Shear-tension connection structure and application in steel-uHPC bridge engineering

Abstract

The application discloses a kind of anti-shear-tension connecting structure and application in steel-UHPC bridge engineering, solve the problem of poor mechanical properties in negative bending moment area.The anti-shear-tension connecting structure includes shear stud, connecting sleeve and tensile reinforcement, the connecting sleeve is quickly mechanically connected with shear stud, and is fixed at the end of shear stud, the connecting sleeve has larger cross section than shear stud, the tensile reinforcement is perpendicular to shear stud and is mechanically fixed on the connecting sleeve, and provides tensile resistance along the direction of bridge.The upper surface of the bridge in the negative bending moment area is bridge deck crack resistance structure, the lower side is steel concrete base, and shear stud, connecting sleeve and tensile reinforcement are arranged in the bridge deck crack resistance structure and steel concrete base, wherein the tensile reinforcement is arranged along the bridge direction.This technology inhibits the occurrence conditions of bridge deck cracking in negative bending moment area, and enhances the bridge deck crack resistance by elastic concrete or elastic asphalt.

Description

TECHNICAL FIELD

[0001] The application relates to a'shear-tension' resisting connecting structure suitable for a steel-UHPC structure and application in a negative bending moment area of a steel-UHPC beam, and belongs to the technical field of civil construction. BACKGROUND

[0002] The combination of UHPC and steel forms a combined structure, which is beneficial to the development of bridges in the direction of light weight and large span, and can avoid structural cracking and enhance the durability of bridges. In the traditional steel-UHPC combined structure, UHPC is generally applied to the compression area above the steel structure (steel beam, steel box girder, etc.), and the steel structure is generally applied to the tensile area below, wherein the stud is located at the connecting surface of the steel structure and the UHPC, and the stud functions as a shear connecting key to connect the steel-UHPC to form a whole, and in the structure, the stud mainly bears the shear force.

[0003] However, with the progress of bridge design concepts and construction technologies, the concept of a large-span steel-UHPC continuous beam is proposed. Unlike the traditional steel-UHPC simply supported beam, in the large-span steel-UHPC continuous beam, reference Figure 1 and Figure 2 is made to the continuous beam, which has both a positive bending moment area A and a negative bending moment area B. Specifically, the beam body near the bridge support is the negative bending moment area, and the span section is the positive bending moment area. Specifically, the stress state of the concrete filling area of the bridge deck is different in the positive bending moment area A and the secondary bending moment area B. Specifically, in the positive bending moment area A, the surface of the super-strong concrete is in compression and is not prone to cracking and other defects. In the secondary bending moment area B, the surface of the super-strong concrete is in tension and is prone to cracking on the road surface. This is also the main reason why the bridge deck is prone to cracking in the negative bending moment area of the large-span steel-UHPC continuous beam. Therefore, the application proposes a scheme to improve the stress performance of the negative bending moment area of the bridge, and through the improvement, test and simulation of the stud and the cross-section structure of the negative bending moment area of the bridge, a new structure that can comprehensively improve the shear and tensile resistance is sought, which also has the characteristics of convenient installation and economy.

[0004] The traditional steel-UHPC combined structure often uses studs and the like as shear connectors and uses a steel mesh to form a tensile structure. The stud shear connector is a semi-rigid shear connecting key, has small welding difficulty, has isotropic excellent mechanical properties, has strong shear resistance, but has extremely weak tensile resistance. The stud and the steel mesh have a relative opposition, and therefore, the overall performance is poor. SUMMARY

[0005] Technical problem: The purpose of the present application is to provide an anti-shear-tension connection structure and its application in the negative moment area of a steel-UHPC bridge, to solve the mechanical characteristics of the traditional bolt shear connector that is not resistant to shear but is resistant to tension, and to improve the economy and installation convenience of the steel-UHPC structure, especially to solve the problem of poor mechanical performance in the negative moment area, and to solve the cracking problem of the existing technology in the negative moment area of the bridge deck concrete pavement layer or asphalt pavement layer.

[0006] The technical solution adopted by the present application to solve its technical problem is:

[0007] The anti-shear-tension connection structure comprises a shear pin, a connecting sleeve and a tension-resistant rib, characterized in that:

[0008] The end of the shear pin is welded vertically on the steel beam to provide horizontal shear resistance.

