CN111074744A

CN111074744A - A truss type steel reinforced concrete box girder

Info

Publication number: CN111074744A
Application number: CN201911281919.1A
Authority: CN
Inventors: 曹大富; 曹思琦; 孟睿智; 王宇航; 周雁玲; 刘嘉琪; 董政
Original assignee: Yangzhou University
Current assignee: Yangzhou University
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-04-28

Abstract

This invention discloses a truss-type steel-reinforced concrete box girder, which has a high degree of industrialization and assembly, and a reasonable stress structure. The truss-type steel-reinforced concrete box girder of this invention includes a steel truss (1), a sealing pipe (2) placed on the central axis of the steel truss (1), and a concrete layer (3) cast on the outside of the sealing pipe (2) and completely covering the outer periphery of the steel truss (1).

Description

Truss type steel reinforced concrete box girder

Technical Field

The invention belongs to the technical field of assembly type building components, and particularly relates to a truss type steel reinforced concrete box girder which is high in industrialization and assembly degree and reasonable in stress structure.

Background

Assembly technology is becoming increasingly important in the current construction industry. Particularly in the field of bridge construction, a large number of reinforced concrete continuous box girder bridges are built in China for nearly 20 years.

Compared with the common reinforced concrete beam, the reinforced concrete box beam has the advantages of being hollow in structure, good in durability and integrity and the like due to the fact that flanges are arranged on two sides of the upper portion of the reinforced concrete box beam and similar to a box, and is widely applied to bridge structures.

However, the reinforced concrete box girder uses more steel bars, a reinforcement cage needs to be bound on site, then cast-in-place is carried out, the construction is complex and tedious, and the site construction time is long. And the reinforced concrete continuous box girder easily produces horizontal crack at parts such as girder roof, flange board, diaphragm roof beam, influences the durability of structure and increases the later stage maintenance degree of difficulty.

At present, corrugated steel and I-shaped steel are mainly adopted for replacing a web plate of a concrete box girder or a steel-concrete combined box girder with a steel structure and a concrete structure combined outside.

In the aspect of connection structure, the details such as girder steel, concrete bridge panel, steel-concrete connection are covered in the structure of steel-concrete combination box girder bridge, the continuous beam changes greatly from the fulcrum to the stress condition of midspan section, especially the stress problem is more complicated in the hogging moment area, need consider suitable connecting piece type, arrangement scope, set up parameter such as interval, it is unsuitable to design the connecting piece completely based on bearing capacity's theory, a large amount of detail processing has reduced construction speed and production efficiency, so the industrialization of reinforcing bar concrete system, the degree of assemblization are not high yet.

In the aspect of mechanical characteristics, under the action of positive bending moment, a tension area of the section of the continuous beam is a steel plate with higher tensile strength, a compression area is a concrete bridge deck with higher compressive strength and lower cost, but in a negative bending moment area of a pier, the stress of the section is really inverted, so that the performances of two materials cannot be fully exerted, and the stress of the bridge deck is in the most unfavorable position.

Therefore, the prior art has the problems that: the box girder of the reinforced concrete structure has low industrialization and assembly degree and unreasonable stress structure.

Disclosure of Invention

The invention aims to provide a truss type steel reinforced concrete box girder which is high in industrialization and assembly degree and reasonable in stress structure.

The technical solution for realizing the purpose of the invention is as follows:

a truss type steel reinforced concrete box girder comprises a steel truss 1, a sealing pipe 2 arranged on the central axis of the steel truss 1 and a concrete layer 3 poured on the outer side of the sealing pipe 2 and integrally covering the periphery of the steel truss 1.

Compared with the prior art, the invention has the following remarkable advantages:

1. the stress structure is reasonable: compared with the common concrete beam, the concrete beam has the advantages of high bearing capacity, high rigidity, good durability, convenience in construction and the like, can be applied to a large-span bridge, and has important significance for building a bridge structure meeting the modernization requirement. Compared with the common concrete box girder, the truss type steel reinforced concrete box girder structure uses less steel when the same bearing capacity is met, saves the steel resource and conforms to the concept of green development; compared with a reinforced concrete combined box girder, the design principle is simple, the calculation method of reinforced concrete is directly applied after the conversion of the reinforcing steel bars, the structure is convenient to manufacture and construct, and the performances of steel and concrete can be fully exerted;

2. the industrialization and assembly degree is high: the truss type steel reinforced concrete structure can be prefabricated and maintained in batches in a factory, internal nodes of the truss are welded or high-strength bolts, assembling workload is small, and the aim of saving cost is fulfilled; through the pre-buried tensile bolt that excels in of beam column node and the trompil steel sheet of beam-ends welded, can realize the quick dry joint of job site node, reduce wet joint operation, shorten construction cycle, green.

