Steel-concrete combined arch seat structure and construction method suitable for multi-span basket handle arch bridge

Abstract

The present application belongs to the technical field of arch bridge structure, and particularly relates to a steel-concrete combined arch seat structure suitable for multi-span basket handle arch bridges and a construction method thereof. The present application sets a lower single steel mesh unit, an upper steel mesh unit with a ring, a concrete block inside the framework, and a concrete block outside the framework on the closed ring steel framework unit, so that: 1. The lower single steel mesh unit and the upper steel mesh unit with a ring can select appropriate steel mesh sizes according to the gap between the outer contour size of the arch seat and the size of the closed ring steel framework unit, so as to ensure that even the relatively large concrete block outside the framework still has sufficient steel structure support and reinforcement effect; 2. The upper steel mesh unit with a ring and the closed ring steel framework unit can be used together to reinforce and install the arch rib pipe, so as to ensure that the arch rib pipe has sufficient structural stability on the arch seat.

Description

Technical Field

[0001] This invention belongs to the field of arch bridge structure technology, and particularly relates to a steel-concrete composite arch seat structure suitable for multi-span basket arch bridges and its construction method. Background Technology

[0002] The structure of a common steel-concrete composite arch bridge mainly includes: arch abutments, arch ribs, tie rods, and bridge deck. Based on the relative height of the arch ribs and bridge deck, arch bridges can be classified as upper-deck, mid-deck, and lower-deck.

[0003] The aforementioned multi-span basket arch bridge refers to an arch bridge that simultaneously possesses the following two structural characteristics: first, the number of its arch ribs is ≥3 pairs; second, the upper part of its paired arch ribs slopes inward, resembling a basket.

[0004] On the other hand, compared with single-span and double-span arch bridges, and compared with parallel arch rib arch bridges, multi-span arch bridges have higher requirements for the structural strength of the arch abutments. The reason for this is that the stress situation of the arch abutments of multi-span arch bridges and inward-sloping arch bridges is more complex, including: the axial force transmitted by the arch ribs, the transverse prestress transmitted by the end beams, the transverse component of the axial force transmitted by the arch ribs, and the bidirectional unbalanced tension of the tie rods.

[0005] Therefore, the arch abutment design for multi-span arch bridges and inward-sloping arch bridges cannot be the relatively outdated single concrete structure, but must be a steel-concrete composite arch abutment. This requirement is even more pronounced for multi-span basket arch bridges. The most fundamental advantage of the steel-concrete composite arch abutment is that it combines the tensile strength of steel structures with the compressive strength of concrete structures.

[0006] For example, Chinese utility model patent with patent publication number CN215925696U and publication date of March 1, 2022, discloses a full-span arch seat embedded plate support, including at least three rows of uprights arranged in parallel, with at least two layers of connecting rods welded between each upright, an upper crossbeam welded between the upper ends of the two middle uprights in each row, and a diagonal bracing beam welded to each end of each upper crossbeam at a certain height on the two outermost uprights, with an internal embedded steel plate of the arch seat welded to each upper crossbeam and diagonal bracing beam, and an arch seat top surface embedded steel plate welded to the top of the arch seat internal embedded steel plate welded to the upper crossbeam, and two sides of the arch seat top surface embedded steel plate welded to the upper ends of the outermost uprights of each row of uprights.

[0007] The arch seat embedded plate bracket in this utility model patent has the following usage method and advantages: the bracket is not removed during the pouring of the arch seat concrete, but is poured as a whole with the arch seat concrete, which can enhance the overall load-bearing capacity of the arch seat. The embedded steel plate will not be misaligned during the pouring, which can ensure the installation accuracy of the embedded steel plate.

[0008] However, the pre-embedded plate support for the arch seat still has at least two shortcomings in actual construction and use, which are the technical problems that this invention aims to solve:

[0009] 1. Its steel structure frame, composed of "uprights, connecting rods, upper crossbeams, and diagonal bracing beams", lacks the extension function in the transverse and longitudinal directions of the bridge. When the concrete size of the arch abutment is required to be large, the relatively outer concrete area is just concrete without steel structure support. Therefore, the relatively outer concrete area is relatively easy to crack quickly. In other words, its steel structure frame can only match the arch abutment concrete structure that is slightly larger than its own size.

