A method for reinforcing a bridge cap beam against overturning

Abstract

This invention relates to a method for reinforcing bridge cap beams against overturning, belonging to the field of building reinforcement technology. The invention addresses the problem of insufficient performance of steel plates in steel-plate reinforcement of cap beams. First, several chemical anchors are installed on the two sides and two ends of the cap beam. Stiffening ribs are installed at both ends of the cap beam. Second steel plates are installed on the outer sides of the two stiffening ribs. First steel plates are installed on the front and rear sides of the cap beam. Two second steel plates and two first steel plates are sequentially connected end-to-end to form a retaining frame. Each chemical anchor on both ends of the cap beam is threadedly connected to a tension nut. Several tension nuts are screwed in the opposite direction, applying pressure to the second steel plate on the same side, which in turn applies tension to the first steel plate. Finally, epoxy resin is injected between the first steel plate and the cap beam to form a unified structural load-bearing structure. The prestressed first steel plates on the front and rear sides of the cap beam significantly improve their utilization efficiency and save material usage.

Description

Technical Field

[0001] This invention belongs to the field of building reinforcement technology, and in particular relates to a method for reinforcing bridge cap beams against overturning. Background Technology

[0002] A cap beam is a reinforced concrete crossbeam installed on top of a pier in a bridge structure to support, distribute, and transfer the loads of the superstructure. Its main function is to support the superstructure of the bridge and transfer all loads to the substructure.

[0003] Steel plate bonding reinforcement involves bonding steel plates to the surface of a concrete structure using a high-performance epoxy adhesive, forming a unified whole between the steel plate and the concrete. This method utilizes the excellent tensile strength of the steel plate to enhance the load-bearing capacity and stiffness of the concrete structure. This method is currently a mainstream and effective reinforcement method for the anti-overturning reinforcement of existing bridge cap beams. Its advantages include simple and quick operation, and no increase in the self-weight of the cap beam structure. However, its disadvantage is that the reinforcement of the cap beam is passive; the performance of the bonded steel plate cannot be fully utilized. Generally, the effective load-bearing capacity of the steel plate is only within 20% of its design capacity, making it unsuitable for cap beam structures requiring a significant increase in load-bearing capacity after reinforcement. Summary of the Invention

[0004] The purpose of this invention is to provide a method for strengthening bridge cap beams against overturning, thereby addressing the problem that the performance of steel plates used in steel-plate reinforcement of cap beams cannot be fully utilized. The technical solution adopted in this invention is as follows:

[0005] A method for strengthening bridge cap beams against overturning, wherein the cap beams are positioned on the left and right sides, includes the following steps:

[0006] Step 1: Repair the existing cracks in the cap beam;

[0007] Step 2: Roughen the areas to be bonded on the front and rear sides and left and right ends of the cap beam to expose the aggregate of the cap beam. Use an iron brush or compressed air to clean the surface dust of the cap beam.

[0008] Step 3, Rebar Installation: Detect the main reinforcement bars of the cap beam. Drill several types of reinforcement holes on the front, back, left, and right ends of the cap beam, avoiding the main reinforcement bars. First, inject rebar adhesive into each type of reinforcement hole. Then, insert several chemical anchors into the corresponding type of reinforcement holes one by one. Wait for the rebar adhesive to solidify so that the chemical anchors are bonded to the cap beam as one.

[0009] Step 4: Fabricate the first steel plate, second steel plate, stiffening ribs, tension nuts, and reinforced semi-frame, and perform surface rust removal and cleaning. The first steel plate, second steel plate, and stiffening ribs are all rectangular steel plates. The length of the stiffening ribs is determined based on the width of the cap beam. The length of the first steel plate is equal to the sum of the length of the cap beam and the width of the two stiffening ribs. The length of the second steel plate is equal to the sum of the width of the cap beam and the thickness of the two first steel plates. Let the cross-sectional area of ​​the first steel plate be S (in meters). 2 S is determined by the following formula:

[0010]

[0011] In the formula:

[0012] F represents the compressive stress that needs to be applied to the end face of the cap beam, in N.

[0013] L is the length of the first steel plate, in meters (m).

