CN213625177U

CN213625177U - double-T beam structure

Info

Publication number: CN213625177U
Application number: CN202021253677.3U
Authority: CN
Inventors: 马骉; 颜海; 张春雷; 黄虹; 苏俭; 赵鹏; 肖容; 赵陈嘉皇; 祝林盛; 魏明光; 崔伟; 张耀生
Original assignee: Shanghai Municipal Engineering Design Insitute Group Co Ltd
Current assignee: Shanghai Municipal Engineering Design Insitute Group Co Ltd
Priority date: 2020-07-01
Filing date: 2020-07-01
Publication date: 2021-07-06
Anticipated expiration: 2030-07-01

Abstract

The utility model relates to the technical field of bridge engineering, in particular to a double-T beam structure, which is characterized in that the double-T beam structure comprises a prefabricated part and a cast-in-place part, the prefabricated part consists of two webs and a top plate, the lower end of each web is provided with a symmetrical horseshoe structure, prestressed steel strands are arranged in the webs, and a pre-tensioning folding line process is adopted to bend part of the steel strands at the beam end; and connecting the prefabricated parts through cast-in-place parts along the width direction of the double T-shaped beam to form a whole. The utility model discloses a two T roof beam structure economic nature is better, and transportation, installation stability are good, and application scope is wide, its opening cross-section, do not have characteristics such as cross-centre crossbeam, pretension broken line prestressing force technology, very big promotion construction convenience, the later stage maintenance of being convenient for, the theory is built in the adaptation industrialization, and the view effect also promotes greatly simultaneously, has fine environmental benefit, social and economic benefits, is worth promoting and using.

Description

double-T beam structure

Technical Field

The utility model relates to a bridge engineering technical field, concretely relates to two T beam structure.

Background

In the bridge construction of China at present, the superstructure generally takes a beam bridge as a basic structural form, and can adopt prefabricated hollow slab beams, prefabricated T beams, prefabricated small box beams, segmental prefabricated box beams, cast-in-place concrete box beams, steel-concrete composite beams, steel beams and the like.

The prefabricated hollow slab beam is applicable to a small span range and is generally only used for bridge structures with the span of less than 22 m. The traditional prefabricated T roof beam's diaphragm is more, and cast-in-place work load is great, and transportation installation stability is poor, and the view effect is not good enough. The section precast box girder has poor adaptability to a wide section bridge, has high requirements on prefabrication, transportation, hoisting and bridge erection assembling equipment when the section is large, has poor adaptability to the construction environment, has high construction cost and is long in construction period. The cast-in-place concrete box girder has long construction period, great traffic and environmental influence and difficult control of construction quality. The steel-concrete combined beam and steel beam has high construction cost and large later maintenance workload, and is generally only used for crossing special nodes. The prefabricated small box girder is widely applied at present, but due to the existence of a structural inner cavity, the manufacturing, the installation and the disassembly of the prefabricated inner die of the girder body are difficult, and the beam body prefabrication speed, the manufacturing cost, the quality and other aspects are limited by the limit and cannot be further improved.

In order to break through the bottleneck, the design concept must be taken as a source and an entry point, the existing traditional design concept is broken through, and a design concept and a structure suitable for an industrial construction mode are provided.

SUMMERY OF THE UTILITY MODEL

To the problem, the utility model provides a two T beam structure has the opening cross-section, does not have characteristics such as cross-beam, pretension broken line prestressing force technology.

The utility model discloses a realize by following technical scheme and accomplish: a double-T beam structure is characterized by comprising a prefabricated part and a cast-in-place part, wherein the prefabricated part comprises two webs and a top plate, the lower end of each web is provided with a symmetrical horseshoe structure, prestressed steel strands are arranged in the webs, and a pre-tensioning folding line process is adopted to bend part of the prestressed steel strands at the beam end; and connecting the prefabricated parts through cast-in-place parts along the width direction of the double T-shaped beam to form a whole.

Furthermore, the cast-in-place part adopts welding or lap joint for the connection of the steel bars between the adjacent prefabricated parts, adopts a linear bar or an annular bar for the form of the connecting steel bars, and adopts an ultra-high performance concrete material or a common concrete material corresponding to cast-in-place concrete.

Furthermore, the double-T beam structure adopts an open cross section, only end cross beams are arranged, and no cross center cross beam is arranged.

Furthermore, the double-T beam structure is characterized in that the applicable span is 25-40 m.

Further, the thickness of the double-T beam web is different along the length direction, wherein the midspan shearing force is smaller, and the thickness of the web is smaller; the shearing force near the pivot is larger, and the thickness of the web plate is larger; and a local transition section is arranged at the middle part of the span-middle and fulcrum, so that the thickness of the web plate is changed in the local transition section, and the length of the local transition section is 0.4-0.6 m.

The utility model discloses a two T roof beam structure economic nature is better, and transportation, installation stability are good, and application scope is wide, its opening cross-section, do not have characteristics such as cross-centre crossbeam, pretension broken line prestressing force technology, very big promotion construction convenience, the later stage maintenance of being convenient for, the theory is built in the adaptation industrialization, and the view effect also promotes greatly simultaneously, has fine environmental benefit, social and economic benefits, is worth promoting and using.

Drawings

The invention will be described in more detail hereinafter with reference to the accompanying drawings. Wherein:

fig. 1 is a schematic cross-sectional view of a double-T beam structure of the present invention;

fig. 2 is a schematic elevation view of a double-T beam structure of the present invention;

FIG. 3 is a schematic diagram of a prefabricated part of a middle double T-beam structure of the present invention;

in the drawings, like parts are provided with like reference numerals.

