COMPOSITE DECK STRUCTURE FOR BRIDGE AND BRIDGE STRUCTURE AND CONSTRUCTION METHOD THEREOF

Abstract

Disclosed are a composite deck structure for a bridge, and a bridge structure and a construction method thereof. The composite deck structure includes a top plate (1), longitudinal ribs (2), and transverse ribs (3), where the longitudinal ribs (2) are fixedly connected to the transverse ribs (3), and are connected to the diaphragms (4) by means of the transverse ribs (3), and the transverse ribs (3) are not provided with cutouts for accommodating the longitudinal ribs (2). According to the composite deck structure, no cutout is provided on the diaphragms (4), and stress generated by the cutouts is reduced; hot-rolled section steel is used for longitudinal ribs (2) and transverse ribs (3) instead of welded steel plates, such that welding seams are reduced and fatigue resistance of the composite deck structure is improved.

Claims

1. A composite deck structure for a bridge, comprising a top plate (1) and longitudinal ribs (2) fixed to a lower surface of the top plate (1), and further comprising transverse ribs (3) spliced on diaphragms (4) of a main beam structure (5) of the bridge, wherein the longitudinal ribs (2) are fixedly connected to the transverse ribs (3), and are connected to the diaphragms (4) by means of the transverse ribs (3), and the transverse ribs (3) are not provided with cutouts for accommodating the longitudinal ribs (2).

2. The composite deck structure according to claim 1, wherein the longitudinal ribs (2) and the transverse ribs (3) are made of hot-rolled section steel commercially available on the market.

3. The composite deck structure according to claim 2, wherein the longitudinal rib (2) comprises a longitudinal web plate (21) and a longitudinal flange plate (22): the transverse rib (3) comprises a transverse web plate (32) and a transverse flange plate (31); and the longitudinal rib (2) is fixedly connected to the transverse rib (3) by means of contact surfaces of the longitudinal flange plate (22) and the transverse flange plate (31).

4. The composite deck structure according to claim 3, wherein the longitudinal ribs (2) and the transverse ribs (3) are made of one of H-shaped steel, angle steel, I-shaped steel, and T-shaped steel.

5. The composite deck structure according to claim 3, wherein both the longitudinal flange plate (22) and the transverse flange plate (31) have a width greater than or equal to 100 mm.

6. The composite deck structure according to claim 3, wherein the longitudinal web plate (21) has a thickness greater than or equal to 6 mm, and the transverse web plate (32) has a thickness greater than or equal to 8 mm.

7. The composite deck structure according to claim 1, wherein the top plate (1) is a composite plate, and the composite plate comprises a steel panel (12) and an ultra-high-performance concrete plate (11) poured on a surface of the steel panel (12); and the steel panel (12) is provided with studs (13), and the studs (13) each have a diameter of 10 mm-30 mm and a height of 25 mm-65 mm.

8. A bridge structure comprising the composite deck structure according to claim 1, comprising a composite deck structure (6) and a main beam structure (5), wherein the main beam structure (5) is a steel box beam, a steel truss beam, or a steel plate beam; and the main beam structure (5) comprises diaphragms (4), the composite deck structure (6) is fixed onto the main beam structure (5), and transverse ribs (3) are spliced on the diaphragms (4) of the main beam structure (5).

9. The bridge structure according to claim 1, wherein the diaphragms (4) are arranged at intervals in the main beam structure (5), and an interval between two adjacent diaphragms (4) is 2.5 m-8.0 m.

10. A construction method of the bridge structure according to claim 1, comprising the following steps: S1, placing the steel panel (12) at a bottom layer, and welding the longitudinal ribs (2) onto the steel panel (12); and prefabricating steel beam segments comprising the diaphragms (4) below a deck; S2, fixedly connecting the transverse ribs (3) to the longitudinal ribs (2), so as to form an orthogonal composite deck unit; S3, overturning the orthogonal composite deck unit, and correspondingly welding the transverse ribs (3) to the diaphragms (4) of the steel beam segments, so as to form main steel beam segments of an entire bridge; and S4, welding the studs (13) to the steel panel (12) after the main steel beam segments are transported to a bridge construction site and spliced into a full-length main beam segment by segment, arranging a reinforced steel mesh, and pouring ultra-high-performance concrete on site, so as to finally form a complete bridge structure.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1 is a schematic diagram of a three-dimensional structure of a composite deck structure for a bridge according to Embodiment 1;

[0037] FIG. 2 is a schematic diagram of a steel panel provided with studs through welding according to Embodiment 1;

[0038] FIG. 3 is a schematic diagram of a connection relation between longitudinal ribs and transverse ribs according to Embodiment 1;

[0039] FIG. 4 is a schematic diagram of a sectional view (i.e. a sectional view of A-A in FIG. 5) of a deck structure in a transverse bridge direction according to Embodiment 1;

[0040] FIG. 5 is a schematic diagram of a sectional view (i.e. a sectional view of B-B in FIG. 4) of a deck structure in a longitudinal bridge direction according to Embodiment 1; and

[0041] FIG. 6 is a schematic diagram of a sectional view of a bridge structure in a transverse bridge direction according to Embodiment 1.

