Fabricated urban large box chamber steel box girder bridge structure and construction method

Abstract

The invention relates to a fabricated urban large-box-chamber steel box girder bridge structure which comprises a steel box girder bottom plate, a steel box girder bridge panel, a steel box girder web plate, a steel box girder transverse partition plate and a steel box girder longitudinal partition plate, the steel box girder transverse partition plate and the steel box girder longitudinal partition plate are of a truss structure, and the large-box-chamber steel box girder bridge structure is composed of a plurality of box girder sections in the longitudinal bridge direction. Each box girder section is composed of a steel box girder left section block body, a steel box girder middle section block body and a steel box girder right section block body in the transverse bridge direction, the adjacent section block bodies are connected through ultra-high performance concrete wet joints, and the adjacent box girder sections are connected through ultra-high performance concrete wet joints; the steel box girder middle segment block body comprises a middle block top plate unit and a middle block bottom plate unit which are independent. The problems of welding seam staggering, ultra-wide welding seams and the like encountered by splicing and welding on a construction site after the steel box girders are transported in blocks are solved, the error tolerance rate of on-site splicing after the steel box girders are transported in blocks can be improved, and structural damage caused by welding seam defects of the steel box girders is reduced.

Description

Technical Field

[0001] The invention relates to an assembled urban large-chamber steel box girder bridge structure and a construction method. Background Art

[0002] With the rapid development of national infrastructure and the increasing prosperity of the economy, the construction of steel bridges has been vigorously developed. Steel box girders are suitable for urban viaducts, curved bridges, large-span bridges and bridges with special requirements due to their good integrity, light weight, strong torsion resistance and easy and fast construction. Many existing steel box girders are divided into several blocks for transportation from the transverse bridge direction and the longitudinal bridge direction during construction and installation, and the method of manual welding connection is used at the construction site. The quality of on-site assembly is worse than that of the production workshop. The steel box girder segment blocks will be deformed during the transportation project, which will affect the assembly at the construction site, and there will be problems such as weld misalignment and over-width, resulting in a large amount of welding residual stress, resulting in structural damage. Manual welding is unstable, which will make it difficult to guarantee the quality of the welds at the connection of the steel box girder segment blocks.

[0003] Based on this, this case proposes an assembled urban large-chamber steel box girder bridge structure and construction method to solve the above technical problems. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide an assembled urban large-chamber steel box girder bridge structure and a construction method.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: an assembled urban large box steel box girder bridge structure, including a steel box girder bottom plate, a steel box girder bridge deck, a steel box girder web plate, a steel box girder transverse diaphragm, and a steel box girder longitudinal diaphragm. The transverse and longitudinal diaphragms of the steel box girder are truss structures. The large box steel box girder bridge structure is composed of a plurality of box girder segments in the longitudinal direction of the bridge, and the box girder segments are composed of a left segment block of the steel box girder, a middle segment block of the steel box girder, and a right segment block of the steel box girder in the transverse direction of the bridge. Adjacent segment blocks and adjacent box girder segments are connected by ultra-high performance concrete wet joints; the middle segment block of the steel box girder includes an independent middle block top plate unit and a middle block bottom plate unit.

[0006] Preferably, the left section block of the steel box girder and the right section block of the steel box girder are both composed of edge block top plate units, edge block bottom plate units, steel box girder webs and partition connecting rods, and the edge block top plate units and edge block bottom plate units both include longitudinal stiffening ribs and connecting ribs along the bridge direction, and the connecting ribs are all surrounded by three sides of the edge block top plate units and the edge block bottom plate units; the partition connecting rods are connected between the connecting ribs of the edge block top plate units and the edge block bottom plate units as vertical webs or diagonal webs of the truss structure.

[0007] Preferably, connecting ribs are arranged on four sides of the middle block top plate unit and the middle block bottom plate unit, and longitudinal stiffening ribs are arranged in the connecting ribs at a certain interval along the bridge direction.

[0008] Preferably, the connecting ribs are provided with high-strength bolt holes for connecting with the partition connecting rods by high-strength bolts; bolts are arranged at a certain interval on the outside of the connecting ribs, and longitudinal stiffening rib-shaped openings are provided on the connecting ribs located in the transverse direction of the bridge for passing the longitudinal stiffening ribs, and the longitudinal stiffening ribs are welded to the top and bottom plates of the steel box girder.

