A type of continuous simply supported composite beam bridge using rubber sleeve-stud connectors

Abstract

This invention belongs to the field of bridge structures and provides a continuous simply supported composite beam bridge using rubber sleeve-stud connectors. It comprises I-beam longitudinal beams, transverse diaphragms, rubber sleeve-stud connectors, and a continuous UHPC bridge deck. This composite beam bridge eliminates the need for traditional, easily damaged expansion joints, saving on maintenance costs. Bridges experience significant shrinkage under wide-range cooling. When the lower steel beams with higher cross-sectional stiffness shrink inwards due to cooling, the stud connector rods undergo relatively free bending and shear deformation within the rubber sleeves, releasing the constraint on the upper bridge deck. Therefore, under wide-range cooling, the upper continuous bridge deck experiences more uniform tensile forces. Thanks to the high tensile strength and high tensile toughness of the ultra-high performance concrete (UHPC) itself, as well as the internal steel mesh, only uniform micro-cracks appear in the bridge deck, ensuring good bridge durability and continuity and preventing beam collapse accidents.

Description

Technical Field

[0001] This invention belongs to the field of bridge structural engineering and relates to a steel-ultra-high performance concrete (UHPC) composite beam bridge using rubber sleeve-stud connectors. It is applied to a continuous simply supported beam bridge system and is suitable for highway engineering in areas with significant temperature differences and strong seismic forces. Background Technology

[0002] Highway bridges often employ multi-span simply supported beam structures, requiring expansion joints between the beams to accommodate deformation caused by temperature changes. However, expansion joints have historically been weak and vulnerable parts of bridge structures: firstly, the significant diurnal and annual temperature differences in cold regions lead to substantial shrinkage during cooling, easily causing deformation and damage to expansion joints and drastically shortening their service life; secondly, under seismic loads, expansion joints struggle to effectively restrain and connect the main beams, greatly increasing the risk of beam collapse. Therefore, for simply supported highway beam bridges, employing specialized seamless construction techniques to eliminate traditional expansion joints and enhance the continuity between beams has significant engineering practical value in improving the durability and seismic safety of highway bridges.

[0003] To address the aforementioned issues, highway bridges commonly employ "simple-supported first, continuous later" or "continuous deck" construction methods to eliminate bridge expansion joints and enhance the continuity between beams. However, these methods are ill-suited to the effects of wide-range temperature drops. Specifically, traditional simply supported beams experience significant overall shrinkage under wide-range temperature drops. If a "simple-supported first, continuous later" construction method is used, tensile fractures are likely to occur at the beam ends where the stiffness of the main beam section changes abruptly. Conversely, if a "continuous deck" construction method is used, tensile fractures are likely to occur at the weak points of continuity between beams. These fractures directly and severely damage the continuity, durability, and safety of the bridge, increasing the risk of beam collapse under seismic loads.

[0004] Therefore, there is an urgent need to develop a new type of simply supported beam bridge and continuous bridge deck structure that is not easily broken under wide-range cooling environment, and to propose corresponding construction methods to fundamentally improve the bridge's ability to cope with temperature deformation and seismic deformation. Summary of the Invention

[0005] This invention provides a continuous simply supported composite beam bridge using rubber sleeve-stud connectors, comprising I-beam longitudinal beams, transverse diaphragms, a continuous bridge deck, bearings, rubber sleeves, and stud connectors. The rubber sleeves are first fitted onto the rod portion of the stud connectors to form the rubber sleeve-stud connectors. These new connectors are then welded to the upper flange of the I-beam longitudinal beams, connecting to the subsequently cast bridge deck. When temperature or seismic deformation occurs in the continuous simply supported beam bridge, the rubber sleeves ensure that the rod portion of the stud connectors undergoes certain bending and shear deformation, coordinating the temperature or seismic deformation differences and hysteretic energy dissipation between the simply supported steel beams and the continuous bridge deck, thus preventing tensile fracture and beam collapse accidents.

