A continuous beam bridge top slab concrete crack reinforcement structure and repair method thereof

Abstract

The present invention proposes a reinforcement structure for the cracking of the top plate of a continuous beam bridge, which is applied to the cracked area of ​​the top plate, and includes a plurality of groups of first stiffening frames arranged in the equal-thickness section of the top plate and a plurality of groups of second stiffening frames arranged in the thickened section of the top plate. The plurality of groups of first stiffening frames and the plurality of groups of second stiffening frames are arranged at intervals along the longitudinal direction of the bridge, and each group of the first stiffening frames includes a plurality of through bolts arranged at intervals along the transverse direction of the bridge, and the through bolts are passed through the top plate and fixedly connected thereto, and each group of the second stiffening frames includes a plurality of anchor bolts arranged at intervals along the transverse direction of the bridge, and the top ends of the anchor bolts are inserted into the top plate and fixedly connected thereto. The present invention effectively reduces the prestress loss caused by the cracking of the concrete by arranging stiffening frames in the cracked area of ​​the top plate, so that the overall structure meets the design force requirements, and fills the cracked part with a grouting layer, so that the later repaired area is effectively combined with the original structure into a whole.

Description

Technical Field

[0001] The present invention relates to the technical field of highway bridges, and in particular to a reinforcement structure for a cracked top plate of a continuous beam bridge and a repair method thereof. Background Art

[0002] As continuous beam bridges are widely used in various parts of my country, reports of bridge defects during the construction phase have also occurred from time to time. The main reasons are that the prestressed steel strands between the upper and lower layers of steel bars were not set completely according to the requirements during the construction process, and the prestressed steel strands were partially offset.

[0003] There has been no good method for repairing the cracked area of ​​the concrete of the continuous beam bridge, and local mortar repair is usually used. This method has the following disadvantages: 1. After the concrete cracks, the prestressed steel strands are locally deformed and the prestress is lost. This method does not improve the stress loss; 2. After the local mortar repair, the local mortar will hollow out and fall off as the stress changes in the later period. Summary of the invention

[0004] The purpose of the present invention is to provide a reinforcement structure for the cracked top plate of a continuous beam bridge and a repair method thereof, so as to solve the problems in the prior art of local deformation of prestressed steel strands, loss of prestress, and hollowing and falling of local mortar as stress changes in the later stage.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a reinforcement structure for the cracked top plate of a continuous beam bridge, applied to the cracked area of ​​the top plate, including multiple groups of first stiffening frames arranged in the equal thickness section of the top plate and multiple groups of second stiffening frames arranged in the thickened section of the top plate, the multiple groups of first stiffening frames and the multiple groups of second stiffening frames are all arranged at intervals along the longitudinal direction of the bridge, each group of the first stiffening frames includes a plurality of through bolts arranged at intervals along the transverse direction of the bridge, the through bolts are penetrated through the top plate and fixedly connected thereto, each group of the second stiffening frames includes a plurality of anchor bolts arranged at intervals along the transverse direction of the bridge, the top ends of the anchor bolts are inserted into the top plate and fixedly connected thereto.

[0006] As a preferred embodiment, the first stiffening frame also includes a channel steel arranged at the bottom end of the top plate along the transverse bridge direction, and a plurality of one-to-one corresponding through holes are respectively opened on the channel steel and the top plate, and the through bolts pass through the through holes, and the upper and lower ends of the through bolts are respectively fixedly connected to the top end of the top plate and the bottom end of the channel steel.

[0007] As a preferred embodiment, the first stiffening frame also includes a temporary support arranged above the top plate along the transverse bridge direction, and a plurality of corresponding through holes are respectively opened on the temporary support and the top plate, and the through bolts pass through the through holes, and the upper and lower ends of the through bolts are respectively fixedly connected to the top end of the temporary support and the bottom end of the top plate.

[0008] As a preferred solution, the second stiffening frame further includes a channel steel arranged at the bottom end of the top plate along the transverse direction of the bridge, and the anchor bolts penetrate the channel steel and the top ends thereof are inserted into the interior of the top plate.