[0009] Preferably, the ultra-high performance concrete wet joints include four forms: top plate transverse connecting wet joints, top plate longitudinal connecting wet joints, bottom plate transverse connecting wet joints and bottom plate longitudinal connecting wet joints. The top plate transverse connecting wet joints are connected between the edge block top plate units of the left segment block and the right segment block of the steel box girder and the middle block top plate units of the middle segment block. The bottom plate transverse connecting wet joints are connected between the edge block bottom plate units of the left segment block and the right segment block of the steel box girder and the middle block bottom plate units of the middle segment block. The top and bottom plate longitudinal connecting wet joints are connected between two adjacent box girder segments along the bridge direction.

[0010] Preferably, the connecting ribs at the transverse connecting wet joints and the longitudinal connecting wet joints of the top plate are L-shaped connecting ribs, and high-strength bolt holes are arranged on the lower flange plates of the L-shaped connecting ribs. The L-shaped connecting ribs are bolted with plate steel at the longitudinal connecting wet joints of the top plate, and the L-shaped connecting ribs are bolted with T-shaped steel at the transverse connecting wet joints of the top plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the upper end of the partition connecting rod.

[0011] Preferably, the connecting ribs at the transverse connecting wet joints and the longitudinal connecting wet joints of the bottom plate are flat-plate connecting ribs, the flat-plate connecting ribs are at a certain distance from the edge of the bottom plate of the steel box girder, and high-strength bolt holes are arranged on the edge of the bottom plate of the steel box girder. The edge of the bottom plate of the steel box girder is connected with plate steel at the longitudinal connecting wet joints of the bottom plate, and the edge of the bottom plate of the steel box girder is connected with T-shaped steel at the transverse connecting wet joints of the bottom plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the lower end of the partition connecting rod; high-strength bolt holes are arranged on the edges of the longitudinal stiffening ribs at the longitudinal connecting wet joints of the top plate and the longitudinal connecting wet joints of the bottom plate, for high-strength bolt connection between the longitudinal stiffening ribs.

[0012] Preferably, annular steel bars are arranged in the ultra-high performance concrete wet joints, and the wet joints are cast with ultra-high performance concrete; and steel cover plates are used for welding and sealing at the ultra-high performance concrete wet joints of the steel box girder bridge deck.

[0013] A construction method for an assembled urban large-chamber steel box girder bridge structure comprises the following steps:

[0014] (1) Fabrication of various component units of steel box girders: Draw processing drawings and compile manufacturing process documents according to design drawings, perform steel plate straightening, cutting, drilling, grinding, groove processing and bending processing, fabricate longitudinal stiffening ribs, connecting ribs, steel box girder top and bottom plates, steel box girder webs, steel box girder transverse diaphragms and steel box girder longitudinal diaphragms, and then perform hole drilling and bolt welding on the connecting ribs;

[0015] (2) Fabrication of the middle section block of the steel box girder: The middle block top plate unit and the middle block bottom plate unit of the middle section block of the steel box girder are fabricated separately, and longitudinal stiffening ribs are welded on the middle block top plate unit and the middle block bottom plate unit at a certain interval, and then L-shaped connecting ribs are welded at the designed position of the middle block top plate unit, and flat plate-shaped connecting ribs are welded at the designed position of the middle block bottom plate unit;

[0016] (3) Fabrication of the left and right segment blocks of the steel box girder: weld longitudinal stiffening ribs on the edge block top plate unit and the edge block bottom plate unit, weld L-shaped connecting ribs at the designed position on the edge block top plate unit, weld flat plate connecting ribs at the designed position on the edge block bottom plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the flat plate connecting ribs in the transverse direction of the edge block bottom plate unit and fix the position, assemble the steel box girder web on the edge block bottom plate unit, assemble the edge block top plate unit on the steel box girder web and pass the diaphragm connecting rods through the openings between the L-shaped connecting ribs in the transverse direction of the edge block top plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the web of the L-shaped connecting ribs, and the stress of the diaphragm connecting rods can be verified by the following formula:

[0017]

[0018] Where:

[0019] G – total weight exerted on the web and diaphragm connecting rods connected to the steel box girder deck and bottom plate during the steel box girder hoisting process;

[0020] N1——The gravity distributed to the partition connecting rod;

[0021] N 竖 ——Axial force of a single vertical diaphragm connecting rod;

[0022] N 斜 ——Axial force of a single diagonal diaphragm connecting rod;

[0023] A1——Total contact area between web and top plate of steel box girder;

[0024] A2——Total cross-sectional area of ​​the partition connecting rods;

