In-situ reinforcement method for steel truss bridge

Abstract

The present invention provides an in-situ reinforcement method for a steel truss bridge, including reinforcement of compression rods, tension rods, node plates and a connection structure between the node plates of the main trusses and reinforcement components. According to the stress characteristics of the parts to be reinforced of the main trusses, classified reinforcement is carried out. The compression rods are reinforced by increasing the cross-section by bolting reinforcement angle steels and pouring micro-expansive concrete to form combined compression columns according to needs; the tension rods are reinforced by bolting steel plates to increase the net cross-sectional area; the node plates are bolted hollowed-out steel plates; the connection between the node plates and the reinforcement members is overlapped by enlarged ends and cover plates to ensure smooth force transmission between the node plates and the rods. The present invention is a complete set of solutions covering the reinforcement and connection methods of the compression rods, tension rods and node plates of the main trusses. The main trusses are reinforced by this method without the need to move the old bridge to the factory. The reinforcement purpose can be achieved in the original position of the bridge without auxiliary pier support.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to an in-situ reinforcement method for a steel truss bridge. Background Art

[0002] So far, my country's bridge construction has been developing for quite a long time. During this period, a large number of bridges of various types have been built in China, and steel trusses are one of them. According to the standard calculation that most bridges are designed to have a service life of 100 years, as of now, some bridges built earlier have been in service for decades and their service life has exceeded half. In order to make the bridges complete their 100-year service life, it is urgent to maintain and reinforce old bridges.

[0003] Since the reform and opening up, China's economy has developed rapidly, and the demand for transportation has become increasingly strong. The transportation functions of some old bridges can no longer meet the existing transportation needs. In response to this contradiction, it is necessary to build new bridges or widen and renovate existing bridges to improve their traffic capacity. The existing bridge locations are the most reasonable channels given by designers, so each bridge is very precious. Choosing a new site to build a bridge not only takes a long construction period, but also has a high cost; demolishing and rebuilding bridges that have decades of remaining life is even a bad idea. Not only is the cost expensive, but it will also interrupt traffic for a long time and have a great impact on society; moving the bridge to a factory for reinforcement cannot avoid the impact of interrupting traffic. In-situ reinforcement of existing bridges can not only save costs, but also shorten the time of interruption as much as possible, and even achieve continuous traffic through reasonable construction procedures.

[0004] In summary, the number of bridges that need to be improved is increasing, and in-situ reinforcement of these bridges has become the best choice to achieve the above purpose at the lowest cost. This patent will propose a reasonable and feasible reinforcement plan for in-situ reinforcement of steel trusses, a type of bridge. Summary of the invention

[0005] The purpose of the present invention is to provide an in-situ reinforcement method for a steel truss bridge, which can enable the steel truss to meet the bearing capacity required for increased traffic load after in-situ reinforcement, fully utilize the remaining life of the old bridge, and avoid excessively long traffic interruptions.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows: a method for in-situ reinforcement of a steel truss bridge, characterized in that the method comprises:

[0007] According to the stress characteristics of the main truss parts to be reinforced, the main truss parts to be reinforced are divided into main truss compression members to be reinforced, main truss tension members to be reinforced and node plates. At the same time, the reinforced main truss compression members are divided into main truss compression members to be reinforced with smaller reinforcement requirements and main truss compression members to be reinforced with larger reinforcement requirements.

[0008] For the reinforcement of the main truss compression members with less reinforcement requirements, the reinforcement angle steel is bolted to the flange of the main truss compression members to increase the compression section of the compression members, thus achieving the reinforcement of the main truss compression members;

[0009] The reinforcement of the main truss compression rods to be reinforced with greater reinforcement requirements, the rod body of the main truss compression rod to be reinforced is poured with micro-expansion concrete, so that the concrete and the steel structure form a combined compression column, thereby realizing the reinforcement of the main truss compression rod;

[0010] Strengthening the tension rods of the main truss to be strengthened: bolting reinforcement steel plates to the flanges of the tension rods of the main truss to be strengthened to increase the tension section of the tension rods and achieve reinforcement of the tension rods of the main truss;

[0011] The node plate of the main truss is reinforced by bolting node reinforcement steel plates on the original node plates to increase the load-bearing cross-section of the node plates and realize the reinforcement of the node plates of the main truss.

