CN111749114A

CN111749114A - Steel truss-UHPC combined beam bridge hogging moment area structure and construction method

Info

Publication number: CN111749114A
Application number: CN202010752190.8A
Authority: CN
Inventors: 谢明化; 王康宁; 朱玉飞; 伍贤智; 高立强; 王敏; 周亚栋
Original assignee: Wenzhou Qidu Bridge Beichaqiao Construction Co ltd; Wenzhou Design Assembly Co ltd; China Railway Major Bridge Engineering Group Co Ltd MBEC; China Railway Bridge Science Research Institute Ltd; China Railway Bridge Research Technology Co Ltd
Current assignee: Wenzhou Qidu Bridge Beichaqiao Construction Co ltd; Wenzhou Design Assembly Co ltd; China Railway Major Bridge Engineering Group Co Ltd MBEC; China Railway Bridge Science Research Institute Ltd; China Railway Bridge Research Technology Co Ltd
Priority date: 2020-07-30
Filing date: 2020-07-30
Publication date: 2020-10-09

Abstract

The invention discloses a hogging moment area structure of a steel truss-UHPC (ultra high performance concrete) composite beam bridge and a construction method, which relate to the technical field of bridge structures and comprise the following steps: steel trusses and UHPC decking; the steel truss girder comprises two main trusses which are transversely arranged at intervals and connected, each main truss comprises a lower chord and an upper chord, and UHPC is filled in the lower chord; the UHPC bridge deck is connected with the upper surfaces of the two upper chords; the upper chord member and the lower chord member are provided with vertical web members, the two sides of each vertical web member are sequentially symmetrically provided with a compression web member and a tension web member in an alternating mode, and the lower chord member and the upper chord member are connected with an integral gusset plate at the joints. The invention can solve the technical problems that the lower chord of the existing steel truss girder is easy to be stressed and unstable, the bridge deck is easy to be pulled and cracked, and the node is easy to be damaged by fatigue.

Description

Steel truss-UHPC combined beam bridge hogging moment area structure and construction method

Technical Field

The invention relates to the technical field of bridge structures, in particular to a steel truss-UHPC combined beam bridge hogging moment area structure and a construction method.

Background

At present, the steel-concrete composite structure bridge is favored and paid attention by researchers and engineers, and compared with a concrete bridge, the steel-concrete composite structure bridge has the advantages of high strength, light weight, short construction period, good earthquake resistance and the like.

In the related art, the steel truss-concrete composite girder bridge is an important branch of a steel-concrete composite structure bridge and is a novel bridge type based on optimization of a concrete box girder web plate and a concrete box girder bottom plate. After the web plate and the bottom plate of the concrete box girder are respectively replaced by the web member and the chord member of the truss system, the material utilization rate is improved, and the self weight of the structure is greatly reduced, so that the bridge type has great competitive advantage. The main advantages of the steel truss-concrete composite beam bridge are represented in the following two aspects: 1. the truss member mainly takes axial stress as a main part, the material utilization rate is high, and higher bending rigidity can be obtained under the condition of the same material consumption; 2. the construction period is short, and the construction method is flexible.

However, due to the structural and material characteristics, the conventional steel truss-concrete composite girder bridge hogging moment region structure has the following problems:

1. the lower chord of the steel truss girder is easy to be stressed and unstable;

2. the bridge deck is easy to crack under tension;

3. the node is easy to be damaged by fatigue.

Disclosure of Invention

The embodiment of the invention provides a hogging moment area structure of a steel truss-UHPC (ultra high performance concrete) composite beam bridge and a construction method, and aims to solve the technical problems that in the related technology, a lower chord of the steel truss is easy to be subjected to compression instability, a bridge deck is easy to be subjected to tension cracking, and a node is easy to be subjected to fatigue failure.

In a first aspect, a hogging moment zone structure of a steel truss-UHPC composite beam bridge is provided, which includes:

the steel truss girder comprises two main trusses which are transversely arranged at intervals and connected, each main truss comprises a lower chord and an upper chord, and UHPC is filled in the lower chord; vertical web members are arranged at the supporting points of the main trusses between the upper chord member and the lower chord member, compression web members and tension web members are sequentially symmetrically and alternately arranged on two sides of each vertical web member, the lower chord member and the upper chord member are connected with integral type gusset plates at the nodes connected with the compression web members and the tension web members, each integral type gusset plate is extended with two inclined convex side plates, and the two inclined convex side plates are respectively connected with one compression web member and one tension web member;

a UHPC bridge deck connected to the upper surfaces of the two upper chords.

In some embodiments, the compression web member is a box section and the tension web member is an i-section.

In some embodiments, the compression and tension web centerlines intersect the lower chord or upper chord centerline at a point.

