Bridge temporary expansion joint structure and construction method thereof

Abstract

A temporary expansion joint structure for bridges and its construction method are disclosed, comprising a first beam, a second beam, and an expansion joint located at the connection between the first and second beams. The first beam has a first pre-reserved slot communicating with the expansion joint at its end, and the second beam has a second pre-reserved slot communicating with the expansion joint at its end. A supporting steel plate for covering the expansion joint is provided between the first and second beams, resting on the first and second pre-reserved slots. An earthwork cloth is laid on the supporting steel plate, the first and second pre-reserved slots, and filled with a layer of crushed stone. An asphalt layer for easy subsequent removal is backfilled on the crushed stone layer. Compared with existing technologies, this method adds a precise leveling process for the beams, clearly defining multi-level height difference control indicators for the bearing pads, supports, and adjacent beam top surfaces. Quantitative testing and fine-tuning of the supports ensure the flatness of the temporary expansion joint's foundation support from the source.

Description

Technical Field

[0001] This invention relates to the field of temporary expansion joint technology for bridges, and specifically to a temporary expansion joint structure for bridges and its construction method. Background Technology

[0002] Temporary expansion joints on bridges are temporary displacement compensation devices installed at the beam ends and between beam abutments to meet the structural deformation coordination and temporary traffic needs during the non-permanent service phase of bridge construction. They need to be removed and replaced with permanent expansion joints after the bridge is opened to traffic.

[0003] The existing temporary expansion joints for bridges typically consist of a bottom layer of bamboo plywood, a middle layer of gravel, and an upper layer of concrete. Since these temporary expansion joints need to be removed later, the concrete on top, once anchored, is prone to damaging the beam's base surface during removal. This results in time-consuming and labor-intensive repairs of the beam's base surface after removal, affecting the installation progress of permanent expansion joints. Furthermore, these temporary expansion joint materials are mostly for single use, leading to a high waste rate and poor economic efficiency after removal.

[0004] Chinese Patent No. CN115288031A discloses a construction method for temporary expansion joints in bridges. The method includes the following steps: construction preparation; cleaning the original ground; setting up the foundation: setting multiple square timbers at the bottom of the expansion joint, laying multiple bamboo plywoods on top of the square timbers, and laying and fixing a lower layer of geotextile on top of the bamboo plywoods; compacting and filling: laying gravel on the lower layer of geotextile, compacting and verifying the elevation using a joint filling construction device, laying an upper layer of geotextile on top of the gravel, and setting composite foam boards around the top surface of the upper layer of geotextile; pouring concrete and curing; strength testing and opening to traffic.

[0005] The aforementioned construction method still uses concrete pouring for the surface layer. After the concrete is anchored, the beam base surface is easily damaged during the demolition process, resulting in time-consuming and laborious repair of the beam base surface after demolition, which affects the installation progress of the permanent expansion joint. At the same time, the above construction method ignores the pre-leveling process of the beam and slab, and there is no standardized control over the height difference between the beam and the support, which can easily cause the bottom of the expansion joint to be suspended, uneven stress, and subsequent vehicle jumping defects. Summary of the Invention

[0006] The present invention aims to overcome the defects in the prior art and provide a bridge temporary expansion joint structure and its construction method that features controllable beam-slab connection accuracy, reliable connection, convenient dismantling, and no residual hard structural damage to the beam in the later stage.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a temporary expansion joint structure for bridges, comprising a first beam, a second beam, and an expansion joint, wherein the expansion joint is located at the connection between the first beam and the second beam; a first reserved slot communicating with the expansion joint is provided at the end of the first beam, and a second reserved slot communicating with the expansion joint is provided at the end of the second beam; a supporting steel plate for covering the expansion joint is provided between the first beam and the second beam, the supporting steel plate resting on the first reserved slot and the second reserved slot; earthwork cloth is laid on the supporting steel plate, the first reserved slot, and the second reserved slot, the earthwork cloth is filled with a layer of crushed stone, and an asphalt layer for easy subsequent removal is backfilled on the crushed stone layer.