[0012] Furthermore, the specific steps for strengthening the main truss compression member to be strengthened with a smaller reinforcement requirement are as follows:

[0013] A reinforcement angle steel is manufactured, the length of which matches the length of the main truss compression member to be reinforced, bolt holes are punched on the side of the reinforcement angle steel, and an outwardly expanding angle steel weldment extending outward is welded to the end of the reinforcement angle steel;

[0014] Transport the reinforcement angle steel to the bridge site, hoist the reinforcement angle steel to the installation position, match the holes on the bolt holes on the reinforcement angle steel, and then install friction-type high-strength bolts to complete the reinforcement of the compression members to be reinforced;

[0015] The cover plate is used to overlap the expanded angle steel weldment at the end of the reinforced angle steel and the node plate to complete the connection between the node plate and the reinforced component.

[0016] Furthermore, the reinforcement of the main truss compression members to be reinforced with greater reinforcement requirements has the following specific steps:

[0017] Calculate the fill area of ​​micro-expansion reinforced concrete;

[0018] Weld the welded shear keys on the compression members to be reinforced and tie the steel bars in the concrete filling area;

[0019] Install formwork around the compression members to be reinforced;

[0020] Pour micro-expansion reinforced concrete in the concrete filling area.

[0021] Furthermore, the reinforcement of the tension rods of the main truss to be reinforced has the following specific steps:

[0022] Make a reinforcement steel plate, the length of which matches the length of the main truss tension rod to be reinforced, punch bolt holes on the reinforcement steel plate, and expand the end of the reinforcement steel plate by design and processing;

[0023] Transport the reinforcement steel plate to the bridge site, hoist the reinforcement steel plate to the installation position, match the holes on the reinforcement steel plate with the tension rods to be reinforced according to the bolt hole positions, and then install friction-type high-strength bolts to complete the reinforcement of the tension rods to be reinforced;

[0024] The cover plate is used to overlap the enlarged end of the reinforced steel plate and the node plate to complete the connection between the node plate and the reinforced member.

[0025] Furthermore, the main truss node plate is reinforced, and the specific steps are as follows:

[0026] For the node plate to be reinforced, the area of ​​the required reinforcement steel plate shall be determined according to the horizontal shear resistance of the node plate and the tear resistance of the rod connection part, and the number and arrangement of rivets or high-strength bolts shall be determined according to the requirements of the specification;

[0027] According to the calculated area of ​​the reinforcement steel plate, the reinforcement steel plate is manufactured, and holes are opened in the reinforcement steel plate according to the designed positions of the high-strength bolts, and the reinforcement steel plate is hollowed out according to the positions of the original rivets or high-strength bolt groups to form hollowed-out grooves;

[0028] Transport the reinforced steel plates to the bridge site and remove the original rivets or high-strength bolts around the shear section of the node plate;

[0029] Lift the reinforcement steel plate to the installation position, make matching holes on the node plate to be reinforced according to the positions of the bolt holes on the reinforcement steel plate, and then install rivets or high-strength bolts to complete the reinforcement of the node plate to be reinforced.

[0030] The present invention is a complete set of in-situ reinforcement schemes for steel truss bridges, covering the reinforcement of main truss compression rods, tie rods, node plates, and the connection method between node plates and reinforcement members. The method is used to reinforce steel trusses, and the old bridge does not need to be moved to a factory. The reinforcement purpose can be achieved in the original position of the bridge. The patented in-situ reinforcement structure of steel trusses of the present invention has strong pertinence, high reinforcement efficiency, can achieve precise reinforcement with the least amount of materials, saves construction costs, and has high economy, rationality, safety, and ingenuity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the main truss compression rod flange bolted angle steel reinforcement scheme of the present invention.

[0032] Figure 2 This is a schematic diagram of a reinforcement scheme for forming a combined compression column by filling the main truss compression rod with concrete according to the present invention.

[0033] Figure 3 It is a schematic diagram of the reinforcement scheme of bolted steel plates on the flanges of the tension rods of the main truss of the present invention.

[0034] Figure 4 It is a schematic diagram of the main truss node plate reinforcement scheme of the present invention.

[0035] Figure 5 for Figure 4 Schematic diagram of the structure of the reinforcement steel plate.

[0036] Figure 6 for Figure 4 Structural schematic diagram of the node plate to be reinforced.

[0037] Figure 7 It is a schematic diagram of the connection scheme between the main truss node plate and the reinforcement member of the present invention.

[0038] Figure 8 for Figure 7 Schematic diagram of the structure of the expanded and reinforced steel plate at the middle end.

[0039] Fig. 9 for Figure 7 Schematic diagram of the structure of the middle end enlarged reinforcement angle steel.

[0040] Fig.10 for Figure 7 Schematic diagram of the structure of the middle cover.

