CN109610310B

CN109610310B - Profile steel-UHPC combined bridge deck structure suitable for cantilever state and construction method thereof

Info

Publication number: CN109610310B
Application number: CN201811520800.0A
Authority: CN
Inventors: 邵旭东; 李玉祺; 曹君辉
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2018-12-12
Filing date: 2018-12-12
Publication date: 2023-07-25
Anticipated expiration: 2038-12-12
Also published as: CN109610310A

Abstract

The invention discloses a section steel-UHPC combined bridge deck structure suitable for cantilever state and a construction method thereof, wherein a section steel-UHPC light combined bridge deck is mainly formed by combining section steel, steel strips welded with short studs and UHPC plates, the section steel is used as longitudinal ribs and is arranged at intervals along the transverse bridge direction, and the steel strips are arranged on upper flange plates of the section steel at intervals along the bridge direction; the longitudinal and transverse seam structures are T-shaped seams. The invention adopts finished steel, has low manufacturing cost and small welding quantity, greatly reduces the risk of fatigue cracking, simultaneously has higher bending moment of inertia, reduces the cracking risk of the bridge deck, enhances the transverse tensile capacity of the bottom surface of the bridge deck, converts the UHPC at the longitudinal joint from tension into compression, ensures that the bridge deck can not crack in the operation stage without configuring prestress in the transverse cantilever state, simultaneously can avoid cracking in a high tensile stress area, avoids shrinkage cracking, lightens the dead weight of the bridge deck, and is simple to operate and easy to construct.

Description

Profile steel-UHPC combined bridge deck structure suitable for cantilever state and construction method thereof

Technical Field

The invention belongs to the technical field of bridge members and construction thereof, and particularly relates to a cantilever-state section steel-UHPC combined bridge deck structure 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, because the concrete bridge deck plate bears the horizontal component force from the stay cable, 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, so that the upper limit of the economic span of the combined beam cable-stayed bridge is 600m when the span of the steel-concrete continuous system girder bridge exceeds 110m, and for the suspension bridge, the dead weight of the stiffening girder is completely borne by the main cable system, and the ratio of the traditional combined beam to the total weight of the main beam is about twice that of the steel beam, so that the combined beam is uneconomical. 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 fundamental reasons for the problems in the traditional steel-concrete composite beam are the limitation of the mechanical properties of the common concrete material, the compressive strength of the common concrete material is limited, the tensile strength is low, the shrinkage and creep effects and the restraint tensile stress are extremely easy to generate under the action of temperature, so that the traditional steel-concrete composite beam concrete bridge deck has larger thickness, great self weight and cracking risk in the operation process, thereby limiting the development of the traditional steel-concrete composite beam concrete bridge deck.

The Ultra-high performance concrete (Ultra-High Performance Concrete, UHPC for short) has excellent mechanical properties, higher elastic modulus, compression resistance and tensile strength, excellent crack resistance, zero post-shrinkage after high-temperature steam curing, and greatly reduced creep coefficient of only 0.2, so that the creep deformation is very small, and the cracking risk of the concrete bridge deck in the hogging moment area is basically eliminated. 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.

When the steel girder supporting condition is in the middle area (for example, the stay cable 35 of the five bridge in Nanjing is arranged in the middle area of the girder, as shown in fig. 1), the steel girder 36 is in a transversely cantilever state, and the bridge deck is transversely pulled, and the transverse tensile stress is higher due to the influence of constant load and active load, so that the bridge deck is ensured not to generate macroscopic cracks (namely, the maximum crack width is not more than 0.05 mm) under the action of the transverse tensile stress, and the transverse prestress is arranged in the conventional way. However, in order to arrange the prestressed tendons, the bridge deck has larger section size. It is therefore desirable to optimize the deck structure so that it can still meet the requirement of no macroscopic cracking without configuring transverse prestressing.

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, providing the section steel-UHPC combined bridge deck structure which has a simple structure and is convenient to construct and is suitable for cantilever state, greatly reducing the dead weight of the bridge deck, increasing the spanning capacity of the combined beam and simultaneously reducing the cracking risk of the bridge deck under the condition of not configuring transverse prestress.