REFERENCE NUMERALS

[0042] 1, top plate; 2, longitudinal rib; 3, transverse rib; 4, diaphragm; 11, ultra-high-performance concrete plate; 12, steel panel; 13, stud; 14, longitudinal steel bar; 15, transverse steel bar; 21, longitudinal web plate; 22, longitudinal flange plate; 23, first type of welding seam; 24, second type of welding seam; 31, transverse flange plate; 32. transverse web plate; 33, third type of welding seam; 5, main beam structure; 6, composite deck structure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The present disclosure will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Embodiment 1

[0044] As shown in FIGS. 1-5, a composite deck structure for a bridge according to the embodiment includes a top plate 1 and longitudinal ribs 2 fixed to a lower surface of the steel panel 1, and further includes transverse ribs 3 spliced on diaphragms 4 of a main beam structure 5 of a bridge. The longitudinal ribs 2 are fixedly connected to the transverse ribs 3, and are connected to the diaphragms 4 by means of the transverse ribs 3. The transverse ribs 3 and the diaphragms 4 are not provided with cutouts for accommodating and welding the longitudinal ribs 2.

[0045] In the embodiment, the longitudinal ribs 2 and the transverse ribs 3 are made of hot-rolled section steel commercially available on the market.

[0046] In the embodiment, the longitudinal ribs 2 are located on the transverse ribs 3.

[0047] In the embodiment, the longitudinal rib 2 includes a longitudinal web plate 21 and a longitudinal flange plate 22. The transverse rib 3 includes a transverse web plate 32 and a transverse flange plate 31. The longitudinal rib 2 is fixedly connected to the transverse rib 3 by means of contact surfaces of the longitudinal flange plate 22 and the transverse flange plate 31.

[0048] In the embodiment, the longitudinal ribs 2 are made of inverted-T-shaped steel, and the transverse ribs 3 are made of T-shaped steel.

[0049] In the embodiment, the transverse ribs 3 are consistent with the diaphragms 4 in the main beam structure 5 of the bridge in longitudinal arrangement position and interval. A central axis of the transverse web plate 32 is flush with a central axis of the diaphragm 4 in the main beam structure 5 of the bridge in a vertical direction.

[0050] In the embodiment, all dimensional parameters are determined according to conditions of a bridge construction site.

[0051] In the embodiment, both the longitudinal flange plate 22 and the transverse flange plate 31 have a width greater than or equal to 100 mm.

[0052] In the embodiment, the longitudinal web plate 21 has a thickness greater than or equal to 6 mm. The transverse web plate 32 has a thickness greater than or equal to 8 mm.

[0053] In the embodiment, the longitudinal ribs 2 have a height smaller than or equal to 800 mm, and the transverse ribs 3 have a height smaller than or equal to 400 mm.

[0054] In the embodiment, the longitudinal ribs 2 are arranged on the lower surface of the top plate 1 at intervals, and an interval between two adjacent longitudinal ribs 2 is 300 mm-800 mm.

[0055] In the embodiment, the top plate 1 is a composite plate. The composite plate includes a steel panel 12 and an ultra-high-performance concrete plate 11 poured on a surface of the steel panel 12. The steel panel 12 is a flat plate having a thickness of 6 mm-20 mm. A single layer of criss-crossed reinforced steel mesh is arranged in the ultra-high-performance concrete plate 11. Transverse steel bars 15 are located above longitudinal steel bars 14. The transverse steel bars 15 and the longitudinal steel bars 14 have a diameter of 8 mm-20 mm. An interval between the adjacent longitudinal steel bars 14 and an interval between the adjacent transverse steel bars 15 are both 30 mm-300 mm. The ultra-high-performance concrete plate 11 is made of the ultra-high-performance concrete. The ultra-high-performance concrete refers to concrete containing steel fibers and having compressive strength not smaller than 100 MPa and axial tensile strength not smaller than 7 MPa. The ultra-high-performance concrete plate 11 is a uniform-thickness plate, and has a thickness of 30 mm-100 mm. The steel panel 12 is provided with studs 13. The studs 13 have a diameter of 10 mm-30 mm and a height of 25 mm-65 mm.