The invention is described in further detail below with reference to the figures and the detailed description.

Drawings

FIG. 1 is a schematic view of the external structure of the truss steel reinforced concrete box girder of the present invention.

Fig. 2 is a schematic structural view of the steel truss of fig. 1.

Fig. 3 is a front view of fig. 2.

Fig. 4 is a top view of fig. 2.

Fig. 5 is an enlarged view of the node in fig. 3.

Fig. 6 is a front view of fig. 1.

Fig. 7 is a cross-sectional view taken along line I-I in fig. 6.

Fig. 8 is a sectional view taken along line II-II in fig. 6.

Fig. 9 is a schematic diagram of embedding of the beam-column joint screws.

Fig. 10 is a schematic view of the beam-column joint assembly.

In the figure, a steel truss 1, a sealing pipe 2, a concrete layer 3,

upper chord 11, lower chord 12,

vertical web members

13, 131, 132, 133,

diagonal web members

14, 141, 142,

a top plate 15, a bottom plate 16, a gusset plate 17, perforated

steel plates

18, 19, and a stiffener 110.

Detailed Description

As shown in figure 1, the truss type steel reinforced concrete box girder comprises a steel truss 1, a sealing pipe 2 arranged on the central axis of the steel truss 1 and a concrete layer 3 poured outside the sealing pipe 2 and integrally coating the periphery of the steel truss 1.

According to the invention, the steel truss 1 formed by splicing steel materials is wrapped inside the concrete layer 3, and the beam column is quickly dry-jointed on a construction site through the perforated steel plate 7 at the end and the embedded screw at the beam column joint position, so that the wet joint operation is reduced, and the site construction period is shortened.

As shown in fig. 2, 3 and 4, the steel truss 1 includes two upper chords 11 with a full length, two lower chords 12 with a full length, and a plurality of vertical web members 13 vertically connected to the upper chords 11 and the lower chords 12 on the same side, and the plurality of vertical web members 13 are uniformly arranged along the axial direction;

the steel truss structure is characterized by further comprising a plurality of diagonal web members 14, the lower end of a central vertical web member 131 on one side of the steel truss 1 is respectively connected with one end of each of two

diagonal web members

141 and 142, the other end of each of the two

diagonal web members

141 and 142 is respectively connected with the upper ends of the

vertical web members

132 and 133 adjacent to the two sides of the vertical web member 131, the other diagonal web members 14 on the same side are respectively parallel to the two

diagonal web members

141 and 142 on two sides, one end of each diagonal web member is connected with the lower end of a vertical web member 13, and the other end of each diagonal web member is connected with the upper end of an;

the two ends of the upper batten plate 15 are fixedly connected with the two upper chords 11 which are all long, and the two ends of the lower batten plate 16 are fixedly connected with the two lower chords 12 which are all long;

the connecting structure also comprises two perforated

steel plates

18 and 19, and connecting holes for connecting bolts to pass through are formed in the peripheries of the perforated

steel plates

18 and 19;

the perforated

steel plates

18 and 19 are respectively and fixedly connected with two ends of the upper chord 11 and the lower chord 12 in a vertical mode.

As shown in fig. 5, two ends of each vertical web member 13 are fixedly connected to the upper chord 11, the lower chord 12 and the diagonal web member 14 through a gusset plate 17.

As shown in fig. 3 and 6, the upper surface of the upper chord 11 near the two ends and the lower surface of the lower chord 12 near the two ends are also fixedly connected with the perforated

steel plates

18 and 19 through the stiffening ribs 110.

Preferably, the upper chord 11, the lower chord 12, the vertical web members 13 and the diagonal web members 14 are all made of angle steel.

The sealing pipe 2 is a PVC sealing square pipe.

The longitudinal upper chord 11 and the longitudinal lower chord 12 can be a whole continuous angle steel or can be divided into a plurality of sections of short angle steel, and are spliced by a gusset plate 17 during use.

