Profile steel-UHPC composite beam unit, composite beam and beam bridge

Abstract

The utility model discloses a section steel-UHPC composite beam unit, including two rows of H-shaped steel that are arranged oppositely and UHPC Pi beam that is fixedly connected with the H-shaped steel, the UHPC Pi beam includes a top plate and two rows of webs that are connected with the top plate, the two rows of webs are in one-to-one correspondence with the two rows of H-shaped steel, the top surface of the H-shaped steel is provided with a plurality of connecting pieces, and when the UHPC Pi beam is poured, the connecting pieces are connected with the H-shaped steel. The web and the H-shaped steel form a whole through the connecting piece. The utility model further provides a seed profile steel-UHPC composite beam formed by combining a plurality of seed profile steel-UHPC composite beam units, and a seed profile steel-UHPC composite beam bridge. According to the section steel-UHPC composite beam unit, the composite beam and the beam bridge, the section steel is arranged in the highest tensile stress area, the UHPC Pi beam is arranged in the highest compressive stress area, and the section steel and the UHPC Pi beam are combined to bear force together, so that the structure of the steel-concrete composite beam is optimized, the mechanical property is better, and the construction is simpler and more convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of bridges, and in particular to a steel-UHPC composite beam unit, a composite beam and a beam bridge. Background Art

[0002] Steel-concrete composite beam bridge is a type of bridge structure that connects steel beams and concrete bridge decks through shear connectors to form an integral common load-bearing bridge structure. Compared with concrete beam bridges, steel-concrete composite beam bridges have the advantages of small structural size, light weight, good structural ductility, excellent seismic performance and low foundation cost; compared with steel beam bridges, steel-concrete composite beam bridges have the advantages of high rigidity, good stability and good fire resistance. Furthermore, the reduction in the height of the upper structure of the steel-concrete composite beam bridge is conducive to increasing the clearance under the bridge and lowering the bridge deck elevation, so the bridge structure is more slender, enhancing the landscape effect of the bridge.

[0003] Although the mechanical properties and construction performance of steel-concrete composite beam bridges are good, there are also some problems in engineering applications. Ordinary concrete bridge decks are heavy and low in strength, the joint structure is complex and easy to seep water, and the durability is poor. Ultra-high performance concrete (Ultra-high Performance Concrete, UHPC) materials have ultra-high strength and excellent durability due to the high density of the matrix. Using UHPC materials to replace ordinary concrete to form prefabricated steel-UHPC composite beam bridges is expected to overcome the above technical difficulties. The lightweight and high-strength steel-UHPC composite beam bridge is easy to construct and suitable for bridge assembly construction.

[0004] In the prior art, steel-UHPC composite beam bridges usually only use UHPC materials for the bridge deck, and composite beam bridges mostly use a variety of welded steel main beams. The welding steel structure process is complex, the welding workload is large, the cost is high, the weld defects are many, the residual stress is high, and the quality is difficult to control, which affects the safety and fatigue resistance of the main beam; furthermore, most of the webs of the full steel beam are in the low tensile stress area, and some of the webs are in the low compressive area, which fails to give full play to the excellent mechanical properties of steel.

[0005] In view of this, it is necessary to provide a new steel-concrete composite beam to solve the above technical problems. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a steel-UHPC composite beam unit and a composite beam and a beam bridge, wherein the steel is placed in the highest tensile stress area, and the UHPC π beam is placed in the highest compressive stress area, and the two are combined to bear force together, so that the steel-concrete composite beam structure is optimized, the mechanical properties are better, and the construction is simpler.

[0007] The first aspect of the utility model is to provide a steel-UHPC composite beam unit, comprising two rows of H-shaped steels arranged opposite to each other and a UHPC π beam fixedly connected to the H-shaped steels, wherein the UHPC π beam comprises a top plate and two rows of webs connected to the top plate, wherein the two rows of webs correspond to the two rows of H-shaped steels one by one, and a plurality of connectors are arranged on the top surface of the H-shaped steels, and when the UHPC π beams are cast, the webs and the H-shaped steels are integrated through the connectors.

[0008] Furthermore, the connecting member is a bolt.

[0009] Furthermore, the cross-sectional height of the H-shaped steel is 25-60% of the overall height of the steel-UHPC composite beam unit.

[0010] The second aspect of the utility model is to provide a steel-UHPC composite beam, comprising at least two steel-UHPC composite beam units of the first aspect, wherein two adjacent steel-UHPC composite beam units are connected into a whole through a cast-in-place UHPC longitudinal wet joint.

[0011] Furthermore, it also includes a cast-in-place UHPC mid-span diaphragm and a cast-in-place UHPC end diaphragm, wherein the cast-in-place UHPC mid-span diaphragm is located between two rows of webs of the UHPC π beam and is connected to the webs through reserved steel bars of the webs during casting;

[0012] The cast-in-place UHPC end diaphragm is located between two adjacent steel-UHPC composite beam units, and between two rows of webs and two rows of H-shaped steels of each steel-UHPC composite beam unit. During casting, the cast-in-place UHPC end diaphragm forms a whole with the cast-in-place UHPC longitudinal wet joint, and is connected to each steel-UHPC composite beam unit through the reserved steel bars and H-shaped steel of the web.

[0013] Furthermore, the cross-sectional height of the H-shaped steel is 25-60% of the overall height of the steel-UHPC composite beam unit.

[0014] Furthermore, the span of the steel-UHPC composite beam is 30-60m.

[0015] The third aspect of the utility model is to provide a steel-UHPC composite beam bridge, comprising the steel-UHPC composite beam of the second aspect, and a UHPC bridge deck laid on the surface of the steel-UHPC composite beam, wherein the cast-in-place UHPC longitudinal wet joint is cast together with the UHPC bridge deck to form a whole.

[0016] Compared with the prior art, the steel-UHPC composite beam unit, composite beam and beam bridge provided by the utility model have the following beneficial effects:

[0017] 1. The steel-UHPC composite beam unit provided by the utility model connects the H-steel and the UHPCπ beam to form a composite structure that bears force together. The H-steel bears the tensile force in the high tensile stress area, and the lower part of the UHPCπ beam bears part of the tensile force, so that the good compressive performance and strain hardening tensile characteristics of the UHPCπ beam can be exerted in the high pressure stress area and the low tensile stress area respectively. The combination of the two can give full play to the tensile and compressive advantages of the steel and UHPCπ beam, and utilize the good tensile crack resistance and strong compressive capacity of the UHPCπ beam in the positive moment area. The H-steel resists the positive and negative moments of the composite structure, thereby achieving structural optimization and strengthening, and better mechanical properties. The combination of H-steel and UHPCπ beam makes the structure more stable compared to traditional T-beams.

[0018] 2. The steel-UHPC composite beam provided by the utility model has various components which are prefabricated and installed in the factory and then hoisted on the construction site, so the construction is simple.

[0019] 3. Compared with the traditional steel plate beam-ordinary concrete composite structure, the steel-UHPC composite beam provided by the utility model has a lighter self-weight. Taking a span of 30m as an example, two steel-UHPC composite beam units are combined to form a 4.2m wide "π" beam, which weighs only more than 90 tons, which is less than the weight of a concrete T-beam with the same span, and is convenient for on-site hoisting and construction.

[0020] 4. The steel-UHPC composite beam provided by the utility model is connected into a whole through cast-in-place UHPC longitudinal wet joints after the single steel-UHPC composite beam unit is hoisted. Due to the high bending and tensile strength and high density of UHPC materials, the cracking and water seepage problems of wet joints can be better improved.

[0021] 5. The steel-UHPC composite beam provided by the utility model greatly expands the application scope of steel in composite structures. For example, a 1m high hot-rolled H-shaped steel can be used in a steel-UHPC composite beam with a beam height of 2.9m, and this composite beam can adapt to a span of 60m. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a structural schematic diagram of the steel-UHPC composite beam unit of the utility model;

[0024] Figure 2It is a structural schematic diagram of a standard cross section of a steel-UHPC composite beam of the utility model;

[0025] Figure 3 It is a structural schematic diagram of the mid-span cross section of the steel-UHPC composite beam of the utility model;

[0026] Figure 4 It is a structural schematic diagram of the cross section of the side support of the steel-UHPC composite beam of the utility model. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the specific implementation methods of the present invention are further described below.

[0028] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as there is no conflict between them.

[0029] Example 1

[0030] See also Figure 1 , is a structural schematic diagram of a steel-UHPC composite beam unit of the utility model. The steel-UHPC composite beam unit 100 of the utility model comprises two rows of H-shaped steels 1 arranged opposite to each other, and a UHPC π beam 2 fixedly connected to the H-shaped steels 1, wherein the UHPC π beam 2 is supported on the H-shaped steels, and the two are connected into a whole when the UHPC π beam 2 is cast.

[0031] The UHPCπ beam 2 includes a top plate 21 and two rows of webs 22 connected to the top plate 21. The two rows of webs 22 correspond to the two rows of H-shaped steels one by one, and the webs are supported on the top plates of the corresponding H-shaped steels. Specifically, a plurality of connectors 3 are provided on the top surface of the H-shaped steel, and then an integral steel membrane and pre-embedded steel bars are set up on the upper part of the H-shaped steel to form the UHPCπ beam by casting at one time. During the casting process, the webs 22 and the H-shaped steel 21 are formed into a whole through the pre-set connectors 3, that is, a steel-UHPC composite beam unit is obtained.

[0032] In this embodiment, the connecting members 23 are studs, and a plurality of studs are arranged in two rows on the top surface of each H-shaped steel.

[0033] In the present invention, the height of the H-beam 1 is 25-60% of the overall height of the steel-UHPC composite beam unit 100. By optimizing the height of the H-beam and the UHPCπ beam, the tensile stress and compressive resistance of the composite beam are further optimized. Specifically, the design parameters of the steel-UHPC composite beam unit of this embodiment are as follows: the top plate width of the steel-UHPC composite beam unit is 2.1m, the center axis distance between two rows of H-beams is 1.6m, the cross-sectional height of the H-beam is 1m, and the overall height of the steel-UHPC composite beam unit is 2.9m.

[0034] Example 2

[0035] Please combine Figure 2 , Figure 3 and Figure 4 ,in Figure 2 It is a structural schematic diagram of a standard cross section of a steel-UHPC composite beam of the utility model; Figure 3 It is a structural schematic diagram of the mid-span cross section of the steel-UHPC composite beam of the utility model; Figure 4 The utility model is a structural schematic diagram of the cross section of the side support of the steel-UHPC composite beam. The utility model steel-UHPC composite beam 200 is composed of multiple steel-UHPC composite beam units 100 connected together, and two adjacent steel-UHPC composite beam units are connected into a whole through a cast-in-place UHPC longitudinal wet joint 201.

[0036] The steel-UHPC composite beam 200 of the utility model further includes a cast-in-place UHPC mid-span diaphragm 202 and a cast-in-place UHPC end diaphragm 203, wherein the cast-in-place UHPC mid-span diaphragm 202 is located between two rows of webs of the UHPC π beam, and is connected to the webs through the reserved steel bars of the webs during casting; the cast-in-place UHPC end diaphragm 203 is located between two adjacent steel-UHPC composite beam units 100, and between two rows of webs 22 and two rows of H-shaped steels 1 of each steel-UHPC composite beam unit. During casting, the cast-in-place UHPC end diaphragm 203 forms a whole with the cast-in-place UHPC longitudinal wet joint 201, and is connected to the steel-UHPC composite beam unit 100 through the reserved steel bars of the webs and the H-shaped steels.

[0037] The steel-UHPC composite beam of this embodiment is formed by connecting and combining three steel-UHPC composite beam units. The cross-sectional height of the H-shaped steel used is 1m, and the overall height of the steel-UHPC composite beam unit is 2.9m. The corresponding composite beam span can reach 60m.

[0038] By paving the UHPC bridge deck 300 on the steel-UHPC composite beam 200 of the utility model and installing the auxiliary facilities 400, a steel-UHPC composite beam bridge can be obtained. Preferably, in the casting process, the UHPC bridge deck 300 bridge deck and the cast-in-place UHPC longitudinal wet joint form an integral whole.

[0039] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations made to these embodiments without departing from the principle and spirit of the present invention still fall within the scope of protection of the present invention.

Claims

1. A steel-UHPC composite beam unit, characterized in that: It includes two rows of H-shaped steels arranged opposite to each other and a UHPC π beam fixedly connected to the H-shaped steels. The UHPC π beam includes a top plate and two rows of webs connected to the top plate. The two rows of webs correspond to the two rows of H-shaped steels one by one. A plurality of connectors are provided on the top surface of the H-shaped steel. When the UHPC π beam is cast, the webs and the H-shaped steels are integrated through the connectors.

2. The steel-UHPC composite beam unit according to claim 1, characterized in that: The connecting piece is a bolt.

3. The steel-UHPC composite beam unit according to claim 1, characterized in that: The cross-sectional height of the H-shaped steel is 25-60% of the overall height of the steel-UHPC composite beam unit.

4. A steel-UHPC composite beam, characterized in that: It comprises at least two steel-UHPC composite beam units as claimed in claim 1, and two adjacent steel-UHPC composite beam units are connected into a whole through a cast-in-place UHPC longitudinal wet joint.

5. The steel-UHPC composite beam according to claim 4, characterized in that: It also includes a cast-in-place UHPC mid-span diaphragm and a cast-in-place UHPC end diaphragm, wherein the cast-in-place UHPC mid-span diaphragm is located between two rows of webs of the UHPC π beam and is connected to the webs through reserved steel bars of the webs during casting; The cast-in-place UHPC end diaphragm is located between two adjacent steel-UHPC composite beam units, and between two rows of webs and two rows of H-shaped steels of each steel-UHPC composite beam unit. During casting, the cast-in-place UHPC end diaphragm forms a whole with the cast-in-place UHPC longitudinal wet joint, and is connected to each steel-UHPC composite beam unit through the reserved steel bars and H-shaped steel of the web.

6. The steel-UHPC composite beam according to claim 4, characterized in that: The cross-sectional height of the H-shaped steel is 25-60% of the overall height of the steel-UHPC composite beam unit.

7. The steel-UHPC composite beam according to any one of claims 4 to 6, characterized in that: The span of the steel-UHPC composite beam is 30-60m.

8. A steel-UHPC composite beam bridge, characterized in that: It comprises a steel-UHPC composite beam as described in any one of claims 4 to 7, and a UHPC bridge deck laid on the surface of the steel-UHPC composite beam, wherein the cast-in-place UHPC longitudinal wet joint is cast together with the UHPC bridge deck to form a whole.

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