Detailed Description

The features of the present invention will be further explained by describing in detail a preferred embodiment thereof with reference to the attached drawings, so as to facilitate understanding by those skilled in the art:

as shown in fig. 1 to 3, the labels in the figures are: prefabricated part 1, cast-in-place part 2. The prefabricated part comprises a top plate 5 and two webs 6 positioned below the top plate, the lower end of each web is provided with a symmetrical horseshoe structure 7, prestressed steel strands are arranged in the webs, and a pre-tensioning folding line process is adopted to bend part of the prestressed steel strands at the beam end. As shown in the figure, the lower end of the web plate is provided with symmetrically arranged convex parts, the tops of the convex parts are inclined planes, the inner sides of the convex parts are slightly higher and the outer sides of the convex parts are slightly lower near the web plate, and therefore a symmetrical horseshoe structure is formed. Proved by verification, the height of the horseshoe structure is 180-220 mm, the width of the horseshoe structure is 450-550 mm, the inclination of the inclined plane at the upper end of the horseshoe structure is preferably 1:1, and the horseshoe structure can be optimized along with the change of the span.

The prefabricated part 1 in the double-T beam structure is cast and prefabricated in a prefabricating factory, and the prefabricated part 1 is made of common concrete materials. Firstly, positioning and installing a template, then binding common steel bars of a precast beam body, then carrying out bundle penetrating arrangement on pre-tensioned prestressed steel strands, installing a self-balancing pressing anchorage device, then tensioning the prestressed steel strands, and finally sealing the mold and pouring concrete. And (3) when the concrete strength and the elastic modulus of the prefabricated part 1 meet the design requirements, releasing the prestressed steel strand to finish the prefabrication construction of the prefabricated part 1.

And then, transporting the prefabricated part 1 to a construction site through transportation equipment, installing the prefabricated part 1 on a constructed bent cap by adopting hoisting equipment, and finally pouring the concrete of the cast-in-place part 2, wherein the concrete of the cast-in-place part can be made of an ultrahigh-performance concrete material or a common concrete material according to the form of connecting steel bars. And when the concrete strength of the prefabricated part 2 reaches the design requirement, completing the construction of the double-T beam structure.

The double T-shaped beam can be a simple supporting structure or a continuous structure. If the structure is a simple support structure, a broken joint is formed between the beams in the length direction, and an expansion joint or a continuous joint can be arranged at the position of the broken joint. If the beam is of a continuous structure, cast-in-place seams are formed between beams in the length direction, namely after the prefabricated double-T beam is erected, two adjacent beams in the length direction are connected into a whole through pouring concrete.

As shown in fig. 2, the double-T beam structure has an open cross section, and only the end beam 3 is arranged at the support, and no cross beam is arranged. One part of the end beam and the precast beam are precast together in a factory, and after the on-site double T-beam erection is finished, two adjacent beams in the width direction are connected into a whole by pouring concrete.

The thickness of the double T-beam web varies according to the shear force to be borne. The midspan shear force is small, and the thickness of the web plate is small; the shearing force near the pivot is larger, and the thickness of the web plate is larger. The traditional way is to gradually change the length direction within the range of 3m to 6 m. The utility model discloses a set up local changeover portion 4, length is 0.5m, and similar sudden change makes web thickness change in local changeover portion, has both satisfied the atress requirement, and it is unified to make the reinforcing bar full-page proof again, and the industrialization processing preparation of being convenient for, simplification template that can be very big in addition makes the template adopt mechanized dismouting.

The applicable span of a common double T-shaped beam is smaller, generally less than about 20m, and a horseshoe is not arranged.

The utility model discloses a two T roof beams use the span extensively, 25m ~ 40m sets up the horse hoof and mainly considers from aspects such as atress, economic nature:

(1) the span is increased, the stress of the beam body is increased, and the beam height is increased. Set up the horse-shoe and can only locally increase the concrete area of roof beam body lower extreme (form the horse-shoe) under the condition that does not increase web thickness to set up the steel bundle quantity that satisfies the atress needs, improve concrete, steel bundle utilization ratio, satisfy the atress needs of the roof beam body, improve structural rationality.

(2) The arrangement of the horseshoe improves the reasonability of the structure and simultaneously improves the economy. By arranging the horseshoe, the concrete material can be reduced by about 10%, and the steel strand material can be reduced by about 25%.

(3) The utility model discloses a two T roof beams do not have middle cross beam, along with the increase of striding, its horizontal space effect obviously increases, through setting up the horse's hoof, can effectively resist the side direction flexure that the space effect brought, improves structural security.

Although the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention, which is defined by the appended claims.

Claims

1. A double-T beam structure is characterized by comprising a prefabricated part and a cast-in-place part, wherein the prefabricated part comprises two webs and a top plate, the lower end of each web is provided with a symmetrical horseshoe structure, prestressed steel strands are arranged in the webs, and part of the prestressed steel strands are bent at the beam end; and connecting the prefabricated parts through cast-in-place parts along the width direction of the double T-shaped beam to form a whole.

2. The double-T beam structure of claim 1, wherein the cast-in-place part is formed by welding or overlapping the steel bars between the adjacent precast beams, the connecting steel bars are formed by straight bars or annular bars, and the cast-in-place concrete is made of ultra-high performance concrete materials or common concrete materials.

3. A double T-beam structure according to claim 1, wherein an open cross-section is used, with only end beams and no cross beams.

4. The double T-beam structure of claim 1, wherein the applicable span is 25 m-40 m.

5. The double T beam structure of claim 1 wherein the double T beam web thicknesses vary lengthwise, with a smaller mid-span web thickness; the thickness of the web near the pivot is larger; and a local transition section is arranged at the middle part of the span-middle and fulcrum, so that the thickness of the web plate is changed in the local transition section, and the length of the local transition section is 0.4-0.6 m.