CN113652966A

CN113652966A - Construction method of full-prefabricated assembly type concrete beam type bridge structure system

Info

Publication number: CN113652966A
Application number: CN202110790576.2A
Authority: CN
Inventors: 徐声亮; 王金龙; 陈巨峰
Original assignee: Ningbo Municipal Engineering Construction Group Co Ltd
Current assignee: Ningbo Municipal Engineering Construction Group Co Ltd
Priority date: 2021-07-13
Filing date: 2021-07-13
Publication date: 2021-11-16
Anticipated expiration: 2041-07-13
Also published as: CN113652966B

Abstract

The invention discloses a construction method of a fully-prefabricated assembly type concrete beam type bridge structure system, which comprises the following steps of: (1) prefabricating concrete beam type bridge assembly members in batch in an industrial manner; (2) casting the lower supporting structure on the foundation in situ; (3) building a temporary supporting system of the hidden cover beam on the basis of the lower supporting structure; (4) hoisting the hidden cover beam prefabricated sections to the position above the hidden cover beam temporary supporting system according to the requirement; (5) removing the temporary supporting system of the hidden cover beam; (6) constructing a small box girder temporary supporting system on the basis of the assembled hidden cover girder; (7) erecting each prefabricated small box girder; (8) pouring a seam UHPC; (9) tensioning prestressed steel bundles for coupling connection between the anchoring sections; (10) and (5) disassembling the temporary anchoring system and the small box girder temporary supporting system. Therefore, the main body components of the concrete beam type bridge structure system are prefabricated parts, and the application of the prefabricated assembled structure can be popularized with low cost.

Description

Construction method of full-prefabricated assembly type concrete beam type bridge structure system

Technical Field

The invention relates to a construction method of a fully-prefabricated assembled concrete beam type bridge structure system, and belongs to the field of civil engineering bridge design and engineering construction.

Background

Under the promotion of national strategic guidance and the requirements of society and industry development, the bridge construction technology is developing towards the direction of assembly, industrialization and standardization. At present, the development of the 'prefabrication and assembly' of domestic concrete beam bridges mainly has 3 directions:

1) the bridge span upper structure adopts a prefabricated small box girder to replace a cast-in-place box girder

In urban expressway construction, the replacement of cast-in-place box girders by prefabricated small box girders has become a common consensus of all construction parties. On one hand, under the same span, the concrete consumption of the prefabricated small box girder is only 50% of that of the cast-in-place box girder; in a soft soil area, the construction cost of the scheme of prefabricating the small box girder is less than 75 percent of that of a cast-in-place box girder (the engineering quantity of a lower part structure is reduced, and the on-site foundation treatment cost is saved), so that the method has remarkable economic benefit; on the other hand, with the popularization and application of UHPC high-performance concrete, the width of the splicing seam of the prefabricated small box girder is strictly controlled from 50mm in the past and gradually widened to 300mm, so that the scheme of the prefabricated small box girder can meet the construction requirements of a wide section and a bent section by adjusting the width of the splicing seam.

Taking Ningbo city as an example, the 2011 completed airport road viaduct has a main line upper structure which adopts a cast-in-place box girder structure; 75% of the upper structures of the south ring and the north ring which are completed in 2015 adopt a prefabricated small box girder structure or a prefabricated hollow plate girder, and only a curve section, a widening section and a ramp connecting section adopt cast-in-situ box girders; the engineering of airport road overhead south extension started in 2017, western flood large bridge connection and the western city south extension started in 2018 have the advantages that the small prefabricated box girders (the curve section, the widening section and the ramp connecting section are all prefabricated structures) are adopted in 95% of the whole line, and only the section with limited passing clearance is the cast-in-place box girder.

2) The bridge span superstructure adopts a 'short-line method' segment prefabricated assembly beam to replace a cast-in-place box beam

Since the 21 st century, the adoption of the segment prefabrication and assembly technology of the 'short line method' is gradually tried in China, and the segment prefabrication and assembly technology is gradually popularized and applied in major projects, as shown in the specification. The segment prefabrication and assembly technology by the stub method basically solves the problem of factory prefabrication of a bridge span structure, and each prefabricated part is fused into a whole only by adopting 'external prestress' and 'cementing shear key' on site. Over the course of more than 20 years, there has been a move from a conventional single-box, single-chamber cross-section to a wide single-box, multi-chamber cross-section.

3) The bridge substructure (pier stud and capping beam) adopts finished large-tonnage prefabricated components

The integral prefabrication and assembling technology of the bridge pier columns is initially applied to the construction of a cross-sea bridge, namely the integral manufacture of the pier columns is completed on land, the pier columns are transported to a bridge position through a floating pontoon, and finally the pier columns are installed in place at one time by means of the large-tonnage hoisting capacity of a floating pontoon crane.

In nearly 10 years, with the great improvement of the construction requirements of the urban expressway elevated construction site (dust control, noise control, night light control, traffic diversion and transformation restriction and the like), the maintenance cost of the construction site rises due to the water rise. In part of overhead projects built on the existing roads, the pier column and the capping beam are gradually constructed by adopting a prefabrication and assembly technology, namely the integral prefabrication of the upright column or the capping beam is completed in a factory, and the erection is completed by adopting a large-tonnage crane on the spot.

At present, similar engineering construction cases are adopted in Shanghai, Zhejiang, Jiangsu, Guangdong, Shandong, Hunan, Sichuan and other provinces.

When the upright posts or the bent caps are integrally prefabricated and assembled, the sizes of the components are set to be contradictory.

On one hand, the larger the single component is, the stronger the structural integrity is, the smaller the number of on-site abutted seams is, and the structural performance is closer to that of a cast-in-place structure; on the other hand, as the size of the component increases, the weight of the structure increases accordingly, and 3 challenges are faced:

1) the requirement for the bearing capacity of the foundation of the construction area is increased by 40m³The member (2.5 m is multiplied by 6.4m column or 1/3 common cover beams) is taken as an example, the weight of the single body reaches 100 tons, 250-300 tons of hoisting equipment (depending on the working environment) is needed, and the bearing capacity of the foundation is not lower than 150 kPa; and the weight of the single body of the 75m3 component (half width cover beam) reaches 200 tons, 500 tons of hoisting equipment (the upper limit of the conventional hoisting equipment and the hoisting equipment at the higher level are not all provided in provinces) is required, and the foundation bearing capacity is required to be improved to 250 kPa.

2) The difficulty of component transportation is improved: the size of the prefabricated part is also limited by road transportation (the width is multiplied by the height is less than or equal to 3m multiplied by 3 m), and the larger the volume is, the higher the transportation difficulty is.

3) Reduced versatility of factory manufacturing: the larger the size of the member is, the higher the matching requirement of a manufacturing factory is (such as the specification of a portal crane and the scale of a manufacturing field), and meanwhile, the universality of the matching template is weaker (the prefabricated member is produced in batch, a wood template is not selected, and the customization property of a steel template is stronger), so that the cost advantages of the prefabricated member and a cast-in-place member are reduced.

The first two challenges of the above analysis often push up the construction costs of the stud & capping beam components-this makes such prefabricated construction techniques an even more economical choice between "urban civilized construction requirements" and "engineering schedules", the larger the prefabricated components, the more significant the economic disadvantages of the prefabricated assembled components.