[0014] ΔL is the elongation elastic deformation of the first steel plate when both ends are subjected to tensile stress F after the two first steel plates are superimposed and combined, in meters;

[0015] ΔL is determined by the following formula:

[0016] ΔL=(σ / E)×L=[(F / S) / E]×L

[0017] In the formula:

[0018] σ is the allowable tensile stress of the first steel plate, in MPa;

[0019] E is the elastic modulus of the first steel plate, in MPa;

[0020] Step 5: Two stiffening ribs are horizontally arranged at the left and right ends of the cap beam respectively. A number of leakage ports are provided on the stiffening ribs. The front and rear ends of the stiffening ribs are respectively aligned with the front and rear side faces of the cap beam. The inner side edges of the stiffening ribs are abutted against the bonding areas to be bonded on the corresponding end faces of the cap beam. The stiffening ribs are located in the middle vertically of the corresponding bonding areas. Two first steel plates are respectively arranged in parallel on the front and rear sides of the cap beam. The inner end faces of the first steel plates are abutted against the bonding areas to be bonded on the corresponding side faces of the cap beam. A number of long round holes through which a number of chemical anchor bolts on the corresponding side faces of the cap beam can pass are provided on the first steel plates. The long round holes are arranged horizontally. The left and right ends of the first steel plates are respectively aligned with the outer side edges of the two stiffening ribs. Two second steel plates are arranged in parallel on the outer sides of the two stiffening ribs. The upper and lower side edges of the first steel plates and the second steel plates are respectively aligned. The inner end face of the second steel plate is connected to the outer side edge of the same-side stiffening rib. The front and rear ends of the second steel plate are respectively aligned with the outer end faces of the two first steel plates. The tensioning nut includes an internal thread section. One end of the internal thread section is provided with a backing plate. Each chemical anchor bolt on the left and right end faces of the cap beam is threadedly engaged with a tensioning nut and a locknut. A number of tensioning nuts are respectively abutted against the inner end faces of the second steel plates on the same side through the backing plates. The two first steel plates and the two second steel plates are connected end to end in sequence to form an enclosure frame. The reinforcing semi-frame is in a "C" shape. The two reinforcing semi-frames are respectively wrapped on the outer sides of the two second steel plates. The two ends of the reinforcing semi-frame are respectively connected to the two first steel plates;

[0021] Step 6: Select the jack according to the compressive stress F applied to the end face of the cap beam, so that F = f * n, where f is the working force output by the jack and n is the number of jacks;

[0022] Step 7: Set n jacks between the end face of the cap beam and the second steel plate on the same side. When the jacks are jacked between the inner end face of the corresponding second steel plate and the cap beam, the two second steel plates respectively apply tensile forces to the two first steel plates to the left and right sides. A number of strain gauges are horizontally spaced and pasted on the outer end faces of the two first steel plates respectively. The piston rods of n jacks at each end are pressed out in sequence according to the order of first the middle and then the two sides. According to the output data of a number of strain gauges, each jack provides a tensile force of 40%f to the first steel plate. Again, the piston rods of n jacks at each end are pressed out in sequence according to the order of first the middle and then the two sides. According to the output data of a number of strain gauges, the tensile force provided by each jack to the first steel plate is f. Reverse the screwing of a number of tensioning nuts so that a number of tensioning nuts are abutted against the inner end faces of the second steel plates on the same side through the backing plates again;

[0023] Step 8: After the tensioning of the two first steel plates is completed, apply epoxy resin glue with a thickness of ≥2 mm on the bonding areas corresponding to the first steel plates and the side faces of the cap beam respectively, and use pressure injection to bond the first steel plates and the cap beam;

[0024] Step 9: Before the epoxy resin adhesive solidifies, fastening nuts are installed on several chemical anchors on the front and rear sides of the cap beam. Several fastening nuts are tightened to fix the two first steel plates on several chemical anchors on the front and rear sides of the cap beam. Several back nuts are screwed in the opposite direction to make the back nuts abut against the corresponding tension nuts.

[0025] Step 10: Promptly scrape off any excess epoxy resin that has squeezed out from the edge of the first steel plate;

[0026] Step 11: After the epoxy resin has solidified, install the bottom mold between the lower edge of the second steel plate and the cap beam, and fill the cavity between the second steel plate and the cap beam with grout so that the grout covers the stiffening ribs.

[0027] Step 12: After the injected grout has solidified, remove the bottom formwork and apply anti-corrosion coating to the exposed surfaces of the first steel plate, the second steel plate, and the reinforced semi-enclosure frame.

[0028] Furthermore, the first steel plate is a Q355 steel plate.

[0029] Furthermore, the first steel plate is 400mm high.

[0030] Furthermore, the second steel plate is a Q355 steel plate.

[0031] Furthermore, the stiffening ribs are made of Q355 steel plate.

