening beam 4;

[0075] c. Tensioning the temporary sling to unload the force of the upper sling 5, and then removing the upper sling 5;

[0076] d. Gradually loosen the temporary sling to return the upper main cable 1 to the empty cable state;

[0077] e. Release the anchorage of both ends of the upper main cable 1 and the tower top, and remove the upper main cable 1 and the upper main cable clamp 8;

[0078] f. Install new upper main cable 1;

[0079] g. Install the main cable clamp 8;

[0080] h. Install a temporary sling between the upper main cable clamp 8 and the stiffening beam 4;

[0081] i. Tension the temporary slings to make the upper main cable 1 reach the bridge line shape;

[0082] j. Install the sling 5;

[0083] k. Gradually loosen the temporary slings to transfer the sling force to the upper sling 5;

[0084] l. After the new upper main cable 1 is subjected to anti-corrosion treatment, the replacement of the upper main cable 1 is completed.

[0085] The present invention provides a method for replacing a main cable of a long-span suspension bridge, and the specific steps of replacing the main cable are as follows:

[0086] a. Closure of bridge traffic;

[0087] b. Install a temporary sling between the lower main cable clamp 9 and the stiffening beam 4;

[0088] c. Tensioning the temporary sling to unload the force of the lower sling 6, and then removing the lower sling 6;

[0089] d. Remove the transverse ear plate 10 between the lower main cable clamp 9;

[0090] e. Gradually loosen the temporary sling to return the lower main cable 2 to the empty cable state;

[0091] f. Release the anchorage of both ends of the lower main cable and the tower top, and remove the lower main cable 2 and the lower main cable clamp 9;

[0092] g. Install new lower main cable 2;

[0093] h. Install the main cable clamp 9;

[0094] i. Install a temporary sling between the lower main cable clamp 9 and the stiffening beam 4;

[0095] j. Tensioning the temporary slings to make the lower main cable 2 reach the bridge line shape;

[0096] k. Install the lateral ear plate 10 between the lower main cable clamp 9;

[0097] l. Install the lower sling 6;

[0098] m. Gradually loosen the temporary slings to transfer the sling force to the lower sling 6;

[0099] n. After the new lower main cable 2 is subjected to anti-corrosion treatment, the replacement of the lower main cable 2 is completed.

[0100] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A long-span suspension bridge with replaceable main cables, comprising a main cable, a cable tower (3), a stiffening beam (4) and a suspension cable, wherein the cable tower (3) is located on both sides or in the middle of the bridge deck, the stiffening beam (4) is a steel structure main beam, the main cable comprises an upper main cable (1) and a lower main cable (2), the upper main cable (1) is a single main cable, the lower main cable (2) is two main cables with the same diameter, and the sum of the cross-sectional areas of the two lower main cables (2) is equal to the cross-sectional area of ​​the upper main cable (1). The upper main cable (1) and the lower main cable (2) have the same linear shape on the vertical surface, and the upper main cable (1) and the lower main cable (2) are arranged in an isosceles triangle in cross section. The slings include an upper sling (5) and a lower sling (6), and the upper sling (5) connects the upper main cable (1) and the stiffening beam (4), and the lower sling (6) connects the lower main cable (2) and the stiffening beam (4). The upper sling (5) and the lower sling (6) are arranged at equal intervals along the bridge direction. A main cable saddle (7) is provided on the top of the cable tower (3) to support the main cable, and the main cable saddle (7) is provided with three cable receiving grooves arranged in a herringbone shape, the upper cable receiving groove is installed with the upper main cable (1), and the two lower cable receiving grooves are installed with the lower main cables (2); A cable clamp is provided between the main cable and the sling for connection, the cable clamp comprises an upper main cable clamp (8) and a lower main cable clamp (9), the upper main cable clamp (8) and the lower main cable clamp (9) are both in the form of upper and lower separated halves of the cable clamp connected by screws, the upper main cable clamp (8) and the lower main cable clamp (9) are both provided with ear plates and the ear plates are provided with pin holes, the ear plates of the upper main cable clamp (8) are directly pin-connected with the fork-shaped ear plates of the upper sling (5), a transverse ear plate (10) with a pin shaft at the top is connected between the two lower main cable clamps (9), the pin shafts of the transverse ear plates (10) are inserted into the pin holes of the ear plates of the lower main cable clamp (9) and fixed by nuts (11), the transverse ear plates (10) are also provided with pin holes, the transverse ear plates (10) are pin-connected with the fork-shaped ear plates of the lower sling (6); The lateral clearance between the two main cables of the lower main cable (2) is greater than the width of the upper main cable clamp (8); The ear plates of the upper main cable clamp (8) and the lower main cable clamp (9) are also provided with spare pin holes for installing temporary slings, and the stiffening beam (4) is provided with ear plates on the bridge deck below the upper main cable clamp (8) and the lower main cable clamp (9), and the ear plates are provided with spare pin holes for installing temporary slings; The stiffening beam (4) is a steel box beam, a steel truss beam or a steel plate beam; The long-span suspension bridge is a ground-anchored suspension bridge or a self-anchored suspension bridge; The long-span suspension bridge adopts a single-span, double-span or multi-span layout; The long-span suspension bridge adopts a simply supported structure or a continuous structure.

2. According to the method for replacing a long-span suspension bridge with replaceable main cables as described in claim 1, the specific steps are as follows; The specific steps of replacing the upper main cable are as follows: a. Closure of bridge deck traffic; b. Install a temporary sling between the upper main cable clamp (8) and the stiffening beam (4); c. tensioning the temporary sling to unload the force of the upper sling (5), and then removing the upper sling (5); d. Gradually loosen the temporary slings to return the upper main cable (1) to the empty cable state; e. Release the anchoring of both ends of the upper main cable (1) and the tower top, and remove the upper main cable (1) and the upper main cable clamp (8); f. Install new upper main cable (1); g. Install the main cable clamp (8); h. Install a temporary sling between the upper main cable clamp (8) and the stiffening beam (4); i. Tensioning the temporary slings to make the upper main cable (1) reach the bridge alignment; j. Install the upper sling (5); k. Gradually loosen the temporary slings to transfer the sling force to the upper slings (5); l. After the new upper main cable (1) is subjected to anti-corrosion treatment, the replacement of the upper main cable (1) is completed; The specific steps of replacing the lower main cable are as follows: a. Closure of bridge deck traffic; b. Install a temporary sling between the lower main cable clamp (9) and the stiffening beam (4); c. tensioning the temporary sling to unload the force of the lower sling (6), and then removing the lower sling (6); d. Remove the transverse lugs (10) between the lower main cable clamps (9); e. Gradually loosen the temporary sling to return the lower main cable (2) to the empty cable state; f. Release the anchoring of the two ends of the lower main cable (2) and the tower top, and remove the lower main cable (2) and the lower main cable clamp (9); g. Install new lower main cable (2); h. Install the lower main cable clamp (9); i. Install a temporary sling between the lower main cable clamp (9) and the stiffening beam (4); j. Tensioning the temporary slings to make the lower main cable (2) reach the bridge alignment; k. Install the transverse lugs (10) between the lower main cable clamps (9); l. Install the lower sling (6); m. Gradually loosen the temporary slings to transfer the sling force to the lower slings (6); n. After the new lower main cable (2) is subjected to anti-corrosion treatment, the replacement of the lower main cable (2) is completed.

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