[0010] 2. Only "embedded steel plates on both sides" in its steel structure frame can be used to directly install the reinforced arch ribs, which is relatively insufficient. This can easily lead to the unstable installation structure of the arch ribs on the arch seat and the harmful phenomenon of relative displacement between the two.

[0011] Therefore, in summary, there is an urgent need for a new type of steel-concrete composite arch seat with a steel structure frame that has lateral extension function and can be fully and stably set up with arch ribs and concrete blocks on the frame, for use on multi-span basket arch bridges. Summary of the Invention

[0012] This invention provides a steel-concrete composite arch abutment structure suitable for multi-span basket arch bridges. By setting a lower single steel mesh unit, an upper ring-shaped steel mesh unit, an inner concrete block, and an outer concrete block on a closed annular steel frame unit, the following advantages are achieved: 1. The lower single steel mesh unit and the upper ring-shaped steel mesh unit can be selected with appropriate steel mesh sizes based on the difference between the outer contour dimensions of the arch abutment and the dimensions of the closed annular steel frame unit, ensuring sufficient steel structural support and reinforcement even at relatively large outer concrete blocks; 2. The upper ring-shaped steel mesh unit and the closed annular steel frame unit can be used together to reinforce and install the arch rib tube, ensuring sufficient structural stability of the arch rib tube on the arch abutment.

[0013] Furthermore, the present invention also provides a construction method for the above-mentioned steel-concrete composite arch structure, wherein, during the pouring of the concrete blocks inside and outside the frame, the distance L1 between the longitudinal bridge concrete formwork and the closed ring steel frame unit is 0-2m, and the distance L2 between the transverse bridge concrete formwork and the closed ring steel frame unit is 1-2m, ensuring that the size and style of the arch can be flexibly selected as needed, thus expanding its applicable range.

[0014] The technical solution adopted by the present invention to solve the above problems is: a steel-concrete composite arch abutment structure applicable to multi-span basket arch bridges, including an inner concrete block and an outer concrete block, and further including a closed ring steel frame unit disposed between the inner and outer concrete blocks, a lower single steel mesh unit inserted into the closed ring steel frame unit for inserting and reinforcing the outer concrete block, and an upper ring steel mesh unit disposed on the closed ring steel frame unit for sleeve and reinforcing the arch rib tube.

[0015] A further preferred technical solution is that the closed ring steel frame unit includes a base plate, two lifting plates respectively disposed at both ends of the base plate for setting the lower single steel mesh unit, an inclined plate disposed on the lifting plate for installing the arch rib tube, a vertical plate disposed on the inclined plate for installing the upper ring steel mesh unit, and a top plate disposed on the two uppermost vertical plates.

[0016] A further preferred technical solution is that the closed ring-shaped steel frame unit also includes steel mesh installation holes provided on the lifting plate and the vertical plate.

[0017] A further preferred technical solution is that the closed ring-shaped steel frame unit also includes a discharge port disposed on the top plate and used for pouring concrete blocks to form the frame.

[0018] A further preferred technical solution is that the inclined plate and the vertical plate on one side are arranged in pairs, with a quantity of 1-3 pairs.

[0019] A further preferred technical solution is that the lower single steel mesh unit includes longitudinal bridge steel bars disposed on the steel mesh mounting holes, and transverse bridge steel bars disposed on the longitudinal bridge steel bars and located between the two lifting plates.

[0020] A further preferred technical solution is that the lower single steel mesh unit further includes transverse outer bars disposed on the longitudinal reinforcing bars and located outside the closed ring steel skeleton unit, and longitudinal outer bars disposed on the transverse reinforcing bars and located outside the closed ring steel skeleton unit.

[0021] A further preferred technical solution is that the upper ring-shaped steel mesh unit includes an inner steel mesh disposed on the steel mesh mounting hole, and a steel ring disposed on the inner steel mesh, located outside the closed ring-shaped steel skeleton unit, and used to fit the arch rib tube.

[0022] A further preferred technical solution is that the upper ringed steel mesh unit also includes an outer steel mesh disposed on the steel ring and used to insert and reinforce the outer concrete block of the skeleton.