Therefore, the core and the key for the popularization and the application of the technology are to seek the efficient prefabrication and assembly of the small-volume components.

The small prefabricated box girder system is mature in construction process, and a production line and a bridge girder erection machine of a prefabrication factory can be widely applied to various bridge projects, but are limited by the larger structural height (the prefabricated girder and the bent cap) and cannot be used in a clear height limited area.

One solution is to design the bent cap into an inverted T shape, and lay the prefabricated small box girder on a bracket to form a semi-hidden prefabricated small box girder system. At the moment, the upper bridge span structure only maintains a simple support system, which is influenced by the middle section bulge of the inverted T-shaped cover beam, the prefabricated small box beam only maintains the mode that the bridge deck is continuous and the structure is simple in the area, and under the same span, the raw material consumption of the simple support beam is greatly increased compared with that of the continuous system: the consumption of the steel bars is increased by 40%, the consumption of the concrete is increased by 27%, the consumption of the prestressed steel bundles is increased by 32%, and the quantity of the expansion joints is increased by 200% (when the structure is discontinuous, the continuous bridge deck is easy to damage). In addition, the simply supported beam is a static system, is influenced by uneven settlement of a foundation, is easy to break at the end part, and seriously influences the driving comfort, namely the phenomenon of 'jumping' needs to be strictly controlled when the urban expressway overhead with the speed of 80km/h is designed, and the popularization and the application of the system are seriously restricted.

Another solution is a hidden beam structure system. The prefabricated small box girder and the cover girder are arranged in the same plane, and the problem of net height of the prefabricated small box girder is solved. And the hidden cover beam structure system adopts a process of erecting the prefabricated small box beam and then pouring the concrete hidden cover beam during construction, so that the prefabrication of the main body part of the concrete beam type bridge under the condition of effective clearance is met.

However, the above construction method has the following 3 cost concerns:

1) the temporary support measures are invested greatly: the weight of the prefabricated small box girder is larger, the span diameter of the prefabricated small box girder is usually 26-35 m, the weight of a single body is about 75-120 tons, 8-12 prefabricated girders are usually arranged in the direction of an overhead transverse bridge of a city, the total weight is over 2500 tons, a temporary supporting structure of the prefabricated small box girder is comparable to that of a permanent cover girder, and the measure investment is large;

2) the prefabricated beam is erected with high difficulty: in order to ensure the continuity of a structural system, longitudinal steel bars at the end parts of two ends of a prefabricated small box girder extend out by 1.2-1.5 m (namely 1/2 width of a midspan hidden cover girder or 80% width of the hidden cover girder at the end part), the positions of the part of steel bars and a temporary support system are in conflict (along a bridge direction projection plane, a temporary support structure is positioned in the range of the prefabricated small box girder), so that the simplest 'inside-span beam raising' process of the prefabricated small box girder cannot be practiced, if a 'rear-span beam feeding' process is adopted, a bridge erecting machine and rear-span hoisting equipment (the rear-span beam feeding process is also required to be provided with hoisting equipment to lift the prefabricated small box girder to a high erecting plane) need to wait for the pouring time of the hidden cover girder (usually not less than 2 months), and the economic benefit is very low; if an automobile crane erecting process (double-crane lifting) is adopted, the number of small box girders which can be erected by a single supporting leg of the hoisting equipment is limited under the influence of the extending steel bars at two ends (see the hidden cover girder construction scheme for details); if a crawler crane erection process (single machine hoisting and crawler movement) is adopted, higher requirements are put on the foundation bearing capacity of the temporary road on the construction site (400-ton crawler crane operation);

3) the cast-in-place hidden cover beam has high reinforcement ratio: although the cast-in-place hidden cover beam is provided with intensive transverse bridge-direction prestressed steel bundles, a large number of common steel bars are still configured at the design level at the present stage to deal with uncertain complex multidirectional stress effects, namely the design calculation research of the prefabricated small box beam hidden cover beam structure system is relatively less compared with the conventional structure system, compared with the cast-in-place box beam, the hidden cover beam not only bears the end internal force of each prefabricated small box beam (mainly bending moment, shearing force and torque, but also locally mainly takes the positive stress and the shearing stress instead of being transmitted in the internal force mode), but also needs to resist the transverse load effect. Considering that the research on the mechanical characteristics of the joint of the small prefabricated box girder and the hidden cover girder is less (namely the mechanical property of the connection between the prefabricated structure and the cast-in-place structure), a design unit tends to configure a dense steel bar system more so as to ensure the effectiveness of the structure, and meanwhile, the bearing capacity and the normal use state reliability (crack control) of the structure are ensured.

Disclosure of Invention

Aiming at the defects of the prior art, the invention develops a construction method of a full-prefabricated assembled concrete beam type bridge structure system, expands the application range of the prefabricated small box girder structure system by utilizing the existing prefabricated small box girder production line, popularizes the application of the prefabricated assembled structure at low cost, and has higher economic value and social benefit for the construction of urban bridges in China, particularly urban viaducts.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a construction method of a fully-prefabricated assembly type concrete beam type bridge structure system comprises the following steps:

(1) prefabricating concrete beam type bridge assembly members in batch in an industrial manner;

the concrete beam type bridge assembling component comprises a plurality of hidden cover beam prefabricated sections and prefabricated small box beams; wherein:

the hidden cover beam prefabricated sections comprise two types, wherein one type is hidden cover beam middle fulcrum area sections in a middle fulcrum area, and the other type is hidden cover beam end sections in an edge fulcrum area;

the prefabricated small box girder comprises two parts, namely a small box girder conventional section and a small box girder end solid section arranged at the end part of the small box girder conventional section;

(2) casting the lower supporting structure on the foundation in situ;

(3) building a temporary supporting system of the hidden cover beam on the basis of the lower supporting structure;

(4) hoisting the hidden cover beam prefabricated sections to the position above the hidden cover beam temporary supporting system according to the requirement; after the required hidden cover beam prefabricated sections are hoisted in place, tensioning the transverse bridge direction prestressed steel bundles to enable all the hidden cover beam prefabricated sections to be integrally assembled along the transverse bridge direction to form an assembled hidden cover beam;

(5) removing the temporary supporting system of the hidden cover beam; meanwhile, a temporary anchoring system is formed between the assembled hidden cover beam and the lower supporting structure so as to improve the anti-overturning capacity of the assembled hidden cover beam;

(6) constructing a small box girder temporary supporting system on the basis of the assembled hidden cover girder;

(7) based on the principle of span-inside beam raising, erecting each prefabricated small box beam one by one from the upper part of the assembled hidden cover beam by adopting a bridge girder erection machine, so that convex teeth at the beam end of each prefabricated small box beam are embedded into small box beam splicing notches of the hidden cover beam prefabricated sections;

(8) pouring abutted seam UHPC

Pouring UHPC concrete at the position of a splicing seam between the prefabricated small box girder and the prefabricated sections of the hidden cover girder to form a UHPC filling layer;

(9) prestressed steel beam for coupling connection between tension anchor sections

Entering the small box girder prefabricated at one side from a manhole of the conventional section of the small box girder prefabricated at one side of the hidden cover girder prefabricated section, and anchoring one end of a prestressed steel strand for coupling connection among sections to an intersegmental coupling prestressed anchoring area of the solid section at the end part of the small box girder at the side; then, the steel beams enter the small box girder prefabricated on the other side from the manhole of the conventional section of the small box girder on the other side of the prefabricated section of the hidden cover beam, the other end of the prestressed steel beam for coupling connection among the sections is anchored to the coupling prestressed anchoring area among the sections of the solid section at the end part of the small box girder on the side, and the prestressed steel beam for coupling connection among the sections is tensioned;

(10) temporary supporting system for disassembling temporary anchoring system and small box girder

And (4) dismantling the temporary anchoring system and the small box girder temporary supporting system.