[0025] A——Cross-sectional area of ​​a single diaphragm connecting rod. The cross-sectional area of ​​vertical and diagonal diaphragm connecting rods is assumed to be the same;

[0026] n——The number of pairs of partition connecting rods. A vertical partition connecting rod and an inclined partition connecting rod are a pair;

[0027] α——the angle between the vertical diaphragm connecting rod and the diagonal diaphragm connecting rod;

[0028] σ 竖 ——Stress of vertical diaphragm connecting rods;

[0029] σ 斜 ——Stress of connecting rods of diagonal diaphragms;

[0030] [σ]——design value of allowable stress of steel material of diaphragm connecting rod;

[0031] (4) Installation of the middle block bottom plate unit of the middle segment block of the steel box girder: hoist the middle block bottom plate unit of the middle segment block of the steel box girder to the designated position and fix it;

[0032] (5) Installation of the left segment of the steel box girder and casting of wet joints: hoist the left segment of the steel box girder to the corresponding position, bolt the T-shaped steel to the bottom plate between the two flat connecting ribs, bolt the diaphragm connecting rods to the T-shaped steel web, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form;

[0033] (6) Installation of the right segment block of the steel box girder and casting of wet joints: hoist the right segment block of the steel box girder to the corresponding position, fix the bottom plates of the right segment block and the middle segment block with T-shaped steel bolts, bolt the diaphragm connecting rods to the web of the T-shaped steel, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form;

[0034] (7) Installation of the middle block top plate unit and wet joint casting of the middle segment block of the steel box girder: hoist the middle segment block of the steel box girder to the corresponding position, bolt T-shaped steel to the lower flange plate of the longitudinal L-shaped connecting rib plate, bolt the longitudinal diaphragm of the steel box girder to the web plate of the T-shaped steel, arrange circular steel bars between the connecting rib plates, cast ultra-high performance concrete and cure to form;

[0035] (8) Connection of steel box girder segments in the longitudinal direction: Bolt the longitudinal stiffening ribs of two adjacent steel box girder segments, arrange annular steel bars between the two transverse connecting ribs, pour ultra-high performance concrete and cure to form;

[0036] (9) Welding of steel cover plates on wet joints of bridge decks: After the longitudinal and transverse ultra-high performance concrete wet joints of the bridge decks are formed, steel cover plates are welded on the edges of each bridge deck on the wet joints to seal them;

[0037] (10) Circular construction was carried out to complete the construction of the steel box girder bridge.

[0038] Preferably, in steps (5) and (6), the connection and fixation of the left and right segment blocks of the steel box girder and the bottom plate of the middle segment blocks of the steel box girder and the arrangement of the longitudinal diaphragm of the steel box girder can be formed by two methods:

[0039] The first method: the left section block of the steel box girder, the right section block of the steel box girder and the bottom plate of the middle section block of the steel box girder are bolted and fixed with T-shaped steel, the partition connecting rod is connected and fixed with the T-shaped steel web by bolts, and then the annular steel bars are arranged, and the ultra-high performance concrete is poured and cured to form;

[0040] The second method: a wet joint formwork is arranged between the left and right segment blocks of the steel box girder and the bottom plate of the middle segment block of the steel box girder. A T-shaped steel is first bolted on one side on the lower flange plate of the L-shaped connecting ribs of the left and right segment blocks of the steel box girder. The upper part of the partition connecting rod is bolted to the web of the T-shaped steel and fixed in position, and the lower part is extended into the wet joint. Then, ultra-high performance concrete is poured in the lower wet joint and cured. The formwork is removed after forming.

[0041] Compared with the prior art, the present invention has the following beneficial effects: it avoids the problems of weld misalignment and over-width that may be encountered during the assembly and welding of steel box girders at the construction site after the steel box girders are transported in blocks, is beneficial to improving the error tolerance rate of on-site assembly of steel box girders after the steel box girders are transported in blocks, and reduces structural damage to the steel box girders caused by weld defects.