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

a section steel-UHPC combined bridge deck structure suitable for cantilever state, the bridge deck structure comprises a section steel-UHPC light combined bridge deck plate and a peripheral seam structure; the section steel-UHPC light combined bridge deck is mainly formed by combining section steel, steel laths welded with short pegs and UHPC plates; the section steel is used as a longitudinal rib and is arranged at intervals along the transverse bridge direction and is arranged at the bottom of the UHPC board; the steel plate strips are vertical to the section steel and are arranged on the upper flange plate of the section steel at intervals along the longitudinal bridge direction, and the steel plate strips are connected with the UHPC plate through short pegs; the longitudinal and transverse seam structures are T-shaped seams.

Further, the UHPC board is a flat board having an average thickness of no more than 150mm, the average thickness being free of seams.

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, the height of the section steel is not more than 400mm, and the transverse interval is 300 mm-1000 mm.

Further, the length of the steel plate strip is equal to the width of the profile steel-UHPC light combined bridge deck, and the width of the steel plate strip is 50-150 mm.

Further, the steel plate strips are provided with the incisions at the longitudinal joints, so that the steel plate strips at the two sides of the longitudinal joints are staggered at the incisions and spliced into a whole, and short studs are welded on the steel plate strips provided with the incisions above the joints.

Further, short studs are welded on the upper flange plate of the section steel and are used for being connected with the UHPC plate, and the steel plate strip is paved at the gap between the adjacent short studs.

Further, a reinforcing mesh is arranged in the UHPC board, and is positioned above the steel plate strips, and consists of longitudinal reinforcing bars and transverse reinforcing bars which are paved in a staggered manner.

Further, the T-shaped joint is formed by a stepped notch at the upper edge of the UHPC board and a gap between adjacent UHPC boards, and the height of the top layer step 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 slab on the diaphragm plate or the upper flange plate of the beam, the upper flanges of two adjacent section steel of the joint are welded with longitudinal connecting short steel bars, and section steel webs at the joint are connected through transverse stiffening plates.

The construction method of the section steel-UHPC combined bridge deck structure suitable for the cantilever state adopts one of the following two construction methods:

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 a section steel-UHPC combined bridge deck structure suitable for a cantilever state, which can greatly reduce the dead weight of a main beam, so that the section steel-UHPC combined bridge deck structure can still meet the requirement of no macroscopic crack (the maximum crack width is not more than 0.05 mm) under the condition of no transverse prestress. The combined bridge deck 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 steel plate strip welded with the short studs enhances the tensile capacity of the bottom surface of the UHPC plate, so that the bridge deck in a cantilever state cannot crack under the action of constant load and live load under the condition of no transverse prestress.

(4) The steel plate strip is provided with the incisions at the longitudinal joints, so that the steel plate strips at the two sides of the joints are arranged in a staggered mode and can be spliced into a whole, short pegs are welded on the steel plate strip provided with the incisions above the joints, and the stress state of the UHPC at the original longitudinal joints can be converted from tension to compression due to the fact that the steel plate strips at the two sides bear reverse tensile stress, so that the cracking risk of the UHPC is reduced.

(5) 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.

(6) 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.

(7) 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.

(8) 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-is a cross-sectional view of a five-axle box girder in Nanjing;

FIG. 2 is a schematic structural view (top view) of a steel-UHPC lightweight composite bridge deck unit adapted for use in cantilever configuration in accordance with an embodiment of the present invention;

FIG. 3-is a cross-sectional view taken along section A-A in FIG. 2;

FIG. 4-is a cross-sectional view of section B-B of FIG. 2;

FIG. 5-is a cross-sectional view taken along section C-C of FIG. 2;

FIG. 6-schematic top layer structure of longitudinal joint of a lightweight composite bridge deck unit of section steel-UHPC suitable for cantilever in FIG. 2 (top view, F-F section in FIGS. 12 and 13, longitudinal bars in the joint and UHPC plate are not shown);