In some embodiments, the UHPC bridge deck comprises a plurality of UHPC bridge deck segments connected in sequence, two adjacent UHPC bridge deck segments are connected by a wet joint, and the wet joint is provided with an overlap steel bar.

In some embodiments, shear grooves are cast on the upper surface of the main truss at intervals, and shear nails are arranged in the shear grooves.

In some embodiments, the shear groove is elliptical.

In some embodiments, the upper surface of the main truss is further poured with epoxy mortar.

In some embodiments, the two main trusses are connected to form a whole through a flat connection assembly, the flat connection assembly includes a plurality of upper flat links, a plurality of lower flat links, and a plurality of diagonal braces, each upper flat link is connected to the upper chords of the two main trusses at two ends, each lower flat link is connected to the lower chords of the two main trusses at two ends, and each diagonal brace is connected to the upper chord of one main truss and the lower chord of the other main truss at two ends.

In a second aspect, a construction method for the hogging moment area structure of the steel truss-UHPC composite beam bridge is provided, which comprises the following steps:

prefabricating two main trusses of the steel truss girder and a UHPC bridge deck;

filling UHPC inside the lower chords of the two main trusses;

connecting and erecting two main trusses to form a steel truss girder;

and UHPC bridge decks are installed and connected on the upper surfaces of the two main trusses.

The embodiment of the invention provides a steel truss-UHPC (ultra high performance concrete) composite beam bridge hogging moment area structure and a construction method, wherein a steel truss beam is combined with a UHPC bridge deck plate, the material characteristics of steel and UHPC are fully exerted, and the problem that the bridge deck plate in the hogging moment area of a common steel truss composite beam is easy to crack under tension is effectively solved; and the UHPC is filled only in the lower chord, so that the pressure instability of the lower chord can be effectively avoided, and the bearing capacity of the lower chord is improved. Meanwhile, the rigidity of the node can be increased by the integral node plate, and the fatigue resistance of the node is obviously improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a cross-sectional view of a hogging moment zone structure of a steel truss-UHPC composite beam bridge provided by an embodiment of the invention;

FIG. 2 is an elevation view of a hogging moment area structure of a steel truss-UHPC composite beam bridge provided by an embodiment of the invention;

FIG. 3 is an enlarged schematic view of FIG. 2 at node A;

FIG. 4 is a perspective view of FIG. 3;

FIG. 5 is a top view of FIG. 2;

FIG. 6 is a schematic diagram of a two UHPC bridge deck block-wise connection provided by an embodiment of the present invention;

FIG. 7 is a layout view of a parallel component provided by an embodiment of the present invention;

FIG. 8 is another arrangement of the parallel component provided by the embodiment of the present invention;

FIG. 9 is a flow chart of a construction method of a hogging moment zone structure of a steel truss-UHPC composite beam bridge according to an embodiment of the invention;

in the figure: 1. a steel truss beam; 11. a main truss; 111. a lower chord; 112. an upper chord; 1121. a shear groove; 1122. shear nails; 113. a vertical web member; 114. a compression web member; 115. a tension web member; 116. an integral gusset plate; 1161. an inclined convex side plate; 12. a parallel connection component; 121. an upper flat link; 122. a lower horizontal link rod; 123. a diagonal brace; 2. a UHPC bridge deck; 21. partitioning a UHPC bridge deck; 211. longitudinal reinforcing steel bars; 212. transverse reinforcing steel bars; 22. wet seaming; 23. and (5) overlapping the reinforcing steel bars.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the invention provides a hogging moment area structure of a steel truss-UHPC (ultra high performance concrete) combined beam bridge, which can solve the technical problems that a lower chord of the existing steel truss is easy to be stressed and unstable, and a bridge deck is easy to be pulled and cracked.

Referring to fig. 1, a hogging moment area structure of a steel truss-UHPC composite beam bridge comprises: steel truss beams 1 and UHPC bridge decks 2. Wherein, UHPC (Ultra-High Performance Concrete) is Ultra-High Performance Concrete, which is a special engineering material with Ultra-High strength, toughness and High durability.

The steel truss girder 1 comprises two main trusses 11 which are arranged at a transverse interval and connected, each main truss 11 comprises a lower chord 111 and an upper chord 112, and UHPC is filled inside the lower chord 111. Meanwhile, the UHPC bridge deck 2 is attached to the upper surfaces of the two upper chords 112. Specifically, referring to FIG. 2, the lower chord 111 is box-section, with UHPC filled in the box. Preferably, the UHPC filled area is positioned between the left and right two joints of the steel truss-UHPC combined beam bridge hogging moment area structure at the supporting point of the bridge pier, and the length of the UHPC filled area can extend out of the joint area in consideration of the stress of the main truss 11 at the joint.

