阅读说明：本技术 一种用于宽幅箱梁矮塔斜拉桥的上部结构及施工方法 (Superstructure for wide box girder and short tower cable-stayed bridge and construction method ) 是由 王宏博 李怀峰 徐召 王志英 陈国红 白光耀 张常勇 贺攀 王洺鑫 马雪媛 王溧 于 2019-10-31 设计创作，主要内容包括：本发明涉及一种用于宽幅箱梁矮塔斜拉桥的上部结构及施工方法,包括主梁体,所述主梁体为箱梁结构,所述主梁体上表面的两侧分别对称搭接有桥面组件；所述主梁体与桥面组件之间设有斜撑组合件,所述斜撑组合件倾斜布置,所述斜撑组合件的下端与主梁体的下部固定,所述斜撑组合件的上端与斜面组件的下端面接触并实现桥面组合件的支撑；所述桥面组件能够实现主梁体在宽度方向的延伸,所述主梁体与桥面组件形成桥面梁体结构。本发明能够减小宽幅箱梁矮塔斜拉桥主梁体的剪力滞效应,提高主梁体横向受力性能以及解决常规挂篮不能满足矮塔斜拉桥宽幅箱梁悬臂浇筑的问题。(The invention relates to an upper structure and a construction method for a wide box girder and short tower cable-stayed bridge, which comprises a main girder body, wherein the main girder body is of a box girder structure, and bridge deck components are symmetrically lapped on two sides of the upper surface of the main girder body respectively; an inclined strut assembly is arranged between the main beam body and the bridge deck assembly, the inclined strut assembly is obliquely arranged, the lower end of the inclined strut assembly is fixed with the lower part of the main beam body, and the upper end of the inclined strut assembly is in contact with the lower end face of the inclined plane assembly to support the bridge deck assembly; the bridge deck assembly can realize the extension of the main beam body in the width direction, and the main beam body and the bridge deck assembly form a bridge deck beam body structure. The invention can reduce the shear hysteresis effect of the main beam body of the wide-width box girder and the short-tower cable-stayed bridge, improve the transverse stress performance of the main beam body and solve the problem that the conventional hanging basket cannot meet the requirement of cantilever casting of the wide-width box girder of the short-tower cable-stayed bridge.)

1. The upper structure for the wide box girder and short tower cable-stayed bridge is characterized by comprising a main girder body, wherein the main girder body is of a box girder structure, and bridge deck components are symmetrically lapped on two sides of the upper surface of the main girder body respectively;

an inclined strut assembly is arranged between the main beam body and the bridge deck assembly, the inclined strut assembly is obliquely arranged, the lower end of the inclined strut assembly is fixed with the lower part of the main beam body, and the upper end of the inclined strut assembly is in contact with the lower end face of the inclined plane assembly to support the bridge deck assembly;

the bridge deck assembly can realize the extension of the main beam body in the width direction, and the main beam body and the bridge deck assembly form a bridge deck beam body structure.

2. The superstructure for a wide box girder short tower cable-stayed bridge according to claim 1, wherein the diagonal brace assembly comprises a steel pipe, a base is fixedly installed at the lower end of the steel pipe, embedded steel plates are respectively arranged at the lower parts of the two side surfaces of the main girder body, and the base is fixedly connected with the embedded steel plates through embedded bolts.

3. The superstructure for wide box girder short tower cable-stayed bridges according to claim 1, wherein the bracing assembly comprises a U-shaped channel steel, the U-shaped channel steel is horizontally arranged, the U-shaped channel steel is positioned right below the bridge deck component and is fixedly connected with the steel pipe, concrete is poured in the U-shaped channel steel, and the upper surface of the U-shaped channel steel is in contact with the lower surface of the bridge deck component to realize support.

4. The superstructure for a wide box girder short tower cable-stayed bridge according to claim 1, wherein the main girder body is provided at both sides thereof with legs for overlapping the deck assembly, the deck assembly is connected with the upper surface of the main girder body by a wet joint, and the wet joint is a concrete cast-in-place structure.

5. The superstructure for wide box girder short tower cable-stayed bridges according to claim 1, wherein the deck assembly comprises precast slabs, which are square slab members.

6. The superstructure for a wide box girder short tower cable-stayed bridge according to claim 3, characterized in that an end plate is fixedly arranged at one end of the U-shaped channel steel close to the girder body, and a pre-buried bolt is arranged at one side of the girder body close to the U-shaped channel steel and fixedly connected with the end plate.