[0042] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic diagram of a three-dimensional structure of an embodiment of the present invention;

[0044] Figure 2 is a front structural schematic diagram of an embodiment of the present invention;

[0045] Figure 3 It is a schematic diagram of the structure of the horizontally connected wet joint of the top plate;

[0046] Figure 4 It is a schematic diagram of the structure of the horizontal wet joint of the bottom plate;

[0047] Figure 5 is a schematic diagram of a top view of the structure of an embodiment of the present invention;

[0048] Figure 6 is a schematic side view of the structure of an embodiment of the present invention;

[0049] Figure 7 It is a top view structural schematic diagram of the longitudinal wet joint of the top plate;

[0050] Figure 8 yes Figure 6A partial enlarged view of;

[0051] In the figure: 1-steel box girder bridge deck; 101-L-shaped connecting rib; 2-steel box girder web; 3-steel box girder bottom plate; 301-flat connecting rib; 4-longitudinal stiffening rib; 5-stud; 6-bolt; 7-steel box girder transverse diaphragm; 701-diaphragm connecting rod; 8-steel box girder longitudinal diaphragm; 9-ultra-high performance concrete wet joint; 901-circular reinforcement; 902-T-steel; 903-plate steel; 10-steel cover plate. DETAILED DESCRIPTION

[0052] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0053] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0055] like Figures 1 to 8 As shown, this embodiment provides an assembled urban large box steel girder bridge structure, including a steel box girder bottom plate, a steel box girder bridge deck, a steel box girder web plate, a steel box girder transverse diaphragm, and a steel box girder longitudinal diaphragm. The transverse and longitudinal diaphragms of the steel box girder are truss structures. The large box steel box girder bridge structure is composed of a plurality of box girder segments in the longitudinal direction of the bridge, and the box girder segments are composed of a left section block of the steel box girder, a middle section block of the steel box girder, and a right section block of the steel box girder in the transverse direction of the bridge. Adjacent section blocks and adjacent box girder sections are connected by ultra-high performance concrete wet joints; the middle section block of the steel box girder includes an independent middle block top plate unit and a middle block bottom plate unit.

[0056] Wet joints have the advantages of easy construction, high error tolerance and high connection strength. The use of ultra-high performance concrete to cast wet joints can further improve the connection strength of wet joints, avoiding the problems of weld misalignment and excessive width encountered when assembling and welding steel box girders at the construction site after being transported in blocks. It improves the error tolerance of on-site assembly of steel box girders after being transported in blocks, and reduces structural damage to steel box girders caused by weld defects.

[0057] In an embodiment of the present invention, the left segment block of the steel box girder and the right segment block of the steel box girder are both composed of an edge block top plate unit, an edge block bottom plate unit, a steel box girder web and a partition connecting rod. The edge block top plate unit and the edge block bottom plate unit both include longitudinal stiffening ribs and connecting ribs along the bridge direction. The connecting ribs are all surrounded by three sides of the edge block top plate unit and the edge block bottom plate unit; the partition connecting rod is connected between the connecting ribs of the edge block top plate unit and the edge block bottom plate unit as a vertical web member or an inclined web member of the truss structure.

[0058] In the embodiment of the present invention, connecting ribs are arranged on the four sides of the middle block top plate unit and the middle block bottom plate unit, and longitudinal stiffening ribs are arranged in the connecting ribs at a certain interval along the bridge direction.

[0059] In an embodiment of the present invention, the connecting ribs are provided with high-strength bolt holes for connecting with the partition connecting rods by high-strength bolts; bolts are arranged at a certain interval on the outside of the connecting ribs, so that the connection of the ultra-high performance concrete wet joints is more firmly established, and longitudinal stiffening rib-shaped openings are provided on the connecting ribs located in the transverse direction of the bridge for passing the longitudinal stiffening ribs, and the longitudinal stiffening ribs are welded to the top and bottom plates of the steel box girder.

[0060] In an embodiment of the present invention, the ultra-high performance concrete wet joints include four types: transverse connecting wet joints of the top plate, longitudinal connecting wet joints of the top plate, transverse connecting wet joints of the bottom plate, and longitudinal connecting wet joints of the bottom plate. The transverse connecting wet joints of the top plate are connected between the edge block top plate units of the left and right segment blocks of the steel box girder and the middle block top plate units of the middle segment blocks. The transverse connecting wet joints of the bottom plate are connected between the edge block bottom plate units of the left and right segment blocks of the steel box girder and the middle block bottom plate units of the middle segment blocks. The longitudinal connecting wet joints of the top and bottom plates are connected between two adjacent box girder segments along the bridge direction.

[0061] In an embodiment of the present invention, the connecting ribs at the transverse connecting wet joints and the longitudinal connecting wet joints of the top plate are L-shaped connecting ribs, and high-strength bolt holes are arranged on the lower flange plates of the L-shaped connecting ribs. The L-shaped connecting ribs are bolted with plate steel at the longitudinal connecting wet joints of the top plate, and the L-shaped connecting ribs are bolted with T-shaped steel at the transverse connecting wet joints of the top plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the upper end of the partition connecting rod.