[0008] As a preferred embodiment of the present invention, the first beam contains a plurality of first pre-embedded reinforcing bars partially exposed in the first reserved slot, and the second beam contains a plurality of second pre-embedded reinforcing bars partially exposed in the second reserved slot. The first and second pre-embedded reinforcing bars are respectively positioned and engaged with the two sides of the supporting steel plate.

[0009] As a preferred embodiment of the present invention, a plurality of the first pre-embedded reinforcing bars are arranged in rows along the length of the expansion joint, and a first snap-fit ​​groove is formed on the side of the supporting steel plate to snap-fit ​​the first pre-embedded reinforcing bars.

[0010] As a preferred embodiment of the present invention, a plurality of second pre-embedded reinforcing bars are arranged in rows along the length of the expansion joint, and a second snap-fit ​​groove is formed on the side of the supporting steel plate to snap-fit ​​the second pre-embedded reinforcing bars.

[0011] As a preferred embodiment of the present invention, both ends of the first embedded steel bar are located within the first beam, and both ends of the second embedded steel bar are located within the second beam.

[0012] As a preferred embodiment of the present invention, the surface of the asphalt layer smoothly transitions with the top of the first beam and the second beam.

[0013] A construction method for a temporary expansion joint structure for bridges, based on the temporary expansion joint structure for bridges, includes the following steps:

[0014] Step S1: Leveling the beams. Check the smoothness of the first and second beams to ensure that the relative height difference between the end bearing stones of the same beam in the first and second beams is ≤3mm, the height difference between the four corners of the supports is ≤2mm, and the height difference between the top surfaces of adjacent first and second beams is ≤5mm. Adjust the first beam and / or the second beam by adjusting the supports according to the inspection results.

[0015] Step S2: Inspect the condition of the first and second pre-embedded reinforcing bars on site;

[0016] Step S3: Install the support steel plate, which covers the expansion joint. At the same time, the support steel plate is positioned and connected to the first and second pre-embedded steel bars on both sides.

[0017] Step S4: Fill the crushed stone layer. Lay earthwork cloth on the supporting steel plate, the first reserved groove and the second reserved groove, and evenly fill the earthwork cloth with single-diameter crushed stone.

[0018] Step S5: Backfill the asphalt layer;

[0019] Step S6: Inspect the surface smoothness of the asphalt layer along the length of the expansion joint;

[0020] Step S7: Curing the asphalt layer.

[0021] As a preferred embodiment of the present invention, step S3 further includes the following sub-steps:

[0022] Step S3.1: Based on the design location of the expansion joint and the distribution of the first and second pre-embedded reinforcing bars, lay out the layout at the bottom of the expansion joint and the bottom of the abutment to determine the installation position, elevation and fixing points of the supporting steel plate, ensuring that the steel plate can cover the entire bottom of the expansion joint after installation;

[0023] Step S3.2: According to the layout dimensions and the diameter of the embedded steel bars, grooves are cut on the side of the supporting steel plate to ensure that the first and second embedded steel bars can be inserted into the grooves;

[0024] Step S3.3: Accurately place the support steel plate at the layout position, so that the first and second pre-embedded steel bars are inserted into the first and second snap-fit ​​grooves of the support steel plate respectively, and the bottom of the support steel plate is tightly attached to the construction surface without any suspension or looseness.

[0025] As a preferred embodiment of the present invention, step S4 further includes the following sub-steps:

[0026] Step S4.1: Lay multiple layers of earthwork fabric on top of the supporting steel plate. The earthwork fabric should cover the entire construction surface, and the multiple layers of earthwork fabric should overlap each other.

[0027] Step S4.2: Evenly fill the prepared single-size crushed stone onto the supporting steel plate wrapped with earthwork cloth. During the filling process, use manual labor or a small vibrating tool to gently vibrate to ensure that the crushed stone is filled densely, without gaps or looseness. The filling height of the crushed stone is controlled according to the design requirements, leaving room for the backfill thickness of the top recycled asphalt mixture.

