Composite connecting piece of steel-UHPC composite beam and construction method of composite connecting piece

Abstract

The invention particularly discloses a composite connecting piece of a steel-UHPC composite beam and a construction method of the composite connecting piece, and relates to the technical field of bridge engineering. The composite connecting piece comprises transverse steel bars, inverted-T-shaped steel, a steel beam and a bolt connecting piece, reserved holes are formed in the positions, corresponding to the top of the steel beam, of the lower portion of the inverted-T-shaped steel, the transverse steel bars are installed on the left side and the right side of the inverted-T-shaped steel, and the bolt connecting piece fixes the inverted-T-shaped steel to the top of the steel beam through the reserved holes. According to the composite connecting piece of the steel-UHPC composite beam and the construction method of the composite connecting piece, welding operation is not needed, the high-strength bolts provide vertical pre-tightening force and in-plane shear stiffness at the same time and act together with the penetrating steel bars, the structural shear resistance is improved, the stress of concrete is improved, the structural resistance is enhanced, and the construction period is shortened. The problems that in existing stud connection, the shear bearing capacity is small, construction is complex, and a special welding machine is needed are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering, and in particular to a composite connector of a steel-UHPC composite beam and a construction method thereof. Background Art

[0002] As a new structural form, steel-UHPC (ultra-high performance concrete) composite beams are gaining increasing popularity in modern bridge engineering, leveraging the superior strength and toughness of steel with the high compressive resistance and exceptional durability of UHPC. This composite structure leverages the performance advantages of both materials, achieving a synergistic effect that maximizes their strengths and minimizes their weaknesses. The key to its efficient and safe operation lies in the reliable connection between the steel beam and the UHPC panels through shear connectors, ensuring close coordination and shared load-bearing, thus preventing structural degradation due to connection failure.

[0003] In current engineering practice, the shear connectors used in steel-UHPC composite beams are still mainly traditional stud connections. Although stud connections can meet the basic load-bearing requirements of small and medium-sized bridges to a certain extent, they have exposed many significant limitations in actual applications: 1. Insufficient shear capacity is a prominent issue. The shear capacity of individual studs is relatively low. When faced with large loads or complex load conditions, a large number of studs must be densely arranged to meet the overall structural load requirements. This not only significantly increases material consumption and project costs, but excessive studs can also hinder the UHPC pouring process, easily forming defects such as honeycombs and voids during pouring, affecting the UHPC's molding quality and the overall strength of the structure.

[0004] 2. The construction process is highly complex. The installation of studs requires specialized welding equipment, such as stud welders. This equipment has extremely stringent requirements for the construction environment, and even slight changes in factors such as temperature and humidity can affect welding quality. Furthermore, welding operations are highly dependent on the skill level of the technicians, and the welding process is prone to problems such as spatter and deformation. These problems can not only damage surrounding components but can also lead to insufficient connection strength between the studs and steel beams, necessitating secondary repairs. This undoubtedly increases the difficulty, time, and cost of construction.

[0005] 3. The scope of application is significantly limited. In scenarios requiring higher structural performance, such as long-span bridges or heavy-load bridges, the pullout resistance and structural integrity of traditional bolt connections are insufficient to meet the high-order load requirements. Under long-term loads, relative slippage between the steel beam and the UHPC panels is likely to occur. This not only reduces the structure's load-bearing capacity and stiffness, but also exacerbates fatigue damage to the components, severely impacting the safety and durability of the bridge and shortening its service life.

[0006] Therefore, in response to the above-mentioned defects of existing bolt connections, the engineering field urgently needs a new type of composite connector and its supporting construction method, which does not require complex welding operations, has higher shear bearing capacity, a convenient and efficient construction process, and can significantly enhance the integrity of the structure. It can effectively optimize the mechanical performance of steel-UHPC composite beams, improve construction efficiency, reduce project costs, and provide more reliable technical support for the construction of complex bridge projects such as large spans and heavy loads. Summary of the Invention

[0007] The purpose of the present invention is to propose a composite connector for steel-UHPC composite beams and a construction method thereof to address the problems of existing stud connections, such as low shear bearing capacity, large-scale arrangement, reliance on specialized welding equipment, complex construction, a single force transmission path between steel and UHPC, and insufficient integrity, thereby improving the performance of the composite beams and the convenience of construction.