[0023] A construction method applicable to steel-concrete composite arch seat structure of multi-span basket arch bridge, wherein during the pouring of the concrete blocks inside and outside the frame, the distance L1 between the longitudinal bridge concrete formwork and the closed ring steel frame unit is 0-2m, and the distance L2 between the transverse bridge vertical concrete formwork and the lifting plate is 1-2m. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention.

[0025] Figure 2 This is a schematic diagram of the first positional shape of the concrete block outside the skeleton in this invention, viewed from a top-down angle.

[0026] Figure 3 This is a schematic diagram of the second positional shape of the concrete block outside the skeleton in this invention, viewed from a top-down angle.

[0027] Figure 4 This is a top-down view showing the position and structure of the lower single steel mesh unit in this invention.

[0028] Figure 5 This is a schematic diagram showing the position and shape of the concrete blocks within the skeleton in this invention.

[0029] Figure 6 This is a top-down view showing the position and structure of the upper ringed steel mesh unit in this invention.

[0030] Figure 7 This is a schematic diagram of the closed-loop steel frame unit in this invention.

[0031] Figure 8 This is a schematic diagram showing the location and shape of the steel mesh installation holes in this invention.

[0032] The meanings of the markings in the diagram are as follows:

[0033] a) Arch rib tube; b) Longitudinal bridge concrete formwork; c) Transverse bridge concrete formwork.

[0034] Concrete block 11 inside the skeleton; concrete block 12 outside the skeleton;

[0035] Closed ring steel frame unit 1, lower single steel mesh unit 2, upper ring steel mesh unit 3;

[0036] Bottom plate 101, lifting plate 102, inclined plate 103, vertical plate 104, top plate 105, steel mesh installation hole 106, material outlet 107, longitudinal bridge reinforcement 201, transverse bridge reinforcement 202, transverse bridge outer reinforcement 203, longitudinal bridge outer reinforcement 204, inner steel mesh 301, steel ring 302, outer steel mesh 303. Detailed Implementation

[0037] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

[0038] As attached Figure 1-8 As shown, the steel-concrete composite arch abutment structure applicable to multi-span basket arch bridges includes an inner concrete block 11 and an outer concrete block 12, a closed ring steel frame unit 1 disposed between the inner concrete block 11 and the outer concrete block 12, a lower single steel mesh unit 2 inserted into the closed ring steel frame unit 1 for reinforcing the outer concrete block 12, and an upper ring steel mesh unit 3 disposed on the closed ring steel frame unit 1 for sleeve reinforcement of the arch rib tube a.

[0039] In existing technologies, the distance between the outer concrete surface of a steel-concrete composite arch and the inner steel frame, i.e., the thickness of the outer concrete layer, is generally around 0.5m. The dimensions of the steel-concrete composite arch are kept as large as possible within a certain range to improve the stability of its support effect. The reason for limiting further increases in the aforementioned thickness is that the existing internal steel frame is a separate continuous surface structure without appropriate protruding extension structures. This means that the outermost concrete portion lacks the support of the internal steel structure, making it more prone to cracking and peeling.

[0040] In this embodiment, although the outline dimensions of the closed annular steel frame unit 1 are fixed after factory prefabrication, the overall dimensions and outward extension of the lower single steel mesh unit 2 and the upper ring steel mesh unit 3 are adjustable. Ultimately, within a certain range, even with relatively large dimensions of the outer concrete block 12, the lower single steel mesh unit 2 and the upper ring steel mesh unit 3 can provide adequate support, especially strengthening the concrete areas relatively close to the surface of the outer concrete block 12.

[0041] Correspondingly, for a steel structure frame of the same size and specifications, a thicker outer concrete layer, namely the outer concrete block 12 of the frame, can be obtained in this embodiment. At this time, the embedded length of the arch rib tube a in the outer concrete block 12 of the frame is also increased accordingly, providing the necessary basis for the upper ring steel mesh unit 3 to reinforce the arch rib tube a, which is quite ingenious.

[0042] Ultimately, this combination of reinforced concrete arch abutment and arch rib tube a has the following structural advantages:

[0043] First, the steel-concrete composite arch supports a larger area and the steel and concrete composite structure is more comprehensively distributed. The arch is not only large in size, but also has a very comprehensive steel structure reinforcement effect, which ultimately ensures that it can provide greater support strength.