[0009] The connecting sleeve is quickly mechanically connected with the shear pin and fixed at the end of the shear pin, the connecting sleeve has a larger cross section than the shear pin, and slots or holes are formed in the connecting sleeve.

[0010] The tension-resistant rib is perpendicular to the shear pin and is mechanically fixed on the connecting sleeve to provide tension resistance along the bridge direction.

[0011] The shear pin, connecting sleeve and tension-resistant rib are wrapped and covered by ultra-high performance concrete, and steel fibers are uniformly distributed in the ultra-high performance concrete.

[0012] Further, the shear pin has a pin body and a pin head, the connecting sleeve has a sleeve part and a base, and the sleeve part has a clamping groove along the radial direction of the sleeve, and the pin head and the clamping groove are connected by a spherical hinge.

[0013] Further, the shear pin and the connecting sleeve are threadedly connected.

[0014] Further, the shear pin has a pin body and a pin head, the connecting sleeve is composed of two symmetrical modules, and after being buckled, the pin head of the shear pin is held and fastened by using a fastening screw.

[0015] Further, the shear pin has a pin body and a pin head, and the connecting sleeve has a T-shaped insertion slot in the middle, which cooperates with the pin head of the shear pin, the pin head is inserted into the insertion slot, and the embedded block locks the position between the shear pin and the insertion sleeve.

[0016] Further, the tension-resistant rib is a hot-rolled smooth round steel bar or a threaded steel bar.

[0017] The application of the anti-shear-tension connection structure in steel-UHPC bridge engineering, the steel-UHPC bridge is installed by a support and has a positive moment area A and a negative moment area B, characterized in that:

[0018] In the negative bending moment zone, the upper surface of the bridge is a bridge deck crack-resistant structure, the lower side is a steel-concrete base, and shear studs, connecting sleeves and tensile reinforcement are arranged in the bridge deck crack-resistant structure and the steel-concrete base, wherein the tensile reinforcement is arranged along the bridge direction;

[0019] The bridge deck crack-resistant structure is elastic concrete containing a steel mesh;

[0020] The steel-concrete base is ultra-high performance concrete containing a steel mesh, and steel fibers are uniformly distributed in the ultra-high performance concrete;

[0021] In the positive bending moment zone, the upper side of the bridge is a concrete paving structure.

[0022] The beneficial effects of the present application are:

[0023] Firstly, compared with the traditional bolt connection method, the steel-concrete strengthening is performed on the lower surface of the bridge at the abutment matching position to form a steel-concrete base, so that the stiffness of the bridge at this position is effectively improved, the cross section of the lower part of the negative bending moment zone is reinforced, the bearing capacity of the steel-UHPC structure bridge in the negative bending moment zone is stronger, and the shear-tension performance is stronger, which makes the excellent mechanical properties of the UHPC material can be more fully utilized.

[0024] Secondly, the stress area of the steel-UHPC structure is clear and the stress is more reasonable in the steel-concrete base described above, and the crack resistance of the negative bending moment zone of the bridge deck is significantly enhanced, so that the pavement is not prone to cracking and rainwater intrusion.

[0025] Thirdly, the connection structure is convenient and fast to install, and has high construction efficiency. Specifically, the base partial reinforcement structure is completed in the factory, and the construction site only needs to be hoisted and assembled.

[0026] Finally, the implementation of the present technology well inhibits the cracking conditions of the negative bending moment zone of the bridge deck, and enhances the crack resistance of the bridge deck through elastic concrete or elastic asphalt. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the distribution of the positive bending moment zone and the negative bending moment zone in the existing bridge.

[0028] Figure 2 It is a schematic diagram of the support in the bridge direction in the negative bending moment zone in the prior art.

[0029] Figure 3 It is a front view of the shear-tension connection structure in Example 1.

[0030] Figure 4 It is a side view of the shear-tension connection structure in Example 1.

[0031] Figure 5 Figure 1 is a perspective view of a shear-tension connection according to an embodiment of the present application. Figure 4 Figure 2 is a cross-sectional view of the shear-tension connection of Figure 1.

