Beam-to-beam connecting structure for steel and concrete composite beam

Abstract

The utility model provides an inter-beam connecting structure for steel and concrete composite beam: the composite beam comprises a bridge deck slab and a composite rib plate located on the bottom surface of the bridge deck slab, the butt joint end of the bridge deck slab is provided with a third bridge deck post-pouring area, the composite rib plate comprises a concrete rib plate and a steel beam, and the steel beam is provided with a third bridge deck post-pouring area. The concrete rib plates are located between the bridge deck slab and the steel beams. Two adjacent composite beams form a second inter-beam post-pouring area between the two bridge deck slabs and between the two concrete rib plates, and bridge deck slab steel reinforcement frameworks in the bridge deck slabs and rib plate steel reinforcement frameworks in the concrete rib plates extend into the second inter-beam post-pouring area; uHPC concrete is poured in the third bridge deck post-pouring area and the second inter-beam post-pouring area together, and connection between the two bridge deck slabs and the two concrete rib plates is achieved; the steel beams of every two adjacent composite beams are connected in a rigid connection mode. According to the utility model, the two composite beams form a whole, and the connection integrity is excellent.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge engineering, in particular to an inter-beam connection structure used for steel and concrete composite beams. Background Art

[0002] Currently, precast beams for the superstructures of small- and medium-span highway and municipal bridges in my country are mostly prestressed concrete T-beams and small box beams. These structures suffer from high material consumption, frequent concrete defects, heavy weight, and complex on-site construction. Steel-concrete composite beams used in small- and medium-span bridges primarily utilize steel plate composite beam structures, which have numerous joints, require extensive on-site construction, and are prone to concrete cracking in negative bending moment areas. These beam types are typically produced in temporary beam factories and dispersed prefabrication, resulting in low production efficiency and a small transportation radius.

[0003] As an improvement to traditional technology, steel-UHPC composite beams have been gradually promoted and applied in recent years. However, conventional steel-UHPC composite beams also have drawbacks such as insufficient material performance, high steel consumption, and high welding workload. To fully utilize the excellent properties of steel and UHPC materials and further improve the economy and applicability of steel-UHPC composite beams, several new composite beam structures have been proposed. Patent application publication number CN112391932A provides a steel-ultra-high performance concrete composite beam, and patent application publication number CN112342889A provides an assembled lightweight composite beam bridge with a steel-UHPC composite web. Both approaches utilize UHPC to bear the high compressive stress of the upper flange and the low tensile stress of the composite web, while utilizing steel to bear the high tensile stress of the lower portion. However, both studies remain at the component level, with no mention of how to splice together to form a structural system or its effective use in engineering.

[0004] In summary, there is an urgent need for an inter-beam connection structure for steel and concrete composite beams to solve the problems existing in the prior art. Utility Model Content

[0005] The purpose of this utility model is to provide a beam connection structure for steel and concrete composite beams, aiming to solve the problem of how to splice steel and concrete composite beams. The specific technical solution is as follows:

[0006] A beam connection structure for steel and concrete composite beams, comprising:

[0007] A composite beam comprising a bridge deck and a composite rib located on the bottom surface of the bridge deck, wherein a third bridge deck post-cast area is provided at the butt end of the bridge deck, and the composite rib comprises a concrete rib and a steel beam, wherein the concrete rib is located between the bridge deck and the steel beam;

[0008] Two adjacent composite beams form a second inter-beam post-cast area between the two bridge decks and between the two concrete ribs, and the bridge deck steel skeleton in the bridge deck and the rib steel skeleton in the concrete ribs both extend into the second inter-beam post-cast area; the third bridge deck post-cast area and the second inter-beam post-cast area are cast together with UHPC concrete to achieve connection between the two bridge decks and the two concrete ribs;

[0009] The steel beams of two adjacent composite beams are connected by rigid connection.

[0010] Preferably, a plurality of first tooth keys are vertically provided on the end surface of the concrete rib close to the second inter-beam post-cast area.

[0011] Preferably, the steel beam comprises a steel bottom plate and a steel web, the lower side of the steel web is connected to the steel bottom plate, and the upper side thereof is connected to the bottom of the concrete rib;

[0012] The butt joints between the steel webs of the two composite beams and the butt joints between the steel bottom plates of the two composite beams are both butted together using a rigid connection method.

[0013] Preferably, the butt ends of the steel bottom plates of two adjacent composite beams are rigidly connected by connection mode 1 or connection mode 2, and the butt ends of the steel web plates of two adjacent composite beams are also rigidly connected by connection mode 1 or connection mode 2.

[0014] Among them: the first connection method is welding, and the second connection method is bolting using a splicing plate and a bolt assembly four.

[0015] Preferably, when the butt ends of the steel bottom plates of two adjacent composite beams are bolted together by using a splicing plate and a bolt assembly 4, the steel bottom plates are widened at the butt ends.

[0016] Preferably, the concrete rib comprises a rib concrete layer and a rib steel skeleton located inside the rib concrete layer; the bridge deck comprises a bridge deck concrete layer and a bridge deck steel skeleton located inside the bridge deck concrete layer;

[0017] The upper end of the rib steel frame is connected to the bridge deck steel frame in the bridge deck, the upper side of the steel web is embedded in the bottom of the concrete rib, and the steel web is butted against the lower end of the rib steel frame.

[0018] Preferably, the upper edge of the steel web is alternately provided with steel tenons and mortise holes along the longitudinal direction of the bridge, and the steel tenons and mortise holes are embedded in the concrete at the bottom edge of the concrete rib;

[0019] The rib steel bar skeleton includes the bottom layer of longitudinal steel bars, the second bottom layer of longitudinal steel bars, longitudinal distribution steel bars, transverse short steel bars and a vertical stirrup group; the vertical stirrup group includes lower open stirrups and upper open stirrups alternately arranged along the longitudinal bridge direction, the lower open stirrups are arranged in a one-to-one correspondence with the steel tenons, the upper open stirrups are arranged in a one-to-one correspondence with the mortise, the steel tenons are inserted into the openings at the lower ends of the lower open stirrups, the lower ends of the upper open stirrups are placed in the mortise, and transverse short steel bars are provided on both sides of the lower ends of the upper open stirrups; the bottom layer of longitudinal steel bars is used to connect the lower ends of the lower open stirrups along the longitudinal direction, and the second bottom layer of longitudinal steel bars is used to connect the lower ends of the upper open stirrups along the longitudinal direction; a plurality of longitudinal distribution steel bars are arranged inside the vertical stirrup group along the vertical direction, and a single longitudinal distribution steel bar passes through the alternately arranged upper open stirrups and lower open stirrups along the longitudinal direction.

[0020] Preferably, the bottom edge where the concrete ribs are connected to the steel webs is thickened.

[0021] Preferably, the bridge deck steel bar skeleton includes an upper transverse steel bar group, a lower transverse steel bar group and the bridge deck longitudinal main bars; multiple bridge deck longitudinal main bars are arranged at intervals along the transverse direction of the bridge, the upper transverse steel bar group is located on the upper side of the bridge deck longitudinal main bars, and the lower transverse steel bar group is located on the lower side of the bridge deck longitudinal main bars.

[0022] Preferably, the third bridge deck post-cast area does not penetrate the bridge deck in its depth direction.

[0023] The application of the technical solution of the utility model has the following beneficial effects:

[0024] The inter-beam connection structure of the present invention leaves a second inter-beam post-casting area between the bridge decks of the two composite beams and between the concrete ribs. At the same time, a plurality of first splines are provided on the end face of the concrete rib near the second inter-beam post-casting area. The bridge deck steel frame and the rib steel frame both extend into the second inter-beam post-casting area. The third bridge deck post-casting area and the second inter-beam post-casting area are cast with concrete together so that the two composite beams form a whole. The connection integrity between the two composite beams is optimal. The first spline can enhance the connection strength between the composite beam and the newly cast concrete, while also increasing the shear transmission efficiency of the interface and improving the shear bearing capacity of the cross section. A rigid connection method is used to achieve the connection between the butt ends of the two steel webs and the butt ends of the two steel bottom plates. The connection is stable and reliable. When the rigid connection method used is welding, the subsequent maintenance workload can be greatly reduced.