FIG. 7-is a schematic view of a layer structure in a longitudinal seam of a lightweight composite deck unit of the steel-UHPC lightweight composite deck unit of FIG. 2 adapted for cantilever (top view, G-G section in FIGS. 12 and 13);

FIG. 8-a first version of the large sample of steel sheet bars at the longitudinal seams of FIG. 7 (top view, large sample A of FIG. 7);

FIG. 9-a second version of the large sample of steel sheet bars at the longitudinal seams of FIG. 7 (top view, large sample A of FIG. 7);

FIG. 10-a third version of the large sample of steel sheet bars at the longitudinal seams of FIG. 7 (top view, large sample A of FIG. 7);

FIG. 11-is a schematic view of the longitudinal seam floor structure of a lightweight composite deck unit of the steel-UHPC lightweight composite deck unit of FIG. 2 adapted for cantilever use (top view, H-H section in FIGS. 12 and 13);

FIG. 12-is a sectional view of section D-D of FIGS. 6, 7, 11;

FIG. 13 is a cross-sectional view of section E-E of FIGS. 6, 7 and 11;

FIG. 14-is a schematic top-level structural view of a transverse seam of a lightweight composite deck unit of the steel-UHPC lightweight composite deck unit of FIG. 2 adapted for cantilever use (top view, K-K section in FIGS. 17 and 18);

FIG. 15-is a schematic view of the middle layer structure of a transverse seam of a lightweight composite deck unit of the steel-UHPC lightweight composite deck unit of FIG. 2 adapted for cantilever (top view, L-L section in FIGS. 17 and 18);

FIG. 16-is a schematic view of the underlying structure of a transverse seam of a lightweight composite deck unit of the steel-UHPC lightweight composite deck unit of FIG. 2 adapted for cantilever use (top view, M-M section in FIGS. 17 and 18);

FIG. 17-is a cross-sectional view of section I-I of FIGS. 14, 15 and 16;

fig. 18-is a sectional view of section J-J of fig. 14, 15 and 16.

Legend description:

1. UHPC board; 2. section steel; 3. steel plate strip; 4. short pegs on the upper flange plate of the section steel; 5. a short peg; 6. an asphalt pavement layer; 7. longitudinal steel bars; 8. transverse steel bars; 9. cutting off section steel of the upper and lower flange plates at one side at the longitudinal T-shaped joint; 10. the UHPC board top layer steps at the longitudinal T-shaped joint; 11. a bottom step of the UHPC board at the longitudinal T-shaped joint; 12. top layer transverse reinforcing steel bars at the longitudinal T-shaped joints; 13. top longitudinal steel bars at the longitudinal T-shaped joints; 14. a bolt at the joint; 15. longitudinal bulkheads (middle webs, side webs or stringers); 16. upper flange plates of longitudinal partition plates (middle webs, side webs or stringers); 17. sealing the rubber strip; 18. UHPC is cast in situ at the joint; 19. short pegs on the section steel flange plates or the transverse end plates at the joints; 20. the transverse T-shaped joint is subjected to groove treatment; 21. transverse stiffening plates at the transverse T-shaped joints; 22. pegs on the profile steel web plate at the transverse T-shaped joint; 23. the top layer of the UHPC board is stepped at the transverse T-shaped joint; 24. a bottom step of the UHPC board at the transverse T-shaped joint; 25. top layer longitudinal reinforcing steel bar at transverse T-shaped joint; 26. top layer transverse steel bar at transverse T-shaped joint; 27. diaphragm plate (cross beam); 28. a transverse diaphragm plate (cross beam) upper flange plate; 29. short steel bars are transversely connected between the section steel and the section steel at the longitudinal joint; 30. welding seams for transversely connecting short steel bars between the section steel and the section steel at the longitudinal joints; 31. a short steel bar is longitudinally connected between the section steel and the section steel at the transverse joint; 32. welding seams for longitudinally connecting short steel bars between the section steel and the section steel at the transverse joints; 33. reserving length of a top layer transverse reinforcing steel bar at a longitudinal T-shaped joint; 34. reserving length of top layer longitudinal steel bars at transverse T-shaped joints; 35. stay cables; 36. and a steel girder.