[0062] In an embodiment of the present invention, the connecting ribs at the transverse connecting wet joints and the longitudinal connecting wet joints of the bottom plate are flat-plate connecting ribs, the flat-plate connecting ribs are at a certain distance from the edge of the bottom plate of the steel box girder, and high-strength bolt holes are arranged on the edge of the bottom plate of the steel box girder. The edge of the bottom plate of the steel box girder is connected with plate steel at the longitudinal connecting wet joints of the bottom plate, and the edge of the bottom plate of the steel box girder is connected with T-shaped steel at the transverse connecting wet joints of the bottom plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the lower end of the partition connecting rod; high-strength bolt holes are arranged on the edges of the longitudinal stiffening ribs at the longitudinal connecting wet joints of the top plate and the longitudinal connecting wet joints of the bottom plate, for high-strength bolt connection between the longitudinal stiffening ribs.

[0063] In an embodiment of the present invention, annular steel bars are arranged in the ultra-high performance concrete wet joint, and the wet joint is cast with ultra-high performance concrete; the ultra-high performance concrete wet joint connection of the steel box girder bridge deck is welded and sealed with a steel cover plate.

[0064] A construction method for an assembled urban large-chamber steel box girder bridge structure comprises the following steps:

[0065] (1) Fabrication of various component units of steel box girders: Draw processing drawings and compile manufacturing process documents according to design drawings, perform steel plate straightening, cutting, drilling, grinding, groove processing and bending processing, fabricate longitudinal stiffening ribs, connecting ribs, steel box girder top and bottom plates, steel box girder webs, steel box girder transverse diaphragms and steel box girder longitudinal diaphragms, and then perform hole drilling and bolt welding on the connecting ribs;

[0066] (2) Fabrication of the middle section block of the steel box girder: The middle block top plate unit and the middle block bottom plate unit of the middle section block of the steel box girder are fabricated separately, and longitudinal stiffening ribs are welded on the middle block top plate unit and the middle block bottom plate unit at a certain interval, and then L-shaped connecting ribs are welded at the designed position of the middle block top plate unit, and flat plate-shaped connecting ribs are welded at the designed position of the middle block bottom plate unit;

[0067] (3) Fabrication of the left and right segment blocks of the steel box girder: weld longitudinal stiffening ribs on the edge block top plate unit and the edge block bottom plate unit, weld L-shaped connecting ribs at the designed position on the edge block top plate unit, weld flat plate connecting ribs at the designed position on the edge block bottom plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the flat plate connecting ribs in the transverse direction of the edge block bottom plate unit and fix the position, assemble the steel box girder web on the edge block bottom plate unit, assemble the edge block top plate unit on the steel box girder web and pass the diaphragm connecting rods through the openings between the L-shaped connecting ribs in the transverse direction of the edge block top plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the web of the L-shaped connecting ribs, and the stress of the diaphragm connecting rods can be verified by the following formula:

[0068]

[0069] Where:

[0070] G – total weight exerted on the web and diaphragm connecting rods connected to the steel box girder deck and bottom plate during the steel box girder hoisting process;

[0071] N1——The gravity distributed to the partition connecting rod;

[0072] N 竖 ——Axial force of a single vertical diaphragm connecting rod;

[0073] N 斜 ——Axial force of a single diagonal diaphragm connecting rod;

[0074] A1——Total contact area between web and top plate of steel box girder;

[0075] A2——Total cross-sectional area of ​​the partition connecting rods;

[0076] A——Cross-sectional area of ​​a single diaphragm connecting rod. The cross-sectional area of ​​vertical and diagonal diaphragm connecting rods is assumed to be the same;

[0077] n——The number of pairs of partition connecting rods. A vertical partition connecting rod and an inclined partition connecting rod are a pair;

[0078] α——the angle between the vertical diaphragm connecting rod and the diagonal diaphragm connecting rod;

[0079] 竖 ——Stress of vertical diaphragm connecting rods;

[0080] 斜 ——Stress of connecting rods of diagonal diaphragms;

[0081] [σ]——design value of allowable stress of steel material of diaphragm connecting rod;

[0082] (4) Installation of the middle block bottom plate unit of the middle segment block of the steel box girder: hoist the middle block bottom plate unit of the middle segment block of the steel box girder to the designated position and fix it;