[0028] Step S4.3: After the crushed stone filling is completed, check the density and filling height of the crushed stone layer, and check whether the earthwork cloth is intact or damaged, and whether the crushed stone has fallen off.

[0029] As a preferred embodiment of the present invention, step S5 further includes the following sub-steps:

[0030] Step S5.1: Mix the recycled asphalt mixture on site;

[0031] Step S5.2: Evenly backfill the well-mixed recycled asphalt mixture onto the crushed stone layer. The backfill thickness is controlled according to the design. Vibration is carried out during the backfilling process.

[0032] Step S5.3: After the asphalt layer backfill is completed, the surface of the asphalt layer is leveled to ensure a smooth transition with the first and second beam bridge decks.

[0033] Compared with existing technologies, the addition of a precise beam leveling process clarifies the multi-level height difference control indicators for pad stones, supports, and adjacent beam top surfaces. Relying on quantitative testing and correcting deviations through support fine-tuning, the system ensures the flatness of the temporary expansion joint foundation support from the source, avoids structural stress concentration and local damage caused by foundation misalignment, and improves the overall stability of the temporary structure.

[0034] The reserved slot size is precisely customized according to the specifications of the pre-embedded steel bars to achieve precise matching and rigid connection between the support steel plate and the original pre-embedded structure, resulting in a stronger restraint effect. Relying on the overall layout and positioning of the bridge abutment and beam bottom, the support steel plate fully covers the bottom of the expansion joint, eliminating local stress defects and greatly improving the shear resistance and impact resistance of the temporary expansion joint. At the same time, the support steel plate can be recycled and reused after the later removal, reducing costs.

[0035] When under stress, the load is transmitted through the supporting steel plate to the first and second pre-embedded steel bars on both sides, and then dispersed to the overall concrete of the first and second beams. This avoids the load being concentrated on the weak concrete at the edge of the supporting steel plate, effectively preventing the concrete at the corners of the supporting steel plate from being crushed, chipped, or cracked, and extending the overall service life of the temporary expansion joint. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 This is a top view of the present invention;

[0038] Figure 3 This is a structural schematic diagram of the first beam and the second beam;

[0039] Figure 4 This is a schematic diagram of the structure supporting the iron plate;

[0040] Reference numerals in the attached drawings: 1. First beam body; 11. First reserved groove; 12. First embedded steel bar; 2. Second beam body; 21. Second reserved groove; 22. Second embedded steel bar; 3. Expansion joint; 4. Supporting steel plate; 41. First clamping groove; 42. Second clamping groove; 5. Earthwork cloth; 6. Crushed stone layer; 7. Asphalt layer. Detailed Implementation

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0042] like Figure 1-4 As shown, a temporary expansion joint structure for a bridge includes a first beam 1, a second beam 2, and an expansion joint 3, with the expansion joint 3 located at the connection between the first beam 1 and the second beam 2. The first beam 1 has a first reserved slot 11 at its end communicating with the expansion joint 3, and the second beam 2 has a second reserved slot 21 at its end communicating with the expansion joint 3. A supporting steel plate 4 for covering the expansion joint 3 is provided between the first beam 1 and the second beam 2, resting on the first reserved slot 11 and the second reserved slot 21. An earthwork cloth 5 is laid on the supporting steel plate 4, the first reserved slot 11, and the second reserved slot 21, and a layer of crushed stone 6 is filled on the earthwork cloth 5. An asphalt layer 7 for subsequent removal is backfilled on the crushed stone layer 6.

[0043] The first reserved slot 11 is a groove reserved in advance during the prefabrication of the first beam 1, used to embed the first embedded steel bar 12 corresponding to the expansion joint 3. At the same time, the groove is used to reserve space for the setting of subsequent temporary expansion joint structures.

[0044] Similarly, the second reserved slot 21 is a groove reserved in advance during the prefabrication of the second beam 2, used to embed the second embedded steel bar 22 corresponding to the expansion joint 3. At the same time, the groove is used to reserve space for the subsequent temporary expansion joint structure.