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. 2 to 18, a steel-UHPC composite bridge deck structure suitable for cantilever state of the present embodiment comprises a steel-UHPC light composite bridge deck and a peripheral joint structure, the steel-UHPC light composite bridge deck is composed of a steel 2, a steel strip 3 welded with short studs 5 on the upper surface, a UHPC board 1, and short studs 4 on the upper flange plate of the steel for connecting the steel and the UHPC board.

The UHPC plate 1 in the section steel-UHPC light combined bridge deck plate unit is a flat plate, the average thickness (without joints) of the section steel-UHPC light combined bridge deck plate unit is not more than 150mm, a reinforcing steel mesh is required to be arranged in the UHPC plate 1 and is positioned above the steel lath 3, the reinforcing steel mesh consists of longitudinal reinforcing steel bars 7 and transverse reinforcing steel bars 8 in the UHPC precast plate, the diameters of the longitudinal reinforcing steel bars and the transverse reinforcing steel bars are 10 mm-32 mm, and the spacing between the reinforcing steel bars is 70 mm-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 length of the steel plate strip 3 welded with the short studs 5 is equal to the width of the prefabricated steel-UHPC light combined bridge deck, the width of the steel plate strip is 50-150 mm, and the steel plate strip 3 is positioned on the upper flange plate of the steel 2 through spot welding (or adhesive bonding) on two sides. The steel strip 3 welded with the short studs 5 is paved at the gap between the short studs 4 on the adjacent steel upper flange plates.

The UHPC plate 1 in the section steel-UHPC light combined bridge deck unit is connected with the section steel 2 through short studs 4 on the upper flange plate of the section steel, and is connected with the steel lath 3 through short studs 5. The diameter of the short studs 4 on the upper flange plate of the section steel is 9-25 mm, the height is 25-80 mm, the short studs 4 on the upper flange plate of the section steel of 2-4 rows are transversely arranged above each section steel 2, the distance is 50-200 mm, and the longitudinal distance between the adjacent short studs is 100-300 mm. The short studs 5 are welded on the central line of the steel lath 3 in the length direction, the distance between the adjacent short studs 5 is 100-300 mm, the height of the short studs 5 is 25-80 mm, and the diameter of the short studs 5 is 10-25 mm.

The longitudinal joint and the transverse joint in the profile steel-UHPC light combined bridge deck unit are T-shaped joints, the height of a top layer step (such as a top layer step 10 of a UHPC board at the longitudinal T-shaped joint) is generally 30-70% of the height of the UHPC board, and the total height of the joints is the sum of the height of the steel-UHPC light combined bridge deck and the height of a rubber strip for sealing; the width of the top layer step is wider so as to avoid a high tensile stress area of a hogging moment, avoid the situation that the tensile strength is low and cracks occur prematurely due to the fact that steel fibers of a new UHPC interface are discontinuous at the joint, and avoid shrinkage cracks because the wet joint interface between the top layer step and the bottom layer step (such as the longitudinal T-shaped joint UHPC plate bottom layer step 11 and the transverse T-shaped joint UHPC plate bottom layer step 24) is UHPC.