[0032] Furthermore, the two first steel plates and the two second steel plates are sequentially welded together end to end.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0034] This invention applies a tightening force to the steel-bonded retaining frame using jacks, thereby tensioning the first steel plate on both sides of the cap beam via two second steel plates. Finally, epoxy resin is injected between the first steel plate and the cap beam to form a unified structural load-bearing structure. The prestressed first steel plates on both sides of the cap beam significantly improve their efficiency and save material usage. Simultaneously, the pre-pressure from the first and second steel plates helps repair existing structural cracks, greatly enhancing the steel-bonded reinforcement effect. This method of steel-bonded reinforcement for bridge pier cap beams becomes an active reinforcement method, resulting in a high effective load-bearing capacity of the bonded steel plates. Attached Figure Description

[0035] Figure 1 This is a front view of the beam reinforcement method of the present invention;

[0036] Figure 2 This is a left view of the beam reinforcement method of the present invention;

[0037] Figure 3 yes Figure 2 A structural diagram showing the removal of the reinforced semi-enclosed frame and the second steel plate;

[0038] Figure 4 This is a top view of the beam reinforcement method of the present invention;

[0039] Figure 5 yes Figure 4 AA section view;

[0040] Figure 6 yes Figure 4 BB section view;

[0041] Figure 7 This is a cross-sectional view of the tension nut;

[0042] Figure 8 This is a structural schematic diagram of the first steel plate;

[0043] Figure 9 This is a structural schematic diagram of the stiffening rib;

[0044] Figure 10 It is a strain curve diagram measured by several strain gauges on the first steel plate.

[0045] In the diagram, 1. cap beam, 2. first steel plate, 21. oblong hole, 22. strain gauge, 3. second steel plate, 4. stiffening rib, 41. leakage outlet, 5. tension nut, 51. internal thread section, 52. washer, 6. back nut, 7. chemical anchor, 71. fastening nut, 8. reinforced semi-enclosure frame, 9. jack. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0047] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections, also known as non-detachable connections, include but are not limited to conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include but are not limited to conventional disassembly methods such as bolted connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can be found to achieve this function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a bolted connection can be chosen for detachable connections.

[0048] The present invention will be further described in detail below with reference to the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0049] Example: Figures 1-9 As shown, a method for reinforcing bridge cap beams against overturning is described, with cap beam 1 positioned on the left and right sides, including the following steps:

[0050] Step 1: Repair the existing cracks in cap beam 1;

[0051] Step 2: Roughen the areas to be bonded on the front and rear sides and left and right ends of the cap beam 1 to expose the aggregate of the cap beam 1, and clean the surface dust of the cap beam 1 with an iron brush or compressed air.

[0052] Step 3, Rebar Installation: Detect the main reinforcement bars of the cap beam 1. Drill several types of reinforcement holes on the front and rear sides and left and right ends of the cap beam 1, avoiding the main reinforcement bars. First, inject rebar adhesive into each type of reinforcement hole. Then, insert several chemical anchors 7 into the corresponding types of reinforcement holes one by one. Wait for the rebar adhesive to solidify so that the chemical anchors 7 are bonded to the cap beam 1 as one.

[0053] Step 4: Fabricate the first steel plate 2, the second steel plate 3, the stiffening rib 4, the tension nut 5, and the reinforced semi-frame 8, and perform surface rust removal and cleaning. The first steel plate 2, the second steel plate 3, and the stiffening rib 4 are all rectangular steel plates. The length of the stiffening rib 4 is set according to the width of the cap beam 1. The length of the first steel plate 2 is equal to the sum of the length of the cap beam 1 and the width of the two stiffening ribs 4. The length of the second steel plate 3 is equal to the sum of the width of the cap beam 1 and the thickness of the two first steel plates 2. Let the cross-sectional area of ​​the first steel plate 2 be S, in meters. 2 S is determined by the following formula:

[0054]

[0055] In the formula:

[0056] F represents the compressive stress that needs to be applied to the end face of the cap beam 1, in N; F is given by the design unit.

[0057] L is the length of the first steel plate 2, in meters;

[0058] ΔL is the elongation elastic deformation of the first steel plate 2 when both ends are subjected to tensile stress F after the two first steel plates 2 are superimposed and combined, and the unit is m;

[0059] ΔL is determined by the following formula:

[0060] ΔL=(σ / E)×L=[(F / S) / E]×L

[0061] In the formula:

[0062] σ is the allowable tensile stress of the first steel plate 2, with the unit of MPa;

[0063] E is the elastic modulus of the first steel plate 2, with the unit of MPa;