[0009] As a preferred embodiment, the cracked area of ​​the top plate has exposed prestressed steel bundles, characterized in that a steel bundle pad is provided between the prestressed steel bundle and the channel steel, and the upper and lower ends of the steel bundle pad are respectively fixedly connected to the prestressed steel bundle and the channel steel.

[0010] As a preferred solution, a leveling pad is provided between the bottom end of the top plate and the channel steel for adjusting the channel steel to a horizontal state.

[0011] As a preferred solution, steel plates are adhered to the upper and lower surfaces of the top plate, and a grouting layer is filled between the lower surface of the top plate and the steel plate through a glue injection hole arranged on the top plate.

[0012] The present invention also provides a method for repairing cracked top plates of continuous beam bridges, the method comprising the following steps: 1) on-site inspection, investigation and review of the site, verification of the range and relevant dimensions of the top plate cracks, detection of the position of the prestressed steel strands, and use this as a basis for drilling holes, the top plate drilling position should avoid the position of the prestressed steel strands;

[0013] 2) Construction of side reinforcing frames: install the first and second reinforcing frames at the edge of the cracked area of ​​the top plate to prevent secondary cracking caused by disturbances caused by subsequent construction; 3) Remove concrete and clean the peeled concrete in the cracked area section by section; 4) Construction of middle reinforcing frames: install the first reinforcing frames at intervals in the middle of the cracked area along the direction of the prestressed steel bundles, and fix the exposed prestressed steel bundles on the reinforcing frames; 5) Connection of bottom steel bars: correct the exposed bottom longitudinal and transverse steel bars, connect them by binding to form a steel mesh, and connect them with the reinforcing frames; 6) Paste the steel plate: treat the bonding surface between the top plate and the steel plate, and apply adhesive on the bonding surface for pasting; 7) Drill glue holes and pour grouting material: drill glue holes on the top plate, pour grouting material between the bottom end of the top plate and the steel plate through the glue holes, and after the grouting material solidifies and reaches a certain strength, pour structural glue in the gap between the bolts of the reinforcing frame and the top plate.

[0014] As a preferred solution, the specific steps of pasting the steel plate include: top plate surface treatment, grinding the top plate concrete bonding surface, removing 1 to 2 mm thick surface layer, completely exposing the new surface, removing dust with compressed air or rinsing with clean water, spraying the bonding surface with acetone after it is completely dried, and roughening the bonding surface to make the bonding surface rough; steel plate surface treatment, using sandblasting, emery cloth or flat grinding wheel to grind the steel plate bonding surface, the grinding lines are perpendicular to the force direction of the steel plate, until a metallic luster appears, and then wiping the steel plate bonding surface with absorbent cotton dipped in acetone; steel plate drilling, drilling holes in the steel plate, the hole position of the steel plate It should correspond to the position of the through holes in the top plate concrete; install the steel plate, make the bolts of the reinforcing frame pass through the holes in the steel plate and tighten the bolts; prepare the glue, weigh the two components A and B of the adhesive in proportion, pour them into a container and mix them evenly; paste the steel plate, use a spatula to apply the adhesive on the bonding surface of the treated top plate and steel plate, first use a small amount of adhesive to scrape back and forth on the bonding surface several times, and then add more to make the thickness of 1 to 3mm, thick in the middle and thin at the edges, and then paste the steel plate to the predetermined position. After the steel plate is pasted, gently tap the steel plate along the bonding surface with a hammer. If there is no hollow sound, it means it has been densely pasted, otherwise the steel plate should be peeled off and pasted again.

