COMPOSITE BOX GIRDER STRUCTURE AND CONSTRUCTION METHOD THEREFOR

Abstract

Disclosed are a composite box girder structure and a construction method therefor. The composite box girder structure includes a box enclosure and an inner core, where the inner core includes a thin-walled steel shell, shear connectors, and diaphragms, and the thin-walled steel shell is attached and fixed to an interior of the box enclosure by means of the shear connectors. In the present disclosure, the inner core and the box enclosure of the composite box girder structure jointly load force, such that effectiveness of the structure in resisting a use load can be improved. The inner core is directly used as an internal template of UHPC, such that rapid bridge construction can be achieved. Further, not only defects of conventional pouring can be overcome, but problems of excessive lateral local stress, overall stability, cross-section distortion and shear bearing capacity of web plates can be solved.

Claims

1. A composite box girder structure, comprising a box enclosure (12) and an inner core (11), wherein the inner core (11) comprises a thin-walled steel shell (21) and shear connectors (22), and the thin-walled steel shell (21) is attached and fixed to an interior of the box enclosure (12) by means of the shear connectors (22).

2. The composite box girder structure according to claim 1, wherein the inner core (11) further comprises diaphragms (23), the diaphragms (23) are fixed to an inner side of the thin-walled steel shell (21) in a cross-sectional direction of the inner core (11), the plurality of diaphragms (23) are arranged at the inner side of the thin-walled steel shell (21) in a longitudinal bridge direction, and an interval between every two adjacent diaphragms (23) is 2 m-10 m.

3. The composite box girder structure according to claim 2, wherein the diaphragms (23) are made of weathering resistant steel, the diaphragms (23) have a thickness of 0.008 m-0.020 m, and the plurality of diaphragms (23) are connected by several external prestressing tendons (101).

4. The composite box girder structure according to claim 1, wherein the thin-walled steel shell (21) is made of weathering resistant steel, and the thin-walled steel shell (21) has a thickness of 0.008 m-0.020 m.

5. The composite box girder structure according to claim 1, wherein the square-shaped thin-walled steel shell (21) completely covers and is attached and fixed to an inner surface of the ultra-high performance concrete box enclosure (12), and alternatively, the n-shaped thin-walled steel shell (21) partially covers and is attached and fixed to an inner surface of the ultra-high performance concrete box enclosure (12).

6. The composite box girder structure according to claim 1, wherein the box enclosure (12) is composed of ultra-high performance concrete plates, and ultra-high performance concrete is reactive powder concrete or ultra-high-performance fiber reinforced concrete having a compressive strength of not smaller than 100 MPa; and the box enclosure (12) comprises an ultra-high performance concrete (UHPC) bridge deck (61), a UHPC web plate (62), and a UHPC bottom plate (63), wherein the UHPC bridge deck (61) has a thickness of 0.15 m-0.30 m, the UHPC web plate (62) has a thickness of 0.10 m-0.60 m, and the UHPC bottom plate (63) has a thickness of 0.15 m-1.50 m.

7. The composite box girder structure according to claim 6, wherein the UHPC bridge deck (61) is in a shape of a flat plate or a one-way longitudinal rib plate.

8. The composite box girder structure according to claim 1, wherein the box enclosure (12) is internally provided with internal prestressing tendons (102) in the longitudinal bridge direction.

9. A construction method for the composite box girder structure according to claim 2, comprising the following steps: S1, welding thin-walled steel plates to form a thin-walled steel shell (21), welding shear connectors (22) to an outer surface of the thin-walled steel shell (21) at certain intervals, and welding diaphragms (23) to an inner surface of the thin-walled steel shell (21) at certain intervals, so as to form an inner core (11); S2, erecting an external form of a box enclosure (12), and hanging the inner core (11) in the external form of the box enclosure (12) and fixing the inner core; S3, forming the box enclosure (12) through pouring, so as to form the composite box girder structure (1), and conducting high-temperature steam curing on the composite box girder structure (1); S4, transporting the composite box girder structure (1) to a mounting position, and erecting and assembling the composite box girder structure on site by using a girder hoisting device, so as to form a box girder bridge body structure; and S5, completing deck paving and ancillary works of the box girder bridge body structure, that is, completing construction.