[0008] To achieve the above objectives, the present invention proposes a composite connector for a steel-UHPC composite beam, comprising transverse reinforcement, an inverted T-shaped steel, a steel beam, and a bolt connector. Pre-set holes are provided at positions corresponding to the lower portion of the inverted T-shaped steel and the top of the steel beam, and the transverse reinforcement is installed on the left and right sides of the inverted T-shaped steel. The bolt connector fixes the inverted T-shaped steel to the top of the steel beam through the reserved holes.

[0009] Preferably, the reserved holes on the inverted T-shaped steel and the steel beam are distributed in multiple groups at equal intervals, and the transverse length of the inverted T-shaped steel shall not be less than 1 / 2 of the transverse length of the steel beam.

[0010] Preferably, the transverse reinforcement is distributed between the gaps between the bolt connectors; the transverse reinforcement is made of high-strength threaded steel bars, and the diameter of the transverse reinforcement shall not be greater than the spacing between the bolt connectors.

[0011] Preferably, the bolt connectors are high-strength bolts, including bolt rods, nuts and washers, and are distributed in groups at equal intervals along the length of the steel beam.

[0012] Preferably, the steel beam is made of high-quality high-strength steel plate.

[0013] The present invention also provides a construction method for a composite connector of a steel-UHPC composite beam, comprising the following steps: Step S1: Pre-set holes are provided at corresponding positions on the top of the steel beam and the bottom of the inverted T-shaped steel, and the reserved holes on the inverted T-shaped steel and the steel beam are distributed in multiple groups at equal intervals; Step S2: Place the inverted T-shaped steel on top of the steel beam so that the reserved holes of the two are aligned, and use bolt connectors to pass through the reserved holes to fix the inverted T-shaped steel to the top of the steel beam. The bolt connectors are distributed in groups with equal spacing; Step S3: Install transverse reinforcement on the left and right sides of the inverted T-shaped steel. The transverse reinforcement is distributed between the gaps of the bolt connectors. The transverse reinforcement is made of high-strength threaded steel bars. The diameter of the transverse reinforcement should not be greater than the spacing between the bolt connectors.

[0014] Step S4: Tie the longitudinal steel mesh on the top of the assembled steel structure to ensure that the longitudinal steel bars are cross-tied and fixed with the transverse steel bars. Then, pour the UHPC and vibrate it to compact it, and then cure it to the designed strength.

[0015] Therefore, the present invention proposes a composite connector for steel-UHPC composite beams and a construction method thereof, which has the following beneficial effects: (1) The present invention significantly increases the longitudinal bridge's resistance area to horizontal shear force through scientifically designed bolt connectors, making shear force transmission more uniform and efficient. At the same time, the transverse reinforcement and inverted T-shaped steel form a multi-dimensional synergistic effect, further widening the force transmission path, making force transmission more dispersed and stable. This not only significantly improves the shear bearing capacity of the composite beam, effectively coping with shear impact under greater loads, but also significantly enhances the pull-out resistance, avoiding separation or loosening between the steel beam and the UHPC plate due to pull-out force, and ensuring the stability of the structure under complex stress conditions.

[0016] (2) The transverse reinforcement, bolt connectors and inverted T-shaped steel in the present invention cooperate with each other to form a unique "grid structure", which enables the steel beam, inverted T-shaped steel and UHPC to be closely engaged and work together to form a strong common load-bearing body, greatly improving the overall collaborative work performance, avoiding the problem of overload of a single component, and making the entire composite beam more integrated and stable when bearing loads.

[0017] (3) The present invention innovatively uses bolt connections to replace traditional stud welding methods, completely getting rid of the dependence on special welding equipment (such as stud welding machines) and reducing the many troubles caused by welding operations. Not only does it save the transportation and commissioning of welding equipment, but it also reduces the stringent requirements for the construction environment (such as temperature and humidity) and operating techniques. At the same time, the bolt connection assembly method is more convenient, can effectively reduce construction time and workload, facilitate rapid on-site assembly, and improve construction efficiency. It is particularly suitable for engineering scenarios with tight schedules or complex construction conditions.