[0015] Compared with the prior art, the beneficial effects of the present invention include: by setting a reinforcing frame in the cracked area of ​​the top plate, the prestress loss caused by concrete cracking is effectively reduced, so that the overall structure meets the design force requirements; by pasting steel plates on the upper and lower parts of the top plate and filling the cracked parts with a grouting layer, the later repaired area is effectively combined with the original structure into a whole, and will not become hollow or fall off later. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0017] Figure 1 This is a schematic elevation diagram of the top plate of a continuous beam bridge according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic plan view of the top plate of a continuous beam bridge according to an embodiment of the present invention;

[0019] Figure 3 The cross-sectional view of the reinforcement frames A-1 and A-2 of the reinforcement structure for the continuous beam bridge collapse according to the embodiment of the present invention;

[0020] Figure 4 The cross-sectional views of the reinforcement frames A-3 to A-5 of the reinforcement structure for the continuous beam bridge collapse according to the embodiment of the present invention;

[0021] Figure 5 for Figure 4 The local enlarged part at A in the middle;

[0022] Figure 6 The cross-sectional views of the reinforcement frames A-6 and A-7 of the reinforcement structure for the continuous beam bridge collapse according to the embodiment of the present invention;

[0023] Figure 7 for Figure 6 A partial enlarged view of point B in the middle;

[0024] Figure 8 The cross-sectional view of the reinforcement frames B-1 and B-2 of the reinforcement structure for the continuous beam bridge collapse according to the embodiment of the present invention;

[0025] Fig. 9 A flow chart of a method for repairing a cracked continuous beam bridge according to an embodiment of the present invention;

[0026] Fig.10 The figure is a flow chart of pasting steel plates in an embodiment of the present invention.

[0027] Numbers in the figure: 1 top plate, 2 bottom plate, 3 end beam, 4 box chamber, 5 grouting layer, 6 through bolts, 61 screw rods, 62 washers, 63 nuts, 7 anchor bolts, 8 temporary support, 9 channel steel, 10 grouting holes, 11 temporary pads, 12 steel bundle pads, 13 steel plates, 14 prestressed steel bundles, 15 leveling pads. DETAILED DESCRIPTION

[0028] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0029] It should be understood that the continuous beam bridge comprises a top plate 1, a bottom plate 2 and an end cross beam 3, a box chamber 4 is formed between the top plate 1, the bottom plate 2 and the end cross beam 3, the area prone to cracking is located at the bottom end of the top plate 1, the end of the top plate 1 away from the end cross beam 3 is a section of equal thickness, and the end close to the end cross beam 3 is a section that gradually thickens.

[0030] According to one embodiment of the present invention, Figure 1 and Figure 2 A reinforcement structure for cracked top slab of a continuous beam bridge is applied to the cracked area of ​​the top slab 1, comprising a first stiffening frame and a second stiffening frame. The first stiffening frames are 7 in number, which are arranged in equal thickness sections of the top slab 1 in sequence from the segment line to the beam end line (along the bridge direction), namely A-1 to A-7; the second stiffening frames are 4 in number, which are arranged in thickened sections of the top slab 1 in sequence from the beam end line to the segment line (along the bridge direction), namely B-1 to B-4.

[0031] like Figure 1 and Figure 3 As shown, the first stiffening frames A-1 and A-2 are located at the edges of the cracked areas of the top plate 1, and include a channel steel 9 arranged at the bottom end of the top plate 1 along the transverse direction. A plurality of one-to-one corresponding through holes are provided on the channel steel 9 and the top plate 1, and through bolts 6 are passed through the through holes. The upper and lower ends of the through bolts 6 are fixedly connected to the top end of the top plate 1 and the bottom end of the channel steel 9, respectively.

[0032] like Figure 1 and Figure 4 As shown, the first stiffening skeleton A-3, A-4, and A-5 are located in the middle of the cracked area of ​​the top plate 1, and include a temporary support 8 arranged above the top plate 1 along the transverse bridge direction, and a temporary pad 11 is arranged between the temporary support 8 and the top plate 1 to support the temporary support 8. A plurality of one-to-one corresponding through holes are opened on the temporary support 8 and the top plate 1, and through bolts 6 are inserted in the through holes, and the upper and lower ends of the through bolts 6 are fixedly connected to the temporary support 8 and the bottom end of the top plate 1 respectively.