[0006] The technical solution of the present invention is as follows: A continuous simply supported composite beam bridge using rubber sleeve-stud connectors includes a lower section and an upper section. The lower section of the composite beam bridge consists of I-beam longitudinal beams 1 and transverse diaphragms 2, and is placed on bridge bearings 4. The upper section of the composite beam bridge is a continuous bridge deck 3. The upper and lower sections are connected together by stud connectors 5 with rubber sleeves 6, forming a continuous simply supported composite beam bridge.

[0007] A further feature is that the stud connector 5 comprises two parts: a stud head 8 and a stud rod 9; the stud rod 9 is welded to the upper flange of the I-beam longitudinal beam 1; before welding, a rubber sleeve 6 is fitted onto the stud rod 9, and the height of the rubber sleeve 6 is lower than that of the stud rod 9, thus ensuring that the stud head 8 can be firmly embedded into the bridge deck 3, ensuring the pull-out and shear resistance of the composite interface.

[0008] A further feature is that, under the effect of temperature deformation, the continuous bridge deck 3 of the upper part of the composite beam bridge will remain stationary, while the lower I-beam longitudinal beam 1 will undergo significant longitudinal deformation due to temperature. Since the rubber sleeve 6 is made of a viscoelastic material with low elastic modulus and high damping, the stud rod 9 will undergo relatively free bending and shearing deformation within the rubber sleeve 6, releasing the strong constraint between the I-beam longitudinal beam 1 and the continuous bridge deck 3. This ensures that under the effect of temperature changes during normal use, the continuous bridge deck 3 can be uniformly stressed, avoiding excessive stress concentration.

[0009] A further feature is that, under the effect of seismic deformation, the continuous bridge deck 3 of the upper part of the composite beam bridge, containing the stud heads 8, will remain stationary, while the lower I-beam longitudinal beams 1 will sway significantly. However, due to the connecting effect of the stud rods 9, beam collapse accidents can be avoided. In addition, since the rubber sleeve 6 is made of a viscoelastic material with low elastic modulus and high damping, the stud rods 9 will undergo repeated bending and shear deformation and energy dissipation within the rubber sleeve 6, which helps to reduce the safety damage to the bridge caused by seismic action.

[0010] A further feature is that, under the wide-range cooling effect during service, the continuous bridge deck 3 of the upper bridge deck will be subjected to uniform tension. Therefore, the bridge deck can be made of ultra-high performance concrete (UHPC) and equipped with steel mesh 7. Relying on the high tensile strength and high tensile toughness of UHPC itself, the generation of uniformly distributed microcracks in the continuous bridge deck 3 can be controlled to absorb its own cooling deformation.

[0011] A further feature is that the bridge deck continuous simply supported composite beam bridge, by optimizing the parameters and arrangement of the stud connectors 5 and rubber sleeves 6, can improve the serious fracture problem of traditional simply supported continuous beam bridges under wide temperature changes throughout the year, ensure the structural continuity of the highway bridge throughout its entire lifespan, and thus guarantee the anti-falling function under earthquake action for a long time.

[0012] This invention also provides a construction method for a continuous simply supported composite beam bridge using rubber sleeve-stud connectors, comprising the following steps: S1. The factory manufactures the I-beam longitudinal beams and transverse diaphragms, and assembles the substructure of the composite beam bridge; S2. Slide the rubber sleeve onto the stud rod, and then weld the stud connector to the upper flange of the I-beam; S3. Construct bridge deck formwork, tie the steel mesh skeleton inside the bridge deck, then pour and cure the bridge deck concrete to complete the precast simply supported beam; S4. The precast simply supported beams are hoisted and placed on the bridge bearings on site, and the wet joints between the main beams are poured to form a continuous simply supported beam bridge system.

[0013] Compared with the prior art, the present invention has the following advantages: This invention utilizes rubber sleeves to enhance the functionality of stud connectors in traditional composite beam bridge structures: Under temperature changes, the rubber sleeves allow the stud rods to freely bend and shear, enabling relatively free sliding between the lower simply supported beam and the upper continuous bridge deck, effectively preventing breakage under normal service limits. Under seismic loading, the intact continuous bridge deck restricts large displacements in the lower steel beams, and the reciprocating bending and shearing stud rods within the rubber sleeves achieve high-damping hysteresis energy dissipation, effectively reducing bridge seismic sway amplitude and preventing beam collapse.