[0044] Secondly, for the arch rib tube a, its lower end face is welded to the closed ring steel frame unit 1. Its lower "concrete embedded section" is already reinforced with concrete, and can also be fixed by the upper ring steel mesh unit 3. Therefore, it can directly improve the installation stability of the arch rib tube a and indirectly improve the support structure stability of the closed ring steel frame unit 1, avoiding the harmful phenomenon of stress concentration on the closed ring steel frame unit 1.

[0045] The closed ring steel frame unit 1 includes a base plate 101, two lifting plates 102 respectively disposed at both ends of the base plate 101 for mounting the lower single steel mesh unit 2, an inclined plate 103 disposed on the lifting plate 102 for mounting the arch rib tube a, a vertical plate 104 disposed on the inclined plate 103 for mounting the upper ring steel mesh unit 3, and a top plate 105 disposed on the two uppermost vertical plates 104.

[0046] In this embodiment, without the lifting plate 102, the lowest inclined plate 103 would be directly connected to the base plate 101, forming a sharp-angled partial steel structure frame. This would easily lead to stress concentration and self-bending, which are harmful phenomena. Therefore, this is the purpose and advantage of setting up the lifting plate 102.

[0047] In addition, the base plate 101 is provided with forming holes for concrete shear keys, or directly with studs or angle steel shear keys. The purpose of all the above methods is the same: to increase the connection strength between the steel structure and the concrete structure within the arch abutment.

[0048] The closed ring steel frame unit 1 also includes steel mesh mounting holes 106 provided on the lifting plate 102 and the vertical plate 104.

[0049] In this embodiment, all of the lower single steel mesh units 2 are installed on the steel mesh mounting holes 106 of the lifting plate 102, and all of the upper ring steel mesh units 3 are installed on the steel mesh mounting holes 106 of the vertical plate 104.

[0050] In addition, some of the steel mesh installation holes 106 can be left unused. In this case, concrete shear keys can be formed at the steel mesh installation holes 106, which can also strengthen the entire arch seat.

[0051] Finally, the number and position of the corresponding steel mesh installation holes 106 on both sides at the same height are aligned one by one, ensuring that each lower single steel mesh unit 2 and upper ring steel mesh unit 3 can have two insertion installation positions.

[0052] The closed ring steel frame unit 1 also includes a discharge port 107 disposed on the top plate 105 and used for pouring concrete blocks 11 to form the frame.

[0053] In this embodiment, it is precisely because of the presence of the discharge port 107 that the longitudinal bridge concrete formwork b can be fixedly installed against the side of the closed annular steel frame unit 1. In this manner, all the required concrete within the closed annular steel frame unit 1 is obtained at the discharge port 107.

[0054] In other words, the concrete block 12 outside the skeleton in this embodiment has two completely different structural styles:

[0055] First, its longitudinal and transverse bridge dimensions are significantly larger than the outline dimensions of the closed annular steel frame unit 1, as shown in the attached figure. Figure 3 As shown;

[0056] Secondly, its longitudinal bridge dimension is significantly larger than the longitudinal bridge outline dimension of the closed ring steel frame unit 1, but its transverse bridge dimension is, or slightly larger than, the transverse bridge dimension of the closed ring steel frame unit 1, as shown in the attached figure. Figure 2 As shown.

[0057] It should be noted that:

[0058] Firstly, neither of the two methods mentioned above has an absolute advantage or disadvantage; each has its own applicable scenarios.

[0059] Secondly, the surface of the concrete block 12 outside the skeleton does not need to be parallel to the outer surface of the closed ring steel skeleton unit 1 at every point, i.e., as shown in the attached figure. Figure 1 As shown;

[0060] Thirdly, when the outer concrete block 12 of the skeleton is the second type mentioned above, the transverse reinforcing bars of the lower single steel mesh unit 2 and the upper ring steel mesh unit 3 do not need to protrude to the outside of the closed ring steel skeleton unit 1. In other words, there should be no protruding end of the reinforcing bars on the arch seat.

[0061] The inclined plate 103 and vertical plate 104 on one side are arranged in pairs, with a quantity of 1-3 pairs.