[0033] like Figure 5 As shown, the through bolt 6 includes a screw rod 61, a gasket 62 and a nut 63. The screw rod 61 passes through the temporary support 8 and the top plate 1 in sequence. The gasket 62 is sleeved on the upper and lower ends of the screw rod 61, and the upper and lower ends of the screw rod 61 are locked and connected by nuts 63.

[0034] The cracked area of ​​the top plate 1 has an exposed prestressed steel bundle 14, and a steel bundle spacer 12 is provided between the prestressed steel bundle 14 and the channel steel 9, and the upper and lower ends of the steel bundle spacer 12 are fixedly connected to the prestressed steel bundle 14 and the channel steel 9 respectively.

[0035] like Figure 1 and Figure 6 As shown, the first stiffening frames A-6 and A-7 are located in the middle of the cracked area of ​​the top plate 1, and include channel steels 9 respectively arranged at the bottom end of the top plate 1 along the transverse bridge direction and temporary supports 8 arranged at the top end of the top plate 1. The temporary supports 8 and the channel steels 9 are arranged relatively to each other. A plurality of one-to-one corresponding through holes are opened on the channel steels 9, the temporary supports 8 and the top plate 1, and through bolts 6 are passed through the through holes. The through bolts 6 pass through the temporary support 8, the top plate 1 and the channel steels 9 in turn, and the upper and lower ends thereof are fixedly connected to the temporary support 8 and the channel steels 9 respectively. A temporary pad 11 is arranged between the temporary support 8 and the top plate 1 to support the temporary support 8.

[0036] like Figure 7 As shown, there is a gap between the bottom end of the top plate 1 and the channel steel 9, and leveling is performed by arranging a leveling pad 15 in the gap so that the channel steel 9 is in a horizontal state.

[0037] like Figure 1 and Figure 8As shown, the second stiffening frames B-1 and B-2 are located at the edge of the cracked area of ​​the top plate 1 and in the thickened section of the top plate 1. They include channel steel 9 and anchor bolts 7. The channel steel 9 is arranged at the bottom end of the top plate 1. The top end of the anchor bolt 7 is inserted into the top plate 1, and the bottom end thereof is fixedly connected to the channel steel 9.

[0038] The second stiffening frames B-3 and B-4 are fixedly arranged in the thickened section of the top plate 1 between the second stiffening frame B-2 and the first stiffening frame A-7, and include anchor bolts 7, which are inserted into the top plate 1 and fixedly connected thereto.

[0039] Furthermore, steel plates 13 are provided on the upper and lower surfaces of the top plate 1, and holes corresponding to the through bolts 6 or anchor bolts 7 are opened on the steel plates 13. The bolts pass through the holes, and the steel plates 13 are adhered to the upper and lower surfaces of the top plate 1 by applying glue, and then tightened to fix them.

[0040] The top plate 1 is provided with a glue injection hole, through which a grouting layer 5 is filled between the lower surface of the top plate 1 and the steel plate 13 .

[0041] The present invention also provides a method for repairing a cracked top plate 1 of a continuous beam bridge, the method comprising the following steps:

[0042] S1: On-site inspection, investigate and review the site, verify the scope of the top plate 1 cracking and related dimensions, detect the position of the prestressed steel strand 14, and use it as a basis for drilling holes. The drilling holes include drilling glue holes and bolt holes. The drilling position should avoid the position of the prestressed steel strand 14.

[0043] S2: Construction of side reinforcing frames: installing the first reinforcing frames A-1, A-2 and the second reinforcing frames B-1, B-2 at the edge of the cracked area of ​​the top plate 1 to prevent secondary cracking caused by disturbances caused by subsequent construction.

[0044] When installing the first skeleton A-1 and A-2, first drill bolt holes on the top plate 1 according to the drilling basis, align the through holes on the channel steel 9 with the bolt holes, pass the screw 61 through the two through holes, and set gaskets 62 at both ends of the screw 61, and fix it by tightening the nut 63.