[0014] The continuous bridge deck in this invention is subjected to tensile stress under normal service limit conditions. It can rely on the high tensile strength and high tensile toughness of ultra-high performance concrete (UHPC) itself, as well as the configured steel mesh, to control the generation of uniformly distributed micro-cracks in the bridge deck under tensile stress, so as to absorb temperature deformation and ensure the effective continuity of the bridge deck. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of the present invention.

[0016] Figure 2 This is a schematic diagram of the interior of the bridge deck of the present invention.

[0017] In the diagram: 1. I-beam longitudinal beam; 2. Transverse diaphragm; 3. Continuous bridge deck panel; 4. Support; 5. Stud connector; 6. Rubber sleeve; 7. Steel mesh; 8. Stud head; 9. Stud rod. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the technical solutions and accompanying drawings.

[0019] Example 1: A continuous simply supported composite beam bridge structure using rubber sleeve-stud connectors The lower part of the composite beam bridge structure is assembled from multiple I-beam longitudinal beams 1 and transverse diaphragms 2. For example, a factory-prefabricated composite beam typically consists of two I-beam longitudinal beams 1, with transverse diaphragms 2 placed near the ends or mid-span of the I-beam longitudinal beams 1. Rubber sleeve-stud connectors are welded to the upper flange of the I-beam longitudinal beams 1, wherein the thickness of the rubber sleeve 6 is typically 2-5mm, the height is typically 20-60mm, the height of the stud connector 5 is typically 50-200mm, and the diameter of the stud rod 9 is typically 10-25mm.

[0020] The continuous bridge deck 3 refers to a bridge structure in which connecting steel bars or plates are installed on the top of the piers, so that the bridge decks between the main beams form a continuous whole in the longitudinal direction. In prefabricated construction, concrete bridge deck formwork can be erected in the factory first. The height of the bridge deck 3 should be above the stud heads 8. Then, the internal steel mesh 7 is tied, and 50-100cm long steel bars are reserved around the prefabricated bridge deck. After the concrete bridge deck is poured, the factory prefabricated composite beam is completed. Further, the factory prefabricated composite beam is hoisted onto the pier top support 4 on site, and then steel plates and steel bars are installed at each joint. The wet joints are poured on site to form the continuous bridge deck 3.

[0021] The steel mesh 7 is made of HRB400 grade threaded steel with a diameter of 10-25mm, and extends 50-100cm around the precast bridge deck as reinforcement inside the wet joint.

[0022] Example 2: Parameter design and construction method of a rubber sleeve-stud connector The stud connector 5 and the rubber sleeve 6 together form a rubber sleeve-stud connector, which works together to adjust the structural performance of the continuous simply supported composite beam bridge under temperature or seismic loads. The stud connector 5 and the rubber sleeve 6 can be designed with parameters based on the structural effects of temperature and seismic loads. For example, the stud connector 5 can be arranged in a group, either uniformly spaced at 150mm × 150mm intervals on the upper flange plate; or it can have shear holes in the bridge deck, with the stud connector 5 arranged compactly only at the shear hole locations; or even, the stud connector 5 can be densely arranged in the mid-span region where the interface slippage is small, and sparsely arranged in the beam end region where the interface slippage is large.

[0023] The rubber sleeve 6 can be thinner or shorter in the mid-span region where the interface slippage is small, and thicker or taller in the beam end region where the interface slippage is large. In areas with high seismic intensity, the rubber sleeve 6 can be made of a viscoelastic material with a larger damping coefficient to improve hysteretic energy dissipation performance.