[0062] In this embodiment, one pair of inclined plates 103 and vertical plates 104 on one side correspond to one set of arch rib tubes a at the same height. (See attached diagram) Figure 5 As shown, four sets of arch rib tubes a are installed on the steel-concrete composite arch seat.

[0063] The lower single steel mesh unit 2 includes a longitudinal bridge steel bar 201 disposed on the steel mesh mounting hole 106, and a transverse bridge steel bar 202 disposed on the longitudinal bridge steel bar 201 and located between the two lifting plates 102.

[0064] In this embodiment, the ends of the longitudinal bridge reinforcement 201 and the transverse bridge reinforcement 202 can be extended and protruded as needed, that is, a large number of reinforcements with length dimensions significantly larger than the length and width dimensions of the bottom plate 101 are selected.

[0065] On the other hand, when the bottom length and width of the concrete block 12 outside the skeleton are even larger than the size of the lower single steel mesh unit 2 that has been enlarged, the longitudinal bridge steel bars 201 and the transverse bridge steel bars 202 can be further increased in terms of the effective support and reinforcement range of the lower steel mesh by staggering them at intervals.

[0066] For example, half of the transverse reinforcing bars 202 are pulled out to the left, while the other half are pulled out to the right. This effectively increases the support and reinforcement range of the lower reinforcing mesh, which is quite ingenious.

[0067] The lower single steel mesh unit 2 also includes a transverse outer bar 203 disposed on the longitudinal bridge bar 201 and located outside the closed ring steel skeleton unit 1, and a longitudinal outer bar 204 disposed on the transverse bridge bar 202 and located outside the closed ring steel skeleton unit 1.

[0068] In this embodiment, the addition of the transverse bridge outward reinforcement 203 and the longitudinal bridge outward reinforcement 204 significantly enhances the effective reinforcement area of ​​the lower steel mesh.

[0069] Ultimately, this ensures that the concrete near the surface of the outer concrete block 12 is not prone to cracking.

[0070] The upper ring steel mesh unit 3 includes an inner steel mesh 301 disposed on the steel mesh mounting hole 106, and a steel ring 302 disposed on the inner steel mesh 301, located outside the closed ring steel frame unit 1, and used to fit the arch rib tube a.

[0071] In this embodiment, the inner steel mesh 301, like the lower single steel mesh unit 2, adjusts its own length and width according to the actual length and width of the corresponding height of the outer concrete block 12 of the skeleton, so as to ensure that the area of ​​the outer concrete block 12 near the height of the inner steel mesh 301 can obtain the high structural strength of the steel structure plus concrete structure, rather than the concrete structure alone.

[0072] In addition, the longitudinal reinforcing bars of the steel ring 302 and the inner steel mesh 301 are fully welded to ensure that the force transmitted from the arch rib tube a is distributed as quickly as possible to the entire closed ring steel frame unit 1, as well as the concrete block 11 inside the frame and the concrete block 12 outside the frame, so as to avoid the harmful phenomenon of stress concentration at any point in the steel-concrete composite arch seat.

[0073] The upper ring steel mesh unit 3 also includes an outer steel mesh 303 disposed on the steel ring 302 and used to insert and reinforce the outer concrete block 12 of the skeleton.

[0074] In this embodiment, when the corresponding height area of ​​the outer concrete block 12 of the skeleton protrudes significantly from the vertical plate 104, it is necessary to add an additional outer steel mesh 303.

[0075] A construction method applicable to steel-concrete composite arch seat structure of multi-span basket arch bridge, wherein during the pouring of the concrete block 11 inside the frame and the concrete block 12 outside the frame, the distance L1 between the longitudinal bridge concrete formwork b and the closed ring steel frame unit 1 is 0-2m, and the distance L2 between the transverse bridge vertical concrete formwork c and the lifting plate 102 is 1-2m.

[0076] In the construction method of this embodiment, at least four concrete formwork pieces are required, as shown in the attached... Figure 1 The arch shape shown requires six formwork panels. The longitudinal concrete formwork b, due to the presence of the discharge port 107, can adhere to the closed annular steel frame unit 1; otherwise, concrete could not enter the closed annular steel frame unit 1. Therefore, this greatly expands the applicability of this steel-concrete composite arch.

