Arrangement method and construction method of shear connector of fabricated steel-concrete composite beam bridge

Abstract

The application relates to the field of bridge engineering and provides a layout method and a construction method of a shear connector of a fabricated steel-concrete composite girder bridge, which are based on machine-bridge coupling vibration response, a finite element model of a steel-concrete composite taxiway bridge is established, the influence of bolt cluster degree and unevenness parameters on the dynamic performance of the fabricated steel-concrete composite girder bridge is deeply studied, the layout mode of the shear connector is optimized, the vibration response under the machine-bridge coupling effect is effectively reduced, and the performance of the bridge structure under the action of the airplane dynamic load and the operation quality of the airplane are improved. Compared with the prior art, the application can significantly reduce the vibration response of the bridge under the airplane dynamic load, prolong the service life of the bridge, and improve the comfort of airplane operation. The technical scheme of the application provides a new theoretical basis and practical guidance for the design and construction of the steel-concrete composite girder bridge, and has important engineering application value and market promotion prospect.

Description

Technical Field

[0001] This invention relates to the field of bridge structure technology, specifically a method for arranging and constructing shear connectors for prefabricated steel-concrete composite beam bridges based on machine-bridge coupled vibration response. Background Technology

[0002] Taxiway bridges, as a special type of bridge structure, differ significantly from highway, railway, and municipal bridges in terms of service environment, load-bearing capacity, structural form, stress characteristics, and operational requirements. During aircraft taxiing, significant interaction forces are generated between the landing gear wheels and the taxiway bridge. Factors such as aircraft tire imbalance or uneven bridge surfaces further exacerbate this interaction, resulting in the coupling problem of aircraft-bridge vibrations. When the taxiway bridge frequency and the aircraft frequency are close, a resonance effect occurs. For the aircraft, aircraft-bridge coupled vibrations will affect the landing gear and aircraft structural strength, impacting passenger comfort and even aircraft safety. For the bridge, the repeated application of aircraft loads will affect structural strength, causing fatigue damage and reduced durability. Currently, many in-service airport taxiway bridges have suffered serious damage due to aircraft-bridge coupled vibrations.

[0003] For small-to-medium span, ultra-wide, and heavy-load taxiway bridges, prefabricated steel-concrete composite beam bridges offer advantages in both mechanical performance and economics, making them one of the main development directions for future taxiway bridges. In prefabricated steel-concrete composite beam bridges, the precast concrete bridge deck and steel beams are connected by clustered shear connectors to share the load. The arrangement of these shear connectors significantly impacts the bridge's response to aircraft dynamic loads.

[0004] Composite beam shear connection methods include the conventional uniformly distributed type, suitable for cast-in-place bridge decks, where all studs are evenly distributed on the steel beams, such as... Figure 5 As shown; conventional cluster type, suitable for precast bridge decks, with equal spacing between each stud group and a consistent number of studs in the pre-drilled holes, such as... Figure 6 As shown, when the dynamic response of a bridge is too large and the fatigue performance of the studs is poor, methods such as increasing the number of studs, increasing the number of pre-drilled holes, and increasing the stud diameter are often used in engineering. However, these methods increase the workload of steel structure installation and assembly time. The amount of welding at the root of large-diameter studs is larger, and the resulting initial cracks and stress concentration may be more severe than those of smaller-diameter studs, which may affect the fatigue life of the structure. Summary of the Invention

[0005] To address the problems of existing technologies, this invention provides a method for arranging and constructing shear connectors for prefabricated steel-concrete composite beam bridges. This method effectively reduces the maximum mid-span dynamic deflection of the bridge under aircraft loads without increasing the number or diameter of the studs, thereby extending the bridge's service life and improving its structural safety.

[0006] This invention provides a method for arranging shear connectors in a prefabricated steel-concrete composite beam bridge. The method involves arranging stud groups on the surface of the steel beam in a clustered manner. The clustered arrangement includes uneven arrangement and end-densified arrangement. The uneven arrangement is characterized by unequal spacing between stud groups or inconsistent number of studs in the pre-drilled holes. The end-densified arrangement is characterized by a greater number of studs in the pre-drilled holes at the ends of the steel beam than in the middle section.

[0007] Further improvements include two types of uneven arrangement: Type A and Type B. In Type A, the spacing between each group of studs is not equal, but the number of studs in the reserved holes is consistent. In Type B, the spacing between each group of studs is equal, but the number of studs in the reserved holes is inconsistent.