[0041] The figure includes: reinforcing angle steel 11, friction type high-strength bolts 12, compression rods to be reinforced 13, micro-expansion reinforced concrete 21, welded shear keys 22, steel bars 23, compression rods to be reinforced 24, reinforcing steel plates 31, friction type high-strength bolts 32, tension rods to be reinforced 33, reinforcing steel plates 41, node plates to be reinforced 42, new rivets or high-strength bolts 43, original rivets or high-strength bolts 44, vertical rods 45, diagonal rods 46, chord rods 47, hollowed out grooves 48, end-enlarged reinforcing steel plates 51, end-enlarged reinforcing angle steels 52, cover plates 53, connecting rivets or high-strength bolts 54, node plates 55, vertical rods 56, diagonal rods 57, and chord rods 58. DETAILED DESCRIPTION

[0042] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0043] Reference Figure 1The schematic diagram of the reinforcement scheme of the compression rod bolted with angle steel is applicable to the rods with less reinforcement requirements of the compression rods of the main truss. The reinforcement scheme of the compression rod bolted with angle steel of the present invention includes a reinforcement angle steel 11, a friction type high-strength bolt 12, and a compression rod 13 to be reinforced. By bolting the angle steel on the flange of the original rod, the compression cross section is increased, the weak axis force performance of the cross section is improved, the bearing capacity of the compression rod is increased, and the problem of insufficient stability and strength of the compression rod is solved. The scheme performs targeted reinforcement of the cross section by bolting the reinforcement angle steel in the weak axis direction of the rod cross section. In specific implementation, after the compression rod 13 to be reinforced to be reinforced is determined by calculation, the required specifications of the reinforcement angle steel 11 are determined by calculation, and the number and arrangement of the friction type high-strength bolts 12 are determined according to the requirements of the specification. In the factory, holes are drilled in the reinforcement angle steel 11 according to the designed positions of the friction type high-strength bolts 12. The reinforcement angle steel 11 is transported to the bridge site, and is hoisted to the installation position by equipment. Matching holes are made on the compression member 13 to be reinforced according to the positions of the bolt holes on the reinforcement angle steel 11, and then the friction type high-strength bolts 12 are installed to complete the reinforcement of the compression member 13 to be reinforced.

[0044] Reference Figure 2 The schematic diagram of the scheme for reinforcing a combined compression column formed by filling a compression rod with concrete is applicable to rods with a large reinforcement requirement for the compression rod of the main truss. The scheme for reinforcing a combined compression column formed by filling a compression rod with concrete in the present invention comprises micro-expansion reinforced concrete 21, welded shear keys 22, steel bars 23, and a compression rod to be reinforced 24. The micro-expansion reinforced concrete is filled into the cross-sectional space enclosed by the steel structure, and a shear nail connector is welded on the steel structure, so that the concrete and the steel structure form a combined compression column, making full use of the compression performance of the concrete to enhance the stability and strength of the steel member. In specific implementation, for the compressive member 24 to be reinforced whose internal force increases greatly and whose reinforcement scheme of bolted angle steel cannot meet the force requirements, the filling area of ​​the required micro-expansion reinforced concrete 21 is determined according to the calculation, and the number and arrangement of the welded shear keys 22 are determined according to the requirements of the specification. The welded shear keys 22 are welded to the compressive member 24 to be reinforced on site, and the steel bars 23 are tied in the concrete filling area. After the steel bars 23 are tied, the formwork is installed around the compressive member 24 to be reinforced, and the micro-expansion reinforced concrete 21 is poured to complete the reinforcement of the compressive member 24 to be reinforced.

[0045] Reference Figure 3The schematic diagram of the bolted steel plate reinforcement scheme for tension rods of the present invention includes a reinforcement steel plate 31, a friction-type high-strength bolt 32, and a tension rod 33 to be reinforced. By bolting a steel plate on the flange of the original rod, the tension section is increased, the tensile resistance of the net section is improved, the tensile bearing capacity of the net section of the tension rod is increased, and the flange with the largest cross-sectional stress is targetedly reinforced to solve the problem of insufficient net section strength of the tension rod. In specific implementation, the tension rods 33 to be reinforced are determined according to calculations, the specifications of the required reinforcing steel plates 31 are determined according to calculations, the number and arrangement of the friction type high-strength bolts 32 are determined according to the requirements of the specifications, holes are drilled in the reinforcing steel plates 31 according to the designed positions of the friction type high-strength bolts 32 in the factory, the reinforcing steel plates 31 are transported to the bridge site, the reinforcing steel plates 31 are hoisted to the installation position by equipment, matching holes are drilled in the tension rods 33 to be reinforced according to the positions of the bolt holes on the reinforcing steel plates 31, and then the friction type high-strength bolts 32 are installed to complete the reinforcement of the tension rods 33 to be reinforced.

