CN109338866B

CN109338866B - Ultra-light combined beam structure suitable for large-span bridge and construction method thereof

Info

Publication number: CN109338866B
Application number: CN201811354896.8A
Authority: CN
Inventors: 邵旭东; 李玉祺; 曹君辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2024-03-19
Anticipated expiration: 2038-11-14
Also published as: CN109338866A

Abstract

The invention discloses an ultra-light combined beam structure suitable for a large-span bridge and a construction method thereof, wherein the ultra-light combined beam structure is mainly formed by combining steel beams and bridge deck units, and the bridge deck units comprise profile steel-UHPC light combined bridge deck and peripheral seam structures; the section steel-UHPC light combined bridge deck is formed by combining a UHPC plate and section steel, and the section steel is used as a longitudinal rib and is arranged at the bottom of the UHPC plate; the longitudinal and transverse seam structures are T-shaped seams. The invention has the advantages of low manufacturing cost, little welding quantity, extremely reduced fatigue cracking risk, higher bending moment of inertia, reduced cracking risk of the bridge deck, avoidance of cracking in a high tensile stress area, avoidance of shrinkage cracking, convenient matching of the longitudinal and transverse rigidity of the bridge deck, lightening of the dead weight of the bridge deck, low requirement on the field hoisting capacity, reduction of construction risk, small field pouring quantity, small roughening workload, no need of binding reinforcing steel bars at joints, simple operation, easy construction and the like.

Description

Ultra-light combined beam structure suitable for large-span bridge and construction method thereof

Technical Field

The invention belongs to the technical field of bridge members and construction thereof, and particularly relates to an ultra-light combined beam structure suitable for a large-span bridge and a construction method thereof.

Background

The traditional steel-concrete composite beam has reasonable stress, fully utilizes the advantages of steel tension and concrete compression, and has better combined performance than the simple superposition of the two materials, thereby having good technical and economic benefits. However, with the increase of bridge span, when the steel-concrete composite beam is applied to continuous system bridges and large-span flexible system bridges, the risk of tension cracking of upper edge concrete is faced in a hogging moment area, and the effect of conventional anti-cracking measures is not ideal.

In the traditional combined beam cable-stayed bridge, the concrete bridge deck plate bears the horizontal component force from the stay ropes, so that the average thickness is thicker and is generally larger than 26cm, the ratio of the bridge deck plate to the total weight of the main beam is larger, often more than 70%, the overweight main beam is a main factor for limiting the upper limit of the bridge span, and the economic span upper limit of the combined beam cable-stayed bridge is 600m when the span of the steel-concrete continuous system bridge exceeds 110 m. A large number of engineering practices at home and abroad show that the steel-concrete composite girder bridge has the common problems of overlarge dead weight of the girder and easy cracking of a concrete bridge deck, and the steel-concrete composite girder bridge has long trouble to the engineering world and becomes a main technical bottleneck for restricting the further development of the traditional steel-concrete composite girder.

The root cause of the problems in the traditional steel-concrete composite beam is the limitation of the mechanical properties of the common concrete material, the common concrete material has the mechanical characteristics of small cracking stress, low tensile strength and obvious shrinkage creep effect, and the restraint tensile stress is extremely easy to generate under the shrinkage creep effect and the temperature effect, so that the concrete bridge deck has the cracking risk in operation.

Ultra-high performance concrete (UHPC ) has excellent mechanical properties, and the development of bridge building structures tends to be large-span and light. However, because the cost of the UHPC is higher, the economic advantage of the UHPC cannot be fully utilized by adopting a thicker plate thickness, and in an actual bridge structure, the longitudinal and transverse stress of the bridge deck is different, generally one direction is mainly (generally, the longitudinal direction), and only adopting a flat pure UHPC plate as the bridge deck tends to cause excessive redundancy in one direction, material waste and economic deviation; meanwhile, as the steel fibers at the joint between the new and old UHPC interfaces are discontinuous, the tensile strength is reduced, if the traditional vertical plane joint is adopted, the joint is easy to crack due to weak interface and higher tensile stress at the joint, so that the joint structure is optimized for the bridge deck of the steel-UHPC composite beam, and the cracking risk of the joint is reduced.