10. The construction method for the composite box girder structure according to claim 9, wherein in S3, when the box enclosure (12) is formed through pouring, the inner core (11) is used as an internal form.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0033] FIG. 1 is a schematic diagram of a sectional view of a composite box girder structure according to Embodiment 1;

[0034] FIG. 2 is an enlarged view of an ultra-high performance concrete (UHPC) bridge deck in a circle part in FIG. 1;

[0035] FIG. 3 is a schematic diagram of a three-dimensional structure of a sectional view of a UHPC bridge deck and a UHPC web plate of a composite box girder structure according to Embodiment 1;

[0036] FIG. 4 is a schematic diagram of an internal three-dimensional structure of a box shape of a composite box girder structure according to Embodiment 1;

[0037] FIG. 5 is a schematic diagram of a three-dimensional structure of a box enclosure according to Embodiment 1;

[0038] FIG. 6 is a schematic diagram of a sectional view of a composite box girder structure according to Embodiment 2;

[0039] FIG. 7 is an enlarged view of a UHPC bridge deck in a circle part in FIG. 6;

[0040] FIG. 8 is a schematic diagram of a three-dimensional structure of a sectional view of a UHPC bridge deck and a UHPC web plate of a composite box girder structure according to Embodiment 2;

[0041] FIG. 9 is a schematic diagram of a three-dimensional structure of a box enclosure according to Embodiment 2;

[0042] FIG. 10 is a schematic diagram of a sectional view of a composite box girder structure according to Embodiment 3;

[0043] FIG. 11 is a schematic diagram of a three-dimensional structure of a sectional view of a UHPC bridge deck and a UHPC web plate of a composite box girder structure according to Embodiment 3;

[0044] FIG. 12 is a schematic diagram of a sectional view of a composite box girder structure according to Embodiment 4; and

[0045] FIG. 13 is a schematic diagram of a three-dimensional structure of a sectional view of a UHPC bridge deck and a UHPC web plate of a composite box girder structure according to Embodiment 4.

REFERENCE NUMERALS

[0046] 1, composite box girder structure; 11, inner core; 12, box enclosure; 21, thin-walled steel shell; 22, shear connector; 23, diaphragm; 61, UHPC bridge deck; 62, UHPC web plate; 63, UHPC bottom plate; 101, external prestressing tendon; and 102, internal prestressing tendon.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The present disclosure will be described in detail below with reference to specific embodiments.

Embodiment 1

[0048] As shown in FIGS. 1-5, a composite box girder structure 1 of the embodiment includes a box enclosure 12 and an inner core 11. The inner core 11 includes a thin-walled steel shell 21, diaphragms 23, and shear connectors 22. The diaphragms 23 are fixed to an inner side of the thin-walled steel shell 21 in a cross-sectional direction of the inner core 11. The thin-walled steel shell 21 is attached and fixed to an interior of the box enclosure 12 by means of the shear connectors 22.

[0049] The thin-walled steel shell 21 is a box structure having a square-shaped section and completely covers and is attached and fixed to an inner surface of the box enclosure 12. The thin-walled steel shell 21 is made of weathering resistant steel, and the thin-walled steel shell 21 has a thickness of 0.008 m-0.015 m.

[0050] The plurality of diaphragms 23 are T-shaped steel plates, are arranged in a longitudinal bridge direction at intervals of 2 m-10 m, and have a thickness of 0.008 m-0.015 m. The diaphragms 23 are internally provided with external prestressing tendon channels and are connected by several external prestressing tendons 101.

[0051] The shear connectors 22 are stud connectors. The stud connectors have a diameter of 0.01 m-0.02 m and a height of 0.03 m-0.15 m. An interval between the adjacent stud connectors is 0.15 m-0.40 m.

[0052] The box enclosure 12 includes an ultra-high performance concrete (UHPC) bridge deck 61, a UHPC web plate 62, and a UHPC bottom plate 63. The UHPC bridge deck 61 has a thickness of 0.15 m-0.25 m. The UHPC web plate 62 has a thickness of 0.10 m-0.50 m. The UHPC bottom plate 63 has a thickness of 0.15 m-1.20 m. The UHPC bridge deck 61 is in a shape of a flat plate as shown in FIG. 2.

[0053] In the embodiment, the inner core 11, the diaphragms 23, the UHPC bridge deck 61, the UHPC web plate 62 and the UHPC bottom plate 63 are all made of thin plates.

[0054] A construction method for the composite box girder structure 1 according to the embodiment includes the following steps: [0055] S1: thin-walled steel plates are welded to form a thin-walled steel shell 21 in a prefabrication factory, and shear connectors 22 are welded to an outer surface of the thin-walled steel shell 21 at certain intervals, so as to form an inner core 11. [0056] S2: an external template of a box enclosure 12 is erected in the prefabrication factory, and the inner core 11 is hanged in the external template of the box enclosure 12 and fixed. [0057] S3: the inner core 11 is used as an internal template of the box enclosure 12, the box enclosure 12 is formed through pouring in the prefabrication factory, so as to form a segment of the composite box girder structure 1 of the embodiment, and high-temperature steam curing is conducted on the segment of the composite box girder structure 1. [0058] S4: the segment of the composite box girder structure 1 is transported to a mounting position by using a girder transporting vehicle, the composite box girder structure is erected by using a girder hoisting device, all segments of the composite box girder structure 1 are assembled on site, and prestressing tendons are sequentially tensioned. [0059] S5: deck paving and ancillary works of a box girder bridge are completed, that is, construction is completed.