[0046] Reference Figures 4 to 6 . Schematic diagram of the main truss node plate reinforcement scheme, the node positions include: vertical rods 45, chord rods 47, and diagonal rods 46 located on both sides of the vertical rods. The main truss node plate reinforcement scheme of the present invention includes reinforced steel plates 41, node plates to be reinforced 42, new rivets or high-strength bolts 43, and original rivets or high-strength bolts 44. By bolting steel plates to the original node plates, the load-bearing cross-section is increased, the shear and tear resistance of the net cross-section is improved, the bearing capacity of the node plate is increased, and the problems of insufficient horizontal shear strength and insufficient tear surface strength of the node plate are solved. In specific implementation, the node plate 42 to be reinforced is determined according to calculation, the area of ​​the required reinforced steel plate 41 is determined according to the horizontal shear resistance of the node plate and the tear resistance of the rod connection part, the number and arrangement of the new rivets or high-strength bolts 43 are determined according to the specification requirements, and holes are drilled in the reinforced steel plate 41 according to the design position of the new rivets or high-strength bolts 43 in the factory, and the reinforced steel plate 41 is hollowed out according to the position of the original rivets or high-strength bolts to form a hollowed-out groove 48 to avoid interference during installation and the removal of the original rivets or high-strength bolts 44. The reinforced steel plate 41 is transported to the bridge site, the original rivets or high-strength bolts 44 around the shear section of the node plate are removed, and the reinforced steel plate 41 is hoisted to the installation position by equipment. According to the bolt hole position on the reinforced steel plate 41, matching holes are cast, and then new rivets or high-strength bolts 43 are installed to complete the reinforcement of the node plate 42 to be reinforced. The rivets or bolts in the diagonal rivet group with greater stress cannot be removed, while the rivets in the chord where there are relatively more rivets can be partially removed.

[0047] Reference Figures 7 to 10. Schematic diagram of the connection scheme between the main truss node plate and the reinforcement member. The connection scheme between the main truss node plate and the reinforcement member of the present invention includes an end-enlarged reinforcement steel plate 51, an end-enlarged reinforcement angle steel 52, a cover plate 53, a connecting rivet or high-strength bolt 54, and a node plate 55. By enlarging the end of the rod reinforcement member, it is avoided to remove the original connecting rivet or high-strength bolt. The node plate and the rod reinforcement steel plate or reinforcement angle steel are connected together through new high-strength bolts or rivets using a steel cover plate to achieve smooth force transmission between the node plate and the rod. The end-enlarged reinforcement steel plate 51 and the end-enlarged reinforcement angle steel 52 do not extend to the node plate, so they need to be connected through the cover plate, that is, one end of the cover plate is connected to the node plate, and the other end of the cover plate is connected to the reinforcement member. In specific implementation, the number of connecting rivets or high-strength bolts 54 required for force transmission between the end enlarged and reinforced steel plate 51 or the end enlarged and reinforced angle steel 52 and the node plate is determined by calculation, the connecting rivets or high-strength bolts 54 are arranged according to the specifications, the end size of the end enlarged and reinforced steel plate 51 or the end enlarged and reinforced angle steel 52 is determined, and then the size of the cover plate 53 is obtained, and the end of the end enlarged and reinforced angle steel 52 is fully welded to the reinforcing angle steel in the factory, and holes are opened in the end enlarged and reinforced steel plate 51 or the end enlarged and reinforced angle steel 52 and the cover plate 53 according to the designed positions of the connecting rivets or high-strength bolts 54. The end enlarged reinforcement steel plate 51, the end enlarged reinforcement angle steel 52 and the cover plate 53 are transported to the site, and the end enlarged reinforcement steel plate 51 and the end enlarged reinforcement angle steel 52 are hoisted to the installation position by equipment, and the high-strength bolts on the rod body to be reinforced are connected. According to the rivet or high-strength bolt holes on the cover plate 53, holes are drilled at the corresponding positions on the node plate, and the cover plate is connected with the end enlarged reinforcement steel plate 51, the end enlarged reinforcement angle steel 52 and the node plate by connecting rivets or high-strength bolts 54, thereby realizing the connection between the node plate and the end enlarged reinforcement steel plate 51 and the end enlarged reinforcement angle steel 52, and ensuring smooth force transmission between the node plate and the reinforced rod.