Claims

1. A bridge of continuous simply supported composite girder with rubber sleeve-dowel connectors, characterized in that, The bridge deck continuous simply supported composite beam bridge includes a lower part and an upper part; the lower part of the composite beam bridge is composed of I-beam longitudinal beams (1) and transverse diaphragms (2), and the lower part is placed on bridge bearings (4); the upper part of the composite beam bridge is a continuous bridge deck panel (3); the upper part and the lower part are combined together by stud connectors (5) with rubber sleeves (6) to form a continuous simply supported composite beam bridge.

2. A continuous simply supported composite girder bridge with rubber sleeve-dowel connectors according to claim 1, characterized in that, The stud connector (5) consists of two parts: a stud head (8) and a stud rod (9). The stud rod (9) is welded to the upper flange of the I-beam longitudinal beam (1). Before welding, a rubber sleeve (6) is fitted onto the stud rod (9), and the height of the rubber sleeve (6) is lower than that of the stud rod (9), so that the stud head (8) can be firmly embedded into the bridge deck (3) to ensure the pull-out and shear resistance of the composite interface.

3. A continuous simply supported composite girder bridge with rubber sleeve-dowel connectors as claimed in claim 1, wherein, Under the effect of temperature deformation, the continuous bridge deck (3) of the upper part of the composite beam bridge will remain stationary, while the lower I-beam longitudinal beam (1) will undergo significant longitudinal deformation due to temperature. Since the rubber sleeve (6) is made of viscoelastic material with low elastic modulus and high damping, the stud rod (9) will undergo relatively free bending and shearing deformation in the rubber sleeve (6), and release the strong constraint between the I-beam longitudinal beam (1) and the continuous bridge deck (3), ensuring that the continuous bridge deck (3) can be uniformly stressed under the effect of temperature changes during normal use, and avoiding excessive stress concentration.

4. A continuous simply supported composite girder bridge with rubber sleeve-dowel connectors according to claim 1, wherein, Under the effect of earthquake deformation, the continuous bridge deck (3) of the upper part of the composite beam bridge containing the stud head (8) will remain stationary, while the lower I-beam longitudinal beam (1) will sway significantly. However, due to the connecting effect of the stud rod (9), the beam falling accident can be avoided. In addition, since the rubber sleeve (6) is made of viscoelastic material with low elastic modulus and high damping, the stud rod (9) will undergo repeated bending and shearing deformation and energy dissipation in the rubber sleeve (6), which helps to reduce the bridge safety damage caused by earthquake.

5. A continuous simply supported composite beam bridge using rubber sleeve-stud connectors as described in claim 1, characterized in that, During service, under the wide-range cooling effect, the continuous bridge deck (3) of the upper bridge deck will be subjected to uniform tension. Therefore, the bridge deck can be made of ultra-high performance concrete (UHPC) and equipped with steel mesh (7). Relying on the high tensile strength and high tensile toughness of UHPC itself, it can control the generation of uniformly distributed microcracks in the continuous bridge deck (3) to absorb its own cooling deformation.

6. A continuous simply supported composite beam bridge using rubber sleeve-stud connectors as described in claim 1, characterized in that, The aforementioned continuous simply supported composite beam bridge can improve the serious fracture problem of traditional simply supported continuous beam bridges under wide temperature changes throughout the year by optimizing the parameters and arrangement of the stud connectors (5) and rubber sleeves (6), ensuring the structural continuity of the highway bridge throughout its entire lifespan, and thus guaranteeing the anti-falling beam function under earthquake action for a long time.

7. A construction method for a continuous simply supported composite beam bridge using rubber sleeve-stud connectors as described in any one of claims 1-6, comprising the following steps: S1. The factory manufactures the I-beam longitudinal beams and transverse diaphragms, and assembles the substructure of the composite beam bridge; S2. Slide the rubber sleeve onto the stud rod, and then weld the stud connector to the upper flange of the I-beam; S3. Construct bridge deck formwork, tie the steel mesh skeleton inside the bridge deck, then pour and cure the bridge deck concrete to complete the precast simply supported beam; S4. The precast simply supported beams are hoisted and placed on the bridge bearings on site, and the wet joints between the main beams are poured to form a continuous simply supported beam bridge system.

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