7. The superstructure for a wide box girder short tower cable-stayed bridge according to claim 1, wherein the deck assembly at each side of the main girder is formed by sequentially splicing a plurality of precast slabs, and the precast slabs at the same side are connected by wet joints.

8. A construction method suitable for a wide box girder and short tower cable-stayed bridge, which is characterized in that the constructed wide box girder and short tower cable-stayed bridge utilizes the superstructure for the wide box girder and short tower cable-stayed bridge as claimed in any one of claims 1 to 7, and comprises the following steps:

step 1, bottom structure construction: the construction method comprises the following steps of constructing a pile foundation, a cushion cap and a pier body;

step 2, constructing the middle beam body, the connecting sections and the tower column by adopting a support method, and installing a hanging basket;

step 3, adopting cantilever construction for the ropeless area beam section of the main beam body, and tensioning longitudinal prestress; lagging one or more beam sections, firmly connecting the steel inclined strut assembly with the embedded part of the main beam body, hoisting the precast slab, and pouring a transverse wet joint;

step 4, constructing the girder section with the cable of the main girder body by using a cantilever, moving the hanging basket from the bridge tower to two sides, symmetrically constructing the main girder body, and tensioning longitudinal prestress; sequentially installing stay cables and tensioning in place;

the transverse inclined strut combination section lags behind one or more beam sections to carry out construction synchronously; installing a side span cast-in-place support, and pouring a side span cast-in-place section;

and 5, completing construction of the closure section of the middle span and the side span of the main girder body, tensioning longitudinal prestressed steel bundles of the closure section, synchronously constructing a steel diagonal bracing assembly, and pouring a longitudinal wet joint of the bridge deck.

9. The construction method for the wide box girder short tower cable-stayed bridge according to claim 8, wherein in the step 3, concrete is poured into the steel pipe; and when the concrete in the steel pipe reaches the designed strength, hoisting the precast slab above the steel inclined strut assembly.

Technical Field

The invention belongs to the technical field of bridges, and particularly relates to an upper structure and a construction method for a wide box girder and short tower cable-stayed bridge.

Background

A short-tower cable-stayed bridge, also called a partial cable-stayed bridge, is a beam and cable combined system bridge between a continuous beam and a cable-stayed bridge. The short-tower cable-stayed bridge has the advantages that due to the fact that the short tower is rigid, the fatigue of the stay cable is reduced, the utilization rate of the stay cable is improved, and the short-tower cable-stayed bridge has good economic performance; the cloth span is flexible, the single span reasonable span is 100-300 m, and the application range is wide; the height of the main beam body is about 1/2 of the same span continuous beam, and the appearance is light; therefore, the method has wide application prospect.

Due to the characteristic of stress on the section of the main beam body, most of the cable towers of the short-tower cable-stayed bridge are arranged in the central separation belt, and a central cable surface is adopted. In recent years, with the increasing of domestic traffic volume, the construction of six-lane and eight-lane width projects is started on the high-grade roads in China, particularly on the large-span bridges spanning large rivers, because the transverse width is increased, the transverse stress of the main beam body of the short-tower cable-stayed bridge is more complicated, the shear hysteresis effect is more obvious, the stress performance of the main beam body is reduced, and the application and popularization of the short-tower cable-stayed bridge in wide box beams are influenced.

The inventor knows that: in the construction of short-tower cable-stayed bridge, the construction is generally carried out by adopting a hanging basket cantilever casting method, and compared with the construction of full-space supports, the method can overcome unfavorable terrains, so that the construction of the upper structure of the bridge in sections is realized, and the method has the advantages of simplicity and convenience in construction, less cost, good structural integrity, relatively simple maintenance and smaller maintenance workload.

But the inventor believes that: for the central cable-plane short-tower cable-stayed bridge with six bidirectional lanes and eight bidirectional lanes, because the box girder is wider, the transverse width of the cradle is increased, the conventional cradle can not meet the stress requirement, the design must be strengthened again, the cost is increased, and brand-new challenges are brought to the design and manufacture of the wide cradle and the safety of the wide cradle in the cantilever construction process.

Disclosure of Invention

The invention aims to provide an upper structure and a construction method for a wide box girder and short tower cable-stayed bridge, which can reduce the shear hysteresis effect of a main girder body of the wide box girder and short tower cable-stayed bridge, improve the transverse stress performance of the main girder body and solve the problem that the conventional cradle can not meet the requirement of cantilever casting of the wide box girder of the short tower cable-stayed bridge.