[0018] (4) The present invention achieves precise control of component usage by optimizing the arrangement of connectors and the form of force: reasonable bolt spacing and inverted T-shaped steel distribution avoid redundant use of materials and reduce unnecessary component consumption; at the same time, the bolt connection method reduces defects such as leaking welds and cold welds that may occur during welding, reducing the rework cost caused by welding quality problems.

[0019] (5) The composite connector and its construction method proposed in this invention have wide adaptability and are particularly suitable for complex scenarios such as large-span, heavy-load bridges. Its high-strength bolt connection and multi-dimensional force transmission structure can meet high-order force requirements and cope with the shear force and bending moment challenges brought about by the large span of large-span bridges, as well as the complex force system effects generated by the large load of heavy-load bridges.

[0020] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a front structural schematic diagram of a composite connector for a steel-UHPC composite beam according to the present invention; Figure 2 This is a schematic side structural diagram of a composite connector for a steel-UHPC composite beam according to the present invention; Figure 3 This is a schematic diagram of an inverted T-shaped steel structure in a composite connector of a steel-UHPC composite beam of the present invention; Figure 4 The figure is a schematic diagram of the overall structure of a composite connector of a steel-UHPC composite beam according to the present invention.

[0022] Reference numerals 1. Horizontal reinforcement; 2. Inverted T-shaped steel; 3. Bolt connectors; 4. Steel beams; 5. Reserved holes. DETAILED DESCRIPTION

[0023] To make the technical solutions, advantages, and objectives of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0025] Example 1 like Figures 1-4 As shown, the present invention provides a composite connector for a steel-UHPC composite beam, comprising a transverse reinforcement 1, an inverted T-shaped steel 2, a bolt connector 3, and a steel beam 4; reserved holes 5 are provided at corresponding positions of the top of the inverted T-shaped steel 2 and the steel beam 4, transverse reinforcement 1 is installed on the left and right sides of the inverted T-shaped steel, and the bolt connector 3 fixes the inverted T-shaped steel 2 to the top of the steel beam 4 through the reserved holes 5.

[0026] The steel beam 4 is made of high-quality high-strength steel plates, and the bolt connectors 3 are made of high-strength bolts, including bolt rods, nuts and washers, and are distributed in groups at equal intervals along the length of the steel beam 4; the transverse length of the inverted T-shaped steel 2 shall not be less than 1 / 2 of the transverse length of the steel beam 4, and the transverse steel bars 1 are distributed between the gaps of the bolt connectors 3. The transverse steel bars 1 are made of high-strength threaded steel bars, and the diameter of the transverse steel bars 1 shall not be greater than the spacing between the bolt connectors 3.

[0027] The reserved holes 5 are distributed in multiple groups at equal intervals and are set at the top of the steel beam 4 and the bottom of the inverted T-shaped steel 2. The bolt connector 3 connects the two steel components through the reserved holes 5. The transverse steel bar 1 is welded to the corresponding positions on the left and right parts of the inverted T-shaped steel 2. The transverse steel bar 1, the bolt connector 3, the inverted T-shaped steel 2, the steel beam 4 and the concrete form a common load-bearing body. Figure 1 The arrangement of the bolt connectors 3 shown in the figure effectively increases the resistance area of ​​the longitudinal bridge to the horizontal shear force through the bolt connectors 3, improves the shear resistance, saves materials, reduces the amount of welding, and facilitates construction; at the same time, the transverse steel bars 1 are welded together with the inverted T-shaped steel 2 to increase the force transmission path of the steel-concrete composite beam and improve its pull-out resistance. The three interact with each other to form a network-point structure, which greatly improves the integrity; the inverted T-shaped steel 2 and the steel beam 4 are connected by the bolt connector 3, which only requires conventional processing and does not require special welding equipment like the stud connector. The structure is simple, solves the problem of steel-UHPC connection, increases the shear bearing capacity of the steel-concrete composite beam, improves the integrity of the composite structure, and is easy to arrange, suitable for construction use, and has certain promotion value.