[0032] Figure 6 Figure 3 is a perspective view of a shear-tension connection according to an embodiment of the present application.

[0033] Figure 7 Figure 4 is a partial view of the support at the pier of the shear-tension connection of Figure 3.

[0034] Figure 8 Figure 5 is a cross-sectional view of the shear-tension connection of Figure 3. Figure 7 Figure 6 is a cross-sectional view of the shear-tension connection of Figure 3.

[0035] Figure 9 Figure 7 is a perspective view of a shear-tension connection according to an embodiment of the present application. Figure 7 Figure 8 is a cross-sectional view of the shear-tension connection of Figure 7.

[0036] Figure 10 Figure 9 is a schematic view of the support at the beam end.

[0037] Figure 11 Figure 10 is a perspective view of a shear-tension connection according to an embodiment of the present application.

[0038] Figure 12 Figure 11 is a cross-sectional view of the shear-tension connection of Figure 10. Figure 11 Figure 12 is a cross-sectional view of the shear-tension connection of Figure 10.

[0039] Figure 13 Figure 13 is a perspective view of a shear-tension connection according to an embodiment of the present application.

[0040] Figure 14 Figure 14 is a cross-sectional view of the shear-tension connection of Figure 13. Figure 13 Figure 15 is a cross-sectional view of the shear-tension connection of Figure 13.

[0041] Figure 15 Figure 16 is a perspective view of a shear-tension connection according to an embodiment of the present application.

[0042] Figure 16 Figure 17 is a cross-sectional view of the shear-tension connection of Figure 16.

[0043] Figure 17 Figure 18 is a cross-sectional view of the shear-tension connection of Figure 16.

[0044] Figure 18 Figure 19 is a further view of the shear-tension connection of Figure 16. Figure 16 Figure 20 is a further view of the shear-tension connection of Figure 16.

[0045] Figure 19 Figure 21 is a further improvement of the shear-tension connection of Figure 16.

[0046] In the drawings:

[0047] 10 shear pin, 11 pin head, 12 pin body;

[0048] 20 connection sleeve, 21 sleeve portion, 211 catch slot, 22 base;

[0049] 30 hot rolled round bar

[0050] 00 Steel beams, 01 Steel-concrete base, 02 Crack-resistant bridge deck structure, 03 Ordinary concrete paving structure, 04 Steel mesh, 05 Elastic concrete;

[0051] 10' shear stud, 11' external thread, 20' connecting sleeve, 21' milled groove, 30' threaded steel bar;

[0052] 20” connecting sleeve, 21” insertion slot, 22” insert block. Detailed Implementation

[0053] To facilitate understanding of the structure of the present invention, the following description is provided in conjunction with the accompanying drawings and embodiments.

[0054] Example 1

[0055] like Figures 3 to 6 As shown, this invention is a shear-tension resistant connection structure applicable to steel-UHPC structures. The structure utilizes a steel-UHPC structure as its carrier. Specifically, a shear stud 10 is vertically welded to the surface of the steel structure. This shear stud has a body of uniform diameter and an enlarged head 11. The body 12 is circular, square, or polygonal. The head 11 is spherical, cylindrical, prismatic, or other shaped. The size of the head is significantly larger than the size of the body. This shear stud is fixed to the steel structure by welding and is vertically positioned.

[0056] refer to Figure 6 In this embodiment, the nail head 11 is a sphere.

[0057] like Figure 3 As shown, a connecting sleeve is installed via a plug-in connection. The connecting sleeve 20 is a carbon steel part, consisting of a sleeve portion 21 and a base 22. The sleeve portion 21 is a cylinder with a diameter significantly larger than that of the shear stud. The base 22 is located at the lower end of the sleeve portion. A spherical groove 211 is provided in the upper middle section of the sleeve portion, running radially along the sleeve. The spherical space reserved in the groove 211 engages with the spherical head of the shear stud. Specifically, the connecting sleeve is fixed by the connection between the spherical groove and the spherical stud head.

[0058] Additionally, threads are provided on the outer surface of the connecting sleeve 20 to ensure full engagement with the concrete.

[0059] And, the sleeve part of the connecting sleeve 20 is provided with four through holes, wherein, the four through holes are evenly distributed in the upper and lower and left and right four directions of the spherical clamping groove in two groups, and the through holes are vertically arranged with the axial direction of the sleeve. The role of the through hole is to install the hot rolled smooth round steel bar 30, that is, to insert four hot rolled smooth round steel bars on the connecting sleeve. The hot rolled smooth round steel bar has a long length and is arranged along the bridge direction to provide tensile mechanical properties.

[0060] Further, the end of the hot rolled smooth round steel bar 30 is bent by 90 degrees to improve the tensile property.

[0061] Further, along the bridge direction, two adjacent hot rolled round steel bars 30 can be welded and connected into one body through the embedded steel bar to form a tensile effect.

[0062] The role of the hot rolled smooth round steel bar is to provide tensile capacity, so it is also called tensile bar, and is arranged along the negative bending moment of the bridge direction, which can effectively offset the tensile stress in the negative bending moment area.

[0063] As shown in Figure 1 , Figure 7 , Figure 10 A steel-UHPC bridge based on the above structure, the steel-UHPC bridge has a positive bending moment area A and a negative bending moment area B, wherein in the negative bending moment area, the bridge cross section has a steel beam 00, a shear-tension connecting structure located below the steel beam in the negative bending moment area and a UHPC composed steel concrete base 01, a bridge deck crack resisting structure 02 located above the steel beam, and a common concrete paving structure 03 located above the steel beam in the positive bending moment area.

[0064] In the negative bending moment area,

[0065] The bridge deck crack resisting structure 02 above includes shear studs, steel mesh and elastic concrete paving layer, wherein the studs are welded on the upper surface of the steel beam, the steel mesh is tied, and the elastic concrete is paved to form the elastic concrete paving layer.

[0066] The shear-tension connecting structure located below the steel beam is welded and fixed with shear studs 10 on the lower surface of the steel beam, then the connecting sleeve 20 is installed on the shear studs, coaxially nested and centered, then the hot rolled smooth round steel bar is inserted and fixed in the through hole of the connecting sleeve, the steel mesh 04 is tied, and the elastic concrete is paved to form the elastic concrete paving layer, and the steel concrete base 01 is formed by formwork grouting at this part, which is a steel concrete structure.

[0067] The steel concrete base structure containing the shear-tension connecting structure covers the negative bending moment area.

[0068] The elastic concrete paving layer covers the negative bending moment area.

[0069] The negative bending moment area forms the area of the steel-concrete structure with the upper part of elastic concrete 05 and the lower part of rigid compression, which can fully exert the mechanical properties of UHPC compression resistance, and is placed at the lower part of the steel beam, which leads to the shear-tension connecting structure and the connecting key of UHPC to not only bear huge shear force but also bear huge tension. Meanwhile, the upper part of the elastic concrete paving layer can well adapt to the repeated tension status of the negative bending moment area and has good anti-cracking performance, and the elasticity of the elastic concrete paving layer itself is sufficient to solve the problem of easy cracking of the existing bridge deck concrete.

[0070] The abovementioned base and the shear-tension connecting structure covered thereby are prefabricated by a steel structure manufacturer.

[0071] In the positive bending moment area,

[0072] The upper bridge anti-cracking structure includes studs, steel mesh and a concrete paving layer, wherein the studs are welded on the upper surface of the steel beam, the steel mesh is bound, and the concrete paving layer is formed by laying the concrete.

[0073] The studs in the positive bending moment area can also adopt the structure of the shear stud, connecting sleeve and tension bar of the present application.

[0074] The abovementioned concrete paving layer and elastic concrete paving layer above the bridge are uniformly laid and constructed in the later stage after the completion of the bridge composition. The concrete paving layer is located above the positive bending moment area and fully exerts the compression resistance. The elastic concrete paving layer is located in the negative bending moment area and adaptively deforms with the tensile deformation of the steel beam in the negative bending moment area of the bridge, and the elastic concrete does not crack or have other defects in this process.

[0075] The abovementioned steel-concrete base can be applied to the part where the support is arranged in the middle section of the continuous beam ( Figure 7 ) or the part where the support is arranged at the end of the beam ( Figure 10 ). Specifically, the steel-concrete base is applied to the part with the support and enhances the bending strength of the support part by calculating or the length range of the negative bending moment area.

[0076] Construction process:

[0077] Manufacture of the steel structure, which is completed in the factory, and prefabrication of the steel-concrete base on the lower surface of the steel beam in the negative bending moment area.

[0078] Transportation, hoisting and installation

[0079] After the completion of the steel beam construction, the elevation of the beam surface is re-measured, the upper surface of the steel bridge is cleaned and derusted, the short studs are welded and the steel mesh is laid, the positive and negative bending moment areas are delimited, the concrete grout is poured and leveled at the bridge deck in the positive bending moment area, and the elastic concrete material is laid at the bridge deck in the negative bending moment area, and is cured until completion.

[0080] Embodiment Two

[0081] Another embodiment structure, reference Figures 11 to 14 , in this structure, the structure, the connecting sleeve has a modification. Specifically, the connecting sleeve and the shear pin does not use the ball hinge nest connection mode, but uses the threaded connection mode. Specifically, the end of the shear pin 10' is provided with external threads 11', and the corresponding end of the connecting sleeve 20' is provided with internal threads, and the two are connected by threads. And, a groove 21' is milled on the connecting sleeve, and several threaded steels 30' are welded, which are perpendicular to the shear pin.

[0082] In this embodiment, the connecting sleeve is obtained by simple processing of a large diameter threaded steel, which has lower implementation cost than the first embodiment. Specifically, a threaded steel segment of a predetermined length is cut off, a hole is drilled at one end of the threaded steel segment, and an internal thread is formed. A positioning groove is formed on the surface of the other end of the threaded steel segment by milling. Several threaded steels are placed and welded in the groove, which are perpendicular to the drilled hole, which is a simple and efficient processing technology.

[0083] Embodiment Three

[0084] Another embodiment structure, the connecting sleeve is formed by two symmetrical modules, specifically, including left half and right half, after buckling, the nail head of the shear pin is clamped, and the fastening screw is used for fastening.

[0085] And a hot rolled smooth round steel is arranged in the two halves, which is basically the same as the first embodiment.

[0086] Embodiment Four

[0087] Reference Figures 15 to 18 , in this embodiment, the bolt uses a common model, and the connecting sleeve 20" is designed optimally. Specifically, the connecting sleeve is a cylinder as a whole, and has a T-shaped insertion slot 21" in the middle of the connecting sleeve, which is used to cooperate with the nail head 11 of the bolt. Specifically, the insertion slot is composed of a horizontal slot and a vertical slot, wherein the horizontal slot is used for the bolt to cut in a horizontal manner, and the position is locked in the vertical slot. Specifically, the locking uses an embedded block 22", which locks the position between the bolt and the connecting sleeve.

[0088] A hole is drilled in the connecting sleeve and a hot rolled smooth round steel is installed, which is arranged along the bridge direction.

[0089] Further, reference Figure 19 , the above connecting sleeve top groove and welded hot rolled smooth round steel 30 can also have similar effects.

[0090] The above embodiments are only used to describe the preferred embodiments of the present application, and not intended to limit the scope of the present application, and various changes and modifications of the present application can be made by those skilled in the art without departing from the spirit and scope of the present application, and all these changes and modifications shall fall within the scope of the claims of the present application.

Claims

1. Application of shear-tension connection structure in steel-UHPC bridge engineering, where the steel-UHPC bridge is installed via supports and has positive and negative bending moment zones; the shear-tension connection structure includes shear studs, connecting sleeves, and tension bars, characterized in that: The shear studs are vertically welded to the steel beams at their ends, providing horizontal shear resistance. Each shear stud has a body and a head, and a T-shaped insertion slot in the connecting sleeve. This slot mates with the head of the shear stud, which is inserted into the slot. An insert block locks the position between the shear stud and the connecting sleeve. The connecting sleeve is quickly mechanically connected to the shear stud and fixed to its end. The connecting sleeve has a larger cross-section than the shear stud and is slotted or perforated. Tensile reinforcement is perpendicular to the shear studs and mechanically fixed to the connecting sleeve, providing tensile resistance along the longitudinal direction of the bridge. The shear studs, connecting sleeves, and tensile reinforcement are encased and covered by ultra-high performance concrete, with steel fibers evenly distributed within the ultra-high performance concrete. In the negative bending moment zone, the cross-section of the steel-UHPC bridge includes steel beams, a steel-concrete base, and a bridge deck crack-resistant structure. The upper surface of the steel-UHPC bridge is the bridge deck crack-resistant structure, and the lower side is the steel-concrete base. Shear studs, connecting sleeves, and tensile reinforcements are installed in the bridge deck crack-resistant structure and the steel-concrete base, wherein the tensile reinforcements are arranged along the longitudinal direction of the bridge. The bridge deck crack-resistant structure is elastic concrete containing a steel mesh, and the paving layer of the elastic concrete covers the negative bending moment zone. The steel-concrete base is ultra-high performance concrete containing a steel mesh, and steel fibers are evenly distributed within the ultra-high performance concrete. Shear studs are welded and fixed to the lower surface of the steel beams, and then connecting sleeves are installed on the shear studs, nested coaxially and aligned at the center. Hot-rolled plain round steel bars are inserted and fixed at the through holes of the connecting sleeves, and steel mesh is tied. The steel-concrete base is formed by grouting through a template at this location. The steel-concrete base is located in the middle section of the continuous beam or in a location below the beam end with a support. The steel-concrete base covers the negative bending moment zone. In the positive bending moment region, the upper side of the steel-UHPC bridge has a concrete paving structure, which includes shear studs, steel mesh and concrete paving layer. The shear studs are welded to the upper surface of the steel beam, and the steel mesh is tied to it. Concrete is then laid to form the concrete paving layer.

2. Application of shear-tension connection structure in steel-UHPC bridge engineering. The steel-UHPC bridge is installed through supports and has positive and negative bending moment zones. The shear-tension connection structure includes shear studs, connecting sleeves, and tensile reinforcement, characterized in that: The shear studs are vertically welded to the steel beams at their ends to provide horizontal shear resistance. Each shear stud has a body and a head. A connecting sleeve has a sleeve portion and a base, with a groove along the radial direction of the sleeve portion. The head and groove are connected by a ball joint. The connecting sleeve is quickly mechanically connected to the shear stud and fixed to its end. The connecting sleeve has a larger cross-section than the shear stud and is slotted or perforated. Tensile reinforcement is perpendicular to the shear studs and mechanically fixed to the connecting sleeve, providing tensile resistance along the longitudinal direction of the bridge. The shear studs, connecting sleeves, and tensile reinforcement are encased and covered by ultra-high performance concrete, with steel fibers evenly distributed within the ultra-high performance concrete. In the negative bending moment zone, the cross-section of the steel-UHPC bridge includes steel beams, a steel-concrete base, and a bridge deck crack-resistant structure. The upper surface of the steel-UHPC bridge is the bridge deck crack-resistant structure, and the lower side is the steel-concrete base. Shear studs, connecting sleeves, and tensile reinforcements are installed in the bridge deck crack-resistant structure and the steel-concrete base, wherein the tensile reinforcements are arranged along the longitudinal direction of the bridge. The bridge deck crack-resistant structure is elastic concrete containing a steel mesh, and the paving layer of the elastic concrete covers the negative bending moment zone. The steel-concrete base is ultra-high performance concrete containing a steel mesh, and steel fibers are evenly distributed within the ultra-high performance concrete. Shear studs are welded and fixed to the lower surface of the steel beams, and then connecting sleeves are installed on the shear studs, nested coaxially and aligned at the center. Hot-rolled plain round steel bars are inserted and fixed at the through holes of the connecting sleeves, and steel mesh is tied. The steel-concrete base is formed by grouting through a template at this location. The steel-concrete base is located in the middle section of the continuous beam or in a location below the beam end with a support. The steel-concrete base covers the negative bending moment zone. In the positive bending moment region, the upper side of the steel-UHPC bridge has a concrete paving structure, which includes shear studs, steel mesh and concrete paving layer. The shear studs are welded to the upper surface of the steel beam, and the steel mesh is tied to it. Concrete is then laid to form the concrete paving layer.

3. The application of the shear-tension connection structure according to claim 1 or 2 in steel-UHPC bridge engineering, characterized in that: The tensile reinforcement is hot-rolled plain round steel bar or threaded steel bar.

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