Referring to fig. 2, a vertical web member 113 is provided between the upper chord 112 and the lower chord 111 at a fulcrum of each main truss 11, wherein the fulcrum of the main truss 11 refers to a supporting point of the pier. The compression web members 114 and the tension web members 115 are sequentially and symmetrically arranged on two sides of the vertical web member 113 in an alternating manner, the integral gusset plates 116 are respectively connected to the lower chord 111 and the upper chord 112 at the joints connected with the compression web members 114 and the tension web members 115, as shown in fig. 3 and 4, two inclined convex side plates 1161 extend from each integral gusset plate 116, and the two inclined convex side plates 1161 are respectively connected with one compression web member 114 and one tension web member 115.

Specifically, the lower chord 111 and the upper chord 112 are both box-shaped in cross section, the compression web 114 is box-shaped in cross section, and the tension web 115 is i-shaped in cross section. The center lines of the compression web member 114 and the tension web member 115 are intersected with the center line of the lower chord 111 or the upper chord 112 at one point, so that the influence of an additional bending moment caused by node eccentricity can be eliminated. For each node structure, the integral node plate 116 is welded on the side plate of the lower chord 111 or the upper chord 112, so that the integral node plate 116 and the side plates of the lower chord 111 and the upper chord 112 are in the same vertical plane, the integral node plate 116 extends to form two obliquely convex side plates 1161, the two obliquely convex side plates 1161 are connected with the side plates of the compression web member 114 and the tension web member 115, the integral node plate 116, the side plates of the lower chord 111 or the upper chord 112 and the side plates of the compression web member 114 and the tension web member 115 are in the same vertical plane, and the force of the compression web member 114 and the tension web member 115 is not borne by the top plates of the lower chord 111 and the upper chord 112 but is directly transmitted to the side plates of the lower chord 111 and the upper chord 112, so that the node bearing capacity is improved. The compression web member 114 and the tension web member 115 use different cross sections, so that the advantages of a closed cross section and an open cross section are fully exerted, the connection is more convenient, and the fatigue resistance of the node is improved.

Compared with the prior art, the steel truss-UHPC combined beam bridge hogging moment area structure combines the steel truss beam 1 and the UHPC bridge deck plate 2, gives full play to the material characteristics of steel and UHPC, and effectively solves the problem that the bridge deck plate in the hogging moment area of the common steel truss combined beam is easy to tension and crack; only the UHPC is filled in the lower chord 111, so that the pressure instability of the lower chord 111 can be effectively avoided, the bearing capacity of the lower chord 111 is improved, and the attractive structure is not influenced. Meanwhile, the rigidity of the node can be increased by the integral node plate, and the fatigue resistance of the node is obviously improved.

As a preferred embodiment, referring to fig. 5, the UHPC bridge deck 2 includes a plurality of UHPC bridge deck segments 21 connected in series, two adjacent UHPC bridge deck segments 21 are connected by a wet joint 22, and an overlap reinforcement 23 is disposed at the wet joint 22.

Specifically, as shown in fig. 5 and 6, the UHPC bridge deck slab segment 21 is paved with the longitudinal steel bars 211 and the transverse steel bars 212, and a high reinforcement ratio can be adopted, and because the UHPC has good fluidity and self-compactness, it can be considered that reinforcement with a high reinforcement ratio does not affect the UHPC pouring quality, and the construction process is simplified. The overlap reinforcement 23 overlaps the longitudinal reinforcement 211 provided in the two UHPC deck slab sections 21.

In a preferred embodiment, referring to fig. 1 and 5, shear grooves 1121 are cast on the upper surface of the upper chord 112 of the main truss 11 at intervals, shear nails 1122 are arranged in the shear grooves 1121, and the shear grooves 1121 are oval. An elliptical shear groove is adopted to reduce the stress concentration degree of the corner part in the groove. The UHPC bridge deck may be prefabricated in full width. Because UHPC board thickness is little, wet seam 22 department does not set up complicated structures such as annular steel bar, only sets up straight overlap joint reinforcing bar 23 after the chisel hair can, and the chisel hair degree of depth is not less than 5mm, wet seam 22 department overlap joint reinforcing bar 23 need not the welding.

In a preferred embodiment, epoxy mortar is further poured on the upper surface of the upper chord 112 of the main truss 11 to adjust gaps, so that the UHPC bridge deck can be conveniently installed.

As a preferred embodiment, referring to fig. 1, 7 and 8, two main trusses 11 are connected to form a whole through a parallel connection assembly 12, the parallel connection assembly 12 includes a plurality of upper parallel links 121, a plurality of lower parallel links 122 and a plurality of diagonal braces 123, two ends of each upper parallel link 121 are respectively connected to the upper chords 112 of two main trusses 11, two ends of each lower parallel link 122 are respectively connected to the lower chords 111 of two main trusses 11, and two ends of each diagonal brace 123 are respectively connected to the upper chords 112 of one main truss 11 and the lower chords 111 of the other main truss 11.