[0028] Example 2 The present invention also provides a construction method for a composite connector of a steel-UHPC composite beam, the specific steps of which are as follows: S1. Pre-set holes are provided at corresponding positions on the top of the steel beam and the bottom of the inverted T-shaped steel. Multiple groups of pre-set holes are evenly spaced and distributed on the inverted T-shaped steel and the steel beam. S2. Place the inverted T-shaped steel on top of the steel beam so that the reserved holes of the two are aligned. Use bolt connectors to pass through the reserved holes to fix the inverted T-shaped steel to the top of the steel beam. The bolt connectors are distributed in groups with equal spacing. S3. Install transverse reinforcement on the left and right sides of the inverted T-shaped steel. The transverse reinforcement is distributed between the gaps of the bolt connectors. The transverse reinforcement is made of high-strength threaded steel bars. The diameter of the transverse reinforcement should not be greater than the spacing between the bolt connectors.

[0029] S4. Tie the longitudinal steel mesh on the top of the assembled steel structure to ensure that the longitudinal steel bars are cross-tied and fixed with the transverse steel bars. Then pour the UHPC and vibrate it to make it dense, and then cure it to the design strength.

[0030] It is worth noting that the contents not elaborated in detail in the present invention are all prior art and are well known to those skilled in the art.

[0031] Therefore, the present invention provides a composite connector for a steel-UHPC composite beam and a construction method thereof. Through the combined design of bolt connectors and inverted T-steels, the resistance area of ​​the longitudinal bridge direction to horizontal shear force is effectively increased. The "grid structure" formed by the transverse steel bars not only greatly improves the shear bearing capacity and pullout resistance of the composite beam, but also strengthens the coordinated force between the steel beam, inverted T-steel and UHPC, significantly enhancing the structural integrity. At the same time, bolt connection is used to replace traditional stud welding, without the need for special welding equipment, reducing the amount of welding work, simplifying the construction process, reducing dependence on operating technology, facilitating rapid on-site assembly, and reducing material consumption by optimizing the arrangement of connectors. It is both economical and practical, suitable for complex bridge scenarios such as large spans and heavy loads, and can better meet the engineering force requirements and durability requirements.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A composite connector for steel-UHPC composite beams, characterized in that: It includes transverse steel bars, inverted T-shaped steel, steel beam and bolt connectors. Reserved holes are provided at the corresponding positions of the lower part of the inverted T-shaped steel and the top of the steel beam. The transverse steel bars are installed on the left and right sides of the inverted T-shaped steel. The bolt connector fixes the inverted T-shaped steel to the top of the steel beam through the reserved holes.

2. The composite connector of a steel-UHPC composite beam according to claim 1, characterized in that: The reserved holes on the inverted T-shaped steel and the steel beam are distributed in multiple groups at equal intervals, and the transverse length of the inverted T-shaped steel shall not be less than 1 / 2 of the transverse length of the steel beam.

3. The composite connector of a steel-UHPC composite beam according to claim 1, characterized in that: The transverse reinforcements are distributed between the gaps between the bolt connectors; the transverse reinforcements are made of high-strength threaded steel bars, and the diameter of the transverse reinforcements shall not be greater than the spacing between the bolt connectors.

4. The composite connector of a steel-UHPC composite beam according to claim 1, characterized in that: The bolt connectors are high-strength bolts, including bolt rods, nuts and washers, and are distributed in groups with equal intervals along the length of the steel beam.

5. The composite connector of a steel-UHPC composite beam according to claim 1, characterized in that: The steel beam is made of high-quality high-strength steel plate.

6. A construction method for a composite connector of a steel-UHPC composite beam, characterized in that: The following steps are involved: Step S1: Pre-set holes are provided at corresponding positions on the top of the steel beam and the bottom of the inverted T-shaped steel, and the reserved holes on the inverted T-shaped steel and the steel beam are distributed in multiple groups at equal intervals; Step S2: Place the inverted T-shaped steel on top of the steel beam so that the reserved holes of the two are aligned, and use bolt connectors to pass through the reserved holes to fix the inverted T-shaped steel to the top of the steel beam. The bolt connectors are distributed in groups with equal spacing; Step S3: Install transverse reinforcement on the left and right sides of the inverted T-shaped steel. The transverse reinforcement is distributed between the gaps between the bolt connectors. The transverse reinforcement is made of high-strength threaded steel bars. The diameter of the transverse reinforcement should not be larger than the spacing between the bolt connectors. Step S4: Tie the longitudinal steel mesh on the top of the assembled steel structure to ensure that the longitudinal steel bars are cross-tied and fixed with the transverse steel bars. Then, pour the UHPC and vibrate it to compact it, and then cure it to the designed strength.

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