[0045] S3: Chisel away the concrete. For areas with severe cracks, the peeled concrete should be cleaned up section by section to ensure the safety of the box girder structure and construction.

[0046] S4: Construction of the middle stiffening frame: Install the first stiffening frames A-3 to A-7 and the second stiffening frames B-3 and B-4 at intervals in the middle of the cracked area along the direction of the prestressed steel strands 14, and fix the exposed prestressed steel strands 14 to the stiffening frames through the steel strand pads 12 to prevent the prestressed steel strands 14 from loosening. After the steel strands are fixed, tighten the bolts with an electric or torque wrench.

[0047] Install the first stiffening frames A-3 to A-7. First, drill bolt holes on the top plate 1 according to the drilling criteria, and align the holes on the channel steel 9 or temporary support 8 with the bolt holes. Pass the screw 61 through the two holes, and set gaskets 62 at both ends of the screw 61, and fix them by tightening the nuts 63.

[0048] S5: When loose concrete in the cracked area is removed during the bottom layer steel bar connection, the exposed bottom layer longitudinal and transverse steel bars are promptly corrected and connected by binding to form a steel mesh, which is then connected to the reinforcing frame.

[0049] S6: Pasting the steel plate 13, processing the bonding surface of the top plate 1 and the steel plate 13, and applying adhesive on the bonding surface for pasting. Specifically, pasting the steel plate 13 includes the following steps:

[0050] S601: Surface treatment of top plate 1. For a relatively clean concrete surface, the bonding surface can be directly polished to remove the 1-2 mm thick surface layer to completely expose the new surface. Use compressed air to remove dust or rinse with clean water. After it is completely dry, spray the surface with acetone.

[0051] For new concrete surfaces, first use a wire brush to brush away loose scum on the surface to reveal the new surface, then use a stiff-bristle brush dipped in detergent to scrub the surface or rinse with clean water and wait until it is completely dry.

[0052] For concrete surfaces with high humidity, in addition to meeting the above requirements, artificial drying treatment is also required. In order to better ensure the pasting effect, the surface should also be roughened to make the concrete surface rough. During construction, according to the requirements of the drawings and combined with the actual measurement conditions, ensure that the hard concrete is exposed and a flat rough surface is formed, and then use a wire wheel to remove the surface scum and remove the loose materials on the surface. For concrete defects, epoxy structural adhesive should be used to repair them, and then grind them after curing. Finally, use compressed air to blow away the dust particles on the surface, and wipe the surface with toluene or industrial acetone several times and then dry it.

[0053] S602: Surface treatment of steel plate 13. If the steel plate 13 is not rusted or slightly rusted, it can be polished by sandblasting, emery cloth or flat grinding wheel until the metallic luster appears. Then wipe the adhesive surface of the steel plate 13 clean with absorbent cotton dipped in acetone. The greater the polishing roughness, the better. The polishing lines should be perpendicular to the force direction of the steel plate 13 as much as possible. If the steel plate 13 is severely rusted, it must be soaked in moderate hydrochloric acid for 20 minutes to make the rust layer fall off, then rinsed with lime water, and finally polished with a flat grinding wheel to create the lines.

[0054] S603: Drill holes in the steel plate 13. The positions of the holes in the steel plate 13 should correspond to the positions of the through holes in the concrete of the top plate 1.

[0055] S604: Install the steel plate 13, pass the bolts of the stiffening frame through the holes of the steel plate 13 and tighten the bolts.

[0056] S605: Glue preparation. The adhesive is a two-component adhesive with a ratio of 3:1. It must be prepared temporarily on site. Strictly follow the instructions for use when preparing the adhesive. Weighing equipment is configured on site to strictly measure and ensure the correct ratio. Pour components A and B into a clean container and use a mechanical method to stir in the same direction until the color is uniform. The proportion of the adhesive should be adjusted appropriately according to the local climate conditions and the length of effective time.