Embodiment 2

[0060] As shown in FIGS. 6-9, a composite box girder structure 1 of the embodiment includes a box enclosure 12 and an inner core 11. The inner core 11 includes a thin-walled steel shell 21, diaphragms 23, and shear connectors 22. The diaphragms 23 are fixed to an inner side of the thin-walled steel shell 21 in a cross-sectional direction of the inner core 11. The thin-walled steel shell 21 is attached and fixed to an interior of the box enclosure 12 by means of the shear connectors 22.

[0061] The thin-walled steel shell 21 is a box structure having a square-shaped section and completely covers and is attached and fixed to an inner surface of the box enclosure 12. The thin-walled steel shell 21 is made of weathering resistant steel, and the thin-walled steel shell 21 has a thickness of 0.008 m-0.020 m.

[0062] The plurality of diaphragms 23 are T-shaped steel plates, are arranged in a longitudinal bridge direction at intervals of 2 m-10 m, and have a thickness of 0.008 m-0.020 m. The diaphragms 23 are internally provided with external prestressing tendon channels and are connected by several external prestressing tendons 101.

[0063] The shear connectors 22 are stud connectors. The stud connectors have a diameter of 0.01 m-0.02 m and a height of 0.03 m-0.15 m. An interval between the adjacent stud connectors is 0.15 m-0.40 m.

[0064] The box enclosure 12 includes a UHPC bridge deck 61, a UHPC web plate 62, and a UHPC bottom plate 63. The box enclosure 12 is internally provided with internal prestressing tendons 102 in the longitudinal bridge direction. The UHPC bridge deck 61 has a thickness of 0.15 m-0.30 m. The UHPC web plate 62 has a thickness of 0.10 m-0.60 m. The UHPC bottom plate 63 has a thickness of 0.15 m-1.50 m. As shown in FIGS. 7 and 9, the UHPC bridge deck 61 is in a shape of a one-way longitudinal rib plate, and the UHPC web plate 62 and the UHPC bottom plate 63 are both in a shape of a flat plate.

[0065] In the embodiment, the inner core 11, the diaphragms 23, the UHPC bridge deck 61, the UHPC web plate 62 and the UHPC bottom plate 63 are all made of thin plates.

[0066] A construction method for the composite box girder structure 1 according to the embodiment is the same as the construction method according to Embodiment 1.

Embodiment 3

[0067] As shown in FIGS. 10 and 11, a composite box girder structure 1 of the embodiment includes a box enclosure 12 and an inner core 11. The inner core 11 includes a thin-walled steel shell 21, diaphragms 23, and shear connectors 22. The diaphragms 23 are fixed to an inner side of the thin-walled steel shell 21 in a cross-sectional direction of the inner core 11. The thin-walled steel shell 21 is attached and fixed to an interior of the box enclosure 12 by means of the shear connectors 22.

[0068] The thin-walled steel shell 21 is a structure having an n-shaped section and completely covers and is attached and fixed to inner surfaces of a UHPC bridge deck 61 and a UHPC web plate 62. The thin-walled steel shell 21 is made of weathering resistant steel, and the thin-walled steel shell 21 has a thickness of 0.008 m-0.015 m.

[0069] The plurality of diaphragms 23 are T-shaped steel plates, are arranged in a longitudinal bridge direction at intervals of 2 m-10 m, and have a thickness of 0.008 m-0.015 m. The diaphragms 23 are internally provided with external prestressing tendon channels and are connected by several external prestressing tendons 101.

[0070] The shear connectors 22 are stud connectors. The stud connectors have a diameter of 0.01 m-0.02 m and a height of 0.03 m-0.15 m. An interval between the adjacent stud connectors is 0.15 m-0.40 m.

[0071] The box enclosure 12 includes the UHPC bridge deck 61, the UHPC web plate 62, and a UHPC bottom plate 63. The box enclosure 12 is internally provided with internal prestressing tendons 102 in the longitudinal bridge direction. The UHPC bridge deck 61 has a thickness of 0.15 m-0.25 m. The UHPC web plate 62 has a thickness of 0.10 m-0.50 m. The UHPC bottom plate 63 has a thickness of 0.15 m-1.20 m. The UHPC bridge deck 61 is in a shape of a flat plate.