[0008] The present invention also provides a prefabricated steel-concrete composite beam bridge structure with unevenly arranged shear connectors, including steel beams, precast concrete bridge decks and stud group connectors. The stud group connectors are arranged on the surface of the steel beams using the arrangement method of the shear connectors for prefabricated steel-concrete composite beam bridges described above. The precast concrete bridge decks are prefabricated with reserved stud holes that cooperate with the stud group connectors. The steel beams and the precast concrete bridge decks are connected by the stud group connectors.

[0009] In a further improvement, the stud group connector is installed on the steel beam by welding or bolting.

[0010] This invention also provides a construction method for prefabricated steel-concrete composite beam bridge shear connectors, comprising the following steps: 1) Based on the span, aircraft load rating and preliminary design dimensions of the steel-concrete composite taxiway bridge, determine the shear force design value of the shear connectors and select and design the clustered studs. 2) Based on the selection and design of the clustered stud group, determine the size and distribution of the reserved holes in the bridge deck, and prefabricate the concrete bridge deck in the factory; when prefabricating the concrete bridge deck, reserve stud holes on the surface of the concrete bridge deck, and the distribution of the stud holes corresponds to the arrangement position of the stud group connectors. 3) A group of studs is arranged above the steel beam by welding or bolting, wherein the group of studs is arranged in the manner described in any one of claims 1-2 for the arrangement of shear connectors for prefabricated steel-concrete composite beam bridges. 4) Transporting the concrete bridge deck to the bridge construction site for overall assembly can effectively reduce the number of studs while ensuring the bridge's dynamic response performance. 5) Inject high-performance concrete or other grouting materials with good tensile strength into the reserved holes in the concrete bridge deck.

[0011] The beneficial effects of this invention are as follows: 1. The Type A invention controls the non-uniformity by adjusting the distance between each shear groove, thereby enhancing the local stiffness of the composite bridge and reducing the dynamic deflection of the bridge under aircraft dynamic loads without increasing the total number of studs.

[0012] 2. The present invention, type B, increases the density of studs in areas with higher loads and decreases the density in areas with lower loads by changing the number of rows and columns of studs in a single reserved hole. By controlling the clustering of studs, the dynamic deflection of the bridge under aircraft dynamic loads is reduced without increasing the total number of studs.

[0013] 3. By changing the unevenness or clustering of the studs, the present invention strengthens the combined action of the concrete slab in areas where it is needed and weakens it in areas where it is not needed. This fundamentally changes the combined behavior of the bridge deck and steel beam in different areas of the bridge, effectively reducing the fatigue stress amplitude of the bridge stud group connectors and improving the fatigue life of the stud group connectors.

[0014] 4. This invention only changes the arrangement of the studs, avoiding the additional costs and adverse effects caused by increasing the number and diameter of studs, and achieving economical and efficient structural optimization.

[0015] 5. By optimizing the arrangement of shear connectors, this invention can reduce the difference in mechanical behavior between precast bridge deck composite beams and cast-in-place bridge deck composite beams, improve the dynamic and fatigue performance of traditional clustered shear connection composite beams, and achieve an effect close to that of uniformly distributed shear connections in cast-in-place bridge decks. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the precast bridge deck composite beam of type A of the present invention.

[0018] Figure 2 This is a schematic diagram of a full-bridge type A of the present invention.

[0019] Figure 3This is a schematic diagram of the precast bridge deck composite beam of type B of the present invention.

[0020] Figure 4 This is a schematic diagram of the full-bridge type B of the present invention.

[0021] Figure 5 This is a schematic diagram of the conventional uniformly distributed stud arrangement for cast-in-place bridge deck composite beams.

[0022] Figure 6 This is a schematic diagram of the conventional clustered stud arrangement for precast bridge deck composite beams.

[0023] Figure 7 This represents the maximum dynamic deflection value at mid-span for different shear connection degrees.

[0024] Figure 8 The values ​​represent the mid-span dynamic deflection for different shear connection stiffnesses.

[0025] Figure 9 The dynamic deflection of the machine-bridge coupled vibration of the composite beam bridge under different shear connection arrangements.

[0026] Figure 10 This diagram illustrates the rate of change of dynamic deflection during machine-bridge coupled vibration of a composite beam bridge under different shear connection arrangements.