[0025] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 It is a longitudinal cross-sectional view of the composite structural bridge system based on steel and concrete of the present invention;

[0028] Figure 2 yes Figure 1 Structural diagram of the composite beam;

[0029] Figure 3 yes Figure 2 Schematic diagram of the arrangement of the upper and lower open stirrups;

[0030] Figure 4 yes Figure 2 A partial cross-sectional view of the connection structure between the steel web and the concrete ribs;

[0031] Figure 5 (a) Yes Figure 2 Schematic diagram of the cross section of the composite beam;

[0032] Figure 5 (b) Yes Figure 2 Strain distribution diagram in the cross section of the composite beam;

[0033] Figure 5 (c) Yes Figure 2 Stress distribution diagram in the cross section of the composite beam;

[0034] Figure 6 yes Figure 1 Schematic diagram of concrete pouring construction for the middle pier top connection structure;

[0035] Figure 7 yes Figure 1 Schematic diagram of the reinforcement arrangement of the middle pier top connection structure;

[0036] Figure 8 yes Figure 7 Top view of the reinforcement arrangement of the middle pier top connection structure;

[0037] Figure 9 yes Figure 1 Schematic diagram of the end structure of the standard simply supported unit;

[0038] Figure 10 yes Figure 9 Cross-sectional view of the longitudinal wet joint along the transverse direction;

[0039] Figure 11 yes Figure 1Schematic diagram of the first structural form of the connection structure between the central beams;

[0040] Figure 12 yes Figure 11 Cross-sectional view of the connecting structure between the middle beams along the transverse direction;

[0041] Figure 13 It is a schematic diagram of the first-view of the transport state of the composite beam;

[0042] Figure 14 It is a schematic diagram of the second perspective of the transport state of the composite beam;

[0043] Figure 15 This is a schematic diagram of the second structural form of the connection structure between the middle beams of the utility model;

[0044] Figure 16 yes Figure 15 Cross-section of the connection structure between the middle beams;

[0045] Figure 17 yes Figure 15 Partial view of the connection structure between the center beams;

[0046] Figure 18 This is a schematic diagram of the third structural form of the connection structure between the middle beams of the utility model;

[0047] Figure 19 yes Figure 18 Axonometric drawing of the composite beam in the beam-to-beam connection structure shown;

[0048] Figure 20 This is a schematic diagram of the fourth structural form of the connection structure between the middle beams of the utility model;

[0049] Figure 21 yes Figure 20 The schematic diagram of the structure of the beam connection structure shown is when no concrete is poured;

[0050] Among them, 100, composite beam; 110, bridge deck, 111, bridge deck transverse main reinforcement, 112, bridge deck longitudinal main reinforcement, 113, thickened transition section, 114, thickened section, 115, thickened area longitudinal reinforcement; 120, composite rib, 121, concrete rib, 122, transverse short reinforcement, 123, steel bottom plate, 124, steel web, 125, lower open stirrup, 126, steel tenon, 127, mortise, 128, upper open stirrup, 129, longitudinal distribution reinforcement, 1210 , the bottom longitudinal reinforcement, 1211, the second bottom longitudinal reinforcement; 130, transverse diaphragm; 200, beam connection structure; 210, connection plate 1, 211, web splicing plate 1, 212, bottom plate splicing plate 1, 213, bolt assembly 1, 214, vertical butt joint area 1, 215, shear key groove 1; 220, connection plate 2, 221, web splicing plate 2, 222, first bridge deck post-cast area, 223, vertical butt joint area 2, 224, shear key groove 2, 225, bolt assembly 2, 2 26. Connecting rod; 230. Second bridge deck post-cast area; 231. First shear stud; 232. First inter-beam post-cast area; 233. Vertical butt joint area three; 240. Third bridge deck post-cast area; 241. First tooth key; 242. Second inter-beam post-cast area; 300. Pier top connection structure; 301. End steel plate; 302. Second shear stud; 303. Second tooth key; 304. Beam casting area; 305. Fourth bridge deck post-cast area; 306. Anchor bolts; 307. Longitudinal reinforcement in post-cast area; 308. Transverse reinforcement in post-pouring area, 309. Crossbeam lap reinforcement, 3010. Crossbeam stirrups, 3011. Crossbeam transverse reinforcement; 400. Longitudinal wet joints, 401. Sealing strips, 402. Wet joint casting area, 403. Transverse reinforcement at the edge of the bridge deck; 500. Transport vehicle, 501. Guardrail, 502. Pad, 503. Sleeper, 504. Hand hoist; 600. Cap beam, 601. Jack, 602. Temporary support, 603. Support shim, 604. Permanent support. DETAILED DESCRIPTION

[0051] To facilitate understanding of the present invention, the following provides a more comprehensive description of the present invention and presents preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to facilitate a more thorough and comprehensive understanding of the disclosure of the present invention.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0053] Example 1:

[0054] See also Figures 1-12 This embodiment provides a composite structural bridge system based on steel and concrete, including:

[0055] The composite beam 100 includes a bridge deck 110 and a composite rib 120 located on the bottom surface of the bridge deck 110. The composite rib 120 includes a concrete rib 121 and a steel beam (not shown). The concrete rib 121 is located between the bridge deck 110 and the steel beam. That is, the concrete rib 121 and the bridge deck 110 are cast together with concrete to form a T-shaped structure. The upper edge of the steel beam is connected to the lower end of the concrete rib 121.

[0056] A standard simply supported beam comprises a plurality of composite beams 100 arranged along the longitudinal direction of the bridge, with adjacent composite beams 100 being connected by inter-beam connection structures 200;

[0057] The standard simply supported unit comprises a plurality of standard simply supported beams arranged along the transverse direction of the bridge, and two adjacent standard simply supported beams are connected by longitudinal wet joints 400;

[0058] Two adjacent standard simply supported units on the longitudinal bridge are connected via the pier top connection structure 300 to form a continuous structural system.

[0059] The bridge structure system in this embodiment is applicable to a span of 16 to 50 meters, which can cover the span range of traditional prefabricated hollow slabs, prefabricated T-beams, and prefabricated small box beams. The beam height-span ratio is 1 / 25 to 1 / 30, and the overall structure is light and high-performance.

[0060] like Figure 2 and Figure 4 As shown, the steel beam includes a steel bottom plate 123 and a steel web 124 arranged on the steel bottom plate 123, which form a T-shaped structure. The upper edge of the steel web 124 (i.e., the side close to the concrete rib 121) is alternately provided with steel tenons 126 and mortises 127 along the longitudinal direction of the bridge. Figure 4 As shown, Figure 4 The gray area in the figure is the mortise 127, and the distance between two adjacent tenons 126 is e x The height of the steel tenon (ie the depth of the mortise) is h D The steel tenon 126 and the mortise 127 are embedded in the concrete at the lower end of the concrete rib 121. The distance between the lower edge of the concrete rib 121 and the bottom edge of the mortise 127 is C D Preferably, the spacing e of the steel tenons is x Generally 150~500mm, height h D With spacing e x The ratio of the cutting shape is between 0.27 and 0.4, and the thickness of the steel tenon is hD The ratio range is 0.08 to 0.5; the distance C between the bottom edge of the mortise 127 and the lower edge of the concrete rib 121 D Should be greater than 20mm. Under the same cutting shape, the spacing of steel dowels does not affect the horizontal shear bearing capacity of the composite beam and is inversely proportional to the ductility.

[0061] Preferably, the bridge deck 110 includes a bridge deck concrete layer and a bridge deck steel frame located inside the bridge deck concrete layer, the concrete rib 121 includes a rib concrete layer and a rib steel frame located inside the rib concrete layer, the rib steel frame is connected to the bridge deck steel frame, and the bridge deck concrete layer and the rib concrete layer are cast together.

[0062] like Figure 2 As shown, the bridge deck reinforcement skeleton includes an upper transverse reinforcement group, a lower transverse reinforcement group and a bridge deck longitudinal main reinforcement 112; a plurality of bridge deck longitudinal main reinforcements 112 are arranged at intervals along the transverse direction of the bridge, the upper transverse reinforcement group is located on the upper side of the bridge deck longitudinal main reinforcement 112, the upper transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements 111 arranged at intervals along the longitudinal direction of the bridge, the bridge deck longitudinal main reinforcement 112 is overlapped with the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group, and the bridge deck longitudinal main reinforcement 111 is connected to the bridge deck longitudinal main reinforcement 111 through the bridge deck longitudinal main reinforcement 111. 2 and the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group provide bending and crack resistance in the longitudinal and transverse directions respectively; the lower transverse reinforcement group is located on the lower side of the bridge deck longitudinal main reinforcement 112, and the lower transverse reinforcement group includes a plurality of bridge deck transverse main reinforcements 111 arranged at intervals along the longitudinal direction of the bridge. The bridge deck transverse main reinforcements 111 in the lower transverse reinforcement group and the bridge deck longitudinal main reinforcements 112 are not overlapped, and the bridge deck transverse main reinforcements in the lower transverse reinforcement group provide bending and crack resistance in the transverse positive moment of the bridge. The arrangement of the bridge deck reinforcement skeleton in this embodiment can avoid the problem of concrete pouring quality caused by too dense steel bars in the thin plate. Due to the small thickness of the bridge deck, the arrangement of the bridge deck transverse main reinforcements 111 and the bridge deck longitudinal main reinforcements 112 generally adopts the method of dense distribution of fine bars. The diameter of the steel bars generally does not exceed 16 mm, and the spacing is generally between 80 and 120 mm.

[0063] Furthermore, the ribbed steel frame includes the bottom longitudinal steel bar 1210, the second bottom longitudinal steel bar 1211, the longitudinal distribution steel bar 129, the transverse short steel bar 122 and the vertical stirrup group (not shown in the figure); the vertical stirrup group includes the lower open stirrups 125 and the upper open stirrups 128 arranged alternately along the longitudinal bridge direction, as shown in FIG. Figure 2 and Figure 3As shown, the lower open stirrup 125 and the steel tenon 126 are arranged in a one-to-one correspondence, the upper open stirrup 128 and the mortise 127 are arranged in a one-to-one correspondence, the steel tenon 126 is inserted into the opening at the lower end of the lower open stirrup 125, the lower end of the upper open stirrup 128 is placed in the mortise 127, and transverse short steel bars 122 are provided on both sides of the lower end of the upper open stirrup 128, and the transverse short steel bars 122 are spaced from the lower end of the upper open stirrup 128 (that is, the two are not overlapped, and the distance between the two in the longitudinal bridge upward direction is greater than 0), as shown. Figure 4 As shown; the position of the lower end of the lower open stirrup 125 is lower than the position of the lower end of the upper open stirrup 128, the bottom layer of longitudinal steel bars 1210 is used to connect the lower ends of each lower open stirrup 125 along the longitudinal direction, and the second bottom layer of longitudinal steel bars 1211 is used to connect the lower ends of each upper open stirrup 128 along the longitudinal direction. Specifically, in this embodiment, the number of the bottom layer of longitudinal steel bars 1210 and the second bottom layer of longitudinal steel bars 1211 are both two, and are symmetrically arranged on both sides of the steel web 124; a plurality of longitudinal distribution steel bars 129 are arranged inside the vertical stirrup group along the vertical direction, specifically, a single longitudinal distribution steel bar 129 passes through the alternating upper open stirrups 128 and lower open stirrups 125 along the longitudinal direction.

[0064] Specifically, the vertical sections of the upper open stirrups 128 and the lower open stirrups 125 can improve the shear resistance of the oblique section of the concrete rib, and the horizontal section of the lower end of the upper open stirrups 128 and the transverse short steel bars 122 can improve the anti-pushing ability of the steel tenons in the concrete rib, and the diameters of both need to be above 10 mm; the bottom layer of longitudinal steel bars 1210 and the second bottom layer of longitudinal steel bars 1211 are beneficial supplements to the anti-bending cracking ability of the concrete rib 121 under the action of positive bending moment, and the diameter should be above 12 mm, and the distance between the two in the height direction should be greater than 0.15 times the spacing of the steel tenons 126.

[0065] Preferably, the bridge deck concrete layer and the rib concrete layer are both cast using UHPC concrete, and the UHPC concrete is ultra-high performance concrete with ultra-high durability and ultra-high mechanical properties.

[0066] Preferably, the lower end of the upper opening stirrup 128 in this embodiment is located at 1 / 2h D The upper end of the lower open stirrup 125 is connected to the bridge deck steel frame, specifically, overlapped with the bridge deck longitudinal main reinforcement 112.

[0067] Preferably, the lower end of the concrete rib 121 is thickened at the buried steel tenon 126 and mortise 127 to ensure that the horizontal distance from the steel tenon to the edge of the concrete rib 121 is generally not less than 5 times the height of the steel tenon, thereby improving the fault tolerance of the centering error between the steel web 124 and the concrete rib 121, and at the same time providing bending space for the upper open stirrups and the lower open stirrups and reserving sufficient protective layer thickness for the stirrups, thereby improving the bonding ability of the steel web and the concrete rib 121.

[0068] Furthermore, in the composite beam 100 of this embodiment, the number of composite ribs 120 is at least two. When the span of the composite beam is large, a diaphragm 130 (the diaphragm 130 is cast using UHPC concrete) can be provided between two adjacent concrete ribs 121. Figure 12 As shown, the diaphragm 130 can increase the structural stability of the composite beam. The composite beam 100 includes at least two composite ribs 120, providing the composite beam 100 with a self-stabilizing system (i.e., the multiple composite ribs 120 enable the composite beam 100 to be stably placed), facilitating the transportation and installation of the composite beam 100. Of course, in some embodiments, the composite beam 100 may not require a self-stabilizing system. In this case, it is also feasible for a single composite beam 100 to include only one composite rib 120.

[0069] Preferably, the thickness of the concrete ribs 121 is generally 12 to 20 cm. For larger bridge spans, the ribs can be thickened at the pier supports. The concrete ribs 121 are cast in the factory, and the overall beam height can be adjusted as needed to accommodate changes in bridge span. Furthermore, a pre-throw height can be added to the continuous structural system based on calculation results and design requirements to offset beam deformation under dead loads and some live loads.

[0070] Preferably, the bridge deck can be a flat plate or a plate with transverse ribs for carrying vehicles. The thickness of a flat plate is generally 10 to 14 cm, and is used when the transverse spacing between adjacent concrete ribs 121 is not large; the thickness of a plate with transverse ribs is generally 8 to 12 cm, and the transverse ribs generally adopt an inverted T-shaped cross-section. The transverse rib height ranges from about 10 to 16 cm, and the transverse rib spacing is 50 to 70 cm. The spacing between two concrete ribs 121 in the transverse direction of the bridge is generally 1.2 to 2.4 m, and is usually determined based on the transverse bending resistance of the bridge deck under the action of wheels and the angle for convenient transportation and lifting.

[0071] Preferably, the T-shaped steel beam can be cut from an H-shaped steel or welded from two steel plates. The thickness of the steel bottom plate is preferably 24 to 50 mm and the width is 200 to 600 mm. The thickness of the steel web is preferably 14 to 20 mm, and the ratio of its height to the height of the composite beam is generally 0.2 to 0.8 times, which requires taking into account the crack resistance of the lower edge of the concrete rib, the internal force arm of the cross section, and the production specifications of the H-shaped steel; the smaller the ratio of its height to the height of the composite beam, the smaller the internal force arm of the cross section, the lower the efficiency of the steel beam, and the greater the crack resistance risk faced by the lower end of the concrete rib.

[0072] like Figure 5 (a)- Figure 5 As shown in Figure (c), the composite beam in this embodiment utilizes UHPC to bear the high compressive stresses of the upper flange and the low tensile stresses of the composite web, while the steel beam bears the high tensile stresses of the lower portion, fully utilizing the material properties. The steel beam bears high tensile stress away from the neutral axis of the cross section, significantly improving the structure's positive moment bearing capacity. Because the steel beam is arranged externally, unlike an internal arrangement, its construction is not restricted by the concrete ribs, significantly increasing the internal moment resistance of the internal force arm and allowing for flexible allocation of steel material usage.

[0073] Preferably, Figures 6 to 9 As shown, the pier top connection structure 300 in this embodiment is specifically:

[0074] After two adjacent standard simply supported units are butt-jointed, a cross-beam casting area 304 is formed between their ends. The composite beam 100 participating in the butt-jointing in the standard simply supported units is provided with an end steel plate 301, a second shear stud 302, a second tooth key 303, and a fourth bridge deck post-casting area 305. A plurality of second tooth keys 303 are provided on the end surface of the concrete rib 121 near the cross-beam casting area 304. The fourth bridge deck post-casting area 305 is located at one end of the bridge deck 110 near the cross-beam casting area 304. The end steel plate 301 is provided at one end of the steel beam near the cross-beam casting area 304, and a plurality of second shear studs 302 are provided on a surface of the end steel plate 301 facing away from the steel beam.

[0075] A crossbeam steel skeleton is provided in the crossbeam casting area 304, and a post-casting area steel mesh is provided in the fourth bridge deck post-casting area 305 of two adjacent standard simply supported units. The crossbeam steel skeleton and the post-casting area steel mesh are overlapped with the composite beams on both sides; concrete (preferably UHPC concrete) is poured together in the crossbeam casting area 304 and the fourth bridge deck post-casting area 305 to form a connecting crossbeam in the crossbeam casting area 304, and the concrete poured in the fourth bridge deck post-casting area is flush with the upper surface of the bridge deck.

[0076] The pier top connection structure 300 in this embodiment can simultaneously realize the combined force transmission of the bridge deck and the combined rib 120, and utilizes a smaller thickness and simplified steel bar connection to provide a reliable connection effect and integrity.

[0077] Specifically, such as Figure 7 As shown, the beam reinforcement skeleton includes a beam lap reinforcement 309, a beam stirrup group and a plurality of beam transverse reinforcements 3011 arranged at intervals along the inner side of the beam stirrup group; the beam stirrup group includes a plurality of beam stirrups 3010 arranged at intervals along the transverse bridge direction in the beam casting area 304, and a single beam transverse reinforcement 3011 is arranged along the transverse bridge direction and overlapped with each beam stirrup 3010; the longitudinal distribution reinforcement 129 in the concrete rib 121 extends into the beam casting area 304, and the longitudinal distribution reinforcement 129 on both sides of the beam casting area 304 are overlapped by the beam lap reinforcement 309. Preferably, the horizontal spacing of the cross beam stirrups 3010 is generally 10 to 15 cm, and when arranged, they should avoid the position of the combined ribs 120 and meet the minimum protective layer thickness of the UHPC; the spacing of the cross beam transverse reinforcement 3011 is generally 10 to 20 cm (this spacing refers to the vertical spacing or the longitudinal bridge spacing), and when arranged, they should avoid the second tooth key 303 and the second shear nail 302.

[0078] Furthermore, the bridge deck 110 has a thickened area at its bottom near one end of the crossbeam casting area 304. The thickened area includes a thickened transition section 113 and a thickened section 114. Thickened area longitudinal reinforcement 115 is embedded in the thickened area. One end of the thickened area longitudinal reinforcement 115 overlaps the bridge deck longitudinal main reinforcement 112, and the other end extends into the crossbeam casting area 304. The thickened area longitudinal reinforcement 115 on both sides of the crossbeam casting area 304 is also connected by crossbeam lap reinforcement 309. Preferably, the length of the thickened section 114 is generally 20-50 cm, and the length of the thickened transition section 113 is generally 50-100 cm. The thickened bridge deck and the thickened area longitudinal reinforcement 115 facilitate force transmission between the bridge deck and the connecting crossbeam, thereby enhancing the bridge deck's bending bearing capacity and crack resistance.

[0079] Furthermore, the bottom longitudinal reinforcement 1210 and the second bottom longitudinal reinforcement 1211 in the concrete rib 121 also extend into the beam casting area 304; in this embodiment, no beam lap reinforcement 309 is provided between the bottom longitudinal reinforcement 1210 on both sides of the beam casting area and between the second bottom longitudinal reinforcement 1211 on both sides. Figure 7 As shown; of course, this does not exclude the possibility that in some embodiments, beam lap reinforcement 309 may be provided between the lowest layer of longitudinal reinforcement 1210 on both sides of the beam casting area and between the second lowest layer of longitudinal reinforcement 1211 on both sides.

[0080] Specifically, such as Figure 7 and Figure 8 As shown, the post-casting area steel mesh includes a plurality of post-casting area longitudinal steel bars 307 arranged at intervals along the transverse direction of the bridge and a plurality of post-casting area transverse steel bars 308 arranged at intervals along the longitudinal direction of the bridge. The post-casting area longitudinal steel bars 307 and the post-casting area transverse steel bars 308 are overlapped, and the two ends of the post-casting area longitudinal steel bars 307 are overlapped with the bridge deck longitudinal main bars 112 on the composite beams on both sides of the crossbeam casting area 304.

[0081] In this embodiment, the excellent tensile properties of UHPC materials can effectively address the problem of cracking in the bridge deck in the negative bending moment zone at the pier top. By using the fourth post-cast area, the post-cast interface of the surface layer is shifted to a location with less negative bending moment, thereby improving the bridge deck's crack resistance under negative bending moment. Preferably, to further improve the crack resistance in the negative bending moment zone, at least one post-cast area longitudinal steel bar 307 can be added between adjacent post-cast area longitudinal steel bars 307. Since these additional post-cast area longitudinal steel bars 307 lack corresponding longitudinal main bars 112 for the bridge deck, they are only overlapped with the post-cast area transverse steel bars 308. This means that by increasing the density of the steel mesh in the post-cast area, the crack resistance in the negative bending moment zone is improved. Specifically, the diameter and spacing of the post-cast area longitudinal steel bars 307 and the post-cast area transverse steel bars 308 are calculated and determined based on the bending bearing capacity of the negative bending moment zone and the bending bearing capacity of the beam, respectively. The clear spacing of the steel bars should not be less than 1.5 times the nominal diameter of the steel bar and should not be less than 2 cm.

[0082] See also Figure 6 and Figure 7 In this embodiment, when pouring concrete simultaneously in the crossbeam casting area 304 and the fourth bridge deck post-casting area 305, the bottom surface of the connecting crossbeam is controlled to protrude beyond the bottom surface of the steel beam. Preferably, the bottom surface of the connecting crossbeam protrudes 10-20 cm beyond the bottom surface of the steel beam. This configuration can adjust for the cumulative elevation errors of the composite beam and cap beam during production and installation. Preferably, anchor bolts 306 are pre-embedded in the bottom of the connecting crossbeam during casting. These anchor bolts 306 are used to connect the formed connecting crossbeam to the permanent support 604.

[0083] Specifically, the end steel plates 301 are welded to the ends of the steel web and bottom plates. The height and width of the end steel plates 301 exceed the height and width of the steel web and bottom plates by at least 20 mm, respectively, to provide good welding conditions. The second shear studs 302 are welded to the end steel plates 301. The size and spacing of the second shear studs 302 are determined based on shear resistance calculations, and the spacing should not exceed 20 cm. The outermost second shear studs are at least 2.5 cm away from the edge of the end steel plate.

[0084] Preferably, the overlap length of the lap joint in the pier top connection structure 300 is generally not less than 16 cm and not less than 10 d, where d is the diameter of the steel bar. Compared with traditional welding connections, the lap joint in the pier top connection structure 300 provides reliable anchoring while greatly simplifying construction operations and avoiding welding operations in narrow spaces.

[0085] Preferably, the fourth bridge deck post-cast area 305 and the crossbeam casting area 304 are cast with UHPC concrete to form a T-shaped structure. The thickness of the fourth bridge deck post-cast area 305 is generally 6-12 cm, and the total length of the fourth bridge deck post-cast area of ​​the standard simply supported units on both sides of the pier top connection structure is generally not less than 0.1L, where L is the larger span of the two adjacent standard simply supported units at the pier support point.

[0086] Preferably, see Figure 6 The depth-to-height ratio D / H of the second tooth key 303 is generally 1 / 3 to 1 / 2, and the key tooth depth D can generally be 5 cm; the second tooth key is prefabricated together with the concrete rib in the composite beam to avoid the loss of shear resistance of the UHPC connection interface due to discontinuous steel fibers, and the staggered key teeth are formed in the cast-in-place connecting beam, which can effectively enhance the interface shear resistance.

[0087] Furthermore, in the pier top connection structure of this embodiment, the shear resistance of the joint interface is shared by the second tooth key 303 and the second shear stud 302. The shear bearing capacity verification method of the pier top connection structure is:

[0088] Calculate the shear capacity V of the second tooth key ku , unit N:

[0089]

[0090] Calculate the shear bearing capacity V of the second shear stud su , unit N:

[0091]

[0092] Calculate the shear bearing capacity V of the pier top connection structure u , unit N:

[0093] V u =V ku +V su (3),

[0094] If the shear bearing capacity of the pier top connection structure V u If formula (4) is satisfied, the shear bearing capacity of the pier top connection structure is considered qualified:

[0095] γ0V d ≤0.9V u (4),

[0096] Where: f ck is the standard value of the axial compressive strength of concrete, in MPa; f td A is the design value of the axial tensile strength of concrete, in MPa; k is the shear surface area of ​​the second tooth key, in mm 2 ; M is the number of the second shear studs; A s is the cross-sectional area of ​​the second shear stud, in mm 2 ;E c is the elastic modulus of concrete, in MPa; f cd is the design value of the axial compressive strength of concrete, in MPa; f su is the minimum tensile strength of the second shear stud, in MPa; γ0 is the importance coefficient of the bridge structure; V d is the shear design value of the pier top connection structure, in N. The finite element software is used to calculate the maximum shear force of the interface under the ultimate bearing capacity limit state.

[0097] In the pier top connection structure of this embodiment, the width of the connecting beam (in the longitudinal direction of the bridge) generally only needs to be 40 to 60 cm, and the width of the connecting beam is only about 1 / 3 to 1 / 2 of the width of the traditional beam, which reduces the volume of concrete during pouring construction and greatly reduces the amount of on-site work.

[0098] It should be noted that the pier top connection structure 300 in this embodiment can also be applied to bridges composed of multiple longitudinally arranged standard simply supported beams (i.e., a standard simply supported unit contains only one standard simply supported beam), or multiple longitudinally arranged composite beams. In other words, the pier top connection structure 300 can be used to connect two adjacent standard simply supported beams in the longitudinal direction of the bridge, or two adjacent composite beams in the longitudinal direction of the bridge. Furthermore, the pier top connection structure 300 in this embodiment can also be applied to composite beams of other structural forms, such as composite beams in which the steel beams are I-beams, and the ribs and bridge deck are cast using ordinary concrete.

[0099] This embodiment also provides a construction method of the pier top connection structure 300, comprising the following steps:

[0100] S1. Prefabricate the composite beam 100 in the factory, and simultaneously complete the construction of the pier, cap beam 600, and support pedestal 603 at the lower part of the bridge. Specifically, the second tooth key 303 is cast together with the concrete rib 121. The end steel plate 301 and the second shear stud 302 are welded during the prefabrication of the composite beam. The end steel plate 301 is welded to the end of the steel beam, and the second shear stud 302 is welded to the side of the end steel plate 301 facing the crossbeam casting area 304. The cap beam 600 falls on the pier, and the support pedestal 603 is installed on the cap beam 600.

[0101] S2. Temporary supports 602 are provided on both sides of the support pedestal 603, and the ends of the two composite beams 100 to be connected are supported by the temporary supports 602 respectively; specifically, the temporary supports 602 are installed on the cap beam 600, and the temporary supports 602 are located on the inner side of the span of the support pedestal. The temporary supports are sand bucket temporary supports;

[0102] S3. Measure the elevations of the four corner points of the composite beam bridge deck and compare the measured elevations with the designed elevations to determine the error.

[0103] S4. Install a jack 601 on the cap beam 600 to adjust the elevation of the composite beam. After the composite beam is adjusted to the design elevation, the elevation of the temporary support 602 is locked. Specifically, the elevation of the composite beam is adjusted by lifting or unloading the jack 601. The jack's lifting force must be greater than or equal to 1 / 3 of the weight of the composite beam. The elevation adjustment range of the composite beam = the design elevation of the bridge deck - the thickness of the bridge deck pavement - the measured elevation of the precast beam. A positive value indicates an upward jacking, and a negative value indicates an opposite jacking. Furthermore, the locking elevation of the temporary support 602 is equal to the measured elevation of the composite beam minus the measured beam height of the composite beam.

[0104] S5. Install the permanent support 604 and the anchor bolts 306, ensuring that the upper surface of the permanent support 604 is in a horizontal state. Specifically, the permanent support 604 is set on the support pad 603. In this step, the anchor bolts 306 should be installed and connected to the permanent support 604.

[0105] S6. Complete the installation and binding of the steel bars according to the construction sequence of the beam stirrups 3010, the beam transverse reinforcement 3011 and the post-casting area reinforcement mesh;

[0106] S7. Install the bottom casting template. The upper surface of the bottom casting template at the permanent support 604 must be flush with the upper surface of the permanent support 604 to ensure that the connecting beam can be cast and formed to fall smoothly on the permanent support.

[0107] S8. Install the side casting formwork and close the mold;

[0108] S9. Concrete is poured into the crossbeam pouring area and the fourth bridge deck post-casting area, and curing is performed after the pouring is completed;

[0109] S10, dismantling the bottom casting formwork, side casting formwork and temporary support 602, and dropping the composite beams onto the permanent supports to form a continuous structural system;

[0110] S11. Remeasure the elevations of the four corner points of the composite beam bridge deck.

[0111] The pier top connection structure 300 of this embodiment provides a structure and construction method for converting a standard simply supported beam into a continuous beam with adjustable installation errors, solving the problems of empty supports, uneven reaction forces, and poor paving construction conditions.

[0112] See also Figure 10 Specifically, the longitudinal wet joint 400 is as follows: a wet joint casting area 402 is formed between the bridge decks 110 of two standard simply supported beams adjacent to each other in the transverse direction of the bridge, and a sealing strip 401 is provided between the bottoms of the two bridge decks 110. Concrete (preferably UHPC concrete) is poured into the wet joint casting area 402 to complete the construction of the longitudinal wet joint 400.

[0113] Preferably, the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group of the bridge deck 110 extends into the wet joint casting area 402, and the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group of two adjacent bridge decks are staggered in the longitudinal direction and have overlapping sections in the transverse direction. The length of the overlapping section should not be less than 10d, where d is the diameter of the steel bar, that is, the bridge deck transverse main reinforcement of one bridge deck 110 is staggered and inserted into the gap between the bridge deck transverse main reinforcement of another bridge deck 110, thereby enhancing the transverse bending resistance of the bridge while avoiding circular reinforcement and welding operations in the narrow space of traditional joints.

[0114] Preferably, the bridge deck is thickened at one end close to the longitudinal wet joint on the bottom surface, and additional bridge deck edge transverse reinforcement 403 is provided. Multiple bridge deck edge transverse reinforcements 403 are arranged at intervals along the longitudinal direction of the bridge. One end of a single bridge deck edge transverse reinforcement 403 is overlapped with the bridge deck transverse main reinforcement 111 in the upper transverse reinforcement group and the bridge deck transverse main reinforcement 111 in the lower transverse reinforcement group, and the other end extends to the bottom of the wet joint casting area 402; the bridge deck edge transverse reinforcement 403 in two adjacent bridge decks 110 are staggered in the longitudinal direction and have overlapping sections in the transverse direction. The length of the overlapping section should not be less than 10d, where d is the diameter of the reinforcement. While enhancing the bending resistance in the transverse direction of the bridge, it avoids circular reinforcement and welding operations in the narrow space of traditional joints.

[0115] Preferably, the bottom and upper parts of the wet joint casting area 402 are both arranged with bridge deck longitudinal main reinforcements 112 along the transverse intervals, wherein the bridge deck longitudinal main reinforcements 112 arranged at intervals on the upper part are overlapped with the bridge deck transverse main reinforcements 111 in the upper transverse reinforcement group, and the bridge deck longitudinal main reinforcements 112 arranged at intervals on the bottom are overlapped with the bridge deck edge transverse reinforcements 403, thereby enhancing the longitudinal bending resistance of the bridge through the bridge deck longitudinal main reinforcements.

[0116] Preferably, in the longitudinal wet joint 400 of this embodiment, the lower transverse steel bar group of the bridge deck 110 does not extend into the wet joint casting area 402. Such an arrangement can prevent the steel bars in the wet joint casting area from being too dense and affecting the casting quality of concrete; however, it is not ruled out that in some embodiments, the bridge deck transverse main bars 111 in the lower transverse steel bar group of the bridge deck 110 may also be extended into the wet joint casting area 402 to increase the structural strength of the longitudinal wet joint.

[0117] The longitudinal wet joint 400 in this embodiment can realize the connection between two adjacent standard simply supported beams into a whole. A sealing strip 401 is set between the bottoms of the two bridge decks 110. No formwork is required when pouring concrete in the wet joint casting area 402, which reduces the complexity of the longitudinal wet joint construction. Preferably, in this embodiment, the sealing strip is made of foam padding, and the cross-section of the wet joint casting area 402 is a T-shaped structure.

[0118] Figure 11-12 The diagram illustrates a structural form of an inter-beam connection structure 200: a connecting plate 210 is provided on the butt end surface of the bridge deck 110, and a vertical butt area 214 is provided at the butt end of the steel web 124; the connecting plates 210 of two adjacent composite beams 100 are connected by welding on the upper side and by a bolt assembly 213 on the lower side; the butt ends of the steel bottom plates 123 of two adjacent composite beams 100 and the vertical butt areas 214 of the two composite beams 100 are butt-jointed by a rigid connection method.

[0119] Further, such as Figure 11 As shown, the steel web 124 is provided with a vertical docking area 214 at the docking end, and the vertical docking area 214 and the steel web 124 form an L shape. The steel web 124 and the vertical docking area 214 can be an integral structure (that is, they can be cut and formed by a single plate), or can be formed by welding two plates into an L shape; at the same time, the vertical docking area 214 is alternately provided with steel tenons 126 and mortises 127 along the vertical direction on the side close to the concrete rib 121, and the steel tenons and mortises of the vertical docking area 214 are embedded in the concrete on the vertical side of the concrete rib (that is, the steel tenons and mortises on the upper edge of the steel web are embedded in the concrete at the lower end of the concrete rib, and the steel tenons and mortises on the vertical docking area 214 are also embedded in the concrete on the vertical side of the concrete rib) to increase the connection strength between the vertical docking area 214 and the concrete rib 121.

[0120] Preferably, similar to the thickening setting at the lower end of the concrete rib, in this embodiment, the vertical side where the concrete rib connects with the vertical docking area 214 is also thickened. For specific requirements for the thickening setting and the arrangement of the steel bars, please refer to the description of the lower end of the concrete rib.

[0121] Specifically, the number of the connecting plates 210 can be multiple, and the connecting plates 210 are connected to the longitudinal main reinforcement 112 of the bridge deck. The connecting plates 210 are embedded in the butt end face when the bridge deck 110 is concreted. Furthermore, the upper side of the connecting plate 210 is flush with the upper surface of the bridge deck 110, and the lower side thereof protrudes from the bottom surface of the bridge deck 110. The portion of the connecting plate 210 protruding from the bottom surface of the bridge deck 110 is provided with a connecting hole 1, such as Figure 11-12 shown.

[0122] Furthermore, the vertical butt joint area 214 and the butt joint end of the steel base plate 123 described in this embodiment are also provided with a plurality of connection holes 1. Specifically, the connection holes 1 in this embodiment are used for bolts to pass through to achieve a fastening connection between the bolts and nuts. In this embodiment, the butt joint ends of the steel base plates 123 of the two composite beams 100 are connected by a base plate splicing plate 212 and a bolt assembly 213; the vertical butt joint areas 214 of the two composite beams 100 are connected by a web splicing plate 211 and a bolt assembly 213. Preferably, in order to increase the connection strength between the butt joint ends of the two steel base plates, the width of the steel base plates 123 can be increased as a whole or partially, so that more bolt assembly 213 rows along the longitudinal direction of the bridge can be set between the butt joint ends of the two steel base plates in the transverse direction of the bridge to enhance the connection strength. For example: when using H-shaped steel to cut out steel beams, since the width of the original steel base plate is often narrow, there is not enough space to arrange bolts, and longitudinal quick connection cannot be achieved. Two connecting plates with the same plane, thickness and transition chamfers as the steel base plate can be symmetrically welded on the original steel base plate with the steel web as the center to widen the steel base plate.

[0123] Preferably, in some embodiments, the butt ends of the steel bottom plates 123 of the two composite beams 100 and the vertical butt areas 214 of the two composite beams 100 may be connected by welding; based on the inter-beam connection structure 200 of this embodiment, those skilled in the art may change and adjust the structural form of the rigid connection method.

[0124] like Figure 12As shown, in this embodiment, the inter-beam connection structure 200 further utilizes a shear key groove 215 and a shear key 1 (not labeled) for rapid docking and positioning between two adjacent composite beams 100. Specifically, a shear key groove 215 is provided on the docking end face of the bridge deck 110 of one composite beam, while a shear key 1 is provided on the docking end face of the bridge deck 110 of the other composite beam. When connecting two adjacent composite beams 100, the shear key 1 is inserted into the shear key groove 215 and connected via structural adhesive, enabling rapid docking and positioning of the two composite beams 100. The coordination of the shear key groove 215 and the shear key 1 further enhances the shear resistance of the inter-beam connection structure 200. Preferably, the shear key groove 215 and the shear key 1 are both located on the vertical centerline of the concrete rib 121, 2 to 3 cm from the top surface of the bridge deck 110. The shear key groove 215 is 3 to 5 cm deep, and the shear key 1 is aligned with the shear key groove 215.

[0125] Preferably, the inter-beam connection structure 200 in this embodiment is typically placed at a location with low bending moment, taking into account transportation requirements to reduce the risk of tensile cracking in the bridge deck. Generally, for standard simply supported beams within 35 meters, the inter-beam connection structure is typically located near the 3-point intersection, while for beams within 50 meters, the inter-beam connection structure is typically located near the 4-point intersection. This inter-beam connection structure enables fast and reliable connections under simple on-site conditions, reducing on-site construction difficulty and costs, and significantly improving splicing efficiency.

[0126] Furthermore, the structural dimensions of the composite beam can be adjusted according to the position of the composite beam in the bridge. For example, when the composite beam is located at different positions such as the mid-span, simply supported end, and continuous end, the thickness and density of the steel beams and the steel bars in the concrete ribs in the composite beam can be adjusted in a targeted manner. The adjustment of the structural dimensions of the composite beam can use the position of the connecting structure between beams as a distinguishing point to ensure the standardization of the entire composite beam.

[0127] This embodiment also provides a construction method of the bridge structure system, comprising the following steps:

[0128] A1. Complete the overall prefabrication of the composite beam 100 in a prefabrication plant;

[0129] A1.1. Steel beam production: Use intelligent CNC laser or plasma to cut the H-shaped steel along the centerline of the web into two symmetrical steel beams with steel tenons and mortises; or weld a flat steel plate and a steel plate with steel tenons and mortises cut into a steel beam;

[0130] A1.2. Place the steel beam on the casting pedestal;

[0131] A1.3. Calculate the pre-throw height of the continuous structural system and adjust the formwork structure and steel bar cutting of the composite beam according to the pre-throw height requirements;

[0132] A1.4. Install the reinforcement within the concrete ribs and bridge deck, including upper open stirrups 128, lower open stirrups 125, longitudinal distribution reinforcement 129, bottom-layer longitudinal reinforcement 1210, second-layer longitudinal reinforcement 1211, short transverse reinforcement 122, bridge deck transverse main reinforcement 111, bridge deck longitudinal main reinforcement 112, thickened area longitudinal reinforcement 115, and bridge deck edge transverse reinforcement 403. To avoid floating reinforcement and ensure reinforcement positioning, construction erection reinforcement may be provided.

[0133] A1.5. Use 3D laser scanning to virtually assemble and adjust the composite beams and embedded parts of the same standard simply supported beam;

[0134] A1.6. Install the bottom formwork and side formwork in sequence;

[0135] A1.7. Concrete is poured and vibrated with vibrators. The side forms are vibrated with attached vibrators, and the thickened areas of the concrete ribs are vibrated with inserted vibrators. The bridge deck is leveled with a CNC adjustable track-type leveler to meet the curved surface requirements of the pre-cast bridge deck.

[0136] A1.8. Moisture-curing for 2 days, then dismantling the side and bottom forms in sequence; curing temperature ≥ 90°C, curing humidity ≥ 95%, and steam-covered curing for 2 days;

[0137] A1.9. Composite beams are hoisted from the casting pedestal to the beam storage area. Each composite beam is spray-painted with the serial number and production information QR code. The number of stored beams shall not exceed 2 layers. Sleepers and other isolation materials shall be installed to ensure reliable support.

[0138] A2. Use conventional logistics to deliver the composite beams to the construction site;

[0139] A2.1. According to the on-site construction sequence, the corresponding numbered composite beams are hoisted from the beam storage area to the transport vehicle 500; specifically, Figure 13 and Figure 14 As shown, no more than two sections of composite beams are delivered at a time, and no more than two layers of composite beams are stacked. To protect the composite beams 100 during transportation, sleepers 503 are placed at the bottom of the composite beams 100, and protective pads 502 are installed on both sides of the bridge deck. The composite beams on the lowest layer are also limited by guardrails 501. The upper and lower layers of composite beams are tied together on the transport vehicle 500 using hand winches 504 to protect the composite beams from damage during transportation. To avoid large-scale transportation, reduce logistics costs, and improve efficiency and accessibility, the total height, width, and length of the vehicle and cargo shall not exceed 4 meters, 2.55 meters, and 18.1 meters, respectively, and the total mass shall not exceed 49 tons.

[0140] A2.2. Install signal lights and warning signs at the rear and sides of the composite beam;

[0141] A2.3, shipment and delivery;

[0142] A3. Assembling standard simply supported beams, wherein adjacent composite beams 100 are connected by inter-beam connecting structures 200;

[0143] A3.1. Hang the composite beams that make up the standard simply supported beams on the temporary pedestal on site and accurately adjust the positions of the composite beams;

[0144] A3.2. Adjacent composite beams are connected using an inter-beam connection structure 200. Specifically:

[0145] 1) Install the bottom plate splicing plate 1 and the web plate splicing plate 2, in the order of first the four corners and then the plum blossom, select 50% of the connection holes in the bottom plate splicing plate 1 and the web plate splicing plate 2 respectively and drive nails into them for temporary connection;

[0146] 2) Driving nails into the connection holes of the two composite beam connection plates to make a temporary connection;

[0147] 3) Weld the top of the connecting plate of the two composite beams. To prevent the steel plate temperature from rising during welding and being transferred to the bridge deck, causing cracks, use absorbent wet cloth strips on both sides of the welding position to cool the bridge deck.

[0148] 4) Replace the rivets on the connecting plate 1 with high-strength bolts and tighten them; replace the rivets on the bottom plate splicing plate 1 with high-strength bolts and tighten them; replace the rivets on the web splicing plate 2 with high-strength bolts and tighten them;

[0149] A3.3. Repeat step A3.2 to complete the installation and connection between the remaining composite beams in the standard simply supported beam to obtain a standard simply supported beam.

[0150] A4. Transport and install standard simply supported beams at the bridge site;

[0151] This embodiment provides different transportation and installation methods for areas with different transportation conditions. Specifically, the transportation and installation methods for mountainous and hilly areas and other areas with inconvenient ground transportation conditions are as follows:

[0152] A4.1a, The beam transporter transports the standard simply supported beam to the rear of the abutment and the tail of the bridge erection machine;

[0153] A4.2a, The bridge erection machine is supported on the abutment and pier 1#;

[0154] A4.3a. Use the overhead crane and beam transporter to lift the standard simply supported beam and feed it forward slowly.

[0155] A4.4a. The crane behind the bridge erection machine replaces the beam transporter to lift the standard simply supported beam and continue to feed the beam;

[0156] A4.5a. After the standard simply supported beam reaches the designated position, it is lowered onto the temporary support.

[0157] A4.6a. Measure the installation error and accurately adjust the temporary support elevation using the jack;

[0158] A4.7a. Complete the installation of multiple standard simply supported beams in the transverse direction of the bridge;

[0159] A4.8a. The bridge erection machine moves forward and is supported on piers 1# and 2#;

[0160] A4.9a, The beam transporter transports the standard simply supported beam to the tail of the bridge erection machine through the installed standard simply supported beam;

[0161] A4.10a. Repeat the process of A4.3a-A4.7a to install the standard simply supported beam of the next span.

[0162] The transportation and installation methods for areas with good ground transportation conditions such as cities, suburbs, and plains are as follows:

[0163] A4.1b. Use a trailer to transport the standard simply supported beam to the bottom of the bridge pier to be installed.

[0164] A4.2b. Deploy mobile cranes at the piers at both ends and use them to lift the standard simply supported beams onto the temporary supports.

[0165] A4.3b. Measure the installation error of the standard simply supported beam and accurately adjust the temporary support elevation using a jack.

[0166] A4.4b. Repeat the process of A4.1b-A4.3b to install other standard simply supported beams.

[0167] A5. Construct the longitudinal wet joint between two adjacent standard simply supported beams and perform maintenance.

[0168] A6. Construct the pier top connection structure between two adjacent standard simply supported units according to steps S1-S11;

[0169] A7. Construct bridge deck pavement, railings and other ancillary facilities.

[0170] The construction method for this bridge structure system provides an intelligent manufacturing method for composite beams, addressing the challenges of high-precision steel beam processing, rebar positioning, pre-assembly, and pre-throwing. This construction method offers a lightweight installation method for areas with difficult ground transportation, such as mountainous areas and hilly areas, as well as areas with better ground transportation, such as urban areas, suburban areas, and plains. This method addresses the shortcomings of conventional installation methods, which require large temporary facilities such as temporary piers and gantry cranes. It offers low installation costs and strong adaptability to various terrains.

[0171] Example 2:

[0172] Based on the bridge structure system in Example 1, this embodiment provides a second structural form of the beam connection structure 200, such as Figure 15-17 As shown, specifically:

[0173] The butt joint end of the bridge deck 110 is provided with a first bridge deck post-cast area 222, and the butt joint end surface of the bridge deck 110 is provided with a connecting plate 220 within the range of the first bridge deck post-cast area 222, and the steel web 124 is provided with a vertical butt joint area 223 at the butt joint end; the connecting plates 220 of the two composite beams 100 are connected by a bolt assembly 225, and after the connection is completed, UHPC concrete is poured into the first bridge deck post-cast area 222; the vertical butt joint areas 223 of the two composite beams 100 and the butt joint ends of the steel bottom plates 123 of the two composite beams 100 are butt jointed by a rigid connection method.

[0174] Preferably, the first bridge deck post-casting area 222 in this embodiment does not penetrate the bridge deck panel 110 in its depth direction, and no formwork is required when the first bridge deck post-casting area 222 is subsequently cast.

[0175] Furthermore, the upper side of the second connecting plate 220 is flush with the upper surface of the bridge deck 110, and the lower side thereof is protruding from the bottom surface of the bridge deck 110, as shown in FIG. Figure 16 and Figure 17 The second connecting plate 220 is provided with a plurality of second connecting holes for installing the second bolt assembly 225. Furthermore, the second connecting plate 220 is provided with second connecting holes in the portion protruding from the bottom surface of the bridge deck 110 and in the portion located in the first bridge deck post-casting area 222.

[0176] Preferably, the first bridge deck post-cast area 222 and the second connecting plate 220 are arranged in a one-to-one correspondence, and multiple first bridge deck post-cast area 222 and second connecting plate 220 can be provided; the second connecting plate 220 is connected to the longitudinal main reinforcement 112 of the bridge deck (i.e., welded), and when the first bridge deck post-cast area 222 is subsequently cast, the part of the second connecting plate 220 located in the first bridge deck post-cast area and the bolt assembly 2 225 located in the first bridge deck post-cast area 222 are pre-embedded in the concrete.

[0177] Preferably, if the bolt assembly 225 is installed on the second connecting plate 220 and may interfere with the longitudinal main reinforcement 112 of the bridge deck, a connecting rod 226 can be used to connect the second connecting plate 220 and the longitudinal main reinforcement 112 of the bridge deck to avoid the connection point of the longitudinal main reinforcement 112 of the bridge deck on the second connecting plate 220 and the bolt assembly 2, such as Figure 17 shown.

[0178] See also Figure 15In this embodiment, the steel web 124 is provided with a second vertical docking area 223 at the docking end, and the second vertical docking area 223 and the steel web 124 form an L shape, wherein the steel web 124 and the second vertical docking area 223 can be an integral structure (that is, they can be cut and formed by a single plate), or can be formed by welding two steel plates into an L shape; at the same time, the second vertical docking area 223 is also provided with a steel tenon 126 and a mortise 127 on the side close to the concrete rib 121 (that is, the upper side of the steel web is connected to the lower side of the concrete rib, and the vertical side inside the second vertical docking area is connected to the vertical side of the end of the concrete rib) to increase the connection strength between the second vertical docking area 223 and the concrete rib 121. In this embodiment, Figure 15 For any part not clearly indicated in the vertical docking area 223, please refer to Figure 11 The vertical docking area 1 shown, the vertical docking area 2 in this embodiment is the same as the vertical docking area 1 in Example 1.

[0179] In this embodiment, the vertical docking area 223 is also provided with multiple connection holes 2. In this embodiment, the vertical docking areas 223 of the two composite beams 100 are connected by a web splicing plate 221 and a bolt assembly 225, and the docking ends of the steel bottom plates 123 of the two composite beams 100 are connected by welding.

[0180] In some embodiments, the vertical butt joint area 223 of two composite beams 100 may be connected by welding. Similarly, the butt ends of the steel bottom plates of the two composite beams 100 may be bolted together by using a bottom plate splicing plate 2 and a bolt assembly 2 (when bolting, the steel bottom plate 123 may be widened at the butt ends). Based on the inter-beam connection structure 200 of this embodiment, those skilled in the art may change and adjust the structural form of the rigid connection method.

[0181] like Figure 16 As shown, in the inter-beam connection structure 200 of this embodiment, two adjacent composite beams 100 are also quickly docked and positioned using a second shear key groove 224 and a second shear key (not labeled). Specifically, a second shear key groove 224 is provided on the docking end surface of the bridge deck 110 of one composite beam, and a second shear key is provided on the docking end surface of the bridge deck 110 of the other composite beam. When the two adjacent composite beams 100 are connected, the second shear key is inserted into the second shear key groove 224 and connected using structural adhesive, achieving rapid docking and positioning of the two composite beams 100. The combination of the second shear key groove 224 and the second shear key further improves the shear resistance of the inter-beam connection structure 200.

[0182] In the inter-beam connection structure of this embodiment, the two connecting plates are rigidly connected by bolt connection, and concrete is poured into the post-cast area of ​​the first bridge deck after the bolt connection. The connection between the bridge decks has good integrity, which avoids the heat generated by welding between the connecting plates and affecting the connection between the connecting plate and the bridge deck (i.e., cracking).

[0183] Example 3:

[0184] Based on the bridge structure system in Example 1, this embodiment provides a third structural form of the beam connection structure 200, such as Figure 18-19 As shown, specifically:

[0185] The butt joint end of the bridge deck 110 is provided with a second bridge deck post-cast area 230, and the steel web 124 is provided with a vertical butt joint area three 233 at the butt joint end, and a first shear nail 231 is provided at the upper side of the vertical butt joint area three 233; a first inter-beam post-cast area 232 is formed between the ends of two adjacent composite beams 100, and the bridge deck steel skeleton extends into the first inter-beam post-cast area 232, and the second bridge deck post-cast area 230 and the first inter-beam post-cast area 232 are cast with UHPC concrete together, and the first shear nail 231 is buried in the cast concrete; the vertical butt joint areas three 233 of the two composite beams 100 and the butt joint ends of the steel bottom plates 123 of the two composite beams 100 are butt jointed by a rigid connection method.

[0186] Specifically, such as Figure 19 As shown, in this embodiment, a vertical docking area three 233 is provided at the docking end of the steel web 124, and the vertical docking area three 233 and the steel web 124 form an L shape, wherein the steel web 124 and the vertical docking area three 233 can be an integral structure (that is, they can be cut and formed by a piece of plate), or can be welded by two steel plates to form an L shape. At the same time, the vertical docking area three 233 is also provided with a steel tenon 126 and a mortise 127 on the side close to the concrete rib 121 (that is, the upper side of the steel web is connected to the lower side of the concrete rib, and the vertical side inside the vertical docking area three 233 is connected to the vertical side of the end of the concrete rib) to increase the connection strength between the vertical docking area three 233 and the concrete rib 121.

[0187] Preferably, in this embodiment, the outer vertical sides of the vertical butt joint area 3 233 of the two composite beams 100 and the butt joint ends of the steel bottom plates 123 of the two composite beams 100 are butt jointed by welding.

[0188] In some embodiments, the vertical butt joint areas three 233 of two composite beams 100 may also be bolted together using web splicing plates three and bolt assemblies three. Similarly, the butt joint ends of the steel bottom plates 123 of the two composite beams 100 may also be bolted together using bottom plate splicing plates three and bolt assemblies three (when bolting, the steel bottom plates 123 may be widened at the butt joint ends). Based on the inter-beam connection structure 200 of this embodiment, those skilled in the art may change and adjust the structural form of the rigid connection method.

[0189] Preferably, the second bridge deck post-cast area 230 does not penetrate the bridge deck panel 110 in its depth direction, and no formwork is required when pouring the second bridge deck post-cast area 230.

[0190] In the beam connection structure of this embodiment, a first shear nail 231 is set at the upper side of the vertical docking area three 233 and the first shear nail is subsequently buried in the newly poured concrete, which not only enhances the connection strength between the vertical docking area three 233 and the newly poured concrete, but also enhances the shear resistance; the bridge deck steel skeleton extends to the first inter-beam post-casting area 232, and the second bridge deck post-casting area 230 and the first inter-beam post-casting area 232 are cast with concrete together, and the connection between the two bridge decks has good integrity and high connection strength; a rigid connection method is used to achieve connection between the two vertical docking areas three 233 and between the docking ends of the two steel base plates 123, and the connection is stable and reliable. When the rigid connection method adopted is welding, the subsequent maintenance workload can be greatly reduced.

[0191] Example 4:

[0192] Based on the bridge structure system in Example 1, this embodiment provides a fourth structural form of the beam connection structure 200, such as Figure 20-21 As shown, specifically:

[0193] The butt end of the bridge deck 110 is provided with a third bridge deck post-cast area 240; a second inter-beam post-cast area 242 is formed between the ends of two adjacent composite beams 100, the bridge deck steel frame and the rib steel frame both extend into the second inter-beam post-cast area 242, and the end surface of the concrete rib 121 close to the second inter-beam post-cast area 242 is provided with a plurality of first tooth keys 241; the third bridge deck post-cast area 240 and the second inter-beam post-cast area 242 are cast with UHPC concrete together, and the butt ends of the steel webs 124 of the two composite beams 100 and the butt ends of the steel bottom plates 123 of the two composite beams 100 are butt-jointed by a rigid connection method.

[0194] Preferably, in this embodiment, the butt joints between the butt ends of the steel webs 124 of the two composite beams 100 and the butt joints between the steel bottom plates 123 of the two composite beams 100 are both welded.

[0195] In some embodiments, the butt ends of the steel webs 124 of the two composite beams 100 may also be bolted together using a web splicing plate four and a bolt assembly four. Similarly, the butt ends of the steel bottom plates 123 of the two composite beams 100 may also be bolted together using a bottom plate splicing plate four and a bolt assembly four (when bolting, the steel bottom plate 123 may be widened at the butt ends). Based on the inter-beam connection structure 200 of this embodiment, those skilled in the art may change and adjust the structural form of the rigid connection method.

[0196] Preferably, the third bridge deck post-cast area 240 does not penetrate the bridge deck panel 110 in its depth direction, and no formwork is required when pouring the third bridge deck post-cast area 240.

[0197] In this embodiment, the inter-beam connection structure is constructed by pouring concrete simultaneously in the third deck post-cast area and the second inter-beam post-cast area, forming the two composite beams into a single unit. This optimizes the integrity of the connection between the two composite beams. The first tooth key enhances the connection strength between the composite beam and the newly poured concrete, while also increasing the shear transfer efficiency of the interface and improving the shear bearing capacity of the cross-section. Rigid connections are used to connect the butt ends of the two steel webs and the butt ends of the two steel base plates, resulting in stable and reliable connections. Welding, when used as a rigid connection, significantly reduces subsequent maintenance workload.

[0198] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A beam connection structure for steel and concrete composite beams, characterized in that: include: A composite beam (100) comprises a bridge deck (110) and a composite rib (120) located on the bottom surface of the bridge deck (110); a third bridge deck post-cast area (240) is provided at a butt end of the bridge deck (110); the composite rib (120) comprises a concrete rib (121) and a steel beam; the concrete rib (121) is located between the bridge deck (110) and the steel beam; Two adjacent composite beams (100) form a second inter-beam post-casting area (242) between the two bridge decks (110) and between the two concrete ribs (121); the bridge deck reinforcement skeleton in the bridge deck (110) and the rib reinforcement skeleton in the concrete ribs (121) both extend into the second inter-beam post-casting area (242); the third bridge deck post-casting area (240) and the second inter-beam post-casting area (242) are cast together with UHPC concrete to achieve connection between the two bridge decks (110) and the two concrete ribs (121); The steel beams of two adjacent composite beams (100) are connected in a rigid connection manner.

2. The beam connection structure for steel and concrete composite beams according to claim 1, characterized in that: A plurality of first tooth keys (241) are vertically provided on the end surface of the concrete rib (121) close to the second inter-beam post-casting area (242).

3. The beam connection structure for steel and concrete composite beams according to claim 1, characterized in that: The steel beam comprises a steel bottom plate (123) and a steel web plate (124), wherein the lower side of the steel web plate (124) is connected to the steel bottom plate (123), and the upper side thereof is connected to the bottom of the concrete rib plate (121); The butt joint ends of the steel webs (124) of the two composite beams (100) and the butt joint ends of the steel bottom plates (123) of the two composite beams (100) are both butt jointed in a rigid connection manner.

4. The beam connection structure for steel and concrete composite beams according to claim 3, characterized in that: The butt ends of the steel bottom plates (123) of two adjacent composite beams (100) are rigidly connected by using the first connection method or the second connection method, and the butt ends of the steel web plates (124) of two adjacent composite beams (100) are also rigidly connected by using the first connection method or the second connection method; Among them: the first connection method is welding, and the second connection method is bolting using a splicing plate and a bolt assembly four.

5. The beam connection structure for steel and concrete composite beams according to claim 4, characterized in that: When the butt ends of the steel bottom plates (123) of two adjacent composite beams (100) are bolted together by using a splicing plate and a bolt assembly 4, the steel bottom plates (123) are widened at the butt ends.

6. The beam connection structure for steel and concrete composite beams according to claim 3, characterized in that: The concrete rib (121) includes a rib concrete layer and a rib steel skeleton located inside the rib concrete layer; the bridge deck (110) includes a bridge deck concrete layer and a bridge deck steel skeleton located inside the bridge deck concrete layer; The upper end of the rib reinforcement skeleton is connected to the bridge deck reinforcement skeleton in the bridge deck (110), the upper side of the steel web (124) is embedded in the bottom of the concrete rib (121), and the steel web (124) is butt-jointed with the lower end of the rib reinforcement skeleton.

7. The beam connection structure for steel and concrete composite beams according to claim 6, characterized in that: The upper edge of the steel web (124) is alternately provided with steel tenons (126) and mortises (127) along the longitudinal bridge direction, and the steel tenons (126) and mortises (127) are embedded in the concrete at the bottom edge of the concrete rib (121); The ribbed steel reinforcement skeleton includes the bottom layer of longitudinal steel bars (1210), the second bottom layer of longitudinal steel bars (1211), longitudinal distribution steel bars (129), transverse short steel bars (122) and a vertical stirrup group; the vertical stirrup group includes lower opening stirrups (125) and upper opening stirrups (128) arranged alternately along the longitudinal bridge direction, the lower opening stirrups (125) and the steel tenons (126) are arranged in a one-to-one correspondence, the upper opening stirrups (128) and the mortise (127) are arranged in a one-to-one correspondence, the steel tenon (126) is inserted into the opening at the lower end of the lower opening stirrup (125), and the upper opening stirrups ( The lower end of the upper open stirrup (128) is placed in the mortise (127), and transverse short steel bars (122) are provided on both sides of the lower end of the upper open stirrup (128); the bottom layer of longitudinal steel bars (1210) is used to connect the lower ends of the lower open stirrups (125) in the longitudinal direction, and the second bottom layer of longitudinal steel bars (1211) is used to connect the lower ends of the upper open stirrups (128) in the longitudinal direction; a plurality of longitudinal distribution steel bars (129) are arranged in the vertical direction inside the vertical stirrup group, and a single longitudinal distribution steel bar (129) passes through the alternately arranged upper open stirrups (128) and lower open stirrups (125) in the longitudinal direction.

8. The beam connection structure for steel and concrete composite beams according to claim 7, characterized in that: The bottom edge where the concrete rib (121) is connected to the steel web (124) is thickened.

9. The beam connection structure for steel and concrete composite beams according to claim 6, characterized in that: The bridge deck reinforcement skeleton includes an upper transverse reinforcement group, a lower transverse reinforcement group and a bridge deck longitudinal main reinforcement (112); a plurality of bridge deck longitudinal main reinforcements (112) are arranged at intervals along the transverse direction of the bridge, the upper transverse reinforcement group is located on the upper side of the bridge deck longitudinal main reinforcement (112), and the lower transverse reinforcement group is located on the lower side of the bridge deck longitudinal main reinforcement (112).

10. The beam connection structure for steel and concrete composite beams according to any one of claims 1 to 9, characterized in that: The third bridge deck post-casting area (240) does not penetrate the bridge deck (110) in its depth direction.

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