[0057] S606: Paste the steel plate 13. After the adhesive is prepared, use a spatula to apply the adhesive to the bonding surface of the processed top plate 1 and the steel plate 13. First, use a small amount of adhesive to scrape back and forth on the bonding surface several times, and then add it to a thickness of 1 to 3 mm, thick in the middle and thin at the edges. If it is pasted on the vertical surface, a layer of dewaxed glass cloth can be added to prevent flow. After the steel plate 13 is pasted, use a hammer to gently tap the steel plate 13 along the bonding surface. After the steel plate 13 is pasted, use a hammer to gently tap the steel plate 13 along the bonding surface. If there is no hollow sound, it means that it has been pasted tightly. Otherwise, the steel plate 13 should be peeled off and pasted again. During the construction process of pasting the steel plate 13, the steel plate 13 should be tapped gently continuously to check the fullness of the adhesive under the steel plate 13 in time. If it is found that there is insufficient adhesive in some parts and there are hollows, the bolts should be loosened in time, and the adhesive should be filled into the gap from the side of the steel plate 13 to make the steel plate 13 flat and close.

[0058] S607: Curing. After the steel plate 13 is pasted, it needs to be cured. The curing time is not less than 24 hours. During the curing period, the steel plate 13 must not be disturbed in any way. If the temperature is low, artificial heating can be adopted, generally using infrared lamps for heating.

[0059] S608: Surface protection, surface cleaning of the component outer surface, dry film thickness, coating quality, construction technology, etc. must strictly comply with the technical requirements of "Technical Conditions for Anti-corrosion Coating of Highway Bridge Steel Structures" (JT / T 722-2008).

[0060] S609: Inspection: The quality of the steel plate 13 pasting is tested by non-destructive inspection. The main inspection contents include: the color of the overflow glue on the edge of the steel plate 13, the degree of hardening; knocking the steel plate 13 with a small hammer to test the effective bonding area of ​​the steel plate 13, judging the curing effect of the pasting from the sound, and the effective bonding area of ​​the anchoring area should not be less than 95%, otherwise the pasting is invalid and should be peeled off and pasted again.

[0061] S7: Drill glue injection holes and pour grouting material. Drill glue injection holes on the top plate 1, pour grouting material between the bottom end of the top plate 1 and the steel plate 13 through the glue injection holes, and after the grouting material solidifies to a certain strength, pour structural glue into the gap between the bolts of the reinforcing frame and the top plate 1.

[0062] S8: Remove temporary support 8. After the grouting material and structural adhesive have reached sufficient strength, pre-tighten the bolts to 30KN again, and then remove temporary support 8.

[0063] S9: Quality inspection and acceptance.

[0064] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A reinforcement structure for the cracking of the top plate of a continuous beam bridge, which is applied to the cracking area of ​​the top plate. It is characterized in that It includes a plurality of groups of first stiffening frames arranged at the equal-thickness section of the top plate and a plurality of groups of second stiffening frames arranged at the thickened section of the top plate, wherein the plurality of groups of first stiffening frames and the plurality of groups of second stiffening frames are arranged at intervals along the longitudinal direction of the bridge, each group of the first stiffening frames includes a plurality of through bolts arranged at intervals along the transverse direction of the bridge, the through bolts penetrate the top plate and are fixedly connected thereto, and each group of the second stiffening frames includes a plurality of anchor bolts arranged at intervals along the transverse direction of the bridge, the top ends of the anchor bolts are inserted into the top plate and are fixedly connected thereto; The first stiffening frame further comprises a channel steel arranged at the bottom end of the top plate along the transverse bridge direction, the channel steel and the top plate are respectively provided with a plurality of through holes corresponding to each other, the through bolts penetrate the through holes, and the upper and lower ends of the through bolts are respectively fixedly connected to the top end of the top plate and the bottom end of the channel steel; The second stiffening frame further includes a channel steel arranged at the bottom end of the top plate along the transverse bridge direction, the anchor bolts penetrate the channel steel and the top ends thereof are inserted into the interior of the top plate; The cracked area of ​​the top plate has exposed prestressed steel bundles, and is characterized in that a steel bundle pad is provided between the prestressed steel bundle and the channel steel, and the upper and lower ends of the steel bundle pad are respectively fixedly connected to the prestressed steel bundle and the channel steel.

