A connecting structure of a U-shaped combined cap beam and a column

Abstract

The utility model discloses a kind of connecting structure of U-shaped combined bent cap and stand, the U-shaped combined bent cap is composed of prefabricated U-shaped bent cap and post-cast concrete poured in the notched opening of the prefabricated U-shaped bent cap, the prefabricated U-shaped bent cap is installed on the stand, the connecting structure includes first prestressed steel bundle, rectangular bellows and first tensioning anchorage device, the rectangular bellows is located in the bottom of the two sides of the prefabricated U-shaped bent cap, and both ends of the rectangular bellows are communicated with the outside, the bottom end of the first prestressed steel bundle is fixed in the top of the stand, the top end passes through the rectangular bellows and extends into the notched opening of the prefabricated U-shaped bent cap, and the top end of the first prestressed steel bundle is fixed with the prefabricated U-shaped bent cap by the first tensioning anchorage device.The utility model has the advantages that: effectively solve the problem that the site hoisting condition of oversize, overweight component is limited;Save cost;The comprehensive construction efficiency is higher.

Description

Technical Field

[0001] This utility model relates to the technical field of cap beams, and in particular to a connection structure between a U-shaped composite cap beam and a column. Background Technology

[0002] With the rapid growth of urban traffic, bridge engineering demands increasingly higher levels of efficiency, environmental impact, and cost control. Prefabricated bridge structures are widely used due to their advantages such as fast construction speed and controllable quality. However, for large-span (≥26m) and high-tonnage portal girder projects, traditional construction methods still face the following technical bottlenecks:

[0003] Limitations of precast cap beams

[0004] While traditional precast concrete cap beams ensure structural integrity, their large size (typically exceeding 300 tons) makes long-distance transport and on-site installation difficult due to limitations imposed by road transport clearances (such as maximum transport length and height restrictions) and the lifting capacity of on-site cranes (generally, crawler cranes have a maximum lifting capacity of ≤300 tons). Furthermore, the cantilever sections of ultra-wide pier cap beams are prone to cracking during transport, requiring additional reinforcement measures and further increasing construction costs.

[0005] Economic and durability issues of steel cap beams

[0006] While steel cap beams offer advantages such as light weight and ease of hoisting, their material costs are high (approximately 2-3 times that of concrete cap beams), and regular anti-corrosion maintenance is required during the later operational phase, significantly increasing maintenance costs. Furthermore, the interface between the steel cap beam and the concrete pier is complex, posing a risk of fatigue stress concentration and impacting structural durability.

[0007] Challenges in implementing segmented prefabrication and assembly

[0008] While segmental precast concrete cap beams can reduce the weight of a single segment, they require large assembly scaffolds and temporary support systems on the construction site, placing extremely high demands on site space and foundation bearing capacity. Furthermore, the reinforcement binding, formwork erection, and concrete curing at the cast-in-place joints between segments are time-consuming, making it difficult to meet the rapid construction needs of urban arterial roads. Additionally, joints are prone to becoming weak points in the structure, requiring additional shear keys or prestressed tendons, increasing construction complexity.

[0009] Defects of traditional cast-in-place cap beams

[0010] Cast-in-place cap beams require the erection of full-span scaffolding at the bridge site, occupying a large amount of ground road space and severely interfering with existing traffic. At the same time, the on-site processes of tying steel bars, setting up formwork, and pouring concrete are complicated, with a long construction period (usually 20-30 days) and are subject to weather conditions, making it difficult to meet the rapid construction requirements of high traffic flow areas. Summary of the Invention

[0011] The purpose of this utility model is to address the shortcomings of the prior art by providing a connection structure between a U-shaped composite cap beam and a column. This connection structure consists of a first prestressed steel strand, a rectangular corrugated pipe, and a first tension anchor. The U-shaped composite cap beam is divided into a precast U-shaped cap beam and post-cast concrete. The precast U-shaped cap beam is installed on the column. By dividing the U-shaped composite cap beam into two parts, the precast U-shaped cap beam and the post-cast concrete, it is convenient to first install the precast U-shaped cap beam on the column and then pour the post-cast concrete. The bottom end of the first prestressed steel strand is fixed inside the top of the column, and the top end passes through the rectangular corrugated pipe and extends into the groove of the precast U-shaped cap beam. The top end of the first prestressed steel strand is fixed to the precast U-shaped cap beam through the first tension anchor, ensuring the installation strength of the precast U-shaped cap beam on the column. It can meet the requirements of rapid assembly and construction, reduce the amount of on-site steel bar binding and concrete pouring, and save the cost of temporary turnover materials. Compared with the steel cap beams and segmented precast PC cap beams used in traditional processes, the design and construction of U-shaped composite cap beams is more economical and efficient.