The longitudinal joint in the section steel-UHPC light combined bridge deck unit is formed by reserving sealing rubber strips 17 on upper flange plates 16 of longitudinal partition plates (middle webs, side webs or longitudinal beams) of the section steel-UHPC light combined bridge deck, 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, a longitudinal T-shaped joint is formed by cutting off section steel 9 of the upper flange plates and the lower flange plates at one side, a longitudinal joint section steel and the section steel are welded at the upper flanges of two adjacent section steel at the joint, short steel bars 29 are transversely connected between the section steel at the longitudinal joint and the section steel, the longitudinal distance between the section steel at the longitudinal joint and the short steel bars 29 is 100-1000 mm, and the pin 14 at the joint is welded at the upper flange plates of the longitudinal partition plates. As shown in fig. 7, the steel plate strip 3 is provided with notches at the longitudinal joints, so that the steel plate strips at two sides of the longitudinal joints are staggered at the notches and can be spliced into a whole, the joint can be any one of fig. 8, 9 or 10, and short studs are welded on the steel plate strip provided with the notches above the joints. The reserved width of the top layer ladder is 400-1200 mm, and the top layer ladder is flat-mouth, and roughening treatment is needed 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 the bridge provided with the small longitudinal beams, the bridge can be placed on the upper flange plates of the small longitudinal beams, and for the bridge without the longitudinal partition plates and the small longitudinal beams, the bridge can be placed on the upper flange plates of the side webs directly.

The transverse joint in the section steel-UHPC light combined bridge deck unit is reserved by a sealing rubber strip 17 which is formed by overlapping a section steel-UHPC light combined bridge deck on a transverse partition plate (beam) upper flange plate 28, a section steel and a section steel longitudinal connecting short steel bar 31 are welded at the transverse joint position of two adjacent section steel upper flanges of the joint, the transverse joint position section steel and the section steel longitudinal connecting short steel bar 31 are transversely distributed to form 2-4 sections of each section steel upper flange plate, a joint position stud 14 is welded on the transverse partition plate upper flange plate, section steel webs at the joint position are connected through a transverse T-shaped joint position transverse stiffening plate 21 (steel plate or UHPC), 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 partition plate (beam) upper flange plate 28, the top layer step height is the bridge deck plate height, the reserved width is 400-1200 mm, and the flat mouth is required to be subjected to roughening treatment before pouring; the reserved width of the bottom step is 200-600 mm, if the width of the transverse joint is smaller, the arrangement of the pegs on the upper flange plate of the transverse partition plate (cross beam) 27 is limited, and a groove can be formed from the upper flange plate to the lower flange plate of the section steel, such as the section steel 20 subjected to groove treatment at the transverse T-shaped joint.

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, the steel bars do not need to be lapped or welded, certain lengths are reserved for the transverse steel bars 8 and the longitudinal steel bars 7 on the top layer in the UHPC precast slab along the width direction of the seam and are required to be staggered, the reserved length 33 of the transverse steel bars on the top layer at the longitudinal T-shaped seam and the reserved length 34 of the longitudinal steel bars on the top layer at the transverse T-shaped seam are required to be larger than 10 times of the diameter of the steel bars, the staggered intersecting length is required to be not smaller than 7.5 times of the diameter of the steel bars, the staggered distance is required to be not smaller than 1.5 times of the maximum length of steel fibers, and meanwhile, the parallel transverse T-shaped seam top layer longitudinal reinforcing steel bars 25 and the transverse T-shaped seam top layer transverse steel bars 26 are required to be placed along the width direction of the seam.

The UHPC board 1 and the cast-in-situ UHPC 18 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 UHPC board 1.

Some other descriptions in the drawings: the longitudinal steel bar 13 is arranged on the top layer of the longitudinal T-shaped joint, the short studs 19 are arranged on the flange plates or the transverse end plates of the section steel at the joint, the studs 22 are arranged on the web plates of the section steel at the transverse T-shaped joint, the welding seam 30 is formed by transversely connecting the section steel with the section steel at the longitudinal joint, and the welding seam 32 is formed by longitudinally connecting the section steel with the section steel at the transverse joint.

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 21 at a transverse T-shaped joint between section steel at the joint with the section steel 2, positioning a steel strip 3 welded with short studs 5 on an upper flange plate of the section steel through spot welding or adhesive connection, manufacturing a template of a UHPC bridge deck unit, welding the short studs 4 on the upper flange plate of the section steel 2 on the upper flange plate of the section steel, placing the bound longitudinal steel bars 7 and transverse steel bars 8, reserving steel bars with a certain length outside the template, and pouring UHPC (ultra high temperature plastic) after curing is finished to form the section steel-UHPC light combined bridge deck unit; prefabricating the lower steel girder, prefabricating the lower steel girder according to a conventional steel-concrete combined bridge construction method, and welding splice joint resistant studs 14 on the upper flange plates 16 of the longitudinal steel girder partition plates (middle webs, side webs or longitudinal beams) and the upper flange plates 28 of the transverse partition plates (transverse beams);