2. The reinforcement structure for the continuous beam bridge top plate collapse according to claim 1, It is characterized in that The first stiffening frame also includes a temporary support arranged above the top plate along the transverse bridge direction, and a plurality of corresponding through holes are respectively opened on the temporary support and the top plate, and the through bolts pass through the through holes, and the upper and lower ends of the through bolts are respectively fixedly connected to the top end of the temporary support and the bottom end of the top plate.

3. The reinforcement structure for the continuous beam bridge top plate collapse according to claim 1, It is characterized in that A leveling pad is provided between the bottom end of the top plate and the channel steel for adjusting the channel steel to a horizontal state.

4. According to the reinforcement structure for cracked top plates of continuous beam bridges as described in claim 1, steel plates are adhered to the upper and lower surfaces of the top plate, and a grouting layer is filled between the lower surface of the top plate and the steel plate through a glue injection hole arranged on the top plate.

5. A method for repairing cracked top slabs of continuous beam bridges. It is characterized in that The repair method comprises the following steps: 1) On-site inspection: conduct on-site investigation and review, verify the scope of roof cracking and related dimensions, detect the position of prestressed steel strands, and use it as a basis for drilling. The location of roof drilling should avoid the location of prestressed steel strands; 2) Side reinforcement frame construction: install the first reinforcement frame and the second reinforcement frame at the edge of the roof crack area to prevent secondary cracking caused by disturbances caused by subsequent construction; 3) Chisel away the concrete and clean the peeled concrete section by section in the cracked area; 4) Construction of the middle stiffening frame: the first stiffening frame is set at intervals in the middle of the cracked area along the direction of the prestressed steel strands, and the exposed prestressed steel strands are fixed on the stiffening frame; 5) Connect the bottom steel bars: modify the exposed bottom longitudinal and transverse steel bars, connect them by tying to form a steel mesh, and connect them to the reinforcing frame; 6) Paste the steel plate, process the bonding surface between the top plate and the steel plate, and apply adhesive on the bonding surface for pasting; 7) Drill glue injection holes and pour grouting material. Drill glue injection holes on the top plate and pour grouting material between the bottom end of the top plate and the steel plate through the glue injection holes. After the grouting material solidifies and reaches a certain strength, pour structural glue into the gap between the bolts of the stiffening frame and the top plate.

6. The method for repairing cracked top slab of a continuous beam bridge according to claim 5, It is characterized in that The specific steps of pasting the steel plate include: Surface treatment of the roof: grind the concrete bonding surface of the roof to remove 1-2mm thick surface layer to completely expose the new surface, remove dust with compressed air or rinse with clean water, spray the bonding surface with acetone after it is completely dry, and chisel the bonding surface to make it rough; Steel plate surface treatment: Use sandblasting, emery cloth or flat grinding wheel to grind the steel plate bonding surface, with the grinding lines perpendicular to the force direction of the steel plate until the metallic luster appears, and then wipe the steel plate bonding surface clean with absorbent cotton dipped in acetone; Drill holes in the steel plate. The holes in the steel plate should correspond to the holes in the top plate concrete. Install the steel plate, pass the bolts of the stiffening frame through the holes of the steel plate and tighten the bolts; Prepare the adhesive: weigh the two components of the adhesive in proportion, pour them into a container and stir evenly; To paste the steel plates, use a spatula to apply the adhesive on the treated top plate and the bonding surface of the steel plate. First, use a small amount of adhesive to scrape back and forth on the bonding surface several times, and then add more to a thickness of 1 to 3 mm, thick in the middle and thin at the edges. Then stick the steel plate to the predetermined position. After the steel plate is pasted, use a hammer to gently tap the steel plate along the bonding surface. If there is no hollow sound, it means that it has been densely pasted. Otherwise, the steel plate should be peeled off and pasted again.

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