[0072] In the embodiment, the inner core 11, the diaphragms 23, the UHPC bridge deck 61, the UHPC web plate 62 and the UHPC bottom plate 63 are all made of thin plates.

[0073] A construction method for the composite box girder structure 1 according to the embodiment includes the following steps: [0074] S1: thin-walled steel plates are welded to form a thin-walled steel shell 21 in a prefabrication factory, and shear connectors 22 are welded to an outer surface of the thin-walled steel shell 21 at certain intervals, so as to form an inner core 11. [0075] S2: an external form of a box enclosure 12 is erected in the prefabrication factory, and the inner core 11 is hanged in the external form of the box enclosure 12 and fixed. [0076] S3: the inner core 11 is used as part of an internal form of the box enclosure 12, an internal form of a UHPC bottom plate 63 is erected, the box enclosure 12 is formed through pouring in the prefabrication factory, so as to form a segment of the composite box girder structure 1 of the embodiment, and high-temperature steam curing is conducted on the segment of the composite box girder structure 1. [0077] S4: the segment of the composite box girder structure 1 is transported to a mounting position by using a girder transporting vehicle, the composite box girder structure is erected by using a girder hoisting device, all segments of the composite box girder structure 1 are assembled on site, and prestressing tendons are sequentially tensioned. [0078] S5: deck paving and ancillary works of a box girder bridge are completed, that is, construction is completed.

Embodiment 4

[0079] As shown in FIGS. 12 and 13, a composite box girder structure 1 of the embodiment includes a box enclosure 12 and an inner core 11. The inner core 11 includes a thin-walled steel shell 21, diaphragms 23, and shear connectors 22. The diaphragms 23 are fixed to an inner side of the thin-walled steel shell 21 in a cross-sectional direction of the inner core 11. The thin-walled steel shell 21 is attached and fixed to an interior of the box enclosure 12 by means of the shear connectors 22.

[0080] The thin-walled steel shell 21 is a structure having an n-shaped section and covers and is attached and fixed to an entire inner surface of a UHPC bridge deck 61 and an upper part of an inner surface of a UHPC web plate 62. The thin-walled steel shell 21 is made of weathering resistant steel, and the thin-walled steel shell 21 has a thickness of 0.008 m-0.015 m.

[0081] The plurality of diaphragms 23 are T-shaped steel plates, are arranged in a longitudinal bridge direction at intervals of 2 m-10 m, and have a thickness of 0.008 m-0.015 m. The diaphragms 23 are internally provided with external prestressing tendon channels and are connected by several external prestressing tendons 101.

[0082] The shear connectors 22 are stud connectors. The stud connectors have a diameter of 0.01 m-0.02 m and a height of 0.03 m-0.15 m. An interval between the adjacent stud connectors is 0.15 m-0.40 m.

[0083] The box enclosure 12 includes the UHPC bridge deck 61, the UHPC web plate 62, and a UHPC bottom plate 63. The box enclosure 12 is internally provided with internal prestressing tendons 102 in the longitudinal bridge direction. The UHPC bridge deck 61 has a thickness of 0.15 m-0.25 m. The UHPC web plate 62 has a thickness of 0.10 m-0.50 m. The UHPC bottom plate 63 has a thickness of 0.15 m-1.20 m. The UHPC bridge deck 61 is in a shape of a flat plate.

[0084] In the embodiment, the inner core 11, the diaphragms 23, the UHPC bridge deck 61, the UHPC web plate 62 and the UHPC bottom plate 63 are all made of thin plates.

[0085] A construction method for the composite box girder structure 1 according to the embodiment includes the following steps: [0086] S1: thin-walled steel plates are welded to form a thin-walled steel shell 21 in a prefabrication factory, and shear connectors 22 are welded to an outer surface of the thin-walled steel shell 21 at certain intervals, so as to form an inner core 11. [0087] S2: an external form of a box enclosure 12 is erected in the prefabrication factory, and the inner core 11 is hanged in the external form of the box enclosure 12 and fixed. [0088] S3: the inner core 11 is used as part of an internal form of the box enclosure 12, internal forms of a UHPC web plate 62 and a UHPC bottom plate 63 are erected, the box enclosure 12 is formed through pouring in the prefabrication factory, so as to form a segment of the composite box girder structure 1 of the embodiment, and high-temperature steam curing is conducted on the segment of the composite box girder structure 1. [0089] S4: the segment of the composite box girder structure 1 is transported to a mounting position by using a girder transporting vehicle, the composite box girder structure is erected by using a girder hoisting device, all segments of the composite box girder structure 1 are assembled on site, and prestressing tendons are sequentially tensioned. [0090] S5: deck paving and ancillary works of a box girder bridge are completed, that is, construction is completed.

[0091] 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.