The preparation method of the invention comprises the following steps:

the

chord members

11, 12 and the

web members

13, 14 are connected at the inner surface of the gusset plate 17 by high-strength bolts or welding to constitute two plane trusses of the vertical surface of the present invention. And then, the upper surface of the upper chord 11 and the lower surface of the lower chord 12 are welded with

lacing plates

15 and 16, and two trusses are spliced into a space steel truss. For effective transmission of internal force and axial stress of each part, the chord member and the web member are connected at the gusset 17 such that the section shape center lines of the angle steels intersect at a point.

Then, the PVC sealing square pipe 2 is placed and fixed in the steel truss, and then the beam end opening

steel plates

18 and 19 and the stiffening rib 110 are welded. The perforated

steel plates

18 and 19 are fully welded with the vertical web members 13 and the

gusset plates

15 and 16 at the ends of the truss, and then the stiffening ribs 110 are welded with the upper chord members 11 and the

perforated steel plates

18 and 19 at the joints, so that the steel truss is manufactured.

As shown in fig. 7 and 8, after the steel truss is spliced, concrete is poured, and a middle cavity of the section of the box girder is formed by the PVC sealing square tube 2 which is placed in advance. It should be noted that the PVC sealing square pipe 2 is always placed inside the truss without being drawn out.

As shown in fig. 9, according to the requirements of the positions of the holes of the perforated

steel plates

18 and 19 at the beam ends, screw portions of high-strength friction bolts are embedded in the positions of beam-column joints on the concrete columns.

As shown in fig. 10, bolt anchoring assembly of the beam-column joint can be performed on the construction site according to the positions of the holes of the beam-end perforated

steel plates

18 and 19 and the positions of the embedded screws on the concrete column.

The truss type steel reinforced concrete box girder assembled by the method can greatly improve the industrialization and the assembly degree of a steel reinforced concrete structure, facilitate construction, accelerate the construction speed and the production efficiency of the structure, save the construction period and the engineering cost, optimize the size and the dead weight of a large span structure in the field of bridges by a box type structure, improve the structural strength, and improve the structural integrity, the crack resistance and the durability, thereby realizing the aims of saving the cost, shortening the period and protecting the environment.

Claims

1. a truss type steel reinforced concrete box girder is characterized in that:

It comprises a steel truss (1), a sealing pipe (2) placed on the central axis of the steel truss (1), and a concrete layer ( 3).

2. truss type reinforced concrete box girder according to claim 1, is characterized in that:

The steel truss (1) includes two full-length upper chords (11), two full-length lower chords (12), and a plurality of vertically connected upper chords (11) and lower chords (12) on the same side vertical web rods (13), the plurality of vertical web rods (13) are evenly arranged along the axial direction;

It also includes a plurality of oblique web bars (14), and the lower ends of a vertical web bar (131) in the center of one side of the steel truss (1) are respectively connected with one end of the two oblique web bars (141, 142). The other ends of the diagonal web rods (141, 142) are respectively connected with the upper ends of the vertical web rods (132, 133) adjacent to both sides of the vertical web rod (131), and the remaining diagonal web rods (14) on the same side are divided into two sides. are respectively parallel to the two inclined web rods (141, 142), and one end is connected to the lower end of a vertical web rod (13), and the other end is connected to the upper end of the adjacent vertical web rod (13);

It also includes an upper trim plate (15) and a lower trim plate (16). ) both ends are respectively fixedly connected with the two long lower chords (12);

Also includes two perforated steel plates (18, 19), and the perforated steel plates (18, 19) are provided with connecting holes for connecting bolts to pass through near the periphery;

The perforated steel plates (18, 19) are respectively vertically and fixedly connected to both ends of the upper and lower chords (11, 12).

3. truss type reinforced concrete box girder according to claim 2 is characterized in that:

Both ends of each of the vertical web bars (13) are fixedly connected to the upper and lower chord bars (11, 12) and the oblique web bar (14) through a gusset plate (17) respectively.

4. truss type reinforced concrete box girder according to claim 2, is characterized in that:

The upper surfaces of the upper chord (11) close to the two ends and the lower surfaces of the lower chord (12) close to the two ends are also fixedly connected to the perforated steel plates (18, 19) through stiffening ribs (110).

5. truss type reinforced concrete box girder according to claim 2 is characterized in that:

The upper chord rod (11), the lower chord rod (12), the vertical web rod (13) and the inclined web rod (14) are all made of angle steel.

6. truss type reinforced concrete box girder according to claim 1, is characterized in that:

The sealing tube (2) is a PVC sealing square tube.