Disclosure of Invention

The invention aims to solve the technical problems of overcoming the defects and the shortcomings in the prior art, and providing an ultra-light combined beam structure suitable for a large-span bridge, which can greatly reduce the dead weight of a bridge deck, increase the spanning capacity of the combined beam and reduce the cracking risk.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the ultra-light combined beam structure is mainly formed by combining a lower steel beam and an upper bridge deck unit, wherein the bridge deck unit comprises a profile steel-UHPC light combined bridge deck and a peripheral seam structure; the section steel-UHPC light combined bridge deck is mainly formed by combining a UHPC plate and section steel, wherein the section steel is used as a longitudinal rib and is arranged along a longitudinal bridge direction and is arranged at the bottom of the UHPC plate; both the longitudinal and transverse seam configurations are T-shaped seams consisting of stepped notches at the upper edges of the UHPC boards and gaps between adjacent UHPC boards.

Furthermore, the steel beams are PK beams, steel box beams, steel plate beams or steel truss beams for canceling orthotropic steel bridge decks, and only the longitudinal partition plates, the middle webs, the side webs or the longitudinal beams and the upper flange plates with certain widths for connecting the steel-UHPC light combined bridge deck units are arranged above the transverse partition plates or the transverse beams.

Further, the UHPC plate is a flat plate or a flat plate subjected to thickening treatment at the joint with the profile steel, the average thickness of the UHPC plate is not more than 140mm, and the average thickness does not contain joints.

Further, the section steel is H-shaped steel, I-shaped steel, channel steel, angle steel, T-shaped steel, flat-bulb steel or U-shaped steel.

Further, the height of the profile steel is not more than 400mm, and the transverse spacing is 300-1000 mm.

Further, the height of the T-shaped seam stepped notch is 30-70% of the height of the UHPC board.

Further, the longitudinal joint is reserved by sealing rubber strips which are formed by overlapping steel sections-UHPC light combined bridge deck plates on upper flanges of longitudinal partition plates, middle webs, side webs or longitudinal beams, the section steel at the joint of the longitudinal partition plates, the middle webs, the side webs or the upper flanges of the longitudinal beams is approximately -shaped, the upper and lower flange plates of the section steel face to the outer side to form the boundary of two sides of the joint, and the upper flanges of two adjacent section steel at the joint are welded and transversely connected with short steel bars.

Further, the transverse joint is formed by reserving sealing rubber strips of the section steel-UHPC light combined bridge deck plates on the transverse partition plates or the upper flange plates of the cross beams, the upper flanges of two adjacent section steel joints are welded with longitudinal connecting short steel bars, and section steel webs at the joint are connected through transverse steel plates or UHPC transverse stiffening plates.

Further, the T-shaped joint structure is reserved for a certain length along the top layer reinforcing steel bars in the joint width direction and is staggered.

The construction method of the ultra-light combined beam structure comprises the following steps: one of the following two construction methods is adopted:

the first construction method comprises the following steps: the lower steel beam and the upper section steel-UHPC light combined bridge deck unit are prefabricated separately and then spliced on site to form an ultra-light combined beam structure, and the method comprises the following steps:

s1: respectively completing prefabrication of the section steel-UHPC light combined bridge deck unit and the steel beam;

s2: the steel girder longitudinal partition plates, the middle webs, the side webs or the longitudinal beams are welded with the upper flange plates of the transverse partition plates or the transverse beams, and rubber strips for sealing are arranged at the outer sides of the upper flange plates of the steel girder longitudinal plates and the transverse beams;

s3: installing a profile steel-UHPC light combined bridge deck unit, placing the profile steel-UHPC light combined bridge deck unit on a rubber strip, and then placing reinforcing steel bars along the width direction of the joint;

s4: pouring an ultra-high performance concrete layer to embed the studs and the reinforcing steel bars in the ultra-high performance concrete, so that the section steel-UHPC light combined bridge deck units are combined into a whole, and the construction is completed;

the second construction method comprises the following steps: the lower steel beam and the upper section steel-UHPC light combined bridge deck unit are integrally prefabricated to form ultra-light combined beam sections, and then splicing among the sections is completed on site, and the ultra-light combined beam sections comprise the following steps:

s1: the steel section-UHPC light combined bridge deck unit and the steel beam are integrally prefabricated, and the steel section-UHPC light combined bridge deck unit is connected with shear bolts on the upper flange plate of the diaphragm plate or the cross beam through the longitudinal steel beam diaphragm plate, the middle web plate, the side web plate or the longitudinal steel beam to form an ultra-light combined beam of one section, and the position of a transverse joint between the sections is reserved;

s2: installing the segments of the ultra-light combined beam structure, and then placing longitudinal reinforcing steel bars along the longitudinal direction of the bridge along the transverse joints;

s3: and pouring the ultra-high performance concrete layer to enable the studs and the reinforcing steel bars to be embedded in the ultra-high performance concrete, so that the sections of the ultra-light combined beam structure are combined into a whole, and the construction is completed.