[0083] (5) Installation of the left segment of the steel box girder and casting of wet joints: hoist the left segment of the steel box girder to the corresponding position, bolt the T-shaped steel to the bottom plate between the two flat connecting ribs, bolt the diaphragm connecting rods to the T-shaped steel web, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form;

[0084] (6) Installation of the right segment block of the steel box girder and casting of wet joints: hoist the right segment block of the steel box girder to the corresponding position, fix the bottom plates of the right segment block and the middle segment block with T-shaped steel bolts, bolt the diaphragm connecting rods to the web of the T-shaped steel, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form;

[0085] (7) Installation of the middle block top plate unit and wet joint casting of the middle segment block of the steel box girder: hoist the middle segment block of the steel box girder to the corresponding position, bolt T-shaped steel to the lower flange plate of the longitudinal L-shaped connecting rib plate, bolt the longitudinal diaphragm of the steel box girder to the web plate of the T-shaped steel, arrange circular steel bars between the connecting rib plates, cast ultra-high performance concrete and cure to form;

[0086] (8) Connection of steel box girder segments in the longitudinal direction: Bolt the longitudinal stiffening ribs of two adjacent steel box girder segments, arrange annular steel bars between the two transverse connecting ribs, pour ultra-high performance concrete and cure to form;

[0087] (9) Welding of steel cover plates on wet joints of bridge decks: After the longitudinal and transverse ultra-high performance concrete wet joints of the bridge decks are formed, steel cover plates are welded on the edges of each bridge deck on the wet joints to seal them;

[0088] (10) Circular construction was carried out to complete the construction of the steel box girder bridge.

[0089] In the embodiment of the present invention, in steps (5) and (6), the connection and fixation of the left and right segment blocks of the steel box girder and the bottom plate of the middle segment blocks of the steel box girder and the arrangement of the longitudinal diaphragm of the steel box girder can be formed by two methods:

[0090] The first method: the left section block of the steel box girder, the right section block of the steel box girder and the bottom plate of the middle section block of the steel box girder are bolted and fixed with T-shaped steel, the partition connecting rod is connected and fixed with the T-shaped steel web by bolts, and then the annular steel bars are arranged, and the ultra-high performance concrete is poured and cured to form;

[0091] The second method: a wet joint formwork is arranged between the left and right segment blocks of the steel box girder and the bottom plate of the middle segment block of the steel box girder. A T-shaped steel is first bolted on one side on the lower flange plate of the L-shaped connecting ribs of the left and right segment blocks of the steel box girder. The upper part of the partition connecting rod is bolted to the web of the T-shaped steel and fixed in position, and the lower part is extended into the wet joint. Then, ultra-high performance concrete is poured in the lower wet joint and cured. The formwork is removed after forming.

[0092] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. An assembled urban large box-chamber steel box girder bridge structure, comprising a steel box girder bottom plate, a steel box girder bridge deck, a steel box girder web plate, a steel box girder transverse diaphragm, and a steel box girder longitudinal diaphragm, wherein the steel box girder transverse and longitudinal diaphragms are truss structures, characterized in that: The large box-chamber steel box girder bridge structure is composed of a plurality of box girder segments in the longitudinal direction of the bridge, and the box girder segments are composed of a left segment block of a steel box girder, a middle segment block of a steel box girder, and a right segment block of a steel box girder in the transverse direction of the bridge. Adjacent segment blocks and adjacent box girder segments are connected by ultra-high performance concrete wet joints; the middle segment block of the steel box girder includes an independent middle block top plate unit and a middle block bottom plate unit.

2. The assembled urban large-chamber steel box girder bridge structure according to claim 1 is characterized in that: The left section block of the steel box girder and the right section block of the steel box girder are both composed of edge block top plate units, edge block bottom plate units, steel box girder webs and partition connecting rods. The edge block top plate units and edge block bottom plate units both include longitudinal stiffening ribs and connecting ribs along the bridge direction. The connecting ribs are all surrounded by three sides of the edge block top plate units and the edge block bottom plate units. The partition connecting rods are connected between the connecting ribs of the edge block top plate units and the edge block bottom plate units as vertical webs or diagonal webs of the truss structure.

3. The assembled urban large-chamber steel box girder bridge structure according to claim 1 is characterized in that: The four sides of the middle block top plate unit and the middle block bottom plate unit are all provided with connecting ribs, and longitudinal stiffening ribs are arranged in the connecting ribs along the bridge direction at a certain interval.