s2: erecting a steel beam and a prefabricated profile steel-UHPC light combined bridge deck slab: according to a conventional steel-concrete combined bridge construction method, performing on-site splicing procedures of steel beams, 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 17 of longitudinal partition plates (middle webs, side webs or longitudinal beams) 15 and upper flange plates of transverse partition plates (transverse beams), adding small longitudinal beams 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 without the longitudinal partition plates on the upper flange plates of the side webs, and welding longitudinal joint section steel and section steel between the section steel at the section steel upper flange plates at the joint to transversely connect short steel bars 29;

s3: pouring wet joints: roughening the top layer steps 10 and 23 of the UHPC plate at the longitudinal T-shaped joint of the plain mouth shape, placing parallel top layer transverse reinforcing steel bars 12 and 25 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 6: 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 6 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 utility model provides a shaped steel-UHPC combination bridge floor structure suitable for cantilever state which characterized in that: the bridge deck structure 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 section steel, steel laths welded with short pegs and UHPC plates; the section steel is used as a longitudinal rib and is arranged at intervals along the transverse bridge direction and is arranged at the bottom of the UHPC board; the steel plate strips are vertical to the section steel and are arranged on the upper flange plate of the section steel at intervals along the longitudinal bridge direction, and the steel plate strips are connected with the UHPC plate through short pegs; the longitudinal joint structure and the transverse joint structure are T-shaped joints, short pegs are welded on the upper flange plates of the section steel, the UHPC plates are connected with the section steel through the short pegs on the upper flange plates of the section steel, steel strips welded with the short pegs are paved at gaps among the short pegs on the upper flange plates of the adjacent section steel, the section steel is H-shaped steel, I-shaped steel, channel steel, angle steel, T-shaped steel, flat-bulb steel or U-shaped steel, the height of the section steel is not more than 400mm, the transverse spacing is 300 mm-1000 mm, the length of the steel strips is equal to the width of the section steel-UHPC light combined bridge panel, the width of the steel strips is 50 mm-150 mm, the cut is arranged at the longitudinal joint of the steel strips, the steel strips at two sides of the longitudinal joint are staggered at the cut and spliced into a whole, the short pegs are welded on the steel strips with the cut, a reinforcing steel bar net is configured in the UHPC plates, the reinforcing bar net is positioned above the steel strips, the reinforcing bar net consists of staggered longitudinal reinforcing bars and transverse reinforcing bars, the T-shaped joint is formed by the notch of the upper edge of the UHPC plates and the gap of the adjacent step-shaped plates, and the height of the top layer is 70% of the UHPC plates.

2. The section steel-UHPC composite deck structure adapted for cantilever state according to claim 1, wherein: the UHPC board is a flat board having an average thickness of no more than 150mm, the average thickness being free of seams.

3. The section steel-UHPC composite deck structure adapted for cantilever state according to claim 2, wherein: the longitudinal joint is formed by reserving sealing rubber strips which are formed by overlapping steel sections-UHPC light combined bridge decks 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 boundaries on two sides of the joint, and the two adjacent upper flanges of the section steel are welded and transversely connected with short steel bars.

4. A section steel-UHPC composite deck structure suitable for use in cantilever form according to claim 3, wherein: the transverse joint is formed by reserving sealing rubber strips which are formed by overlapping profile steel-UHPC light combined bridge decks on transverse partition plates or upper flange plates of the transverse beams, welding longitudinal connecting short steel bars on upper flanges of two adjacent profile steels at the joint, and connecting profile steel webs at the joint through transverse stiffening plates.

5. A construction method of a section steel-UHPC combined bridge deck structure applicable to a cantilever state according to any one of claims 1 to 4, characterized in that: one of the following two construction methods is adopted: