Segmental beam-truss composite bridge with longitudinal limited locking connection key

Abstract

The application discloses a segmental beam-truss combined bridge adopting longitudinal limited locking connecting keys, which comprises a concrete beam, the concrete beam is assembled by a plurality of segmental short beams in the bridge direction, and the concrete beam is arranged above a steel truss beam and used for directly bearing the load of a bridge deck; a multidirectional locking connecting key for connecting the segmental short beam and the steel truss beam is arranged between the segmental short beam and the steel truss beam, the upper end of the multidirectional locking connecting key is fixed with a pre-buried part in the segmental short beam, and the lower end of the multidirectional locking connecting key is connected with a top plate in the steel truss beam. The application can effectively release additional stress caused by the shrinkage and creep accumulation of the bridge deck and the temperature difference of long-span steel concrete, can realize the continuity of the longitudinal force transmission of the concrete beam, does not need to pour concrete on site, the prestress efficiency of the segmental short beam is high, the shrinkage and creep effect of the structure in the later period can be greatly reduced, the load transmission path of external load is shorter and more direct, the stress is more explicit, and more space is provided for optimizing the section form and size of the chord.

Description

Technical Field

[0001] This invention belongs to the field of composite bridge technology, specifically relating to a segmental beam-truss composite bridge employing longitudinally limited locking connection keys. Background Technology

[0002] Long-span steel-concrete composite bridges can fully utilize the properties of concrete and steel, offering advantages such as outstanding economy, high overall structural stiffness, suitability for high-speed traffic and ballastless track laying, and strong energy dissipation capacity. However, composite bridges generally suffer from drawbacks, including complex design and construction of the steel-concrete combination, high requirements for construction precision, additional stresses caused by temperature changes, cumbersome construction due to the need for secondary concrete pouring to connect shear keys to the bridge deck, the risk of cracking in the concrete slab, and low prestressing efficiency due to the shared stress on the slab and girder when prestressing the bridge deck. Summary of the Invention

[0003] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a segmental beam-truss composite bridge using longitudinally limited locking connection keys.

[0004] The technical solution of the present invention is: a segmental beam-truss composite bridge using longitudinally limited locking connection keys, comprising a concrete beam, wherein the concrete beam is assembled from several segmental short beams in the longitudinal direction of the bridge, the concrete beam is set above the steel truss beam to directly bear the bridge deck load; a multi-directional locking connection key is provided between the segmental short beams and the steel truss beam to connect the two, the upper end of the multi-directional locking connection key is fixed to the embedded part in the segmental short beam, and the lower end of the multi-directional locking connection key is connected to the top plate in the steel truss beam.

[0005] Furthermore, the cross-section of the segmental short beam is a π-shaped cross-section or a box-shaped cross-section, with an outwardly protruding beam end tenon on one side of the segmental short beam and an inwardly concave beam end tenon on the other side, and the beam end protruding tenons and beam end concave tenons of adjacent segmental short beams overlap.

[0006] Furthermore, expansion joints are provided between the segmental short beams, and the segmental short beams are prestressed concrete beams.

[0007] Furthermore, the steel truss includes an upper chord node and an upper crossbeam, and the multi-directional locking connection key includes a fixed connection key and a longitudinal limited locking connection key. The fixed connection key connects the upper chord node and the segmental short beam, and the longitudinal limited locking connection key connects the upper crossbeam and the segmental short beam.

[0008] Furthermore, the fixed connection key includes an upper pad, a lower pad, and a fixed support steel plate that vertically connects the two. The upper pad is fixed to the pre-embedded concrete beam of the fixed connection key in the segmental short beam, and the lower pad is fixed to the top plate of the upper chord node.

[0009] Furthermore, the longitudinally limited locking connection key includes an upper sliding support plate connected to the segmental short beam and a lower support channel connected to the top plate of the upper crossbeam. The upper sliding support plate is inserted into the lower support channel, and the two are in contact through the sliding surface between the upper and lower plates.

[0010] Furthermore, a longitudinal elastic device is also provided between the upper sliding support plate and the lower support channel.

[0011] Furthermore, the upper end of the upper sliding support plate is fixed to the longitudinally limited locking connection key concrete beam embedded part in the segmental short beam.

[0012] Furthermore, the lower support channel is fixed to the steel truss upper beam top plate connector at the upper end of the upper beam top plate.

[0013] Furthermore, the steel truss is a constant-height truss or a variable-height truss, and the truss of the steel truss adopts a large-span steel truss. The upper chord nodes of the steel truss are equipped with local stiffening structures to meet local bearing requirements.

[0014] The beneficial effects of this invention are as follows: This invention divides the long bridge deck into several equal-span short beam segments, with expansion joints between the segments. This effectively releases the additional stress caused by the cumulative shrinkage and creep of the bridge deck and the temperature difference between the steel and concrete sections over a long span.

[0015] The segmental short beams of this invention are prefabricated in the factory and hoisted on site, avoiding on-site concrete pouring. Shear studs for bonding with the bridge deck are not required on the top of the steel truss. At the same time, the construction is simple, the technology is mature, and the quality is easier to guarantee.

[0016] The present invention provides a segmental short beam with a protruding tenon at one end and a concave tenon at the other end. Adjacent segmental beams are joined by matching protruding and concave tenons, which can not only release some beam end displacement, but also achieve the continuity of longitudinal force transmission in concrete beams.

[0017] The segmental short beam of this invention uses prestressed concrete components and is tensioned in the prefabrication yard. The prestress can be completely converted into the preload of the concrete beam, resulting in high prestress efficiency and ensuring that the concrete beam has sufficient crack resistance. At the same time, the storage time of the prefabricated components in the factory can be appropriately extended, which can significantly reduce the shrinkage and creep effects of the structure in the later stage.

[0018] The external load borne by the concrete beam of this invention can be directly transmitted to the upper chord node of the steel truss through a multi-directional locking connection key. The force transmission path is shorter and more direct, and the force is more clearly defined, providing more room for optimizing the cross-sectional shape and size of the chord members.

[0019] The present invention features a side support point supported by the upper chord node, which can reduce the truss height of the side support point, and make the transition with the height of the adjacent beams and the change in structural stiffness more uniform.

[0020] This invention is not limited to concrete beam-steel truss composite bridges, but is also applicable to other types of composite bridges such as concrete beam-steel box girder and concrete beam-I-beam. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural schematic diagram of embodiment 1 provided by the present invention; Figure 2 This is a schematic elevation view of the arrangement relationship between the segmental short beam and the multi-directional locking connection key provided by the present invention; Figure 3 This is a schematic diagram of the arrangement relationship between the segmental short beam and the multi-directional locking connection key provided by the present invention; Figure 4 This is a schematic diagram of the cross-sectional structure of the fixed connection key provided by the present invention; Figure 5 This is a schematic diagram of the cross-sectional structure of the longitudinally limited locking connection key provided by the present invention; Figure 6 This is a schematic diagram of the fixed connection key along the bridge direction provided by the present invention; Figure 7 This is a schematic diagram of the longitudinal limited locking connection key bridge structure provided by the present invention; Figure 8 These are the construction steps of embodiment 1 provided by the present invention; Figure 9 This is a three-dimensional structural diagram of embodiment 2 provided by the present invention; The components include: 1. Concrete beam; 2. Multi-directional locking key; 2A. Fixed key; 2A-1. Embedded part of fixed key concrete beam; 2A-2. Steel truss top plate connector; 2A-3. Upper pad; 2A-4. Lower pad; 2A-5. Fixed support steel plate; 2A-6. Dust cover for fixed key; 2B. Longitudinal limited locking key; 2B-1. Embedded part of longitudinal limited locking key concrete beam; 2B-2. Top plate connector for upper crossbeam of steel truss; 2B-3. Upper sliding support plate; 2B-4. Lower support channel; 2B-5. Longitudinal elastic device; 2B-6. Dust cover for limited locking key; 2B-7. Sliding surface between upper and lower plates; 3. Steel truss beam; 3-1. Top plate of upper chord node; 3-2. Top plate of upper crossbeam; 4. Substructure; 5. Segmental short beam; 5-1. Tenon at beam end; 5-2. Tenon at beam end; 6. Expansion joint; 7. Side support point; 8. Intermediate support point. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: like Figures 1 to 9As shown, a segmental beam-truss composite bridge employing a longitudinally limited locking connection key includes a concrete beam 1, which is assembled from several segmental short beams 5 along the bridge direction. The concrete beam 1 is positioned above a steel truss beam 3 to directly bear the bridge deck load. A multi-directional locking connection key 2 is provided between the segmental short beams 5 and the steel truss beam 3 to connect the two. The upper end of the multi-directional locking connection key 2 is fixed to a pre-embedded part in the segmental short beam 5, and the lower end of the multi-directional locking connection key 2 is connected to the top plate in the steel truss beam 3.

[0023] The cross-section of the segmental short beam 5 is a π-shaped cross-section or a box-shaped cross-section. One side of the segmental short beam 5 forms an outwardly protruding beam end tenon 5-1, and the other side of the segmental short beam 5 forms an inwardly concave beam end tenon 5-2. The beam end tenons 5-1 and beam end tenons 5-2 between adjacent segmental short beams 5 overlap.

[0024] Expansion joints 6 are provided between the segmental short beams 5, and the segmental short beams 5 are prestressed concrete beams.

[0025] The steel truss 3 includes an upper chord node and an upper crossbeam. The multi-directional locking key 2 includes a fixed key 2A and a longitudinal limited locking key 2B. The fixed key 2A connects the upper chord node and the segmental short beam 5, and the longitudinal limited locking key 2B connects the upper crossbeam and the segmental short beam 5.

[0026] The fixed connection key 2A includes an upper pad 2A-3, a lower pad 2A-4, and a fixed support steel plate 2A-5 that vertically connects the two. The upper pad 2A-3 is fixed to the fixed connection key concrete beam embedded part 2A-1 in the segmental short beam 5, and the lower pad 2A-4 is fixed to the top plate 3-1 of the upper chord node.

[0027] The longitudinal limited locking connection key 2B includes an upper sliding support plate 2B-3 connected to the segmental short beam 5 and a lower support channel 2B-4 connected to the top plate 3-2 of the upper crossbeam. The upper sliding support plate 2B-3 is inserted into the lower support channel 2B-4, and the two are in contact through the sliding surface 2B-7 between the upper and lower plates.

[0028] A longitudinal elastic device 2B-5 is also provided between the upper sliding support plate 2B-3 and the lower support channel 2B-4.

[0029] The upper end of the upper sliding support plate 2B-3 is fixed to the longitudinal limited locking connection key concrete beam embedded part 2B-1 in the segmental short beam 5.

[0030] The lower support channel 2B-4 is fixed to the steel truss upper beam top plate connector 2B-2 at the upper end of the upper beam top plate 3-2.

[0031] The steel truss 3 is a truss of equal height or a truss of variable height. The truss of the steel truss 3 adopts a large-span steel truss, and the upper chord node of the steel truss is equipped with a local stiffening structure to meet the local bearing requirements.

[0032] Specifically, such as Figure 1 As shown and Figure 9 As shown, Figure 1 For variable height trusses, Figure 9 As a truss of equal height, the main truss of the steel truss beam 3 adopts two or more truss pieces, the side support 7 of the steel truss beam 3 is supported on the upper chord node, and the middle support 8 of the steel truss beam 3 is supported on the lower chord node.

[0033] Meanwhile, the concrete beam 1 is composed of segmental short beams 5, which are prestressed concrete beams, prefabricated in the factory, and hoisted and installed on site. The segmental short beams 5 are lapped together by beam end tenons 5-1 and beam end recesses 5-2, and expansion joints 6 are provided at the joints of the segmental short beams 5.

[0034] Specifically, such as Figure 2 and Figure 3 As shown, the outer convex top of the beam end tenon 5-1 forms an inclined slope, and the width and groove bottom of the beam end tenon 5-2 are consistent with those of the beam end tenon 5-1.

[0035] Meanwhile, the longitudinal limited locking key 2B is located at the lower end of the beam end tenon 5-1, and the fixed key 2A is located on both sides of the groove of the beam end tenon 5-2.

[0036] Specifically, such as Figure 4 and Figure 6 The fixed connection key concrete beam embedded part 2A-1 is embedded in the segmental short beam 5, and a number of through holes through which steel bars pass are formed in the fixed connection key concrete beam embedded part 2A-1. The fixed connection key concrete beam embedded part 2A-1 provides a pre-embedded fixed foundation.

[0037] Specifically, the upper pad 2A-3 is connected to the concrete beam embedded part 2A-1 by bolts, the steel truss top plate connector 2A-2 is connected to the lower pad 2A-4, and the two can be welded or bolted together. The fixed support steel plate 2A-5 is welded to the upper pad 2A-3 and the lower pad 2A-4.

[0038] Meanwhile, the dust cover 2A-6 is screwed into the pre-drilled bolt holes of the upper pad 2A-3 to facilitate future maintenance and replacement.

[0039] Specifically, such as Figure 5 and Figure 7As shown, the longitudinally limited locking key concrete beam embedded part 2B-1 is embedded in the beam end tenon 5-1. Several through holes for steel bars are formed in the longitudinally limited locking key concrete beam embedded part 2B-1. The longitudinally limited locking key concrete beam embedded part 2B-1 provides a pre-embedded fixing foundation.

[0040] Specifically, the upper sliding support plate 2B-3 in the longitudinal limited locking connection key 2B is connected to the longitudinal limited locking connection key concrete beam embedded part 2B-1 by bolts.

[0041] Specifically, the lower support channel 2B-4 and the connecting piece 2B-2 of the top plate of the upper crossbeam of the steel truss can be welded or bolted together.

[0042] Specifically, the upper sliding support plate 2B-3 is provided with an inverted T-shaped steel piece in the transverse direction, and the lower support channel 2B-4 is provided with two inverted L-shaped steel pieces in opposite directions in the transverse direction. The inverted L-shaped steel pieces hook onto the two flange plates of the inverted T-shaped steel pieces to achieve the function of vertical and lateral limiting.

[0043] Specifically, the contact surface between the upper sliding support plate 2B-3 and the lower support channel 2B-4 forms a sliding surface 2B-7 between the upper and lower plates, which is composed of two sliding steel plates stacked on top of each other.

[0044] Specifically, a longitudinal elastic device 2B-5 is provided between the upper sliding support plate 2B-3 and the lower support channel 2B-4 in the bridge direction to achieve the function of longitudinal limited locking.

[0045] Specifically, the limited locking connection key dust cover 2B-6 is screwed into the reserved bolt hole of the upper sliding support plate 2B-3 by bolts to facilitate later maintenance and replacement.

[0046] like Figure 8 As shown, the construction process of a segmental beam-truss composite bridge using longitudinally finite locking connection keys according to the present invention is as follows: Step 1: Construct the lower structure 4 and steel truss 3. The side support 7 of the steel truss 3 is supported by the upper chord node, and the middle support 8 of the steel truss 3 is supported by the lower chord node.

[0047] Step two, in sync with step one, involves prefabricating segmental short beams 5 in the factory.

[0048] The 2A-1 pre-embedded part of the fixed connection key concrete beam is pre-embedded into the beam body at the specified position, and the concrete curing, prestressing tensioning and placement for a certain period of time are completed in the factory.

[0049] Step 3: Simultaneously with Step 1, manufacture the multi-directional locking connection key 2 in the factory.

[0050] The fixed support steel plate 2A-5 of the fixed connecting key 2A is welded to the upper pad 2A-3 and the lower pad 2A-4. The dust cover 2A-6 of the fixed connecting key is screwed into the reserved bolt hole of the upper pad 2A-3 by bolts.

[0051] The upper sliding support plate 2B-3 of the longitudinal limited locking connecting key 2B is provided with an inverted T-shaped steel piece in the transverse direction, and the lower support channel 2B-4 is provided with two inverted L-shaped steel pieces in opposite directions in the transverse direction. The inverted L-shaped steel pieces hook the two flange plates of the inverted T-shaped steel pieces. The upper sliding support plate 2B-3 and the lower support channel 2B-4 form a sliding surface 2B-7 between the upper and lower plates. The sliding surface 2B-7 between the upper and lower plates is composed of two sliding steel plates stacked on top of each other. A longitudinal elastic device 2B-5 is provided between the upper sliding support plate 2B-3 and the lower support channel 2B-4 in the longitudinal direction. The dust cover 2B-6 of the limited locking connecting key is screwed into the reserved bolt hole of the upper sliding support plate 2B-3 by bolts.

[0052] Step 4: Install the multi-directional locking key 2 on the steel truss beam 3.

[0053] The lower part of the fixed connection key 2A is installed on the top plate 3-1 of the upper chord node of the steel truss beam 3 via the steel truss top plate connector 2A-2.

[0054] The lower part of the longitudinally limited locking connection key 2B is installed on the top plate 3-2 of the upper crossbeam of the steel truss beam 3 through the steel truss upper crossbeam top plate connector 2B-2.

[0055] Step 5: Starting from one side beam end, install the first segmental short beam 5. Install the upper pad 2A-3 of the fixed connection key 2A into the fixed connection key concrete beam embedded part 2A-1 with the tenon at the end of the segmental short beam 5 using bolts. Install the upper sliding support plate 2B-3 of the longitudinal limited locking connection key 2B into the longitudinal limited locking connection key concrete beam embedded part 2B-1 with the tenon at the end of the segmental short beam 5 using bolts.

[0056] Step 6: Align the tenon 5-2 at the end of the second beam with the tenon 5-1 at the end of the first beam and lower the beam into place. Install the upper pad 2A-3 of the fixed connection key 2A into the embedded part 2A-1 of the fixed connection key concrete beam with tenon at the end of the segmental short beam 5 using bolts. Install the upper sliding support plate 2B-3 of the longitudinal limited locking connection key 2B into the embedded part 2B-1 of the longitudinal limited locking connection key concrete beam with tenon at the end of the segmental short beam 5 using bolts.

[0057] Step 7: Complete Steps 5 and 6 in sequence until the construction of concrete beam 1 is completed.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the description above. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, using the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A segmental beam-truss composite bridge employing longitudinal finite locking connection keys, comprising a concrete beam (1), characterized in that: The concrete beam (1) is assembled from several segmented short beams (5) along the bridge direction. The concrete beam (1) is set above the steel truss beam (3) to directly bear the bridge deck load. A multi-directional locking key (2) is provided between the segmented short beams (5) and the steel truss beam (3). The upper end of the multi-directional locking key (2) is fixed to the embedded part in the segmented short beam (5), and the lower end of the multi-directional locking key (2) is connected to the top plate in the steel truss beam (3). The cross section of the segmental short beam (5) is a π-shaped cross section or a box-shaped cross section. A convex beam end tenon (5-1) is formed on one side of the segmental short beam (5), and a concave beam end tenon (5-2) is formed on the other side of the segmental short beam (5). The beam end tenons (5-1) and beam end tenons (5-2) between adjacent segmental short beams (5) overlap. The steel truss (3) includes an upper chord node and an upper crossbeam. The multi-directional locking connection key (2) includes a fixed connection key (2A) and a longitudinal limited locking connection key (2B). The fixed connection key (2A) connects the upper chord node and the segmental short beam (5), and the longitudinal limited locking connection key (2B) connects the upper crossbeam and the segmental short beam (5). The outer convex top of the beam end tenon (5-1) forms an inclined slope, and the bottom width of the groove of the beam end tenon (5-2) is consistent with that of the beam end tenon (5-1). The longitudinal limited locking key (2B) is located at the lower end of the beam end tenon (5-1), and the fixed key (2A) is located on both sides of the groove of the beam end tenon (5-2). The longitudinal limited locking connection key (2B) includes an upper sliding support plate (2B-3) connected to the segmental short beam (5) and a lower support channel (2B-4) connected to the top plate (3-2) of the upper crossbeam. The upper sliding support plate (2B-3) is inserted into the lower support channel (2B-4), and the two are in contact through the sliding surface (2B-7) between the upper and lower plates.

2. A segmental girder-truss composite bridge employing longitudinal finite locking connection keys according to claim 1, characterized in that: Expansion joints (6) are provided between the segmental short beams (5), and the segmental short beams (5) are prestressed concrete beams.

3. A segmental girder-truss composite bridge employing longitudinal finite locking connection keys as claimed in claim 1, wherein: The fixed connection key (2A) includes an upper pad (2A-3), a lower pad (2A-4), and a fixed support steel plate (2A-5) that vertically connects the two. The upper pad (2A-3) is fixed to the fixed connection key concrete beam embedded part (2A-1) in the segmental short beam (5), and the lower pad (2A-4) is fixed to the top plate (3-1) of the upper chord node.

4. A segmental girder-truss composite bridge employing longitudinal finite locking connection keys as claimed in claim 3, wherein: A longitudinal elastic device (2B-5) is also provided between the upper sliding support plate (2B-3) and the lower support channel (2B-4).

5. A segmental girder-truss composite bridge employing longitudinal finite locking connection keys as claimed in claim 1, wherein: The upper end of the upper sliding support plate (2B-3) is fixed to the longitudinal limited locking connection key concrete beam embedded part (2B-1) in the segmental short beam (5).

6. A segmental girder-truss composite bridge employing longitudinal finite locking connection keys as claimed in claim 4, wherein: The lower support channel (2B-4) is fixed to the steel truss upper beam top plate connector (2B-2) at the upper end of the upper beam top plate (3-2).

7. A segmental beam-truss composite bridge employing longitudinally finite locking connection keys according to claim 1, characterized in that: The steel truss (3) is a truss of equal height or a truss of variable height. The truss of the steel truss (3) adopts a large-span steel truss. The upper chord node of the steel truss is equipped with a local stiffening structure to meet the local bearing requirements.

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