4. The assembled urban large-chamber steel box girder bridge structure according to claim 2 or 3 is characterized in that: The connecting ribs are provided with high-strength bolt holes for connecting with the partition connecting rods by high-strength bolts; bolts are arranged at a certain interval on the outside of the connecting ribs, and longitudinal stiffening rib-shaped openings are provided on the connecting ribs located in the transverse direction of the bridge for passing the longitudinal stiffening ribs, and the longitudinal stiffening ribs are welded to the top and bottom plates of the steel box girder.

5. The assembled urban large-chamber steel box girder bridge structure according to claim 1 is characterized in that: The ultra-high performance concrete wet joints include four types: transverse connecting wet joints of the top plate, longitudinal connecting wet joints of the top plate, transverse connecting wet joints of the bottom plate and longitudinal connecting wet joints of the bottom plate. The transverse connecting wet joints of the top plate are connected between the edge block top plate units of the left and right segment blocks of the steel box girder and the middle block top plate units of the middle segment blocks. The transverse connecting wet joints of the bottom plate are connected between the edge block bottom plate units of the left and right segment blocks of the steel box girder and the middle block bottom plate units of the middle segment blocks. The longitudinal connecting wet joints of the top and bottom plates are connected between two adjacent box girder segments along the bridge direction.

6. The assembled urban large-chamber steel box girder bridge structure according to claim 5 is characterized by: The connecting ribs at the transverse wet joints and the longitudinal wet joints of the top plate are L-shaped connecting ribs, and high-strength bolt holes are arranged on the lower flange plates of the L-shaped connecting ribs. The L-shaped connecting ribs are bolted with plate steel at the longitudinal wet joints of the top plate, and the L-shaped connecting ribs are bolted with T-shaped steel at the transverse wet joints of the top plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the upper end of the partition connecting rod.

7. The assembled urban large-chamber steel box girder bridge structure according to claim 5 is characterized by: The connecting ribs at the transverse wet joints and the longitudinal wet joints of the bottom plate are flat-plate connecting ribs, which are at a certain distance from the edge of the bottom plate of the steel box girder. High-strength bolt holes are arranged on the edge of the bottom plate of the steel box girder. The edge of the bottom plate of the steel box girder is connected with plate steel at the longitudinal wet joints of the bottom plate, and the edge of the bottom plate of the steel box girder is connected with T-shaped steel at the transverse wet joints of the bottom plate. High-strength bolt holes are arranged on the web of the T-shaped steel for high-strength bolt connection with the lower end of the partition connecting rod; high-strength bolt holes are arranged on the edges of the longitudinal stiffening ribs at the longitudinal wet joints of the top plate and the longitudinal wet joints of the bottom plate, which are used for high-strength bolt connection between the longitudinal stiffening ribs.

8. The assembled urban large-chamber steel box girder bridge structure according to claim 1 is characterized by: Annular steel bars are arranged in the ultra-high performance concrete wet joints, and the wet joints are cast with ultra-high performance concrete; the ultra-high performance concrete wet joints of the steel box girder bridge deck are welded and sealed with steel cover plates.