Referring to fig. 9, an embodiment of the present invention provides a construction method for a hogging moment area structure of a steel truss-UHPC composite beam bridge, including the following steps:

step S1, two main girders 11 of the steel girder 1 and the UHPC bridge deck 2 are prefabricated. Specifically, two main trusses 11 and UHPC bridge decks 2 of the steel truss girder 1 are prefabricated in a factory, and the longitudinal two ends of the prefabricated UHPC bridge deck 2 are chiseled, wherein the chiseled depth is not less than 5 mm.

In step S2, UHPC is filled inside the lower chords 111 of the two main trusses 11. The lower chord 111 is box-shaped in cross section, and filled with UHPC in the box shape, the length of the UHPC filling can extend to the outside of the node area, and the shear pins 1122 are welded to the upper surface of the upper chord 112 of the main truss 11.

And step S3, connecting and erecting two main trusses 11 to form the steel truss girder 1. Specifically, two main girders 11 are connected by a flat connection member 12 to form the steel girder 1.

Step S4, installing and connecting UHPC bridge deck 2 on the upper surfaces of the two main girders 11. Specifically, epoxy mortar filling gaps are uniformly distributed on the upper surface of an upper chord 112 of a main truss 11, a UHPC bridge deck 2 is erected on a steel truss beam 1, a shear groove 1121 is poured, a steel bar 23 is lapped at a wet joint 22, and pouring and maintenance are carried out, so that the UHPC bridge deck 2 and the steel truss beam 1 form a steel truss-UHPC combined beam bridge.

In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

It is to be noted that, in the present invention, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a steel purlin-UHPC composite beam bridge hogging moment district structure which characterized in that includes:

the steel truss girder (1) comprises two main trusses (11) which are arranged at intervals in the transverse direction and connected, each main truss (11) comprises a lower chord (111) and an upper chord (112), and UHPC is filled in the lower chord (111); a vertical web member (113) is arranged between the upper chord member (112) and the lower chord member (111) at the pivot of each main truss (11), compression web members (114) and tension web members (115) are sequentially symmetrically and alternately arranged on two sides of the vertical web member (113), integral node plates (116) are respectively connected to the nodes connected with the compression web members (114) and the tension web members (115) of the lower chord member (111) and the upper chord member (112), two inclined convex side plates (1161) extend from each integral node plate (116), and the two inclined convex side plates (1161) are respectively connected with one compression web member (114) and one tension web member (115);

a UHPC bridge deck (2) connected to the upper surfaces of the two upper chords (112).

2. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that:

the compression web members (114) are box-shaped in cross section, and the tension web members (115) are I-shaped in cross section.

3. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that:

the center lines of the compression web members (114) and the tension web members (115) are intersected with the center line of the lower chord member (111) or the upper chord member (112) at one point.

4. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that:

the UHPC bridge deck slab (2) comprises a plurality of UHPC bridge deck slab blocks (21) which are sequentially connected, two adjacent UHPC bridge deck slab blocks (21) are connected through a wet joint (22), and lap-joint steel bars are arranged at the position of the wet joint (22).

5. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that:

shear grooves (1121) are poured on the upper surface of the main truss (11) at intervals, and shear nails (1122) are arranged in the shear grooves (1121).

6. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 5, characterized in that: the shear groove (1121) is oval.

7. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that: epoxy mortar is poured on the upper surface of the main truss (11).

8. The hogging moment zone structure of steel truss-UHPC composite beam bridge of claim 1, characterized in that:

the two main trusses (11) are connected through a flat connection assembly (12) to form a whole, the flat connection assembly (12) comprises a plurality of upper flat connecting rods (121), a plurality of lower flat connecting rods (122) and a plurality of inclined supporting rods (123), two ends of each upper flat connecting rod (121) are respectively connected with the upper chords (112) of the two main trusses (11), two ends of each lower flat connecting rod (122) are respectively connected with the lower chords (111) of the two main trusses (11), and two ends of each inclined supporting rod (123) are respectively connected with the upper chord (112) of one main truss (11) and the lower chord (111) of the other main truss (11).

9. A construction method for the hogging moment zone structure of the steel truss-UHPC composite girder bridge according to claim 1, comprising the steps of:

two main trusses (11) of the prefabricated steel truss girder (1) and a UHPC bridge deck (2);

filling UHPC inside the lower chords (111) of the two main trusses (11);

two main trusses (11) are connected and erected to form a steel truss girder (1);

and UHPC bridge decks (2) are installed and connected on the upper surfaces of the two main trusses (11).