[0045] Expansion joint 3 is located between the first beam 1 and the second beam 2. Under the action of the supporting steel plate 4, the first beam 1 and the second beam 2 are connected. At the same time, under the action of the supporting steel plate 4, the expansion joint 3 is covered and the subsequent crushed stone layer 6 and asphalt layer 7 are supported.

[0046] The first beam 1 has a number of first embedded steel bars 12 partially exposed in the first reserved slot 11, and the second beam 2 has a number of second embedded steel bars 22 partially exposed in the second reserved slot 21. The first embedded steel bars 12 and the second embedded steel bars 22 are respectively positioned and connected to the two sides of the supporting steel plate 4.

[0047] The first embedded steel bar 12 and the second embedded steel bar 22 are respectively snapped onto both sides of the support steel plate 4, so that the installation of the support steel plate 4 does not require on-site welding and drilling for fixing. The support steel plate 4 can be positioned by directly snapping it between the first embedded steel bar 12 and the second embedded steel bar 22.

[0048] At the same time, the first embedded steel bar 12 and the second embedded steel bar 22 form a lateral limit on the support steel plate 4, firmly restricting the lateral sliding of the support steel plate 4, and always keeping the support steel plate 4 flush with the top surface of the first beam 1 and the second beam 2.

[0049] The vehicle wheel pressure is transmitted through the supporting steel plate 4 to the first embedded steel bar 12 and the second embedded steel bar 22, and then dispersed to the overall concrete of the first beam 1 and the second beam 2. This avoids the load being concentrated on the weak concrete at the edge of the supporting steel plate 4, effectively preventing the concrete at the edge of the supporting steel plate 4 from being crushed, chipped, or cracked, and extending the overall service life of the temporary expansion joint.

[0050] The side of the supporting steel plate 4 is engaged with the first embedded steel bar 12 and the second embedded steel bar 22, and the bottom of the supporting steel plate 4 abuts against the first beam 1 and the second beam 2. The supporting steel plate 4 can be moved upward with a certain amount of leeway to meet the installation requirements of the supporting steel plate 4.

[0051] A number of the first embedded steel bars 12 are arranged in rows along the length of the expansion joint 3. The side of the supporting steel plate 4 is formed with a first snap-fit ​​groove 41 that is corresponding to the first embedded steel bar 12. The number of first snap-fit ​​grooves 41 is consistent with the number of first embedded steel bars 12, and the first snap-fit ​​grooves 41 are snap-fitted one-to-one with the first embedded steel bars 12.

[0052] A number of the second pre-embedded steel bars 22 are arranged in rows along the length of the expansion joint 3. The side of the supporting steel plate 4 is formed with a second snap-fit ​​groove 42 that is corresponding to and snaps into the second pre-embedded steel bars 22. The number of second snap-fit ​​grooves 42 is consistent with the number of second pre-embedded steel bars 22, and the second snap-fit ​​grooves 42 are snapped into the second pre-embedded steel bars 22 one by one.

[0053] Both ends of the first embedded steel bar 12 are located inside the first beam 1, and both ends of the second embedded steel bar 22 are located inside the second beam 2, ensuring the connection strength of the first embedded steel bar 12 and the second embedded steel bar 22 to the supporting steel plate 4.

[0054] The surface of the asphalt layer 7 transitions smoothly with the top of the first beam 1 and the second beam 2.

[0055] A construction method for a temporary expansion joint structure for bridges, based on the temporary expansion joint structure for bridges, includes the following steps:

[0056] Step S1: Leveling the beams. Check the smoothness of the first beam 1 and the second beam 2 to ensure that the relative height difference of the bearing pads at both ends of the same beam of the first beam 1 and the second beam 2 is ≤3mm, the height difference of the four corners of the support is ≤2mm, and the height difference of the top surfaces of adjacent first beam 1 and second beam 2 is ≤5mm. Adjust the first beam 1 and / or the second beam 2 by adjusting the support according to the inspection results.

[0057] Use a 3-meter straightedge to measure the height difference between beams and slabs. If the height difference exceeds the allowable range, it can be finely adjusted using the supports.