Preferably, the hidden bent cap middle fulcrum section comprises a middle fulcrum bent cap middle section body and a middle fulcrum bent cap end section body;

the hidden bent cap edge fulcrum section comprises an edge fulcrum bent cap middle section body and an edge fulcrum bent cap end section body;

the whole hidden cover beam prefabricated sections are all arranged in a cuboid shape;

the two end surfaces in the bridge direction of the middle section body of the middle fulcrum bent cap/the end section body of the middle fulcrum bent cap are both provided with bent cap joint surfaces which are correspondingly a first bent cap joint surface and a second bent cap joint surface; the middle section body of the middle fulcrum bent cap/the end section body of the middle fulcrum bent cap are provided with prestressing force pore channels along the bridge direction through the first bent cap joint surface and the second bent cap joint surface;

the two end surfaces in the transverse bridge direction of the middle section body/side fulcrum bent cap middle section body of the middle fulcrum bent cap are respectively provided with a bent cap section splicing surface which is a first bent cap section splicing surface and a second bent cap section splicing surface correspondingly; the middle section body of the middle fulcrum bent cap/the middle section body of the side fulcrum bent cap penetrates through the splicing surface of the first bent cap section and the splicing surface of the second bent cap section to form a transverse bridge-direction prestressed steel beam pore channel;

the middle fulcrum bent cap end section body/side fulcrum bent cap end section body is positioned in two end faces in the transverse bridge direction, and the end face only positioned on the inner side is provided with a bent cap section splicing face;

the hidden cover beam edge fulcrum section is positioned in two end faces along the bridge direction, and the end face close to the middle fulcrum area is provided with a cover beam splicing surface;

the capping beam joint surface is provided with a small box girder joint notch penetrating through the top surface of the corresponding hidden capping beam prefabricated section;

the splicing surface of the first bent cap section is arranged away from the middle point of the spliced hidden bent cap, and a plurality of concave tooth blocks are arranged on the splicing surface of the first bent cap section;

the splicing surface of the second bent cap section is arranged close to the middle point of the spliced hidden bent cap, and the splicing surface of the second bent cap section is provided with an outer convex tooth block; the positions of the concave tooth blocks at two sides of the middle section body of each middle fulcrum bent cap/side fulcrum bent cap correspond to the positions of the convex tooth blocks;

the transverse bridge-direction prestressed steel beam channels are arranged in a staggered manner with the convex tooth blocks/concave tooth blocks;

transverse bridge-direction prestressed steel beams are pre-embedded in the end section body of the middle fulcrum bent cap/the end section body of the side fulcrum bent cap, the end section body of the middle fulcrum bent cap/the end section body of the side fulcrum bent cap is positioned on the splicing surface of the bent cap section in the transverse bridge direction, and an outer convex tooth block matched with the inner concave tooth block of the middle section body of the middle fulcrum bent cap/the middle section body of the side fulcrum bent cap is arranged; each transverse bridge-direction prestressed steel beam pore corresponds to a transverse bridge-direction prestressed steel beam pre-embedded in the middle fulcrum bent cap end section body/side fulcrum bent cap end section body;

the end part of the solid section at the end part of the small box girder is provided with a plurality of girder end convex teeth;

the beam end convex teeth are distributed in three rows at the end part of the small box girder end solid section in a row shape, and correspondingly comprise middle row beam end convex teeth and side beam end convex teeth symmetrically arranged at two sides of the middle row beam end convex teeth; each row of beam end convex teeth are arranged along the height direction of the small box beam end solid section and can be embedded in the small box beam splicing seam notch.

Preferably, in the step (1), each of the sections of the central fulcrum region of the hidden canopy beam and the side fulcrum sections of the hidden canopy beam is a section of the central fulcrum region of the hidden canopy beam, which is capable of being supported on the lower support structure, and is marked as a section of the central fulcrum region of the hidden canopy beam; according to design requirements, a circle of temporary anchoring through holes which are uniformly distributed are arranged on the outer side of a middle area corresponding to the top end of the lower supporting structure of the middle section of the hidden cover beam;

the lower supporting structure in the step (2) comprises a bearing platform and an upright post; during construction, a bearing platform is cast and formed on site, then an upright post is cast and formed on the bearing platform, and a plurality of connecting steel bars for temporary anchoring are pre-embedded at the top end of the upright post;

the temporary anchoring through holes arranged on the middle section of the hidden cover beam are in one-to-one correspondence with the temporary anchoring connecting steel bars;

in the step (4), after the middle section of the hidden cover beam is hoisted in place, ensuring that the temporary anchoring through holes on the hidden cover beam correspond to the temporary anchoring connecting steel bars one by one, and enabling the temporary anchoring connecting steel bars to penetrate through the corresponding temporary anchoring through holes;

and (5) anchoring each temporary anchoring connecting steel bar and the corresponding middle section of the hidden cover beam to form a temporary anchoring system between the assembled hidden cover beam and the lower supporting structure.

Preferably, the temporary supporting system for the hidden cover beam in the step (3) comprises two sections of a cushion layer, 2 first outer supporting columns, 4 middle supporting columns, 2 second outer supporting columns, 2 supporting cross beams and a plurality of distributing beams;

the construction method of the hidden cover beam temporary support system comprises the following steps:

3.1 laying the cushion layer

Respectively laying a section of cushion layer on each of two sides of the bearing platform, wherein the outer side end of the cushion layer exceeds the end of a preset assembled hidden cover beam;

3.2, building a supporting upright post system

Respectively casting a middle supporting upright column and a first outer supporting upright column and a second outer supporting upright column in a middle fulcrum area and a side fulcrum area of the concrete beam bridge structure system, so that the first outer supporting upright column and the second outer supporting upright column are symmetrically distributed at two ends of the middle supporting upright column, the middle supporting upright column is distributed in the middle fulcrum area of the concrete beam bridge structure system, and the first outer supporting upright column and the second outer supporting upright column are distributed in the side fulcrum area of the concrete beam bridge structure system; the middle supporting upright post, the first outer supporting upright post and the second outer supporting upright post form the supporting upright post system;

3.3 building a supporting beam system

Laying a supporting beam along the length extending direction of the preset assembled hidden cover beam, and supporting and fixing the supporting beam through a first outer side supporting upright post, a second outer side supporting upright post and a middle supporting upright post below the supporting beam, so as to form a supporting beam system;

3.4 building a distribution beam system

According to the preset size of the hidden cover beam prefabricated section, building each distribution beam above the supporting beam system according to the requirement to form the distribution beam system;

and (5) hoisting the hidden cover beam prefabricated sections in the step (4) to the upper part of the distribution beam system as required.

Preferably, the temporary supporting system for the small box girders in the step (6) comprises 2 supporting beams and a plurality of temporary supporting structures for the small box girders, which are arranged along the length direction of the supporting beams; each small box girder temporary supporting structure comprises 2 lower cushion girders, 2 lower anchor girders, 2 suspenders, 2 upper cushion girders and 2 upper anchor girders; the construction method of the small box girder temporary supporting system comprises the following steps:

6.1, building an upper pad beam structure system

Respectively placing an upper cushion beam with the length direction extending along the transverse direction of the assembled hidden cover beam above two adjacent hidden cover beam prefabricated sections to form an upper cushion beam structure system;

6.2 building the upper part of the boom system

Two upper anchor beams are arranged above the two upper cushion beams at intervals, two ends of each upper anchor beam are lapped with the corresponding upper cushion beam, and a suspender is anchored at the middle position of each upper anchor beam to form the upper part of the suspender system;

6.3 building a lower bolster structure system

Respectively placing a lower cushion beam with the length direction extending along the transverse direction of the assembled hidden cover beam at the position corresponding to the upper cushion beam below the two adjacent hidden cover beam prefabricated sections to form a lower cushion beam structure system;

6.4 building the lower part of the hanger rod system

The lower anchor beam is placed at a position corresponding to the upper part of the suspender system below the lower cushion beam structure system, and the lower end of the suspender is anchored with the lower anchor beam to form the lower part of the suspender system;

6.5 building a support beam

The supporting beams are directly placed above the lower cushion beam structure system on two sides of the assembled hidden cover beam;

and (4) directly erecting the prefabricated small box girder in the step (7) between two adjacent supporting beams in the span.

Preferably, the prestressing force pore canal along the bridge direction penetrates through a small box girder splicing seam notch of the first bent cap splicing seam surface and a small box girder splicing seam notch of the second bent cap splicing seam surface.

Preferably, the end part of the solid section at the end part of the small box girder is provided with a web plate anchoring area and a bottom plate bundle anchoring area, the solid section at the end part of the small box girder corresponds to each box girder cross-internal prestressed steel bundle extended from the conventional section of the small box girder, and a plurality of box girder cross-internal prestressed steel bundle ducts which are respectively communicated with the web plate anchoring area and the bottom plate bundle anchoring area are correspondingly arranged; and the cross-internal prestressed steel strand pore channels of the box girders are distributed along the cross-internal prestressed steel strand pore channels of the box girders and are tensioned and anchored in the corresponding web plate anchoring area/bottom plate strand anchoring area.

Preferably, the web plate anchoring area is provided with three wedge-shaped anchoring blocks along the height direction of the box girder splicing seam surface, and each wedge-shaped anchoring block is uniformly provided with a box girder internal prestressed steel strand pore channel; the wedge-shaped anchoring blocks can meet the requirement of 5-degree inclined arrangement of prestressed steel bundles in a box girder span extending from a conventional section web of a small box girder.

Preferably, the prestressed anchor plates of the web anchoring area and the bottom plate bundle anchoring area extend for a length less than that of the beam-end convex teeth.

Compared with the prior art, the technical scheme of the invention has the following advantages:

1. the fully-prefabricated assembled hidden cover beam structure system can adopt the erection mode of firstly covering the beam and then prefabricating the beam, simplifies a temporary support system required to be built in the construction process of the hidden cover beam structure system, and effectively saves the cost.

2. In the construction process, the finished bent cap can be used as a temporary support, so that the problem of large-scale temporary measure investment is solved.

3. The fully prefabricated assembled joint is adopted, the reinforcing steel bars at the end parts of the small box girders are eliminated, and the steel bars can be hoisted by adopting the most economical 'span-inside beam lifting' process;

4. the hidden cover beam also adopts a prefabricated assembly type structure, defines a mechanical transmission path and uses materials on the cutting edge.

Drawings

FIG. 1 is a schematic structural view of a fully precast assembled concrete beam bridge structural system according to the present invention;

in fig. 1: 1-conventional section of small box girder; 2-small box girder end solid section; 3-hiding the middle fulcrum section of the bent cap; 4-UHPC filling layer; 5-the middle fulcrum bent cap end segment;

FIG. 2 is a schematic structural view of a conventional section of the mini-box beam of FIG. 1;

in the figure: 1-1, a conventional section body; 1-2, spanning an internal prestressed steel bundle by a box girder;

FIG. 3 is a schematic structural view of a solid end section of the mini-box girder of FIG. 1;

FIG. 4 is a schematic structural view of another direction of the end solid section of the box girder;

in fig. 3 and 4: 2-1, a beam end solid section body; 2-2, splicing and sewing surfaces of box girders; 2-3, beam end convex teeth; 2-4, coupling prestressed ducts among the segments; 2-5, anchoring blocks; 2-6, spanning an internal prestressed steel strand pore channel of the box girder; 2-7, splicing surfaces of the box girders; 2-8, coupling and connecting the segments by using prestressed steel bundles; 2-9, coupling the tension end of the steel bundle for connection;

FIG. 5 is a schematic structural view of the middle section body of the mid-pivot bent cap depicted in FIG. 1 (the prestressed tendon channels are not shown);

FIG. 6 is a schematic view of the construction of the middle section body of the mid-pivot bent cap in another orientation;

in fig. 5 and 6, 3-1, the first lid beam segment splice plane; 3-2, a first bent cap joint surface; 3-3, splicing and sewing the notch with the small box girder; 3-4, transverse bridge direction prestress steel beam pore paths; 3-5, concave tooth blocks; 3-6, a middle section body of the middle fulcrum bent cap; 3-7, convex tooth blocks;

FIG. 7 is a schematic structural view of the body of the end segment of the mid-pivot bent cap depicted in FIG. 1 (without the pre-stressed steel-bundle channels shown);

FIG. 8 is a schematic view of the construction of the body of the end segment of the mid-pivot cap beam in another orientation;

in fig. 7 and 8: 5-1, a middle fulcrum bent cap end segment body; 5-2, transversely bridging the prestressed steel bundles; 5-3, a small box girder splicing seam notch of the middle fulcrum bent cap end section body; 5-4, a bent cap splicing surface of the bent cap end section body of the middle fulcrum bent cap; 5-5, an outer convex tooth block of the middle fulcrum bent cap end section body; 5-6 and P anchor.

FIG. 9 is a schematic structural view of a fully precast assembled concrete beam bridge structural system in a mid-pivot region;

fig. 10 is a schematic structural view of a fully precast assembled concrete beam bridge structural system in an edge pivot area.

FIG. 11 is a flow chart of the construction of the fully precast assembled concrete beam bridge structure system according to the present invention;

FIG. 12 is a schematic structural view of the temporary support system of the hidden canopy beam of the present invention built upon an underlying support structure;

FIG. 13 is a schematic structural diagram of a small box girder temporary supporting system built by the assembled hidden cover girder of the invention;

FIG. 14 is a temporary anchoring system formed between the lower support structure and the hidden cover beam according to the present invention;

in fig. 12-14: 6-1, basic; 6-2, upright columns; 6-3, connecting steel bars for temporary anchoring; 7-1, a first outer support column; 7-2, supporting upright columns in the middle; 7-3, cushion layer; 7-4, a second outer support column; 7-5, supporting the cross beam; 7-6, a distribution beam; 8-1, a first underbeam; 8-2, a second lower bolster; 8-3, a first support beam; 8-4, a second support beam; 8-5, a suspender; 8-6, a first upper bolster; 8-7 and a second upper cushion beam.

Detailed Description

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 only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The relative arrangement of the components and steps, expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may also be oriented in other different ways (rotated 90 degrees or at other orientations).

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In addition, for the purpose of convenience of description, the vertical direction, the transverse direction and the longitudinal direction are perpendicular to each other, and the two directions in the vertical direction are up and down directions respectively.

As shown in fig. 1 to 10, the fully-prefabricated assembly type concrete beam bridge structure system of the present invention includes a lower supporting structure and an upper structure disposed above the lower supporting structure, wherein the upper structure includes a plurality of hidden cover beams disposed along a transverse bridge direction and a plurality of prefabricated small box beams disposed at two sides of each hidden cover beam and along a bridge direction; wherein:

the prefabricated box girder comprises two parts, namely a conventional section 1 of the box girder and a solid section 2 at the end part of the box girder, as shown in figures 1 and 10.

The conventional section 1 of the small box girder, as shown in fig. 2, refers to a section of the cross section of the prefabricated small box girder, which is the same as the middle cross section of a general prefabricated small box girder span, and comprises a conventional section body 1-1, wherein a box girder span internal prestress steel bundle 1-2 extends outwards from the end of a web plate and the end of a bottom plate, in addition, the conventional section body 1-1 is provided with an operation manhole 1-1-1 with the diameter of 45cm in a top plate area, the center of the manhole 1-1-1 is 50-60 cm away from the edge of the conventional section body 1-1, and reinforcing steel bars are arranged on the periphery of the manhole 1-1-1.

The end solid section of the small box girder is arranged at the end of the conventional section of the small box girder, and the length of the end solid section is not less than 2m and not more than 4 m. The reason is that according to the holy-vican principle, the stress of the end part is within the range of 1 time of the beam height, the stress can be uniformly diffused, the length of the solid section is not less than the beam height (1.6 m or 1.8 m), and the length of the solid section is not less than 2m considering the range occupied by structures such as the end part toothed block, the anchor plate and the like.

As shown in fig. 3-4, the solid section at the end of the small box girder comprises a solid section body 2-1 at the end of the girder, the solid section body 2-1 at the end of the girder comprises two end faces which are arranged oppositely and correspond to a box girder splicing face and a box girder splicing seam face 2-2, the box girder splicing face is directly poured at the end of the conventional section 1 of the small box girder and is integrally formed with the conventional section of the small box girder, and the box girder splicing seam face 2-2 is adjacent to the hidden cover girder. The box girder splicing seam surface 2-2 is divided into a tooth block area and a prestressed anchoring area. The prestressed anchoring area is divided into a web plate bundle anchoring area and a bottom plate bundle anchoring area. The web plate bundle anchoring area is provided with a web plate prestressed steel bundle pore canal for the web plate prestressed steel bundle to pass through, the bottom plate bundle anchoring area is provided with a bottom plate prestressed steel bundle pore canal for the bottom plate prestressed steel bundle to pass through, the web plate prestressed steel bundle and the bottom plate prestressed steel bundle jointly form a box girder inner-crossing prestressed steel bundle 1-2 shown in figure 2, and the web plate prestressed steel bundle pore canal and the bottom plate prestressed steel bundle pore canal jointly form a box girder inner-crossing prestressed steel bundle pore canal 2-6. Specifically, the web plate bundle anchoring area adopts a 'notch' on which a 'wedge-shaped anchoring block 2-5' is arranged to meet the requirement of 5-degree inclined arrangement of the web plate prestressed steel bundles, and the bottom plate bundle anchoring area and the tooth block area are in the same plane.

The prestressed anchoring area is divided into a tooth block area, a plurality of rows of beam-end convex teeth 2-3 are arranged in the tooth block area, and each beam-end convex tooth 2-3 is of a male tooth structure. The side edge of the beam end convex tooth 2-3 keeps level with the side edge of the prestressed anchoring area sealing anchor, and is used as a part extending into the notch of the hidden cover beam section. In addition, beam-end lobes 2-3 described herein have three rows in total, including a middle row of beam-end lobes and side beam-end lobes that are symmetrically disposed on either side of the middle row of beam-end lobes.

And (2) setting coupling prestressed ducts 2-4 among the sections by taking four adjacent beam end convex teeth 2-3 as centers, wherein in order to ensure that the distance from the coupling prestressed ducts 2-4 among the sections to the inner edge of the prefabricated small box girder is not less than 100mm, the coupling prestressed ducts 2-4 among the sections are only arranged on two sides of the convex teeth at the beam end of the middle row, and are totally set in 6 rows from top to bottom. The prestressed steel beams for coupling connection between the sections are arranged in the coupling prestressed ducts between the sections, so that the prefabricated sections of the hidden cover beam are respectively connected with the solid sections at the end parts of the small box beams on the two longitudinal sides of the prefabricated sections of the hidden cover beam, and the arrangement of the coupling prestressed ducts between the sections ensures that the prestressed steel beams for coupling connection between the sections are distributed in the hollow projection range of the prefabricated small box beams. And web bundle anchoring areas are symmetrically arranged on two sides of the tooth block area, and a bottom plate bundle anchoring area is arranged on the lower side of the tooth block area.

The prestressed steel beams for coupling connection between the sections do not penetrate through the range of the beam-end convex teeth so as to ensure the reliability of the beam-end convex teeth.

The coupling prestress pore channels between the sections adopt the principle of 'more distribution and less use', namely, the end part of a single prefabricated small box girder only needs to be provided with 4 holes, but 12 coupling prestress pore channels between the sections are reserved, so that the prefabricated small box girder can not be customized along with the characteristics of hidden cover girder sections in a factory manufacturing stage (the specification number of the factory prefabrication stage is reduced), and the product generalization is realized.

The small box girder end solid section corresponds to each box girder span internal prestressed steel strand, and a plurality of box girder span internal prestressed steel strand ducts which are respectively communicated with the web plate strand anchoring area and the bottom plate strand anchoring area are arranged, so that the box girder span internal prestressed steel strands can be anchored in the corresponding web plate strand anchoring area and the bottom plate strand anchoring area after being arranged along the corresponding box girder span internal prestressed steel strand ducts in the small box girder end solid section on site.

The web plate anchoring area is provided with three wedge-shaped anchoring blocks along the height direction of the box girder splicing surface, each wedge-shaped anchoring block is uniformly provided with a box girder internal-span prestressed steel strand pore passage, and the requirement of 5-degree inclined arrangement of the web plate prestressed steel strands can be met.

The side edge of the beam end convex tooth is kept flat with the side edge of the anchor sealing of the prestressed anchoring area to serve as a part extending into the groove of the precast segment of the hidden cover beam. The relative positions of the beam-end convex teeth, the prestressed anchor backing plates of the web plate bundle anchoring area and the bottom plate bundle anchoring area are necessarily coordinated, and the extension lengths of the prestressed anchor backing plates of the web plate bundle anchoring area and the bottom plate bundle anchoring area are slightly smaller than that of the beam-end convex teeth. If the extension lengths of the prestressed anchor backing plates of the web plate anchoring area and the bottom plate bundle anchoring area are too large, the effective coupling depth of the beam end convex teeth and the hidden cover beam prefabricated sections is reduced, and the reliability of a connecting area is reduced. Considering that the prefabricated small box girder web plate steel bundles are arranged in an inclined mode at an angle of 5 degrees, the anchor backing plate on the outermost side needs to be used as a reference.

The hidden cover beam is prefabricated in sections and is formed by splicing a plurality of sections of hidden cover beam prefabricated sections along the transverse bridge direction. The single hidden cover beam prefabricated section is matched with 1-2 prefabricated small box beams, the width of the single hidden cover beam prefabricated section is not more than 4.0m when the single prefabricated small box beam is matched, and the width of the single hidden cover beam prefabricated section is not more than 7.5m when the single hidden cover beam prefabricated section is matched with 2 prefabricated small box beams. The hidden cover beam prefabricated sections comprise two types, wherein one type is a hidden cover beam middle fulcrum section and can be spliced to form an assembled hidden cover beam arranged in a middle fulcrum area, and the other type is a hidden cover beam side fulcrum section and can be spliced to form an assembled hidden cover beam arranged in a side fulcrum area. The hidden cover beam prefabricated sections are similar in size and mainly cubic, and conditions are created for industrial manufacturing; on the other hand, the size of the hidden cover beam prefabricated section is small, the requirement on a prefabricated site is low, the manufacturing, transportation and hoisting cost is greatly reduced due to the miniaturization of the component, and the hidden cover beam prefabricated section has a prospect of large-scale popularization and application.

As shown in fig. 7 and 8, the hidden bent cap middle pivot segment includes a middle pivot bent cap middle segment body and a middle pivot bent cap end segment body; the hidden bent cap edge fulcrum section comprises an edge fulcrum bent cap middle section body and an edge fulcrum bent cap end section body.

As shown in fig. 5 and 6, the two end faces of the middle section body of the middle fulcrum bent cap/the end section body of the middle fulcrum bent cap in the bridge direction are both provided with bent cap joint surfaces, and are correspondingly provided with a first bent cap joint surface and a second bent cap joint surface; the middle section body of the middle fulcrum bent cap/the end section body of the middle fulcrum bent cap are provided with prestressing force pore channels along the bridge direction through the first bent cap joint surface and the second bent cap joint surface; the middle fulcrum bent cap middle section body is provided with bent cap section splicing faces which are correspondingly a first bent cap section splicing face and a second bent cap section splicing face, and the middle fulcrum bent cap middle section body is provided with a transverse bridge prestressed steel beam hole channel by penetrating through the first bent cap section splicing face and the second bent cap section splicing face. The middle section body of the side fulcrum capping beam is positioned on two end faces in the transverse bridge direction, the structure of the middle section body of the side fulcrum capping beam is consistent with that of the middle section body of the middle fulcrum capping beam on the two end faces in the transverse bridge direction, the difference between the middle section body of the side fulcrum capping beam and the middle section body of the middle fulcrum capping beam is that the middle section body of the side fulcrum capping beam is positioned in the two end faces in the bridge direction, and the capping beam splicing surface is arranged on the end face only close to the middle fulcrum area.

And small box girder splicing notches 3-3 are arranged on the capping beam splicing surface and run through the top surfaces of the corresponding hidden capping beam prefabricated sections. The depth of the small box girder splicing seam notch 3-3 is 60mm, the distance H from the middle point of the bottom edge of the small box girder splicing seam notch 3-3 to the top edge is H +200mm, the outline shape of the small box girder splicing seam notch 3-3 is similar to the end shape of the prefabricated small box girder (the prefabricated small box girder is horizontally arranged, so the bottom edge is horizontal), and the small box girder splicing seam notch is pulled through only at the top according to the full width of the small box girder. The small box girder splicing seam notch 3-3 is not provided with a tooth block structure, and smooth connection between the small box girder splicing seam notch 3-3 and a prefabricated small box girder with tooth blocks (beam end convex teeth arranged on the solid section at the end part of the small box girder) is completed by pouring UHPC (ultra high performance concrete). In other words, the end part of the prefabricated small box girder can be in butt joint with the corresponding small box girder splicing groove opening 3-3, the depth of the small box girder splicing groove opening 3-3 is matched with the thickness of each beam end convex tooth 2-3 of the solid section at the end part of the small box girder, namely, each beam end convex tooth 2-3 can be just embedded in the small box girder splicing groove opening 3-3, the box girder splicing surface of the solid section at the end part of the small box girder is enabled to be in contact with the open end of the small box girder splicing groove opening 3-3, the end part of the beam end convex tooth 2-3 of the solid section at the end part of the small box girder is enabled to be in contact with the groove bottom of the small box girder splicing groove opening 3-3, and gapless contact between the end part of the prefabricated small box girder and the prefabricated section of the hidden cover girder is achieved.

The splicing surface of the first bent cap section is arranged away from the middle point of the spliced hidden bent cap, and a plurality of concave tooth blocks are arranged on the splicing surface of the first bent cap section; the concave tooth blocks are distributed into 3 rows on the splicing surface of the first bent cap section and correspondingly comprise a first row of concave tooth blocks, a second row of concave tooth blocks and a third row of concave tooth blocks, the first row of concave tooth blocks, the second row of concave tooth blocks and the third row of concave tooth blocks comprise a plurality of concave tooth blocks distributed along the height direction of the splicing surface of the first bent cap section, the first row of concave tooth blocks are positioned in the middle direction of the splicing surface of the first bent cap section, and the second row of concave tooth blocks and the third row of concave tooth blocks are symmetrically distributed on two sides of the first row of concave tooth blocks.

The splicing surface of the second bent cap section is arranged close to the middle point of the spliced hidden bent cap, and the splicing surface of the second bent cap section is provided with a plurality of convex tooth blocks to be matched with the concave tooth blocks of the fulcrum sections in the adjacent hidden bent cap. The outer convex tooth blocks are distributed into 3 rows on the splicing surface of the second cover beam section and correspondingly comprise a first row of outer convex tooth blocks, a second row of outer convex tooth blocks and a third row of outer convex tooth blocks, the first row of outer convex tooth blocks, the second row of outer convex tooth blocks and the third row of outer convex tooth blocks respectively comprise a plurality of outer convex tooth blocks distributed along the height direction of the splicing surface of the first cover beam section, the first row of outer convex tooth blocks are positioned in the middle direction of the splicing surface of the first cover beam section, and the second row of outer convex tooth blocks and the third row of outer convex tooth blocks are symmetrically distributed on two sides of the first row of outer convex tooth blocks.