[0056] In the embodiment, the longitudinal ribs 2 are connected to the steel panel 12 by means of a first type of welding seams 23.

[0057] In the embodiment, the longitudinal flange plates 22 are connected to the transverse flange plates 31 by means of a second type of welding seams 24.

[0058] In the embodiment, bottoms of the transverse ribs 3 are connected to tops of the diaphragms 4 by means of a third type of welding seams 33.

[0059] By analyzing the above structure, it can be known that the first type of welding seams 23 are welding seams between the steel panel 12 and the longitudinal ribs 2, and fatigue details of the welding seams are divided into fatigue details a at the steel panel 12 and fatigue details b at the longitudinal ribs 2; the second type of welding seams 24 are welding seams between the longitudinal flange plates 22 and the transverse flange plates 31, and fatigue details of the welding seams are divided into fatigue details c at the longitudinal ribs 2 and fatigue details d at the transverse ribs 3; fatigue details of the hot-rolled section steel of the longitudinal ribs 2 are divided into fatigue details e at the longitudinal web plates 21 and fatigue details f at the longitudinal flange plates 22; and fatigue details of the hot-rolled section steel of the transverse ribs 3 are divided into fatigue details g at the transverse flange plates 31 and fatigue details h at the transverse web plates 32. Stress of the above fatigue details is compared with a fatigue grade and a constant-amplitude fatigue limit specified in “Specifications for Design of Highway Steel Bridge” JTG D64-2015 (Chinese steel bridge specification), and results are shown in Table 1:

TABLE-US-00001 Fatigue stress analysis results of each position in the embodiment Detail position Steel panel-longitudinal rib welding seam Longitudinal rib-transverse rib welding Longitudinal rib base material Transverse rib base material seam Detail number a b c d e f g h Fatigue stress/MPa 18.7 34.6 24.2 22.5 93.7 35.2 45.6 65.3 Fatigue grade (2×10.sup.6 times) 70 55 160 Constant-amplitude fatigue limit (5×10.sup.6 times) 44.8 35.2 102.5

[0060] In Table 1, a finite element model of the stress of the fatigue details is created according to the embodiment, and fatigue stress under the most unfavorable working condition is obtained by loading a fatigue load in the model. A single-vehicle model specified in “Specifications for Design of Highway Steel Bridge” JTG D64-2015 is used for the fatigue load, with a total weight of 480 kN and a single axle weight of 120 kN.

[0061] Therefore, stress at all the fatigue details of the deck structure of the present disclosure is below the constant-amplitude fatigue limit, such that fatigue cracking caused by excessive fatigue stress of materials is effectively avoided. Moreover, if the transverse ribs 3 and the longitudinal ribs 2 are made of welded steel, fatigue stress at welding seams is greater than the constant-amplitude fatigue limit, and does not satisfy specification requirements, such that the longitudinal ribs 2 and the transverse ribs 3 are made of integrally rolled hot-rolled section steel instead of the welded steel.

[0062] As shown in FIG. 6, a bridge structure according to the embodiment includes a composite deck structure 6 and a main beam structure 5. The main beam structure 5 is a steel box beam. The main beam structure includes diaphragms 4. The composite deck structure 6 is fixed onto the main beam structure 5. Transverse ribs 3 are spliced on the diaphragms 4 of the main beam structure 5.

[0063] In the embodiment, the diaphragms 4 are arranged at intervals in the main beam structure 5, and an interval between two adjacent diaphragms 4 is 2.5 m-8 m.

[0064] A construction method of the bridge structure according to the embodiment includes the following steps:

[0065] S1, in a factory prefabrication workshop, the steel panel 12 is placed at a bottom layer, and the longitudinal ribs 2 are welded onto the steel panel 12; and steel beam segments including the diaphragms 4 below a deck are also prefabricated in a factory;

[0066] S2, the transverse ribs 3 are fixedly connected to the longitudinal ribs 2, so as to form an orthogonal composite deck unit;

[0067] S3, after the orthogonal composite deck unit is overturned, the transverse ribs 3 of the orthogonal composite deck unit are correspondingly welded to the diaphragms 4 of the steel beam segments, so as to form main steel beam segments of an entire bridge; and

[0068] S4, the studs 13 are welded to the steel panel 12 after the main steel beam segments are transported to a bridge construction site and spliced into a full-length main beam segment by segment, a reinforced steel mesh is arranged, and ultra-high-performance concrete is poured on site, so as to finally form a complete bridge structure.

[0069] Merely preferred implementation modes of the present disclosure are described above, and the protection scope of the present disclosure is not limited to the above embodiments. Improvements and modifications obtained by those skilled in the art without departing from the technical concept of the present disclosure should be regarded as falling within the scope of the present disclosure.