Compared with the prior art, the invention has the remarkable effects that:

the invention provides an ultra-light combined beam structure suitable for a large-span bridge, which firstly provides a double-combined structure of a main beam and a bridge deck plate combined, and aims to greatly reduce the dead weight of the main beam. The ultra-light combined beam structure has the following advantages:

(1) In the traditional steel-concrete composite beam, because the shrinkage of common concrete is larger, in order to avoid shrinkage cracking, the steel and the common concrete slab are generally required to be prefabricated separately, concrete at a pouring joint is reappeared to form a whole, the stress is that the steel beam is stressed first and then the steel beam is stressed, and the steel and the UHPC slab in the steel-UHPC light composite bridge deck slab are prefabricated integrally, so that the mechanical property of the steel-UHPC light composite bridge deck slab is better.

(2) The section steel in the section steel-UHPC light combined bridge deck has the main functions of acting as a stiffening rib of the UHPC plate and bearing the tensile stress of the lower edge of the plate, has smaller span and is a diaphragm (beam) interval, so the height of the section steel is not required to be very high, and is generally not more than 400mm. The steel longitudinal ribs are arranged on the bottom surface of the UHPC board, so that the mechanical properties of the steel and UHPC materials are fully exerted, the utilization rate of the materials is higher, and the bending rigidity is higher; as the finished section steel is adopted in the bridge deck plate, the manufacturing cost is low, the bridge deck plate has higher bending moment of inertia, and the cracking risk of the bridge deck plate is reduced. Compared with the traditional orthotropic steel bridge deck, the welding amount is small, and the risk of fatigue cracking is greatly reduced.

(3) The bridge deck UHPC material consumption is small, the bending rigidity is high, the requirements of longitudinal and transverse stress of the bridge deck are met, the dead weight of the bridge deck is obviously reduced, the dead weight of the main beam structure is obviously reduced, and the spanning capacity of the combined beam is increased. Compared with the traditional steel-concrete composite beam, the self weight of the main beam can be reduced by 40-50%, and compared with a pure steel beam, the self weight of the main beam is increased by 10-20%, and the span can reach 2000 meters.

(4) The T-shaped joint structure on the periphery of the bridge deck unit arranges the joint position of the top layer at a position far away from the diaphragm plate (the cross beam), so that the joint position avoids a hogging moment peak tensile stress area, and meanwhile, due to the arrangement of the upper and lower steps of the T-shaped joint, the contact surface of the cast-in-situ joint UHPC at the joint and the lower steps is UHPC, the contact surface is longer, the horizontal friction resistance between the contact surfaces can retard the shrinkage of the UHPC, the shrinkage crack of the interface is avoided, and leakage diseases are avoided.

(5) The bridge deck plate and the section steel can be conveniently matched with the longitudinal rigidity and the transverse rigidity by adjusting the sizes of the bridge deck plate and the section steel and the transverse spacing of the section steel.

(6) Because the bridge deck slab is prefabricated in a factory, only longitudinal and transverse wet joints are required to be poured on site, the in-situ pouring quantity is small, the joints only need to be roughened on the steps of the top layer, the workload is small, the reinforcing steel bars at the joints do not need to be bent and bound, and the bridge deck slab does not need to be lapped or welded, has simple operation, small equipment investment, is simple and easy to operate, and has lower requirements on labor quality and process.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1-a cross-sectional view of an example of an application of the present invention with a lower steel beam as the PK beam of a non-orthotropic steel bridge deck;

FIG. 2-is a cross-sectional view of an example of the application of the present invention with a lower steel girder being a steel box girder with an orthotropic steel deck plate removed;

FIG. 3-is a cross-sectional view of an example of the application of the present invention with a lower steel beam being a steel plate beam of a steel deck of a non-orthotropic bridge deck;

FIG. 4-is a cross-sectional view of an example of an application of the present invention in which the lower steel girder is a steel truss girder with no orthotropic steel deck;

FIG. 5-is a top view of a steel beam in an example of the application of the present invention;

FIG. 6-is a schematic structural view (cross section) of a steel section-UHPC lightweight composite bridge deck unit of example 1;

FIG. 7-is a cross-sectional view taken along section A-A in FIG. 6;

FIG. 8-is a cross-sectional view of section B-B of FIG. 6;

FIG. 9-is a schematic structural view (cross section) of a steel section-UHPC light composite bridge deck unit with a UHPC plate being subjected to a thickening treatment at the junction with the steel section;

FIG. 10-is a cross-sectional view taken along section A-A in FIG. 9;

FIG. 11-is a cross-sectional view taken along section B-B in FIG. 9;

FIG. 12-schematic top layer construction of a longitudinal seam of a steel-UHPC lightweight composite bridge deck unit of FIG. 6 (top view, D-D section of FIG. 14);

FIG. 13-is a schematic view of the bottom structure of a longitudinal seam of a lightweight composite bridge deck unit of the steel-UHPC type of FIG. 6 (top view, section E-E of FIG. 14);

fig. 14-is a cross-sectional view of section C-C of fig. 12, 13 (showing the bottom reinforcement bar in the UHPC board);

FIG. 15-is a schematic top layer construction of a transverse seam of the steel-UHPC lightweight composite bridge deck unit of FIG. 6 (top view, H-H section of FIG. 17);

FIG. 16-is a schematic view of the underlying structure of a transverse seam of a steel-UHPC lightweight composite bridge deck unit of FIG. 6 (top view, section I-I of FIG. 17);

FIG. 17-is a cross-sectional view of section F-F of FIGS. 15 and 16;

fig. 18-is a cross-sectional view of section G-G of fig. 15 and 16.

Legend description:

UHPC board; 2. section steel; 3. a short peg; 4. an asphalt pavement layer; 5. cutting off section steel of the upper and lower flange plates at one side at the longitudinal T-shaped joint; 6. the UHPC board top layer steps at the longitudinal T-shaped joint; 7. a bottom step of the UHPC board at the longitudinal T-shaped joint; transverse reinforcing steel bars at the inner top layer of the UHPC precast slab; 9. top layer transverse reinforcing steel bars at the longitudinal T-shaped joints; 10. top longitudinal steel bars at the longitudinal T-shaped joints; 11. a bolt at the joint; 12. longitudinal bulkheads (middle webs, side webs or stringers); 13. upper flange plates of longitudinal partition plates (middle webs, side webs or stringers); 14. sealing the rubber strip; 15. UHPC is cast in situ at the joint; 16. the transverse T-shaped joint is subjected to groove treatment; 17. transverse stiffening plates at the transverse T-shaped joints; 18. pegs on the profile steel web plate at the transverse T-shaped joint; 19. the top layer of the UHPC board is stepped at the transverse T-shaped joint; 20. a bottom step of the UHPC board at the transverse T-shaped joint; longitudinal steel bars at the inner top layer of the UHPC precast slab; 22. top layer longitudinal reinforcing steel bar at transverse T-shaped joint; 23. top layer transverse steel bar at transverse T-shaped joint; 24. diaphragm plate (cross beam); 25. a transverse diaphragm plate (cross beam) upper flange plate; 26. short steel bars are transversely connected between the section steel and the section steel at the longitudinal joint; 27. welding seams for transversely connecting short steel bars between the section steel and the section steel at the longitudinal joints; 28. a short steel bar is longitudinally connected between the section steel and the section steel at the transverse joint; 29. welding seams for longitudinally connecting short steel bars between the section steel and the section steel at the transverse joints; PK steel girder; 31. a steel box girder; 32. a steel plate girder; 33. steel truss girder; 34. a small longitudinal beam; 35. reserving length of a top layer transverse reinforcing steel bar at a longitudinal T-shaped joint; 36. the length of the top longitudinal steel bar at the transverse T-shaped joint is reserved.

Detailed Description

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown, for the purpose of illustrating the invention, but the scope of the invention is not limited to the specific embodiments shown.

Unless defined otherwise, all technical and scientific terms used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the scope of the present invention.

Referring to fig. 1 to 8 and fig. 12 to 18, an ultra-light composite beam structure for a large-span bridge according to the present embodiment is mainly composed of a lower steel beam and an upper section steel-UHPC light composite deck unit.

The steel beams can be PK steel beams 30, steel box beams 31, steel plate beams 32 or steel truss beams 33 of the steel bridge deck plates without orthotropic property, and only the upper flange plates 13 and 25 of the longitudinal partition plates (middle webs, side webs or stringers) 12 and the transverse partition plates (beams) 24 with certain widths are arranged above the longitudinal partition plates (middle webs, side webs or stringers) for connecting the steel-UHPC light combined bridge deck plate units.

The section steel-UHPC light combined bridge deck unit comprises a section steel-UHPC light combined bridge deck and a peripheral seam structure, wherein the section steel-UHPC light combined bridge deck consists of a UHPC plate 1, a section steel 2 and short bolts 3 for connection.

The UHPC plate 1 in the section steel-UHPC light combined bridge deck unit can be a flat plate (shown in figures 6-8) or a flat plate (shown in figures 9-12) subjected to thickening treatment at joints, the average thickness (without joints) of the UHPC plate is no more than 140mm, transverse reinforcing steel bars 8 on the inner top layer of the UHPC precast slab and longitudinal reinforcing steel bars 21 on the inner top layer of the UHPC precast slab are required to be arranged in the UHPC plate 1, the diameters of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars are 10-20 mm, and the spacing between the reinforcing steel bars is 70-300 mm.

The UHPC board 1 in the section steel-UHPC light combined bridge deck unit is arranged above the section steel 2, the section steel 2 mainly acts as a stiffening rib of the UHPC board 1 and bears the action of tensile stress, the section steel 2 is generally H-shaped steel, I-shaped steel, channel steel, angle steel, T-shaped steel, flat-bulb steel or U-shaped steel, the section steel 2 is longitudinally arranged, the transverse distance is 300 mm-1000 mm, the width of the section steel 2 is generally 100 mm-400 mm, and the section steel 2 is smaller in height and generally not more than 400mm due to the action of the stiffening rib.

The UHPC plate 1 in the section steel-UHPC light combined bridge deck unit is connected with the section steel 2 through short bolts 3, the diameter of the short bolts 3 is 9-25 mm, the height of the short bolts 3 is 25-80 mm, the short bolts 3 are welded on the upper flange plate of the section steel 2, 2-4 rows of bolts are transversely and generally arranged above each section steel 2, the interval is 50-200 mm, and the longitudinal interval is 100-300 mm.

The longitudinal and transverse seam structures in the profile steel-UHPC light combined bridge deck unit are T-shaped seams, the step height of the top layer is generally half of the height of the UHPC board, and the total height of the seams is the sum of the height of the steel-UHPC light combined bridge deck and the height of the rubber strip for sealing; the width of the top layer ladder is wider so as to avoid a high tensile stress area of a hogging moment, avoid low tensile strength and premature crack occurrence caused by discontinuous steel fibers at the interface of the new UHPC and the old UHPC, and avoid shrinkage crack due to the fact that the interface of the wet seam between the top layer ladder and the bottom layer ladder is UHPC.

The longitudinal seam in the section steel-UHPC light combined bridge deck unit is formed by reserving sealing rubber strips 14 on upper flange plates 13 of longitudinal partition plates (middle webs, side webs or longitudinal beams) of the section steel-UHPC light combined bridge deck units, at the moment, the section steel at the joint of the upper flanges of the longitudinal partition plates in the prefabricated plates needs to be removed from the upper flange plates and the lower flange plates at one end, short steel bars 26 are transversely connected between the section steel and the section steel at the welding longitudinal seam of two adjacent section steel upper flanges of the seam, the longitudinal distance between the section steel and the section steel at the longitudinal seam is 100-1000 mm, pegs 11 at the joint are welded on the upper flange plates of the longitudinal partition plates, the step width of the top layer is 400-1200 mm, and the section steel needs to be subjected to roughening treatment before pouring; the bottom layer ladder is reserved with the width of 200-600 mm and is flat-mouth, and roughening treatment is not needed before pouring. For bridges with the stringers 34, they can rest on the upper flange plates of the stringers 34, and for bridges without longitudinal bulkheads and stringers, they can rest directly on the upper flange plates of the edge webs.

The transverse joint in the section steel-UHPC light combined bridge deck unit is reserved by a sealing rubber strip 14 which is lapped on a transverse baffle (beam) upper flange plate 25, a section steel and a section steel upper flange at the joint adjacent two section steel upper flanges are welded and are longitudinally connected with a short steel bar 28, the section steel and the section steel longitudinal connection short steel bar 28 at the transverse joint are transversely distributed to form 2-4 sections of each section steel upper flange plate, a joint stud 11 is welded on the transverse baffle upper flange plate, a transverse stiffening plate 17 (UHPC or a steel plate) at the joint is connected between section steel webs at the joint through a transverse T-shaped joint, the transverse stiffening plate 17 at the transverse T-shaped joint is connected with the webs through short studs, wherein the section steel lower flange plate in the section steel-UHPC light combined bridge deck is not required to be welded with the transverse baffle (beam) upper flange plate 25, the top layer step height is the bridge deck plate height, the width is 400-1200 mm, and the section steel webs are required to be subjected to a flat-type front roughening treatment; the reserved width of the bottom layer ladder is 200-600 mm, if the width of the transverse joint is smaller, the arrangement of the studs on the upper flange plate of the diaphragm plate is limited, and a groove can be formed from the upper flange plate of the section steel to the lower flange plate.

The T-shaped seam structure in the profile steel-UHPC light combined bridge deck unit is characterized in that the T-shaped seam structure is adopted, steel bars do not need to be bent, lap joint or welding is not needed between the steel bars, a certain length is reserved for the transverse steel bars 8 on the inner top layer of the UHPC precast slab in the width direction of the seam and the longitudinal steel bars 21 on the inner top layer of the UHPC precast slab are required to be staggered, the reserved length 35 of the transverse steel bars on the top layer of the longitudinal T-shaped seam and the reserved length 36 of the longitudinal steel bars on the top layer of the transverse T-shaped seam are required to be greater than 10 times of the diameter of the steel bars, the staggered length is required to be not less than 7.5 times of the diameter of the steel bars, the staggered length is required to be not less than 1.5 times of the maximum length of steel fibers, and meanwhile, parallel longitudinal reinforcing steel bars and transverse reinforcing steel bars are required to be placed in the width direction of the seam for larger spacing of the steel bars.

The UHPC board 1 and the cast-in-situ UHPC 15 at the joint are formed by casting ultra-high performance concrete, wherein the ultra-high performance concrete is concrete which contains steel fibers and no coarse aggregate, has compressive strength not lower than 100MPa and axial tensile strength not lower than 5 MPa. An asphalt pavement layer is arranged above the ultra-high performance concrete layer.

Compared with a 170mm UHPC flat bridge deck of the Nanjing five bridge, the adoption of the bridge deck is 80mm UHPC plate+HW200×200 section steel-UHPC light combined bridge deck, the dead weight of the bridge deck structure layer is reduced by 20%, the manufacturing cost of the bridge deck structure layer is reduced by 10%, however, the longitudinal rigidity of the bridge deck is 2.53 times that of the Nanjing five bridge, and the bridge deck has obvious technical economy.

The construction method of the ultra-light combined beam structure suitable for the large-span bridge comprises the following steps of:

s1: prefabricated section steel-UHPC light combined bridge deck unit and girder steel: fixing the section steel 2 in position, connecting a template of a transverse stiffening plate 17 at a transverse T-shaped joint between section steel at the joint with the section steel 2, manufacturing a template of a UHPC bridge deck unit, welding short pegs 3 on a flange plate on the section steel 2, placing bound reinforcing steel bars, reserving reinforcing steel bars with a certain length outside the template, pouring UHPC, and curing to form the section steel-UHPC light combined bridge deck unit; prefabricating PK steel beams 30, steel box girders 31, steel plate girders 32 or steel truss girders 33, prefabricating lower steel beams according to a conventional steel-concrete combined bridge construction method, and welding shear studs on upper flange plates 13 of longitudinal steel beam partition plates (middle webs, side webs or longitudinal beams) and upper flange plates 25 of transverse partition plates (transverse beams);