[0058] Step S2: Inspect the condition of the first embedded steel bar 12 and the second embedded steel bar 22 on site, clean up debris at the expansion joint 3 and the bottom of the bridge abutment, and ensure that the construction surface is flat and clean. Check the position and condition of the original first embedded steel bar 12 and the second embedded steel bar 22 at the expansion joint 3. Perform preliminary correction on the bent first embedded steel bar 12 and the second embedded steel bar 22 to ensure that they can be effectively connected to the supporting steel plate 4 in the future.

[0059] Step S3: Install the support steel plate 4, which covers the expansion joint 3. At the same time, the two sides of the support steel plate 4 are simultaneously positioned and engaged with the first embedded steel bar 12 and the second embedded steel bar 22.

[0060] Step S3.1: Based on the design location of the expansion joint 3 and the distribution of the first embedded steel bar 12 and the second embedded steel bar 22, lay out the bottom of the expansion joint 3 and the bottom of the abutment to determine the installation position, elevation and fixing point of the supporting steel plate 4, ensuring that the steel plate can cover the entire bottom of the expansion joint 3 after installation, and that the first snap-fit ​​groove 41 formed on the supporting steel plate 4 corresponds one-to-one with the first embedded steel bar 12, and the second snap-fit ​​groove 42 corresponds one-to-one with the second embedded steel bar 22.

[0061] Step S3.2: According to the layout dimensions and the diameter of the embedded steel bars, grooves are cut on the side of the support steel plate 4. The width of the groove is 2-3 mm larger than the diameter of the first embedded steel bar 12 and the second embedded steel bar 22 to ensure that the first embedded steel bar 12 and the second embedded steel bar 22 can be inserted into the groove, so that the two sides of the support steel plate 4 are tightly connected to the first embedded steel bar 12 and the second embedded steel bar 22 respectively.

[0062] Step S3.3: Accurately place the support steel plate 4 at the layout position, so that the first embedded steel bar 12 and the second embedded steel bar 22 are inserted into the first snap-fit ​​groove 41 and the second snap-fit ​​groove 42 of the support steel plate 4 respectively, and make the bottom of the support steel plate 4 fit tightly with the construction surface without any suspension or looseness.

[0063] Step S4: Fill the crushed stone layer 6. Lay earthwork cloth 5 on the supporting steel plate 4, the first reserved groove 11 and the second reserved groove 21, and evenly fill the earthwork cloth 5 with single-diameter crushed stone.

[0064] Step S4.1: Lay multiple layers of earthwork fabric 5 on top of the supporting steel plate 4. The earthwork fabric 5 should cover the entire construction surface. The multiple layers of earthwork fabric 5 should overlap each other, with an overlap width of not less than 50mm. Ensure that there are no gaps or damage at the overlaps to prevent gravel and concrete from falling.

[0065] Step S4.2: Evenly fill the prepared single-size crushed stone onto the supporting steel plate 4 wrapped with earthwork cloth 5. During the filling process, use manual labor or small vibrating tools to gently vibrate to ensure that the crushed stone is filled densely, without gaps or looseness. The filling height of the crushed stone is controlled according to the design requirements, leaving room for the backfill thickness of the top recycled asphalt mixture.

[0066] Leave a 6cm allowance for the backfill thickness of the recycled asphalt mixture at the top. Avoid damaging the earthwork fabric 5 during the filling process. If damage to the earthwork fabric 5 is found, it should be replaced in time.

[0067] Step S4.3: After the crushed stone filling is completed, check the density and filling height of the crushed stone layer 6, and check whether the earthwork cloth 5 is intact or damaged, and whether the crushed stone has fallen off. If it does not meet the requirements, it needs to be rectified.

[0068] Step S5: Backfill the asphalt layer 7.

[0069] Step S5.1: Mix the recycled asphalt mixture on site using a simple mixer truck. Strictly control the amount of raw materials according to the design mix ratio, and appropriately extend the mixing time to ensure that the mixture is mixed evenly without segregation or clumping. The mixed mixture should be poured in a timely manner to avoid affecting its performance by leaving it for a long time.