[0012] The objective of this utility model is achieved through the following technical solution:

[0013] A connection structure between a U-shaped composite cap beam and a column is disclosed. The U-shaped composite cap beam consists of a precast U-shaped cap beam and post-cast concrete poured into the groove of the precast U-shaped cap beam. The precast U-shaped cap beam is installed on the column. The connection structure includes a first prestressed steel strand, a rectangular corrugated pipe, and a first tensioning anchor. The rectangular corrugated pipe is located inside the bottom of both sides of the precast U-shaped cap beam, and both ends of the rectangular corrugated pipe are connected to the outside. The bottom end of the first prestressed steel strand is fixed inside the top of the column, and the top end passes through the rectangular corrugated pipe and extends into the groove of the precast U-shaped cap beam. The top end of the first prestressed steel strand is fixed to the precast U-shaped cap beam through the first tensioning anchor.

[0014] The first prestressed steel strand is composed of tensioned fine-rolled threaded steel bars and connecting main bars.

[0015] The first tensioning anchor consists of an I-beam fixing seat and a nut. The I-beam fixing seat is set in the slot of the precast U-shaped cap beam. The top end of the tensioned precision rolled threaded steel passes through the I-beam fixing seat and is fixed to the I-beam fixing seat by the nut.

[0016] Both the precast U-shaped cap beam and the post-cast concrete have embedded metal corrugated pipes, and a second prestressed steel strand is installed inside the metal corrugated pipe. The second prestressed steel strand is fixed by a second tension anchor.

[0017] The advantages of this utility model are:

[0018] 1. Effectively solve the problem of limited on-site hoisting conditions for ultra-large and ultra-heavy components: Prefabricated bridge portal girder has a large span and high tonnage. Due to transportation conditions and lifting tonnage, it is impossible to achieve the overall prefabrication and assembly of the girder. On-site construction using integral cast-in-place or segmented prefabrication is not feasible.

[0019] 2. Cost savings: Under the above working conditions, steel cap beams are usually used, but steel cap beams are expensive. U-shaped cap beams are more economical and save on the costs of temporary on-site supports, pouring formwork and other auxiliary materials, as well as traffic organization measures. Each U-shaped cap beam saves about 35% of the total cost compared to steel cap beams and about 20% compared to concrete cap beams.

[0020] 3. Higher overall construction efficiency: Most of the pouring work is completed in the prefabrication plant, which helps to improve construction efficiency and ensure on-site construction safety. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of the connection structure between the U-shaped composite cap beam and the column of this utility model;

[0022] Figure 2 for Figure 1 Cross-sectional view of AA in the middle;

[0023] Figure 3 for Figure 1 Cross-sectional view of BB in the middle;

[0024] Figure 4 This is a cross-sectional view of the U-shaped composite cap beam of this utility model;

[0025] Figure 5 This is a schematic diagram of the horizontal installation of the metal corrugated pipe of this utility model;

[0026] Figure 6 This is a schematic diagram of the longitudinal installation of the metal corrugated pipe of this utility model;

[0027] like Figures 1-6 As shown in the figure, the markings represent:

[0028] 10 precast U-shaped cap beam, 20 post-cast concrete, 30 column, 40 first prestressed steel strand, 401 tensioned fine-rolled threaded steel bar, 402 connecting main reinforcement, 50 rectangular corrugated pipe, 60 first tensioning anchor, 601 I-beam fixing seat, 602 nut, 70 metal corrugated pipe. Detailed Implementation

[0029] The features and other related features of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate the understanding of those skilled in the art:

[0030] Example: Figures 1-4As shown, this embodiment relates to a connection structure between a U-shaped composite cap beam and a column. The U-shaped composite cap beam consists of a precast U-shaped cap beam 10 and post-cast concrete 20 (self-compacting high-performance concrete) poured into the groove (U-shaped groove, the depth of the middle of the groove is deeper than the depth of the sides of the groove) of the precast U-shaped cap beam 10. The precast U-shaped cap beam 10 is installed on the column 30 through a connection structure, and the U-shaped composite cap beam is divided into two parts: the precast U-shaped cap beam 10 and the post-cast concrete 20, so that the precast U-shaped cap beam 10 is installed on the column 30 first, and then the post-cast concrete 20 is poured, thereby reducing the construction difficulty. The connection structure mainly includes a first prestressed steel strand 40, a rectangular corrugated pipe 50, and a first tension anchor 60. The rectangular corrugated pipe 50 is located inside the bottom of both sides of the precast U-shaped cap beam 10, and both ends of the rectangular corrugated pipe 50 are connected to the outside. The bottom end of the first prestressed steel strand 40 is fixed inside the top of the column 30, and the top end passes through the rectangular corrugated pipe 50 and extends into the groove of the precast U-shaped cap beam 10. The top end of the first prestressed steel strand 40 is fixed to the precast U-shaped cap beam 10 through the first tension anchor 60. In this embodiment, concrete is poured into the rectangular corrugated pipe 50 to connect the U-shaped composite cap beam 10, the column 30, and the first prestressed steel strand 40 into a whole. After the concrete has solidified, the first tension anchor 60 can be removed.

[0031] like Figure 1 As shown, the first prestressed steel strand 40 is composed of tensioned fine-rolled threaded steel 401 and connecting main reinforcement 402. The first tensioning anchor 60 is composed of I-beam fixing seat 601 and nut 602. The I-beam fixing seat 601 is set in the slot of the precast U-shaped cap beam 10. The top of the tensioned fine-rolled threaded steel 401 passes through the I-beam fixing seat 601 and is fixed to the I-beam fixing seat 601 by the nut 602. The top of the connecting main reinforcement 402 is located inside the rectangular corrugated pipe 50.

[0032] like Figures 5-6 As shown, corrugated metal pipes 70 are pre-embedded on both sides and at the bottom of the precast U-shaped cap beam 10, as well as within the post-cast concrete 20. Second prestressed steel strands (such as prestressed steel wires) are installed within the corrugated metal pipes 70, and are fixed by second tensioning anchors (such as wedge-type anchors). First, the second prestressed steel strands within the precast U-shaped cap beam 10 are prestressed, i.e., the U-shaped composite cap beam undergoes its first prestressing tension, and grout is injected into the corrugated metal pipes 70 of the precast U-shaped cap beam 10. Then, the second prestressed steel strands within the post-cast concrete 20 are prestressed, i.e., the U-shaped composite cap beam undergoes its second prestressing tension, and grout is injected into the corrugated metal pipes 70 of the post-cast concrete 20.

[0033] like Figures 1-6 As shown, this embodiment also includes the following construction methods:

[0034] 1. Prefabrication stage

[0035] The precast U-shaped cap beam 10 is integrally cast from concrete web and bottom slab. The overall precast construction requirements are: the reinforcing cages of the web and bottom slab are integrally formed and tied on the reinforcing steel binding jig, which is conducive to the precise positioning of the corrugated metal pipe 70; after the reinforcing cage is hoisted into the formwork, the bottom slab and web concrete are poured simultaneously and integrally; the outer formwork adopts a five-piece steel formwork with a longitudinal spacing of 2m and transverse support, one on the top and one on the bottom.

[0036] 1) Rebar tying

[0037] The steel reinforcement cage is constructed using a standardized formwork, with pre-reserved lifting points at the beam ends. It is then formed as a whole and hoisted to the formwork.

[0038] 2) Template Installation

[0039] First, install the outer formwork. After the steel cage is placed into the formwork, install the inner formwork.

[0040] 3) Concrete Engineering

[0041] Pouring, demolding and curing.

[0042] 4) The first prestressing process of the precast U-shaped cap beam 10

[0043] The concrete curing strength and elastic modulus both reach 100% of the design value. The prestressing project (tensioning, grouting, and anchoring) is completed in the prefabrication yard. All prestressed steel strands (second prestressed steel strands) should be tensioned as a whole and should not be tensioned individually.

[0044] 2. Transportation and installation

[0045] 1) Transport to the construction site

[0046] Because the precast U-shaped cap beam 10 is an open thin-walled structure, temporary supports are installed along the inner side of the slot to prevent stress cracks during hoisting and transportation. An additional inner support is added, using steel profiles as the inner support. The support position is 30cm below the upper surface of the U-shaped side wall, and one support is installed at a interval of 2.5m.

[0047] hoisting into place

[0048] The on-site installation of the cap beams uses a traditional crawler crane hoisting process, which does not require temporary supports and is more convenient to operate.

[0049] Vertical connection and prestressing tensioning with column 30

[0050] The connection structure between the precast U-shaped cap beam 10 and the column 30 consists of a first prestressed steel strand 40, a rectangular corrugated pipe 50, and a first tensioning anchor 60, replacing the traditional grouting sleeve and connecting main reinforcement. The connection between the column 30 and the precast U-shaped cap beam 10 is achieved by using several rectangular corrugated pipes 50 pre-embedded in the precast U-shaped cap beam 10 instead of the traditional grouting sleeve. The first prestressed steel strand 40 replaces the traditional pre-embedded connecting reinforcement, and is composed of several tensioned fine-rolled threaded steel bars 401 and connecting main reinforcement bars 402 of varying quantities. The precast U-shaped cap beam 10 is erected on the column 30, and the first prestressed steel strand 40 pre-embedded at the top of the column 30 passes through the rectangular corrugated pipes 50 pre-embedded in the precast U-shaped cap beam 10 and is tensioned in the groove of the precast U-shaped cap beam 10 to achieve the effect of bonding and anchoring.

[0051] In this embodiment, each rectangular corrugated pipe 50 is pre-installed with φ40mm connecting main reinforcement 402 and φ32mm tensioning fine-rolled threaded steel 401; after the prefabricated U-shaped cap beam 10 is installed on site using two crawler cranes, the fine-rolled threaded steel 401 is tensioned and grouting is performed. The tensioning device and the first tensioning anchor 60 can only be removed after the grout reaches the design strength.

[0052] 3. Secondary casting of the cap beam, casting of the pad stones and retaining blocks, and secondary prestressing works.

[0053] Specific construction procedures: inspection and acceptance of steel bars and embedded parts in the trench, corrugated metal pipes 70 → concrete pouring (including core filling concrete, bearings, and pad stones) → concrete surface covering and curing → transverse prestressed engineering (tensioning, grouting, and anchor sealing).

[0054] The beneficial technical effects of this embodiment are as follows:

[0055] 1. Effectively solve the problem of limited on-site hoisting conditions for ultra-large and ultra-heavy components: Prefabricated bridge portal girder has a large span and high tonnage. Due to transportation conditions and lifting tonnage, it is impossible to achieve the overall prefabrication and assembly of the girder. On-site construction using integral cast-in-place or segmented prefabrication is not feasible.

[0056] 2. Cost savings: Under the above working conditions, steel cap beams are usually used, but steel cap beams are expensive. U-shaped cap beams are more economical and save on the costs of temporary on-site supports, pouring formwork and other auxiliary materials, as well as traffic organization measures. Each U-shaped cap beam saves about 35% of the total cost compared to steel cap beams and about 20% compared to concrete cap beams.

[0057] 3. Higher overall construction efficiency: Most of the pouring work is completed in the prefabrication plant, which helps to improve construction efficiency and ensure on-site construction safety.

[0058] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A connection structure between a U-shaped composite cap beam and a column, characterized in that... The U-shaped composite cap beam consists of a precast U-shaped cap beam and post-cast concrete poured into the groove of the precast U-shaped cap beam. The precast U-shaped cap beam is installed on the column. The connecting structure includes a first prestressed steel strand, a rectangular corrugated pipe, and a first tensioning anchor. The rectangular corrugated pipe is located inside the bottom of both sides of the precast U-shaped cap beam, and both ends of the rectangular corrugated pipe are connected to the outside. The bottom end of the first prestressed steel strand is fixed inside the top of the column, and the top end passes through the rectangular corrugated pipe and extends into the groove of the precast U-shaped cap beam. The top end of the first prestressed steel strand is fixed to the precast U-shaped cap beam through the first tensioning anchor.

2. The connection structure between the U-shaped composite cap beam and the column as described in claim 1, characterized in that... The first prestressed steel strand is composed of tensioned fine-rolled threaded steel bars and connecting main bars.

3. The connection structure between the U-shaped composite cap beam and the column as described in claim 2, characterized in that... The first tensioning anchor consists of an I-beam fixing seat and a nut. The I-beam fixing seat is set in the slot of the precast U-shaped cap beam. The top end of the tensioned precision rolled threaded steel passes through the I-beam fixing seat and is fixed to the I-beam fixing seat by the nut.

4. The connection structure between the U-shaped composite cap beam and the column as described in claim 1, characterized in that... Both the precast U-shaped cap beam and the post-cast concrete have embedded metal corrugated pipes, and a second prestressed steel strand is installed inside the metal corrugated pipe. The second prestressed steel strand is fixed by a second tension anchor.

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