s2: and (3) erecting PK steel beams 30, steel box beams 31, steel plate beams 32 or steel truss beams 33 and prefabricated profile steel-UHPC light combined bridge deck plates: performing on-site splicing procedures of steel beams according to a conventional steel-concrete combined bridge construction method, hoisting prefabricated section steel-UHPC light combined bridge deck units, placing the prefabricated section steel-UHPC light combined bridge deck units on sealing rubber strips 14 of upper flange plates of longitudinal partition plates (middle webs, side webs or longitudinal beams) and transverse partition plates (transverse beams), adding small longitudinal beams 34 for a bridge without the longitudinal partition plates, placing the bridge without the longitudinal partition plates on the upper flange plates of the small longitudinal beams or directly placing the bridge deck units on the upper flange plates of the side webs, and welding longitudinal and transverse short steel bars on the upper flange plates of the section steel at joints;

s3: pouring wet joints: roughening the top layer steps 6 and 19 of the UHPC plate at the longitudinal T-shaped joint of the plain mouth shape, placing parallel top layer transverse reinforcing steel bars 9 and 22 at the longitudinal T-shaped joint along the width direction of the joint, and finally pouring ultra-high performance concrete to embed the bolts, reserved steel bars and reinforcing steel bars in the ultra-high performance concrete so that the orthotropic UHPC light bridge deck units are combined into a whole and stressed together;

s4: paving an asphalt pavement layer 4: roughening the top surface of the ultra-high performance concrete of the prefabricated bridge deck and the cast-in-situ joint, and paving an asphalt pavement layer 4 above the roughened top surface to finish the construction of the steel-UHPC combined beam bridge deck structure.

The foregoing is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. The ultra-light combined beam structure is mainly formed by combining a lower steel beam and an upper bridge deck unit, and is characterized in that the bridge deck unit comprises a profile steel-UHPC light combined bridge deck and a peripheral seam structure; the section steel-UHPC light combined bridge deck is mainly formed by combining a UHPC plate and section steel, wherein the section steel is used as a longitudinal rib and is arranged along a longitudinal bridge direction and is arranged at the bottom of the UHPC plate; the longitudinal joint structure and the transverse joint structure are T-shaped joints, and the T-shaped joints are formed by stepped notches at the upper edges of the UHPC boards and gaps between adjacent UHPC boards; the longitudinal joint is reserved by sealing rubber strips of the steel-UHPC light combined bridge deck plate which are lapped on the upper flanges of the longitudinal partition plates, the middle web plates, the side web plates or the longitudinal beam, the section steel at the joint of the longitudinal partition plates, the middle web plates, the side web plates or the upper flanges of the longitudinal beam is approximately -shaped, the upper and lower flange plates of the section steel face to the outer side to form the boundary of two sides of the joint, and the two adjacent upper flanges of the section steel are welded and transversely connected with short steel bars; the transverse joint is formed by reserving sealing rubber strips of a profile steel-UHPC light combined bridge deck plate on a diaphragm plate or a beam upper flange plate, welding longitudinal connecting short steel bars on the upper flanges of two adjacent profile steels at the joint, and connecting profile steel webs at the joint through transverse steel plates or UHPC transverse stiffening plates.

2. The ultra-lightweight composite beam structure according to claim 1, wherein: the steel beam is a PK steel beam, a steel box beam, a steel plate beam or a steel truss beam which cancels orthotropic steel bridge decks, and only a certain width is arranged above a longitudinal partition plate, a middle web plate, a side web plate or a longitudinal beam and a transverse partition plate or a transverse beam for connecting an upper flange plate of a profile steel-UHPC light combined bridge deck unit.

3. The ultra-lightweight composite beam structure according to claim 1, wherein: the UHPC board is a flat board or a flat board subjected to thickening treatment at the joint with the profile steel, the average thickness of the UHPC board is not more than 140mm, and the average thickness does not contain joints.

4. The ultra-lightweight composite beam structure according to claim 1, wherein: the section steel is H-shaped steel, I-shaped steel, channel steel, angle steel, T-shaped steel, flat-bulb steel or U-shaped steel.

5. The ultra-lightweight composite beam structure according to claim 1 or 4, wherein: the height of the section steel is not more than 400mm, and the transverse spacing is 300-1000 mm.

6. The ultra-lightweight composite beam structure according to claim 1, wherein: the height of the T-shaped seam stepped notch is 30-70% of the height of the UHPC board.

7. The ultra-lightweight composite beam structure according to claim 1 or 6, wherein: the T-shaped joint structure is reserved for a certain length along the top layer reinforcing steel bars in the joint width direction and is staggered.

8. A construction method of the ultra-light composite beam structure according to any one of claims 1 to 7, characterized in that: one of the following two construction methods is adopted: