CN219450481U - Cantilever arch ring and stiffness framework combined structure based on large-span arch bridge - Google Patents

Abstract

The utility model discloses a cantilever arch ring and stiffness skeleton combined structure based on a large-span arch bridge, which comprises cantilever arch rings symmetrically arranged on left and right arch seats of the large-span arch bridge, wherein the cantilever arch rings comprise spliced reinforcement skeletons, concrete is wrapped outside the spliced reinforcement skeletons, opening sections are reserved on midspan vaults of the two cantilever arch rings, the reinforcement skeletons at the opening ends of the two cantilever arch rings are exposed connecting sections, the stiffness skeleton is arranged at the opening sections, and two ends of the stiffness skeleton are respectively connected with the connecting sections of the two cantilever arch rings through pre-buried connecting joints. According to the utility model, the embedded type connecting joint is arranged, so that a combined structure with reliable connection is formed between the concrete arch ring and the stiff framework, the stability is good, the reliability is high, the concrete arch ring in the span-middle opening section range does not need to be constructed by adopting a tower cable-stayed buckling construction, the risk of tower stability can be greatly reduced, and the engineering safety and the economic efficiency are greatly improved.

Description

Cantilever arch ring and stiffness framework combined structure based on large-span arch bridge

Technical Field

The utility model relates to a cantilever arch ring and stiffness framework combined structure based on a large-span arch bridge, and belongs to the technical field of bridge construction.

Background

The existing arch bridge construction method mainly comprises a prefabricated segment hoisting method, a stiff framework method, support cast-in-situ, swivel construction and a cable-stayed buckling and hanging cantilever pouring construction method, and the cable-stayed buckling and hanging cantilever pouring construction method has been developed to the present, so that the method has become an extremely effective and economic construction means for building a large-medium-span reinforced concrete arch bridge. The construction method comprises the steps of erecting a tower, buckling and hanging concrete arch ring segments on the tower by adopting stay cables, constructing the concrete arch ring segments to the arch crown section by section from arch feet, setting anchor cables corresponding to buckling ropes in the construction process, anchoring the anchor cables in bedrock or gravity type structures to ensure stability of the tower, and dismantling the cable-stayed buckling and hanging system after the arch rings are formed into arches.

However, when this method was applied, the following disadvantages were found: the whole arch ring segments are constructed by adopting the tower cable-stayed buckling, the number of the segments and the weight of the segments are correspondingly increased along with the increase of the span of the concrete arch bridge, the tower is assembled by a steel structure which is easy to disassemble at the later stage, the stability of the tower is difficult to ensure due to the increase of the compression load, particularly the compression stability of the tower is required to be ensured if the compression stability of the tower is ensured for a reinforced concrete arch bridge with a large span of 200 meters, the construction difficulty and the risk are further increased, and the economical efficiency is reduced.

Disclosure of Invention

In view of the above, the present utility model aims to provide a cantilever arch ring and stiffness skeleton combined structure based on a large span arch bridge, which can overcome the defects of the prior art.

The utility model aims at realizing the following technical scheme:

cantilever arch ring and strength nature skeleton integrated configuration based on long span arch bridge, including the cantilever arch ring of symmetry setting on the left and right side arch seat of long span arch bridge, the cantilever arch ring is including concatenation formula steel reinforcement skeleton, and the parcel has concrete outside, and the mid-span vault of two cantilever arch rings leaves the opening paragraph, and the steel reinforcement skeleton of two cantilever arch ring open ends is the link that exposes, is equipped with strength nature skeleton in opening paragraph department, and the both ends of strength nature skeleton are connected with the link of two cantilever arch rings respectively through pre-buried attach fitting.

The embedded type connecting joint comprises a plurality of shear nails which are respectively arranged on the two cantilever arch ring connecting sections and the stiff framework, wherein two ends of the stiff framework are in scarf joint with the cantilever arch ring connecting sections and form a hoop matching reinforcing structure through binding reinforcing steel bars on the shear nails, and concrete is wrapped outside the hoop matching reinforcing structure.

The stiff framework comprises a plurality of segments of prefabricated framework units spliced together; the prefabricated framework unit comprises a box structure formed by splicing main chords, wherein vertical web members and inclined web members are arranged in the box structure, and the main chords, the vertical web members and the inclined web members are connected with each other through a connecting structure.

And arranging a plurality of shear nails on the connecting structures of the prefabricated skeleton units at the two ends of the stiff skeleton, embedding the connecting sections of the cantilever arch rings into the connecting structures, and binding reinforcing steel bars in a combination mode of a Chinese character 'Hui' shape and a cross shape to form a hoop-matching reinforcing structure.

The length of the opening section left by the midspan vault of the two cantilever arches is not more than 24.65m, and the stiff skeleton is formed by splicing at least 7 prefabricated skeleton units and is arranged at the opening section.

The length of the prefabricated framework units at the two ends of the stiff framework is not less than 3m, and the prefabricated framework units in the rest middle parts are arranged in equal length.

Compared with the prior art, the cantilever arch ring and stiffness skeleton combined structure based on the large-span arch bridge disclosed by the utility model comprises cantilever arch rings symmetrically arranged on left and right arch seats of the large-span arch bridge, wherein the cantilever arch rings comprise spliced reinforcement skeletons, concrete is wrapped outside the spliced reinforcement skeletons, opening sections are reserved on midspan vaults of the two cantilever arch rings, the reinforcement skeletons at the opening ends of the two cantilever arch rings are exposed connecting sections, stiffness skeletons are arranged at the opening sections, and two ends of the stiffness skeletons are respectively connected with the connecting sections of the two cantilever arch rings through embedded connecting joints. According to the utility model, the embedded type connecting joint is arranged, so that a combined structure with reliable connection is formed between the concrete arch ring and the stiff framework, the combined structure is good in stability and high in reliability, the concrete arch ring in the span-middle opening section range in the construction process is free from adopting a tower cable-stayed buckling construction, the stability risk of the tower can be greatly reduced on the premise of meeting the construction strength, and the engineering safety and the economic efficiency are greatly improved.

The beneficial effects of the utility model include:

(1) The length of a large cantilever of the suspension casting arch bridge is effectively reduced, so that the risk in construction is reduced, and the method is particularly suitable for a large-span reinforced concrete arch bridge with a span of 200 meters;

(2) By arranging the embedded type connecting joint, a combined structure with reliable connection is formed between the concrete arch ring and the stiff framework, so that the number of buckling ropes and anchor boxes can be reduced, the height of the buckling tower is further reduced, the number of anchor ropes and the scale of anchor ingots are correspondingly reduced, and the engineering risk is further reduced; the concrete arch ring in the span range of 24.65m can be constructed without adopting a tower to draw and buckle, the height of the tower is reduced by 12 meters, 8 pairs of buckling ropes, 8 pairs of anchor ropes and corresponding anchoring engineering quantity are reduced, and about 120 ten thousand yuan is directly and economically saved.

Additional advantages, objects, and features of the utility model will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the utility model. The objects and other advantages of the utility model may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.

Drawings

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the present utility model will be described in further detail with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic diagram of the front structure of a stiff skeleton 2;

FIG. 3 is a schematic top view of the structure of FIG. 2;

fig. 4 is a schematic diagram of a front connection structure of the embedded connection joint 3;

fig. 5 is a schematic cross-sectional structure of the pre-buried connector 3.

Detailed Description

Hereinafter, preferred embodiments of the present utility model will be described in detail with reference to the accompanying drawings. It should be understood that the preferred embodiments are presented by way of illustration only and not by way of limitation.

As shown in fig. 1-5, a cantilever arch ring and stiffness skeleton combined structure based on a large-span arch bridge comprises cantilever arch rings 1 symmetrically arranged on left and right arch seats 5 of the large-span arch bridge, wherein the cantilever arch rings 1 comprise spliced reinforcement skeletons, concrete is wrapped outside the spliced reinforcement skeletons, opening sections are reserved on midspan arch tops of the two cantilever arch rings 1, the reinforcement skeletons at the opening ends of the two cantilever arch rings are exposed connecting sections, stiffness skeletons 2 are arranged at the opening sections, and two ends of the stiffness skeletons 2 are respectively connected with the connecting sections of the two cantilever arch rings 1 through embedded connecting joints 3.

The embedded type connecting joint 3 comprises a plurality of shear nails which are respectively arranged on the connecting sections of the two cantilever arches 1 and the stiff framework 2, two ends of the stiff framework 2 are in scarf joint with the connecting sections of the cantilever arches 1 and form a hooping reinforcing structure through binding reinforcing steel bars 301 on the shear nails, and concrete 302 is wrapped outside the hooping reinforcing structure. Preferably, the setting length of the concrete 302 is not less than 3m.

The stiff framework 2 comprises a plurality of segments of prefabricated framework units spliced together; the prefabricated framework unit comprises a box structure formed by splicing main chords 201, wherein vertical web members 202 and inclined web members 203 are arranged in the box structure, and the main chords 201, the vertical web members 202 and the inclined web members 203 are connected with each other through a connecting structure 204.

A plurality of shear nails are distributed on the connecting structures 204 of the prefabricated framework units at the two ends of the stiff framework 2, the connecting sections of the cantilever arch rings 1 are embedded into the connecting structures 204, and the reinforcing steel bars 301 are bound in a combination mode of a Chinese character 'hui' shape and a cross shape to form a hoop matching reinforcing structure.

The length of the opening section left by the midspan vault of the two cantilever arches 1 is not more than 24.65m, and the stiff skeleton 2 is formed by splicing at least 7 prefabricated skeleton units and is arranged at the opening section. Preferably, the lengths of the prefabricated framework units at two ends of the stiff framework 2 are not less than 3m, and the prefabricated framework units in the rest middle parts are arranged in equal length.

The construction method of the cantilever arch ring and stiffness framework combined structure based on the large-span arch bridge comprises the following steps:

s1, pouring cantilever arch rings 1 in a bilateral symmetry and sectional manner by adopting a tower diagonal buckling and hanging pouring method until an opening section of a mid-span vault is reserved;

s2, erecting a stiff framework 2 at the opening, closing the opening in advance, connecting two ends of the stiff framework 2 with left and right cantilever arch rings 1 respectively through pre-buried connecting joints 3 to form a mixed arch structure formed by the concrete arch rings and the stiff framework, and under the action of the pre-buried connecting joints 3, performing diagonal buckling and hanging construction on the closure section;

s3, casting concrete of the stiff framework section in sections, and wrapping the stiff framework in the concrete, so that a complete arch ring is formed.

In step s1, adopting a permanent structure tower cable-stayed buckling and hanging 4, and casting cantilever arch rings section by section along the left and right arch seats until 24.65m sections of the mid-span arch crown are reserved.

The left arch seat 5 and the right arch seat 5 are provided with junction piers 6, and bridge piers 7 and bridge abutment 8 are sequentially arranged in the foundation rock of the bridge area on the upper side of the arch seat 5, and the junction piers 6, the bridge piers 7 and the bridge abutment 8 are used as construction temporary anchoring members, and the tower is stayed and buckled and hung 4. As shown in fig. 1, the foundation structures of the bridge abutment No. 0, the bridge pier No. 1, the bridge pier No. 4 and the bridge pier No. 5 can be used as temporary anchors for the construction of the stay cable of the main arch ring, and meanwhile, the boundary pier body is considered to participate in the construction of the cable-stayed buckling, so that the cost of temporary construction measures is greatly reduced.

The concrete pouring steps of the cantilever arch ring comprise:

(1) The original segment connected with the left and right arch seats 5 is cast in situ: setting up a cast-in-situ bracket as a pouring platform, ensuring the inclination angle of an initial section to be 39.6 degrees, pre-burying a slope steel plate with the thickness not less than 20mm on the slope of an arch seat, welding the slope steel plate and a longitudinal girder into a whole, and resisting horizontal thrust generated during concrete pouring, thereby adopting C55 concrete cast-in-situ construction;

(2) And (3) carrying out construction of a cable-stayed buckling and hanging 4 anchoring system: installing a pier top buckling tower, forming a plurality of anchor holes corresponding to the positions on the bridge pier 7 and the bridge abutment 8, constructing foundation rock anchors and arranging anchor cable tensioning ends;

(3) Installing an assembled hanging basket 9: one end of the hanging basket is fixedly connected with the initial section, and the other end of the hanging basket is suspended in the air and reserves the construction space for the suspension arm section of the cable-stayed buckle;

(4) Adopting an assembled hanging basket 9 to gradually move forward and a segmented section to carry out pouring construction of a cable-stayed buckling hanging cantilever section: erecting a reinforced concrete box structure, pouring C55 concrete to wrap the reinforced concrete box structure, and forming a reinforced concrete box arch ring; and reserving a buckling rope anchoring tooth block at the side of the reinforced concrete box-shaped arch ring close to the web plate, and tensioning through a cable-stayed buckling and hanging anchoring system.

When the cable-stayed buckling cantilever segments are cast and constructed in a segmented mode, the upper edge tensile stress of the section of an arch ring of the cast segment and the lower edge tensile stress of an arch foot when the current buckling cable is tensioned are controlled, and the main arch ring is enabled to be smaller than 1.5MPa in tensile stress through cable adjusting and cable loosening treatment, so that cracking does not occur.

In step s2, when the last section of cantilever arch ring constructed by adopting the cable-stayed buckling and hanging 4 is poured with concrete, the last section of cantilever arch ring is connected with the first section of stiff skeleton by adopting a pre-buried connecting joint reinforced by a transverse matching hoop, then the rest sections of the stiff skeleton are hoisted in place by adopting a cable hoisting method, and the stiff skeleton sections are welded and connected, so that the large cantilever arch rings on two sides are converted into a mixed arch consisting of the concrete arch ring and the stiff skeleton.

The specific construction steps of the embedded type connecting joint 3 comprise:

(1) The stiffness skeleton is prefabricated in sections in a factory: the stiffness framework comprises a box structure formed by splicing main chords 201, wherein a vertical web member 202 and an inclined web member 203 are arranged in the box structure, the main chords 201, the vertical web member 202 and the inclined web member 203 are connected with each other through a connecting structure 204, and a plurality of shear nails are distributed on the stiffness framework;

the main chord member 201 is welded I-steel, and the vertical web member 202, the inclined web member 203 and the connecting structure 204 are composed of four-piece grooved steel;

(2) Abutting the steel bar box structure of the last section of cantilever arch ring with the first section of stiff framework, and binding steel bars 301 between the steel bar box structure and shear nails on the stiff framework for reinforcement;

binding the reinforcing steel bars 301 in a combination mode of a back shape and a cross shape;

(3) And pouring concrete to perform embedding treatment on the butt joint section, wherein the embedding depth is not less than 3m.

Preferably, the length of the midspan closure section of the main arch ring is 24.65 and m, the prefabricated stiff frameworks are divided into 7 sections, the stiff frameworks at two ends are connected with the last cantilever arch ring through the embedded connecting joint 3, and the sections of the stiff frameworks in the middle are mutually connected in a welding mode.

In the step s3, casting closure segments in a basket-hanging segmented mode, and casting three times:

1 st time: symmetrically pouring a first section close to the last section of cantilever arch ring by adopting concrete;

2 nd time: the hanging basket on the first section on one side is moved forwards, and a corresponding second section of concrete is poured;

3 rd time: and (3) moving the hanging basket on the first section on the other side forwards, and pouring the corresponding third section of concrete until the full-bridge arch ring closure is completed.

Preferably, the first section close to the last section of cantilever arch ring is symmetrically poured by concrete for the 1 st time, and the length of the first section is about 6.58 m; and (2) moving the hanging basket on the first section on one side forwards for the 2 nd time, pouring the corresponding second section of concrete, wherein the length of the second section of concrete is about 6.6m, and the 3 rd time: and (3) moving the hanging basket on the first section on the other side forwards, and pouring the corresponding third section of concrete to complete the closure of the full-bridge arch ring.

Taking a certain extra-large reinforced concrete suspension casting arch in Jinxian county of Guizhou province as an example:

technical standard:

(1) Road grade: expressway; (2) number of lanes: 4, a step of; (3) design speed: 80 km/h; (4) design load: road-class i; (4) basic intensity of earthquake: VI degrees; (5) designing a basic wind speed: 25.6m/s (1/100).

The total width of the whole bridge deck is 21.5 meters, the main arch ring is designed in two pieces, the hole span arrangement is 2X 30 meters T beam+210 meters (net span) reinforced concrete box arch+3X 30 meters T beam, and the total length of the bridge is 391.4 meters; the main arch traffic lane plate adopts a hollow plate with a span of 13.2 meters.

The construction is carried out by adopting the method:

firstly, dividing a single arch ring into 2 cast-in-situ sections, 26 suspension casting sections and 1 closure section, wherein the maximum length of the suspension casting sections is 8.063m, the maximum cantilever casting weight is 188.6 t, and the arch ring is cast by C55;

secondly, the length of a midspan closure section of the main arch ring is 24.65m, a large-span stiff skeleton arch is built in, the stiff skeleton arch is divided into 7 sections, the pre-buried length of a first section is 3 meters, and two steel trusses weigh 199 tons; and the closure section construction combines the stiff skeleton arch with the suspended reinforced concrete arch.

Structural theory calculation and test:

(1) Stress checking: the stress distribution of the upper edge arch ring and the lower edge arch ring is uniform, and the maximum 12MPa compressive stress near the arch feet meets the requirement;

(2) Deflection checking: the maximum deflection in the midspan is 0.121m and is less than 210 m/1000=0.210 m, so that the requirements are met;

(3) And checking and calculating the embedded type connecting joint by a finite element simulation method:

(1) axial pressure test piece: the axial pressure test is carried out on a kiloton pressure tester, a test piece is placed on the plane of a bottom plate of the kiloton pressure tester, and the H-shaped steel shape of the test piece coincides with the center of a loading top plate of the kiloton pressure tester;

(2) shear test piece: the shearing test is loaded by using a 50t hydraulic jack, and a shearing test piece stands on the ground and is anchored by using a ground anchor bolt;

carrying out axial pressure and shear force tests by designing and manufacturing a local full-scale test piece of the joint, and carrying out comparative analysis on a stress actual measurement value and a stress numerical calculation value: the bearing capacity of the test piece is approximately the bearing capacity of the joint, the actual measurement values of the compression resistance and the shearing resistance bearing capacity are larger than the bearing value of the joint in the construction process, and the joint is safe and reliable.

The foregoing description is only a preferred embodiment of the present utility model, and is not intended to limit the present utility model in any way, and any simple modification, equivalent variations and modification made to the above embodiment according to the technical matter of the present utility model without departing from the technical scope of the present utility model still fall within the scope of the technical scheme of the present utility model.

Claims (6)

1. Cantilever ring and strength nature skeleton integrated configuration based on long span arch bridge, including cantilever ring (1) of symmetry setting on long span arch bridge left and right side hunch seat (5), cantilever ring (1) are including concatenation formula steel reinforcement skeleton, and its parcel has concrete, and the opening paragraph is left to the mid-span vault of two cantilever rings (1), its characterized in that: the steel reinforcement frameworks at the opening ends of the two cantilever arch rings (1) are exposed connecting sections, a stiff framework (2) is arranged at the opening sections, and two ends of the stiff framework (2) are respectively connected with the connecting sections of the two cantilever arch rings (1) through embedded connecting joints (3).

2. The cantilever arch ring and stiff skeleton combined structure based on a large span arch bridge as recited in claim 1, wherein: the embedded type connecting joint (3) comprises a plurality of shear nails which are respectively arranged on the connecting sections of the two cantilever arches (1) and the stiff framework (2), the two ends of the stiff framework (2) are in scarf joint with the connecting sections of the cantilever arches (1) and form a hooping reinforcing structure through binding reinforcing steel bars (301) on the shear nails, and concrete (302) is wrapped outside the hooping reinforcing structure.

3. The cantilever arch ring and stiff skeleton combined structure based on a large span arch bridge as recited in claim 2, wherein: the stiff framework (2) comprises a plurality of segments of prefabricated framework units spliced together; the prefabricated framework unit comprises a box structure formed by splicing main chords (201), wherein vertical web members (202) and inclined web members (203) are arranged in the box structure, and the main chords (201) are connected with the vertical web members (202) and the inclined web members (203) through connecting structures (204).

4. A cantilever arch ring and stiff skeleton combined structure based on a large span arch bridge as in claim 3, wherein: a plurality of shear nails are distributed on the connecting structures (204) of prefabricated framework units at the two ends of the stiff framework (2), the connecting sections of the cantilever arch rings (1) are embedded into the connecting structures (204), and reinforcing steel bars (301) are bound in a combination mode of a shape like a Chinese character 'Hui' and a shape like a Chinese character 'ji', so that a hoop matching reinforcing structure is formed.

5. A cantilever arch ring and stiff skeleton combined structure based on a large span arch bridge as in claim 4, wherein: the length of the opening section left by the midspan vault of the two cantilever arches (1) is not more than 24.65m, and the stiff skeleton (2) is formed by splicing at least 7 prefabricated skeleton units and is arranged at the opening section.

6. A cantilever arch ring and stiff skeleton combined structure based on a large span arch bridge as in claim 5, wherein: the length of the prefabricated framework units at the two ends of the stiff framework (2) is not less than 3m, and the prefabricated framework units in the rest middle parts are arranged in equal length.