[0070] Step S5.2: Evenly backfill the well-mixed recycled asphalt mixture onto the crushed stone layer 6, controlling the backfill thickness to 6cm. During backfilling, use a small vibrator to compact the mixture until there are no voids. Take care to protect the surrounding area during backfilling to avoid contaminating the road surface with the mixture.

[0071] Step S5.3: After the asphalt layer 7 is backfilled, the surface is leveled with a trowel to ensure a smooth transition between the asphalt layer 7 and the bridge deck of the first beam 1 and the second beam 2.

[0072] Step S6: Check the surface flatness of asphalt layer 7 along the length of expansion joint 3. Use a 3-meter straightedge to set a test point every 1 meter along the length of expansion joint. Place the 3-meter straightedge tightly against the cement panel and the temporary expansion joint backfill surface and measure the height difference between the two. If the height difference is found to be greater than 5mm, asphalt layer 7 needs to be treated to ensure that the final height difference is ≤5mm.

[0073] Step S7: Curing of the asphalt layer 7. After the raw asphalt mixture is backfilled, short-term curing is required. The curing time shall not be less than 24 hours. During the curing period, warning signs shall be set up and vehicles shall be prohibited from passing through to avoid the backfill layer being crushed or disturbed, and to ensure the formation of the mixture strength.

[0074] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention; therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0075] Although this document frequently uses reference numerals from the figures, such as first beam 1, first reserved slot 11, first embedded steel bar 12, second beam 2, second reserved slot 21, second embedded steel bar 22, expansion joint 3, supporting steel plate 4, first snap-fit ​​groove 41, second snap-fit ​​groove 42, earthwork fabric 5, crushed stone layer 6, asphalt layer 7, etc., the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A temporary expansion joint structure for a bridge, comprising a first beam (1), a second beam (2), and an expansion joint (3), wherein the expansion joint (3) is located at the connection between the first beam (1) and the second beam (2); characterized in that, The first beam (1) has a first reserved slot (11) at its end that communicates with the expansion joint (3), and the second beam (2) has a second reserved slot (21) at its end that communicates with the expansion joint (3); a supporting steel plate (4) for covering the expansion joint (3) is provided between the first beam (1) and the second beam (2), and the supporting steel plate (4) rests on the first reserved slot (11) and the second reserved slot (21); earthwork cloth (5) is laid on the supporting steel plate (4), the first reserved slot (11) and the second reserved slot (21), the earthwork cloth (5) is filled with a layer of crushed stone (6), and the crushed stone layer (6) is backfilled with an asphalt layer (7) for easy subsequent demolition.

2. The temporary expansion joint structure for bridges according to claim 1, characterized in that, The first beam (1) has a number of first embedded steel bars (12) partially exposed in the first reserved slot (11), and the second beam (2) has a number of second embedded steel bars (22) partially exposed in the second reserved slot (21). The first embedded steel bars (12) and the second embedded steel bars (22) are respectively positioned and connected to the two sides of the supporting steel plate (4).

3. A temporary bridge expansion joint structure according to claim 2, characterized in that, A number of the first pre-embedded steel bars (12) are arranged in a row along the length of the expansion joint (3), and the side of the supporting steel plate (4) has a first snap-fit ​​groove (41) that is corresponding to the first pre-embedded steel bars (12).

4. A temporary expansion joint structure for bridges according to claim 2, characterized in that, Several second pre-embedded steel bars (22) are arranged in rows along the length of the expansion joint (3), and the side of the supporting steel plate (4) has a second snap-fit ​​groove (42) that is corresponding to the second pre-embedded steel bars (22).

5. A temporary bridge expansion joint structure according to claim 2, characterized in that, Both ends of the first embedded steel bar (12) are located inside the first beam (1), and both ends of the second embedded steel bar (22) are located inside the second beam (2).

6. A temporary bridge expansion joint structure according to claim 1, characterized in that, The surface of the asphalt layer (7) smoothly transitions to the top of the first beam (1) and the second beam (2).