[0027] Figure 11 This represents the maximum stress amplitude for fatigue details under different shear connection arrangements.

[0028] Figure 12 The equivalent stress amplitude for fatigue details under different shear connection arrangements.

[0029] Figure 13 The degree of fatigue damage in fatigue details under different shear connection arrangements. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention provides a method for arranging shear connectors in a prefabricated steel-concrete composite beam bridge. The method involves arranging stud groups on the surface of the steel beam in a clustered manner. This clustered arrangement includes both uneven and end-densified arrangements. The uneven arrangement involves unequal spacing between stud groups or inconsistent numbers of studs in the pre-drilled holes. The end-densified arrangement involves a greater number of studs in the pre-drilled holes at the ends of the steel beam compared to the middle section. The uneven arrangement includes two types: Type A, where the stud groups have unequal spacing but the number of studs in the pre-drilled holes remains consistent; and Type B, where the stud groups have equal spacing but inconsistent numbers of studs in the pre-drilled holes.

[0032] This invention provides a prefabricated steel-concrete composite beam bridge structure with unevenly arranged shear connectors, such as... Figure 1-4 As shown: It mainly includes steel beam 1, precast concrete bridge deck 2, and stud group connector 3.

[0033] Install the stud group connector 3 at the designated location on the steel beam 1. The stud group connector 3 is installed by welding or bolting. When prefabricating the precast concrete bridge deck 2, the location of the pre-drilled stud holes must be considered to ensure connection with the steel beam 1. After transportation to the site, first weld or bolt the stud group connector 3 to the upper flange of the steel beam 1. After aligning the pre-drilled holes on the precast concrete bridge deck 2 with the positions of the stud group connector 3, pour high-performance concrete or other grout into the pre-drilled holes to form a unified structure.

[0034] For bridge structures where the side spans or beam ends of cantilever beams or continuous beam bridges are subjected to negative bending moments, the following can be adopted: Figure 1 The invention shown is of type A. This arrangement can optimize the stiffness of the bridge at different locations, reduce the dynamic response of the bridge, and improve the safety and durability of the structure.

[0035] For bridges under complex load conditions, or bridges where the distribution of shear connectors needs to be adjusted according to load changes, the following can be adopted: Figure 2 The present invention, type B, is shown. This arrangement allows for increased stud density in areas of higher load and decreased stud density in areas of lower load, thus optimizing the dynamic and fatigue performance of the bridge without increasing the total number of studs.

[0036] The construction process of this invention is as follows: Steel beams 1 and precast concrete bridge deck 2 are prefabricated in the factory, and slots for stud group connectors 3 are reserved in the precast concrete bridge deck 2.

[0037] Weld or bolt the stud group connector 3 at the designated position on the steel beam 1.

[0038] The prefabricated steel beam 1 was transported to the construction site and installed in the designated position.

[0039] The precast concrete bridge deck 2 is hoisted onto the steel beam 1 and aligned with the reserved slots for the stud connectors.

[0040] After the precast concrete bridge deck 2 is in place, high-strength concrete and other grouting materials are poured into the reserved slots.

[0041] The installed shear connectors are subjected to quality inspection to ensure that they meet the design and safety requirements.

[0042] For aircraft-loaded bridges, multiple steel beams 1 need to be connected laterally by crossbeams to form a multi-main-beam composite beam bridge.

[0043] In the design of prefabricated composite beam bridges, when the dynamic deflection of the composite beam bridge is too large, the traditional method is to improve the bridge performance by increasing the number of studs and changing the stud diameter and length. Therefore, finite element method (FEM) software was used to analyze the influence of the number of studs and stud stiffness on the bridge's dynamic deflection.

[0044] from Figure 7 It can be seen that increasing the number of studs can reduce the dynamic deflection of the bridge to a certain extent, but when the number of studs increases to a certain extent, further increasing the number of studs will not significantly reduce the dynamic deflection.

[0045] from Figure 8 It can be seen that the stiffness of the studs affects the dynamic deflection of the bridge, but when the stud stiffness increases from 10 times to 100 times, the decrease in dynamic deflection is not significant. This indicates that the method of simply increasing the stiffness of the studs to reduce the dynamic deflection of the structure has limited effectiveness. At the same time, an excessively large stud diameter may affect the uniform transmission of stud stress.