In each middle supporting point bent cap middle section body/side supporting point bent cap middle section body, the positions of all concave tooth blocks in the first row of concave tooth blocks correspond to the positions of all convex tooth blocks in the first row of convex tooth blocks, the positions of all concave tooth blocks in the second row of concave tooth blocks correspond to the positions of all convex tooth blocks in the second row of convex tooth blocks, and the positions of all concave tooth blocks in the third row of concave tooth blocks correspond to the positions of all convex tooth blocks in the third row of convex tooth blocks.

And a transverse bridge-direction prestressed steel beam pore passage (not drawn in the attached drawing) are respectively arranged in the middle section body of the middle fulcrum bent cap. The transverse bridge direction prestressed steel beam pore ways are arranged between two adjacent rows of convex tooth blocks, transverse bridge direction prestressed steel beams are arranged in the transverse bridge direction prestressed steel beam pore ways, and the line shapes and the quantity of the transverse bridge direction prestressed steel beams are determined according to transverse bridge direction calculation analysis of the hidden cover beam. The transverse bridge steel beam in the hidden cover beam section and the prefabricated small box beam cross section allowed pore canal position are considered simultaneously along the bridge direction prestressed pore canal, and the total number of the pore canals with the diameter of not less than 4 and the diameter of 25mm (namely the area of the prestressed steel beam configured on the cross section is not less than 1680 mm)²). The splicing seam area (the end part of the small box girder and the end surface of the hidden cover girder in the bridge direction) adopts a non-gap structure, and has a larger difference with the conventional segment splicing technology, necessary pre-stressed steel beams in the bridge direction (arranged in the pre-stressed pore canal in the bridge direction) are applied to the interface area, so that the normal stress of the interface is increased, and the shear-resistant bearing capacity of the interface is improved. One end of the pre-stressed steel beam along the bridge direction is connected with a tensioning end arranged at the end part of the solid section of the prefabricated small box girder at one side of the fulcrum section in the hidden cover girder, and the other end of the pre-stressed steel beam along the bridge direction is connected with a tensioning end arranged at the end part of the solid section of the prefabricated small box girder at the other side of the fulcrum section in the hidden cover girder.

The end section body of the middle fulcrum capping beam is positioned at two ends in the transverse bridge direction, a transverse bridge direction anchoring area is arranged at a position close to the end face of the outer side, a plurality of P anchors are embedded in the transverse bridge direction anchoring area, transverse bridge direction prestress steel bundles (transverse bridge direction prestress steel strands) are embedded in the end section body of the middle fulcrum capping beam directly through the P anchors, the inner side end face is consistent with the splicing surface structure of the second capping beam section of the middle fulcrum section of the hidden capping beam, and outer convex tooth blocks which are distributed in the same way are also arranged to be matched with the inner concave tooth blocks of the adjacent middle fulcrum section of the hidden capping beam.

According to the construction method, the transverse bridge-direction prestressed steel bundles are distributed and tensioned in the transverse bridge-direction prestressed steel bundle pore passages to improve the shearing-resistant bearing capacity of the interface between the sections of the fulcrum areas in the two adjacent sections of hidden cover beams, and then the construction is finished by sealing the pipes by adopting a post-grouting process. The pre-stressed channels in the direction along the bridge run through the splicing notches of the first small box girder and the second small box girder, correspond to partial pre-stressed steel beam channels arranged on the solid sections at the end parts of the small box girders, and are used for distributing pre-stressed steel beams for coupling connection among sections, so that the normal stress of the interface between the section of the fulcrum area in the hidden cover girder and the solid section at the end part of the small box girder is increased, and the shearing resistance bearing capacity of the interface is improved.

As shown in fig. 10, the edge fulcrum sections of the hidden bent cap are located at two ends along the bridge direction, and are provided with anchor areas along the bridge direction at positions close to the outer end face, and are provided with bent cap joint faces at end faces close to the inner side. A plurality of P anchors are pre-buried in the anchoring area along the bridge direction, so that the hidden cover beam edge fulcrum sections are directly connected with one ends of the prestress steel beams for coupling connection among the sections through the P anchors, and the other ends of the prestress steel beams for coupling connection are connected with the conventional section body tensioning ends of the adjacent prefabricated small box beams after sequentially penetrating through the hidden cover beam edge fulcrum sections and the small box beam end solid sections.

The arrangement mode of the end section body of the side fulcrum bent cap in the transverse bridge direction is consistent with that of the end section body of the middle fulcrum bent cap, and the description is omitted here.

The lower supporting structure comprises a bearing platform, two upright posts arranged on the bearing platform and a support arranged above each upright post. The upper structure is supported on the lower support structure by means of a support.

As a brand-new prefabricated assembled concrete beam bridge structure system, 3 sets of temporary systems need to be designed in the construction stage so as to ensure that the system is smoothly implemented:

1) in the assembly stage of the precast sections of the hidden cover beam sections, a hidden cover beam temporary supporting system needs to be designed, and the hidden cover beam temporary supporting system is detached after the hidden cover beam prestressed steel bundles are tensioned;

the hidden cover beam temporary supporting system adopts a steel pipe upright post and steel structure beam system, and the steel pipe upright posts are all positioned in a bearing platform area. The support beams of the first set of temporary support systems directly take over the hidden cover beam prefabricated sections.

2) Before the prefabricated small box girder is erected, a set of temporary anchoring system needs to be arranged on the hidden cover girder so as to prevent the hidden cover girder from overturning due to unbalanced load (such as the prefabricated small box girder assumed on one side, the self weight of a bridge girder erection machine and the like). The temporary anchoring system is dismantled before the prefabricated box girder splicing pouring after the prefabricated box girder is erected (namely, the bridge girder erection machine is not supported on the hidden cover girder), and if the temporary consolidation reaction frame does not influence the pouring of the wet joint and the dismantling of the reaction frame, the temporary anchoring system can be dismantled after the tensioning of the hogging moment beam of the prefabricated box girder is finished.

The temporary anchoring system is only suitable for hidden cover beam structures with cantilever ends, such as double-column type (two-side cantilever) and three-column type (single-side cantilever), and the temporary anchoring system can be omitted for four-column type hidden cover beams.

The temporary anchoring system adopts a 'anchor pressing type' structure, namely 1 channel of section steel beam is respectively arranged on the upper edge and the lower edge of the precast segment of the hidden cover beam, and pre-tensioning force is applied between the section steel beams by using finish rolling screw-thread steel so as to tightly press the 2 channels of section steel beams.

The core element of the temporary anchoring system is the lossless consolidation, namely the temporary consolidation is realized on the premise of not damaging the precast section concrete of the hidden cover beam.

The columns of the temporary anchoring system are usually arranged at the edge of the bearing platform, and the position penetrating through the bridge deck is usually positioned in the splicing area of the hidden cover beams, and if the temporary anchoring holes are arranged at the position, the permanent construction of the temporary anchoring holes is seriously influenced.

3) After the prefabricated small box girder is erected, before seam UHPC pouring and prestress steel beam tensioning, the prefabricated small box girder is required to be placed on a small box girder temporary supporting system, the small box girder temporary supporting system is completed before the prefabricated small box girder is erected (simultaneously with a temporary anchoring system), and the prefabricated small box girder is dismantled after the moment-negative beam tensioning is completed.