7. A construction method for a temporary bridge expansion joint structure, based on the temporary bridge expansion joint structure as described in any one of claims 1-6, characterized in that, Includes the following steps: Step S1: Leveling the beams. Check the smoothness of the first beam (1) and the second beam (2) to ensure that the relative height difference between the pad stones at both ends of the same beam of the first beam (1) and the second beam (2) is ≤3mm, the height difference between the four corners of the support is ≤2mm, and the height difference between the top surfaces of adjacent first beams (1) and second beams (2) is ≤5mm. Adjust the first beam (1) and / or the second beam (2) by adjusting the support according to the inspection results. Step S2: Check the condition of the first embedded steel bar (12) and the second embedded steel bar (22) on site; Step S3: Install the support steel plate (4), which covers the expansion joint (3). At the same time, the two sides of the support steel plate (4) are simultaneously positioned and connected to the first pre-embedded steel bar (12) and the second pre-embedded steel bar (22). Step S4: Fill the crushed stone layer (6), lay earthwork cloth (5) on the supporting steel plate (4), the first reserved groove (11) and the second reserved groove (21), and evenly fill the earthwork cloth (5) with single-diameter crushed stone; Step S5: Backfill the asphalt layer (7); Step S6: Inspect the surface smoothness of the asphalt layer (7) along the length of the expansion joint (3); Step S7: Curing of the asphalt layer (7).

8. The construction method of a temporary expansion joint structure for bridges according to claim 7, characterized in that, Step S3 further includes the following sub-steps: Step S3.1: Based on the design location of the expansion joint (3) and the distribution of the first embedded steel bar (12) and the second embedded steel bar (22), lay out the bottom of the expansion joint (3) and the bottom of the bridge abutment to determine the installation position, elevation and fixing point of the supporting steel plate (4) and ensure that the steel plate can cover the bottom of the entire expansion joint (3) after installation. Step S3.2: According to the layout dimensions and the diameter of the embedded steel bars, grooves are cut on the side of the supporting steel plate (4) to ensure that the first embedded steel bar (12) and the second embedded steel bar (22) can be inserted into the groove; Step S3.3: Place the support steel plate (4) accurately at the layout position, so that the first embedded steel bar (12) and the second embedded steel bar (22) are inserted into the first snap-fit ​​groove (41) and the second snap-fit ​​groove (42) of the support steel plate (4) respectively, and make the bottom of the support steel plate (4) fit tightly with the construction surface without any suspension or looseness.

9. A construction method for a temporary expansion joint structure for bridges according to claim 7, characterized in that, Step S4 further includes the following sub-steps: Step S4.1: Lay multiple layers of earthwork cloth (5) on top of the supporting steel plate (4). The earthwork cloth (5) needs to cover the entire construction surface, and the multiple layers of earthwork cloth (5) overlap each other. Step S4.2: Fill the prepared single-size crushed stone evenly onto the supporting steel plate (4) wrapped with earthwork cloth (5). During the filling process, use manual or small vibrating tools to gently vibrate to ensure that the crushed stone is filled densely, without gaps or looseness. The filling height of the crushed stone is controlled according to the design requirements, and the backfill thickness of the top recycled asphalt mixture is reserved. Step S4.3: After the crushed stone filling is completed, check the density and filling height of the crushed stone layer (6), and check whether the earthwork cloth (5) is intact or damaged, and whether the crushed stone has fallen off.

10. A construction method for a temporary expansion joint structure for bridges according to claim 7, characterized in that, Step S5 further includes the following sub-steps: Step S5.1: Mix the recycled asphalt mixture on site; Step S5.2: The well-mixed recycled asphalt mixture is backfilled evenly above the crushed stone layer (6). The backfill thickness is controlled according to the design. Vibration is carried out during the backfilling process. Step S5.3: After the asphalt layer (7) is backfilled, the surface of the asphalt layer (7) is leveled to ensure a smooth transition with the bridge deck of the first beam (1) and the second beam (2).

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