[0046] Therefore, the design of prefabricated composite beam bridges requires a more comprehensive approach, rather than simply relying on increasing the number or changing the size of the studs. This invention, based on this principle, achieves optimized design by changing only the stud arrangement without altering the number or size of the studs. To better reflect the actual operating conditions of airport taxiway bridges, a large aircraft, the B747-400, was selected. The aircraft load was simulated using moving mass spring damping, while the combin14 element was used to simulate the studs. A uniform stud diameter of 13mm and a stud length of 40mm were used.

[0047] Comparing the stud arrangement methods A and B of this invention with the traditional uniformly distributed and clustered stud arrangements, the dynamic deflection of the bridge under four stud arrangement methods can be obtained, such as... Figure 9 and 10As shown, the traditional uniformly distributed type exhibits the smallest dynamic deflection. However, this method is only suitable for cast-in-place bridge decks. For prefabricated composite beam bridges with precast decks, only clustered studs can be used. The Type A and Type B studs of this invention exhibit smaller dynamic deflections than conventional clustered studs, and their effect is very close to that of the traditional uniformly distributed type. They are significantly beneficial in reducing the dynamic deflection of bridges under aircraft loads.

[0048] The maximum fatigue stress amplitude, fatigue equivalent stress amplitude, and fatigue damage degree of bridges under four different stud arrangement methods are as follows: Figure 11-13 As shown, Type A and Type B of this invention exhibit smaller fatigue stress amplitude and less fatigue damage than conventional clustered studs, and their effects are very close to those of the traditional uniformly distributed type. This demonstrates a significant beneficial effect on improving the fatigue performance of bridges under aircraft loads.

[0049] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for arranging shear connectors in a prefabricated steel-concrete composite beam bridge, characterized in that: The stud group connectors are arranged in a clustered manner on the surface of the steel beam. The clustered arrangement includes uneven arrangement and end densification arrangement. The uneven arrangement means that the intervals between the stud groups are not equal or the number of studs in the reserved holes is inconsistent. The end densification arrangement means that the number of studs in the reserved holes at the ends of the steel beam is greater than that in the middle part.

2. The method for arranging shear connectors in a prefabricated steel-concrete composite beam bridge according to claim 1, characterized in that: The uneven arrangement includes two arrangements: Type A and Type B. In Type A, the spacing between each group of studs is not equal, but the number of studs in the reserved holes is consistent. In Type B, the spacing between each group of studs is equal, but the number of studs in the reserved holes is inconsistent.

3. A prefabricated steel-concrete composite beam bridge structure with unevenly arranged shear connectors, characterized in that: The bridge includes steel beams, precast concrete bridge decks, and stud group connectors. The stud group connectors are arranged on the surface of the steel beams using the arrangement method of the precast steel-concrete composite beam shear connectors as described in any one of claims 1-2. The precast concrete bridge decks are pre-fabricated with reserved stud holes that cooperate with the stud group connectors. The steel beams and the precast concrete bridge decks are connected by the stud group connectors.

4. The prefabricated steel-concrete composite beam bridge shear connection structure according to claim 3, characterized in that: The stud group connectors are installed on the steel beams by welding or bolting.

5. A construction method for shear connectors in prefabricated steel-concrete composite beam bridges, characterized in that... Includes the following steps: 1) Based on the span, aircraft load rating and preliminary design dimensions of the steel-concrete composite taxiway bridge, determine the shear force design value of the shear connectors and select and design the clustered studs. 2) Based on the selection and design of the clustered nail group, determine the size and distribution of the reserved holes in the bridge deck, and prefabricate the concrete bridge deck in the factory. 3) A group of studs is arranged above the steel beam by welding or bolting, wherein the group of studs is arranged in the manner described in any one of claims 1-2 for the arrangement of shear connectors for prefabricated steel-concrete composite beam bridges. 4) Transport the concrete bridge deck to the bridge construction site for overall assembly; 5) Inject high-performance concrete or other grouting materials with good tensile strength into the reserved holes in the concrete bridge deck.

6. The construction method for the prefabricated steel-concrete composite beam bridge shear connector according to claim 5, characterized in that: Step 2) When the concrete bridge deck is prefabricated in the factory, stud holes are reserved on the surface of the concrete bridge deck, and the distribution of stud holes corresponds to the arrangement position of the stud group connectors.

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