In order to achieve the purpose, the invention adopts the following technical scheme: the upper structure for the wide box girder and short tower cable-stayed bridge comprises a main girder body, wherein the main girder body is of a box girder structure, and bridge deck components are symmetrically lapped on two sides of the upper surface of the main girder body respectively;

an inclined strut assembly is arranged between the main beam body and the bridge deck assembly, the inclined strut assembly is obliquely arranged, the lower end of the inclined strut assembly is fixed with the lower part of the main beam body, and the upper end of the inclined strut assembly is in contact with the lower end face of the inclined plane assembly to support the bridge deck assembly;

the bridge deck component is a longitudinal stress member on the support and inclined support combined component, the extension of a main beam body in the width direction can be realized, and the main beam body and the bridge deck component form a bridge deck beam body structure.

Further, the bracing sub-assembly includes the steel pipe, the lower extreme fixed mounting of steel pipe has the base, the lower part of girder body both sides face is equipped with pre-buried steel sheet respectively, the base passes through pre-buried bolt fixed connection with pre-buried steel sheet.

Further, the bracing sub-assembly includes U type channel-section steel, U type channel-section steel level is arranged, and U type channel-section steel is located the bridge floor subassembly under, U type channel-section steel and steel pipe fixed connection, concrete has been pour in the U type channel-section steel, the upper surface of U type channel-section steel and the lower surface contact of bridge floor subassembly are in order to realize supporting.

Furthermore, the two sides of the main beam body are provided with supporting legs which are used for lapping the bridge deck assembly, the bridge deck assembly is connected with the upper surface of the main beam body through wet joints, and the wet joints are of concrete cast-in-place structures.

Further, the bridge deck assembly comprises precast slabs, and the precast slabs are square plates.

Further, the fixed end plate that is equipped with of one end that U type channel-section steel is close to the girder body, one side that the girder body is close to U type channel-section steel is equipped with buried bolt in advance, buried bolt in advance and end plate fixed connection.

Furthermore, the bridge deck assembly on each side of the main beam body is formed by sequentially splicing a plurality of precast slabs, and the precast slabs on the same side are connected through wet joints.

The invention also provides a construction method suitable for the wide box girder short-tower cable-stayed bridge, the constructed wide box girder short-tower cable-stayed bridge utilizes the upper structure for the wide box girder short-tower cable-stayed bridge, and the construction method comprises the following steps:

step 1, bottom structure construction: the construction method comprises the following steps of constructing a pile foundation, a cushion cap and a pier body;

step 2, constructing the middle beam body, the connecting sections and the tower column by adopting a support method, and installing a hanging basket;

step 3, adopting cantilever construction for the ropeless area beam section of the main beam body, and tensioning longitudinal prestress; lagging one or more beam sections, firmly connecting the steel inclined strut assembly with the embedded part of the main beam body, hoisting the precast slab, and pouring a transverse wet joint;

step 4, constructing the girder section with the cable of the main girder body by using a cantilever, moving the hanging basket from the bridge tower to two sides, symmetrically constructing the main girder body, and tensioning longitudinal prestress; sequentially installing stay cables and tensioning in place;

the transverse inclined strut combination section lags behind one or more beam sections to carry out construction synchronously; installing a side span cast-in-place support, and pouring a side span cast-in-place section;

step 5, completing construction of the closure section of the middle span and the side span of the main girder body, tensioning longitudinal prestressed steel bundles of the closure section, synchronously constructing a steel diagonal bracing assembly, and pouring a longitudinal wet joint of the bridge deck;

further, in the step 3, concrete is poured into the steel pipe; and when the concrete in the steel pipe reaches the designed strength, hoisting the precast slab above the steel inclined strut assembly.

The invention has the beneficial effects that:

1) the whole wide box girder of the short-tower cable-stayed bridge is broken into parts, the wide box girder is formed by splicing a narrower main girder body and a bridge deck component, the girder construction is conveniently realized by utilizing a hanging basket, and the stress of each part is clearer and clearer;

2) the cantilever casting construction can be realized by adopting the conventional hanging basket with the width, so that the redesign of the hanging basket with the width is avoided, the construction difficulty is reduced, and the construction cost is saved; the influence of the shear hysteresis effect of the whole wide box girder of the traditional short-tower cable-stayed bridge is reduced.