During construction, firstly hoisting the hidden cover beam prefabricated sections on the hidden cover beam temporary support system, then taking the hidden cover beam prefabricated sections as a support structure for erecting the prefabricated small box beams, and then erecting the prefabricated small box beams.

Specifically, the construction method of the fully-prefabricated assembled concrete beam bridge structure system according to the present invention, as shown in fig. 11 to 14, includes the following steps:

the hidden cover beam prefabricated sections comprise two types, wherein one type is a hidden cover beam middle fulcrum section which can be spliced to form an assembled hidden cover beam arranged in a middle fulcrum area, and the other type is a hidden cover beam side fulcrum section which can be spliced to form an assembled hidden cover beam arranged in a side fulcrum area;

(2) casting the lower supporting structure on the foundation in situ;

(8) pouring abutted seam UHPC

In order to form a temporary anchoring system as shown in fig. 14, in step (1), one of the sections in the fulcrum area of the hidden canopy beam, which is enough to be supported on the lower supporting structure, is marked as a central section of the hidden canopy beam; according to design requirements, a circle of temporary anchoring through holes which are uniformly distributed are arranged on the outer side of a middle area corresponding to the top end of the lower supporting structure of the middle section of the hidden cover beam; the lower supporting structure in the step (2) comprises a bearing platform and an upright post; during construction, a bearing platform is cast and formed on site, then an upright post is cast and formed on the bearing platform, and a plurality of connecting steel bars for temporary anchoring are pre-embedded at the top end of the upright post; the temporary anchoring through holes arranged on the middle section of the hidden cover beam are in one-to-one correspondence with the temporary anchoring connecting steel bars; in the step (4), after the middle section of the hidden cover beam is hoisted in place, ensuring that the temporary anchoring through holes on the hidden cover beam correspond to the temporary anchoring connecting steel bars one by one, and enabling the temporary anchoring connecting steel bars to penetrate through the corresponding temporary anchoring through holes; and (5) anchoring each temporary anchoring connecting steel bar and the corresponding middle section of the hidden cover beam to form a temporary anchoring system between the assembled hidden cover beam and the lower supporting structure.

In order to form the temporary supporting system of the hidden cover beam shown in fig. 12 conveniently, the temporary supporting system comprises two sections of cushion layers, 2 first outer side supporting columns, 4 middle supporting columns, 2 second outer side supporting columns, 2 supporting cross beams and a plurality of distributing beams;

the construction method of the temporary support system of the hidden cover beam in the step (3) comprises the following steps:

3.1 laying the cushion layer

3.2, building a supporting upright post system

3.3 building a supporting beam system

3.4 building a distribution beam system

In order to form the temporary supporting system of the small box girder shown in fig. 13, the temporary supporting system comprises 2 supporting beams and a plurality of temporary supporting structures of the small box girder arranged along the length direction of the supporting beams; each small box girder temporary supporting structure comprises 2 lower cushion girders, 2 lower anchor girders, 2 suspenders, 2 upper cushion girders and 2 upper anchor girders.

The construction step of the small box girder temporary supporting system in the step (6) comprises the following steps:

6.1, building an upper pad beam structure system

6.2 building the upper part of the boom system

6.3 building a lower bolster structure system

6.4 building the lower part of the hanger rod system

6.5 building a support beam

Claims

1. A construction method of a fully-prefabricated assembled concrete beam type bridge structure system is characterized by comprising the following steps:

(2) casting the lower supporting structure on the foundation in situ;

(8) pouring abutted seam UHPC

2. The method of constructing a fully precast fabricated concrete beam bridge structure system of claim 1, wherein the hidden canopy middle pivot segment comprises a middle pivot canopy middle segment body and a middle pivot canopy end segment body;

3. The construction method of the fully prefabricated assembled concrete beam bridge structure system according to claim 2, wherein in the step (1), the sections of the fulcrum area in the hidden canopy beam and the fulcrum sections at the sides of the hidden canopy beam are respectively provided with an energy-saving support which is rightly supported on a lower support structure and is marked as a middle section of the hidden canopy beam; according to design requirements, a circle of temporary anchoring through holes which are uniformly distributed are arranged on the outer side of a middle area corresponding to the top end of the lower supporting structure of the middle section of the hidden cover beam;

4. The construction method of a fully prefabricated assembled concrete beam bridge structure system according to claim 3, wherein the hidden cover beam temporary supporting system in the step (3) comprises two sections of a cushion layer, 2 first outer supporting columns, 4 middle supporting columns, 2 second outer supporting columns, 2 supporting cross beams and a plurality of distributing beams;

3.1 laying the cushion layer

3.2, building a supporting upright post system

3.3 building a supporting beam system

3.4 building a distribution beam system

5. The construction method of a fully precast fabricated concrete beam bridge structure system according to claim 4, wherein the temporary supporting system of the small box girders in the step (6) includes 2 supporting beams and a plurality of temporary supporting structures of the small box girders arranged along the length direction of the supporting beams; each small box girder temporary supporting structure comprises 2 lower cushion girders, 2 lower anchor girders, 2 suspenders, 2 upper cushion girders and 2 upper anchor girders; the construction method of the small box girder temporary supporting system comprises the following steps:

6.1, building an upper pad beam structure system

6.2 building the upper part of the boom system

6.3 building a lower bolster structure system

6.4 building the lower part of the hanger rod system

6.5 building a support beam

6. The construction method of a fully precast fabricated concrete beam type bridge structure system according to claim 2, wherein the bridge-wise prestressing duct is provided to penetrate through the small box girder splicing groove opening of the first capping beam splicing surface and the small box girder splicing groove opening of the second capping beam splicing surface.

7. The construction method of the fully prefabricated assembled concrete beam-type bridge structure system according to claim 2, wherein a web anchoring area and a bottom plate bundle anchoring area are arranged at the end part of the solid section at the end part of the small box girder, the solid section at the end part of the small box girder corresponds to each box girder cross-internal prestressed steel bundle extended from the conventional section of the small box girder, and a plurality of box girder cross-internal prestressed steel bundle ducts which respectively penetrate through the web anchoring area and the bottom plate bundle anchoring area are correspondingly arranged; and the cross-internal prestressed steel strand pore channels of the box girders are distributed along the cross-internal prestressed steel strand pore channels of the box girders and are tensioned and anchored in the corresponding web plate anchoring area/bottom plate strand anchoring area.

8. The construction method of the fully prefabricated assembled concrete beam type bridge structure system according to claim 2, wherein the web anchoring area is provided with three wedge-shaped anchoring blocks along the height direction of the box girder splicing surface, and each wedge-shaped anchoring block is provided with a box girder inter-span prestressed steel strand pore channel; the wedge-shaped anchoring blocks can meet the requirement of 5-degree inclined arrangement of prestressed steel bundles in a box girder span extending from a conventional section web of a small box girder.

9. The method of constructing a fully precast fabricated concrete girder bridge structural system according to claim 2, wherein the prestressed anchor slabs of the web anchoring zone and the floor bundle anchoring zone have an extension length less than that of the girder-end teeth.