9. A construction method for an assembled urban large-chamber steel box girder bridge structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Fabrication of various component units of steel box girders: Draw processing drawings and compile manufacturing process documents according to design drawings, perform steel plate straightening, cutting, drilling, grinding, groove processing and bending processing, fabricate longitudinal stiffening ribs, connecting ribs, steel box girder top and bottom plates, steel box girder webs, steel box girder transverse diaphragms and steel box girder longitudinal diaphragms, and then perform hole drilling and bolt welding on the connecting ribs; (2) Fabrication of the middle section block of the steel box girder: The middle block top plate unit and the middle block bottom plate unit of the middle section block of the steel box girder are fabricated separately, and longitudinal stiffening ribs are welded on the middle block top plate unit and the middle block bottom plate unit at a certain interval, and then L-shaped connecting ribs are welded at the designed position of the middle block top plate unit, and flat plate-shaped connecting ribs are welded at the designed position of the middle block bottom plate unit; (3) Fabrication of the left and right segment blocks of the steel box girder: weld longitudinal stiffening ribs on the edge block top plate unit and the edge block bottom plate unit, weld L-shaped connecting ribs at the designed position on the edge block top plate unit, weld flat plate connecting ribs at the designed position on the edge block bottom plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the flat plate connecting ribs in the transverse direction of the edge block bottom plate unit and fix the position, assemble the steel box girder web on the edge block bottom plate unit, assemble the edge block top plate unit on the steel box girder web and pass the diaphragm connecting rods through the openings between the L-shaped connecting ribs in the transverse direction of the edge block top plate unit, bolt the diaphragm connecting rods of the steel box girder transverse diaphragm to the web of the L-shaped connecting ribs, and the stress of the diaphragm connecting rods can be verified by the following formula: Where: G – total weight exerted on the web and diaphragm connecting rods connected to the steel box girder deck and bottom plate during the steel box girder hoisting process; N1——The gravity distributed to the partition connecting rod; N 竖 ——Axial force of a single vertical diaphragm connecting rod; N 斜 ——Axial force of a single diagonal diaphragm connecting rod; A1——Total contact area between web and top plate of steel box girder; A2——Total cross-sectional area of ​​the partition connecting rods; A——Cross-sectional area of ​​a single diaphragm connecting rod. The cross-sectional area of ​​vertical and diagonal diaphragm connecting rods is assumed to be the same; n——The number of pairs of partition connecting rods. A vertical partition connecting rod and an inclined partition connecting rod are a pair; α——the angle between the vertical diaphragm connecting rod and the diagonal diaphragm connecting rod; σ 竖 ——Stress of vertical diaphragm connecting rods; σ 斜 ——Stress of connecting rods of diagonal diaphragms; σ——design value of allowable stress of steel material of diaphragm connecting rod; (4) Installation of the middle block bottom plate unit of the middle segment block of the steel box girder: hoist the middle block bottom plate unit of the middle segment block of the steel box girder to the designated position and fix it; (5) Installation of the left segment of the steel box girder and casting of wet joints: hoist the left segment of the steel box girder to the corresponding position, bolt the T-shaped steel to the bottom plate between the two flat connecting ribs, bolt the diaphragm connecting rods to the T-shaped steel web, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form; (6) Installation of the right segment block of the steel box girder and casting of wet joints: hoist the right segment block of the steel box girder to the corresponding position, fix the bottom plates of the right segment block and the middle segment block with T-shaped steel bolts, bolt the diaphragm connecting rods to the web of the T-shaped steel, fix the position, arrange the annular steel bars, cast the ultra-high performance concrete and cure it to form; (7) Installation of the middle block top plate unit and wet joint casting of the middle segment block of the steel box girder: hoist the middle segment block of the steel box girder to the corresponding position, bolt T-shaped steel to the lower flange plate of the longitudinal L-shaped connecting rib plate, bolt the longitudinal diaphragm of the steel box girder to the web plate of the T-shaped steel, arrange circular steel bars between the connecting rib plates, cast ultra-high performance concrete and cure to form; (8) Connection of steel box girder segments in the longitudinal direction: Bolt the longitudinal stiffening ribs of two adjacent steel box girder segments, arrange annular steel bars between the two transverse connecting ribs, pour ultra-high performance concrete and cure to form; (9) Welding of steel cover plates on wet joints of bridge decks: After the longitudinal and transverse ultra-high performance concrete wet joints of the bridge decks are formed, steel cover plates are welded on the edges of each bridge deck on the wet joints to seal them; (10) Circular construction was carried out to complete the construction of the steel box girder bridge.

10. The construction method of the assembled urban large-chamber steel box girder bridge structure according to claim 9 is characterized in that: In steps (5) and (6), the connection and fixation of the left and right segment blocks of the steel box girder and the bottom plate of the middle segment block of the steel box girder and the arrangement of the longitudinal diaphragm of the steel box girder can be formed by two methods: The first method: the left section block of the steel box girder, the right section block of the steel box girder and the bottom plate of the middle section block of the steel box girder are bolted and fixed with T-shaped steel, the partition connecting rod is connected and fixed with the T-shaped steel web by bolts, and then the annular steel bars are arranged, and the ultra-high performance concrete is poured and cured to form; The second method: a wet joint formwork is arranged between the left and right segment blocks of the steel box girder and the bottom plate of the middle segment block of the steel box girder. A T-shaped steel is first bolted on one side on the lower flange plate of the L-shaped connecting ribs of the left and right segment blocks of the steel box girder. The upper part of the partition connecting rod is bolted to the web of the T-shaped steel and fixed in position, and the lower part is extended into the wet joint. Then, ultra-high performance concrete is poured in the lower wet joint and cured. The formwork is removed after forming.

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