3) The width of the main beam can adapt to the range of less than 42 meters, and the width requirements of most of the existing bridges of expressways, municipal roads and common roads can be met; the steel structure can be manufactured in factories, hoisted and installed on site, the construction speed is high, and the quality is reliable.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a schematic cross-sectional view of a main beam body according to an embodiment of the present invention;

FIG. 2 is a detailed structural diagram of portion A of FIG. 1;

FIG. 3 is a schematic structural diagram of an end sealing plate according to an embodiment of the present invention;

FIG. 4 is a detailed structural diagram of a portion B in FIG. 1;

FIG. 5 is a schematic plan view of the prefabricated panels according to the embodiment of the present invention;

FIG. 6 is a schematic view of a transverse joint of prefabricated panels according to an embodiment of the present invention;

FIG. 7 is a sectional area division view of a wide box girder according to an embodiment of the present invention;

FIG. 8 is a schematic front view showing the construction of a lower structure in the embodiment of the present invention;

FIG. 9 is a schematic top view of the construction of the substructure according to an embodiment of the present invention;

FIG. 10 is a schematic illustration of the construction of a tower column in a front view direction according to an embodiment of the present invention;

FIG. 11 is a schematic illustration of tower construction in a top view according to an embodiment of the present invention;

FIG. 12 is a schematic illustration of cantilever casting of a main beam body ropeless section in a front view direction according to an embodiment of the present invention;

FIG. 13 is a schematic illustration of the cantilever casting of the funicular zone beam section of the main beam body in the top view direction according to the embodiment of the invention;

FIG. 14 is a schematic view of beam segment cantilever casting and stay cable installation in a cable area of a main beam body in a main viewing direction according to an embodiment of the present invention;

FIG. 15 is a schematic diagram of beam segment cantilever casting and stay cable installation in a cable zone of a main beam body in a top view direction according to an embodiment of the present invention;

FIG. 16 shows the construction of the closure section of the main beam body in the front view direction according to the embodiment of the present invention;

FIG. 17 is a top view of the construction of the closure section of the main beam body according to the embodiment of the present invention;

FIG. 18 illustrates the construction of the auxiliary structure in the front view direction according to the embodiment of the present invention;

FIG. 19 is a top view of an attachment structure according to an embodiment of the present invention;

in the figure: 1. a main beam body; 2. a sprag assembly; 3. a bridge deck section; 4. an end plate; 5. wet seaming; 6. prefabricating a slab; 7. u-shaped channel steel; 8. embedding bolts in advance; 9. embedding a flange steel plate; 10. a flanged steel plate base; 11. a square steel pipe; 12. riveting; 13. a bridge pier; 13A, a bearing platform; 13B, pile foundation; 14. a support is cast in place; 15. hanging a basket; 16. a tower column; 17. a connecting segment; 18. a stay-free segment; 19. a guardrail; 20. side span cast-in-place section; 20A, side span cast-in-place support; 21. and (4) stay cables.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In a typical embodiment of the present invention, as shown in fig. 1 to 3, an upper structure for a wide box girder short-tower cable-stayed bridge comprises a main girder body 1, wherein the main girder body 1 is a box girder structure, and bridge deck assemblies 3 are symmetrically lapped on two sides of the upper surface of the main girder body 1;

an inclined strut assembly 2 is arranged between the main beam body 1 and the bridge deck component 3, the inclined strut assembly 2 is obliquely arranged, the lower end of the inclined strut assembly 2 is fixed with the lower part of the main beam body 1, and the upper end of the inclined strut assembly 2 is in contact with the lower end face of the inclined plane component and supports the bridge deck assembly;

the bridge deck assembly 3 can realize the extension of the main beam body 1 in the width direction, and the main beam body 1 and the bridge deck assembly 3 form a bridge deck beam body structure.

Specifically, the main beam body 1 is a concrete main beam body 1, the concrete main beam body 1 and the bridge deck assembly 3 (precast slab 6) can adopt concrete above C50, and the steel diagonal bracing assembly 2 can adopt Q355, Q370 and Q420 steel materials in national standards. The steel main beam body 1 is connected with the concrete bridge deck slab through cylindrical head welding nails, the types of the shear nails generally adopt M19 and M22, the length of the shear nails is 2/3 of the height of U-shaped channel steel 7, and the length of the shear nails is not less than 15 cm.

When the wide-width box girder structure is constructed, firstly, a hanging basket 15 is adopted to cast a middle main box girder in a cantilever mode, a steel inclined strut assembly 2 is installed behind the middle main box girder and firmly connected with embedded steel bars or embedded bolts 8 of the middle main box girder, then, the prefabricated plates 6 are hoisted, and finally, the wet joints 5 are cast to form a whole body and bear the force jointly.

The inclined strut assembly part 2 comprises a steel pipe, a base is fixedly mounted at the lower end of the steel pipe, embedded steel plates are respectively arranged at the lower parts of the two side faces of the main beam body 1, and the base is fixedly connected with the embedded steel plates through embedded bolts 8.