[0077] Because of the expandable size of the lower single steel mesh unit 2 and the upper ring steel mesh unit 3, the distance between at least the two sides of the bottom longitudinal bridge of the outer concrete block 12 and the lifting plate 102 can be increased to 2m, which also improves the applicability of the steel-concrete composite arch seat.

[0078] Finally, when the longitudinal concrete formwork b is not attached to the closed ring steel frame unit 1, there is essentially no clear, visible boundary between the concrete block 11 inside the frame and the concrete block 12 outside the frame, and the concrete required for both is mixed and added together.

[0079] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various modifications can be made without departing from the spirit of the present invention. These are non-inventive modifications and are protected by patent law as long as they fall within the scope of the claims of the present invention.

Claims

1. A steel-concrete composite arch abutment structure suitable for multi-span basket arch bridges, comprising concrete blocks (11) inside the frame and concrete blocks (12) outside the frame, characterized in that: It also includes a closed ring steel frame unit (1) set between the concrete block (11) inside the frame and the concrete block (12) outside the frame, a lower single steel mesh unit (2) inserted into the closed ring steel frame unit (1) and used to insert and reinforce the concrete block (12) outside the frame, and an upper ring steel mesh unit (3) set on the closed ring steel frame unit (1) and used to sleeve and reinforce the arch rib tube (a). The closed ring steel frame unit (1) includes a base plate (101), two lifting plates (102) respectively set at both ends of the base plate (101) for setting the lower single steel mesh unit (2), an inclined plate (103) set on the lifting plate (102) for installing the arch rib tube (a), a vertical plate (104) set on the inclined plate (103) for installing the upper ring steel mesh unit (3), and a top plate (105) set on the two uppermost vertical plates (104). The closed ring steel frame unit (1) also includes steel mesh installation holes (106) provided on the lifting plate (102) and the vertical plate (104). The upper ring steel mesh unit (3) includes an inner steel mesh (301) set on the steel mesh installation hole (106), and a steel ring (302) set on the inner steel mesh (301), located outside the closed ring steel skeleton unit (1), and used to fit the arch rib tube (a).

2. The steel-concrete composite arch seat structure for multi-span basket arch bridges according to claim 1, characterized in that: The closed ring steel frame unit (1) also includes a discharge port (107) set on the top plate (105) and used for pouring concrete blocks (11) to form the frame.

3. The steel-concrete composite arch seat structure applicable to multi-span basket arch bridges according to claim 1, characterized in that: The inclined plate (103) and vertical plate (104) on one side are arranged in pairs, with a quantity of 1-3 pairs.

4. The steel-concrete composite arch seat structure applicable to multi-span basket arch bridges according to claim 1, characterized in that: The lower single steel mesh unit (2) includes longitudinal bridge steel bars (201) provided on the steel mesh installation hole (106) and transverse bridge steel bars (202) provided on the longitudinal bridge steel bars (201) and located between the two lifting plates (102).

5. The steel-concrete composite arch seat structure for multi-span basket arch bridges according to claim 4, characterized in that: The lower single steel mesh unit (2) also includes a transverse bridge reinforcement (203) disposed on the longitudinal bridge reinforcement (201) and located outside the closed ring steel skeleton unit (1), and a longitudinal bridge reinforcement (204) disposed on the transverse bridge reinforcement (202) and located outside the closed ring steel skeleton unit (1).

6. The steel-concrete composite arch seat structure applicable to multi-span basket arch bridges according to claim 1, characterized in that: The upper ring steel mesh unit (3) also includes an outer steel mesh (303) set on the steel ring (302) and used to insert and reinforce the outer concrete block (12) of the skeleton.

7. The construction method for steel-concrete composite arch abutment structure applicable to multi-span basket arch bridges as described in claim 2, characterized in that: During the pouring construction of the concrete blocks (11) inside the frame and the concrete blocks (12) outside the frame, the distance L1 between the longitudinal bridge concrete formwork (b) and the closed ring steel frame unit (1) is 0-2m, and the distance L2 between the transverse bridge vertical concrete formwork (c) and the lifting plate (102) is 1-2m.

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