[0048] Although the above-mentioned illustrations and descriptions provide a detailed example of an in-situ reinforcement method for a steel truss bridge of the present invention, it is not intended to limit the present invention to the specific structure and applicable scope shown and described. Therefore, all corresponding modifications and equivalents that may be used are within the scope of the patent applied for by the present invention.

Claims

1. A method for in-situ reinforcement of a steel truss bridge, characterized in that The method includes: According to the stress characteristics of the main truss parts to be reinforced, the main truss parts to be reinforced are divided into main truss compression members to be reinforced, main truss tension members to be reinforced and node plates. At the same time, the reinforced main truss compression members are divided into main truss compression members to be reinforced with smaller reinforcement requirements and main truss compression members to be reinforced with larger reinforcement requirements. For the reinforcement of the main truss compression members with less reinforcement requirements, the reinforcement angle steel is bolted to the flange of the main truss compression members to increase the compression section of the compression members, thus achieving the reinforcement of the main truss compression members; The reinforcement of the main truss compression rods with greater reinforcement requirements is to pour micro-expansion concrete into the rod body of the main truss compression rod to be reinforced, so that the concrete and the steel structure form a combined compression column to achieve the reinforcement of the main truss compression rod; Strengthening the tension rods of the main truss to be strengthened: bolting reinforcement steel plates to the flanges of the tension rods of the main truss to be strengthened to increase the tension section of the tension rods and achieve reinforcement of the tension rods of the main truss; The node plate of the main truss is reinforced by bolting node reinforcement steel plates on the original node plates to increase the load-bearing cross-section of the node plates and realize the reinforcement of the node plates of the main truss.

2. The in-situ reinforcement method for a steel truss bridge according to claim 1, characterized in that: The specific steps for strengthening the main truss compression members with less reinforcement requirements are as follows: A reinforcement angle steel is manufactured, the length of which matches the length of the main truss compression member to be reinforced, bolt holes are punched on the side of the reinforcement angle steel, and an outwardly expanding angle steel weldment extending outward is welded to the end of the reinforcement angle steel; Transport the reinforcement angle steel to the bridge site, hoist the reinforcement angle steel to the installation position, match the holes on the bolt holes on the reinforcement angle steel, and then install friction-type high-strength bolts to complete the reinforcement of the compression members to be reinforced; The cover plate is used to overlap the expanded angle steel weldment at the end of the reinforced angle steel and the node plate to complete the connection between the node plate and the reinforced component.

3. The in-situ reinforcement method for a steel truss bridge according to claim 1, characterized in that: The specific steps for strengthening the main truss compression members with greater reinforcement requirements are as follows: Calculate the fill area of ​​micro-expansion reinforced concrete; Weld the welded shear keys on the compression members to be reinforced and tie the steel bars in the concrete filling area; Install formwork around the compression members to be reinforced; Pour micro-expansion reinforced concrete in the concrete filling area.

4. The in-situ reinforcement method for a steel truss bridge according to claim 1, characterized in that: The specific steps for strengthening the tension rods of the main truss to be strengthened are as follows: Make a reinforcement steel plate, the length of which matches the length of the main truss tension rod to be reinforced, punch bolt holes on the reinforcement steel plate, and expand the end of the reinforcement steel plate by design and processing; Transport the reinforcement steel plate to the bridge site, hoist the reinforcement steel plate to the installation position, match the holes on the reinforcement steel plate with the tension rods to be reinforced according to the bolt hole positions, and then install friction-type high-strength bolts to complete the reinforcement of the tension rods to be reinforced; The cover plate is used to overlap the expanded end of the reinforced steel plate and the node plate to complete the connection between the node plate and the reinforced component.

5. The in-situ reinforcement method for a steel truss bridge according to claim 1, characterized in that: The specific steps of main truss node plate reinforcement are as follows: For the node plate to be reinforced, the area of ​​the required reinforcement steel plate shall be determined according to the horizontal shear resistance of the node plate and the tear resistance of the rod connection part, and the number and arrangement of rivets or high-strength bolts shall be determined according to the requirements of the specification; According to the calculated area of ​​the reinforcement steel plate, the reinforcement steel plate is manufactured, and holes are opened in the reinforcement steel plate according to the designed positions of the rivets or high-strength bolts, and the reinforcement steel plate is hollowed out according to the positions of the original rivets or high-strength bolts to form a hollowed-out groove; Transport the reinforced steel plates to the bridge site and remove the original rivets or high-strength bolts around the shear section of the node plate; Lift the reinforcement steel plate to the installation position, make matching holes on the node plate to be reinforced according to the positions of the bolt holes on the reinforcement steel plate, and then install rivets or high-strength bolts to complete the reinforcement of the node plate to be reinforced.

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