Specifically, the steel pipe may be a square steel pipe 11. The base is a flange steel plate base 10, and the embedded steel plate is an embedded flange steel plate 9.

In some embodiments, the width B1 of the top of the main beam body 1 can be 34-42 m; the bottom width B2 is 0.5-0.6B 1; the length B3 of the cantilever of the middle box girder is 0.8-1.0 m; the transverse inclined strut combination section B4 is 0.13-0.15B 1, B5 is 0.08-0.1B 1, and the standard spacing d of the steel inclined struts is 4.0 or 4.5 m; the height H1 of the main beam body 1 is determined according to the actual bridge span; the thickness H2 of the bridge deck is 0.25-0.3 m.

Bracing sub-assembly 2 includes U type channel steel 7, U type channel steel 7 level is arranged, and U type channel steel 7 is located bridge floor component 3 under, U type channel steel 7 and steel pipe fixed connection, concrete has been pour in U type channel steel 7, the upper surface of U type channel steel 7 and bridge floor component 3's lower surface contact are in order to realize supporting.

Specifically, rivets are arranged in the U-shaped channel steel, so that concrete can be fixed conveniently.

The concrete bridge is characterized in that supporting legs are arranged on two sides of the main beam body 1 and used for lapping the bridge deck component 3, the bridge deck component 3 is connected with the upper surface of the main beam body 1 through wet joints 5, and the wet joints 5 are of concrete cast-in-place structures.

The deck assembly 3 comprises precast slabs 6, and the precast slabs 6 are square slabs.

U type channel bar 7 is close to the fixed end plate 4 that is equipped with of one end of the girder body 1, one side that the girder body 1 is close to U type channel bar 7 is equipped with buried bolt 8 in advance, buried bolt 8 and end plate 4 fixed connection in advance.

The bridge deck assembly 3 on each side of the main beam body 1 is formed by sequentially splicing a plurality of prefabricated plates 6, and the prefabricated plates 6 on the same side are connected through wet joints 5.

Specifically, the short-tower cable-stayed bridge has the characteristics of beam rigidity, tower height and cable concentration, the integral rigidity is mainly provided by the main beam, and the stay cable 21 mainly plays a role in stiffening the beam body and adjusting the stress. The middle main box girder provides the overall rigidity of the bridge, meets the space required by longitudinal prestress layout, and bears the longitudinal stress of the main girder; the transverse inclined strut joint section provides enough section width and bears transverse local stress; the ratio of the transverse length to the longitudinal length of the prefabricated plate 6 is close to 2, the prefabricated plate belongs to a one-way plate with a short side bearing load, and only distributed reinforcing steel bars need to be arranged in the long side direction.

The embodiment also provides a construction method suitable for the wide box girder short-tower cable-stayed bridge, and the constructed wide box girder short-tower cable-stayed bridge utilizes the upper structure for the wide box girder short-tower cable-stayed bridge, and the construction method comprises the following steps:

step 1, bottom structure construction: constructing a pier body comprising a pile foundation 13B, a bearing platform 13A and a pier 13;

step 2, constructing the main beam body 1, the connecting sections 17, the sections and the tower column 16 by adopting a support method, and installing a hanging basket 15;

step 3, the stay-cable-free section 18 of the main beam body 1 is constructed by adopting a cantilever, and longitudinal prestress is tensioned; lagging one or more beam sections, firmly connecting the steel inclined strut assembly 2 with an embedded part of the main beam body 1, hoisting a precast slab 6, and pouring a transverse wet joint 5;

step 4, constructing the section with the guy cable of the main beam body 1 by using a cantilever, moving the hanging basket 15 from the bridge tower to two sides, symmetrically constructing the main beam body 1, and tensioning longitudinal prestress; sequentially installing stay cables 21 and tensioning in place;

the transverse inclined strut combination section lags behind one or more beam sections to carry out construction synchronously; installing an edge span cast-in-place support 20A and pouring an edge span cast-in-place section 20;

step 5, completing construction of the closure section of the middle span and the side span of the main girder body 1, tensioning a longitudinal prestressed steel beam of the closure section, synchronously constructing a steel diagonal bracing assembly 2, and pouring a longitudinal wet joint 5 of the bridge deck;

after the maintenance of the bridge deck slab is finished, the construction of auxiliary structures such as bridge deck pavement, guardrails 19, expansion joints, lampposts and the like is carried out.

In the step 3, concrete is poured into the steel pipe; and when the concrete in the steel pipe reaches the designed strength, hoisting the precast slab 6 above the steel inclined strut assembly 2.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.