[0064] Step Five: Two stiffening rib plates 4 are horizontally arranged at the left and right ends of the cap beam 1 respectively. A number of leakage ports 41 are provided on the stiffening rib plates 4. The front and rear ends of the stiffening rib plates 4 are respectively aligned with the front and rear side faces of the cap beam 1. The inner side edges of the stiffening rib plates 4 are abutted against the bonding regions to be bonded on the corresponding end faces of the cap beam 1. The stiffening rib plates 4 are located in the middle vertically of the corresponding bonding regions to be bonded. Two first steel plates 2 are respectively arranged in parallel on the front and rear sides of the cap beam 1. The inner end faces of the first steel plates 2 are abutted against the bonding regions to be bonded on the corresponding side faces of the cap beam 1. A number of long circular holes 21 through which a number of chemical anchor bolts 7 on the corresponding side faces of the cap beam 1 can pass are provided on the first steel plates 2. The long circular holes 21 are arranged horizontally. The left and right ends of the first steel plates 2 are respectively aligned with the outer side edges of the two stiffening rib plates 4. Two second steel plates 3 are arranged in parallel on the outer sides of the two stiffening rib plates 4. The upper and lower side edges of the first steel plates 2 and the second steel plates 3 are respectively aligned. The inner end faces of the second steel plates 3 are connected to the outer side edges of the same-side stiffening rib plates 4. The front and rear ends of the second steel plates 3 are respectively aligned with the outer end faces of the two first steel plates 2. The tension nut 5 includes an internal thread section 51. One end of the internal thread section 51 is provided with a backing plate 52. Each chemical anchor bolt 7 on the left and right end faces of the cap beam 1 is in threaded fit with a tension nut 5 and a locknut 6. A number of tension nuts 5 are respectively abutted against the inner end faces of the second steel plates 3 on the same side through the backing plates 52. The two first steel plates 2 and the two second steel plates 3 are connected end to end in sequence to form an enclosing plate frame. The reinforcing semi-frame 8 is in a "匚" shape. The two reinforcing semi-frames 8 are respectively wrapped on the outer sides of the two second steel plates 3. The two ends of the reinforcing semi-frame 8 are respectively connected to the two first steel plates 2;

[0065] Step Six: Select the type of the jack 9 according to the compressive stress F applied to the end face of the cap beam 1, so that F = f * n, where f is the working force output by the jack 9 and n is the number of jacks;

[0066] Step 7: Set n jacks 9 between the end face of the cap beam 1 and the second steel plate 3 on the same side. When the jacks 9 are pressed between the inner end face of the corresponding second steel plate 3 and the cap beam 1, the two second steel plates 3 apply tension to the two first steel plates 2 to the left and right sides respectively. Attach several strain gauges 22 horizontally at intervals on the outer end faces of the two first steel plates 2 respectively, and press out the piston rods of n jacks 9 at each end in the order of first the middle and then the sides. According to the data output by the strain gauges 22, make each jack provide a tension of 40%f to the first steel plate 2. Again, press out the piston rods of n jacks 9 at each end in the order of first the middle and then the sides. According to the data output by the strain gauges 22, make each jack provide a tension of f to the first steel plate 2. Tighten several tension nuts 5 in the opposite direction, so that the tension nuts 5 again abut against the inner end face of the second steel plate 3 on the same side through the pad 52.

[0067] Step 8: After tensioning the two first steel plates 2, apply epoxy resin adhesive with a thickness of ≥2mm to the bonding areas on the sides of the first steel plates 2 and the cap beam 1, and use pressure injection to bond the first steel plates 2 and the cap beam 1.

[0068] Step 9: Before the epoxy resin adhesive solidifies, fastening nuts 71 are respectively installed on several chemical anchors 7 on the front and rear sides of the cap beam 1. Several fastening nuts 71 are tightened to fix the two first steel plates 2 on several chemical anchors 7 on the front and rear sides of the cap beam 1. Several back nuts 6 are screwed in the opposite direction to make the back nuts 6 abut against the corresponding tension nuts 5.

[0069] Step 10: Promptly scrape off any excess epoxy resin that has been squeezed out from the edge of the first steel plate 2;

[0070] Step 11: After the epoxy resin has solidified, install the bottom mold between the lower edge of the second steel plate 3 and the cap beam 1, and fill the cavity between the second steel plate 3 and the cap beam 1 with grout so that the grout covers the stiffening rib plate 4.

[0071] Step 12: After the injected grout has solidified, remove the bottom formwork and apply anti-corrosion coating to the exposed surfaces of the first steel plate 2, the second steel plate 3, and the reinforced semi-frame 8.

[0072] The first steel plate 2 is a Q355 steel plate.

[0073] The first steel plate is 400mm high.

[0074] The second steel plate 3 is a Q355 steel plate.

[0075] The stiffening rib 4 is made of Q355 steel plate.

[0076] The two first steel plates 2 and the two second steel plates 3 are welded together end to end in sequence.

[0077] The reason why traditional steel-bonded reinforcement does not apply prestress to the external steel plate is that the process of applying prestress is relatively complicated. Generally speaking, applying prestress to the steel plate can only be done by setting tensioning equipment at both ends of the steel plate. This method is not only difficult to operate and requires large anchors at both ends, but also has high cost and very low economic benefits.

[0078] This invention applies a tightening force to the steel-bonded retaining frame using jacks 9, thereby tensioning the first steel plate 2 on both sides of the cap beam 1 through the two second steel plates 3. Finally, epoxy resin is injected between the first steel plate 2 and the cap beam 1 to form an integral structural bearing system. Figure 10 As shown in the strain curve obtained by several strain gauges attached to the first steel plate 2, the second steel plate 3 exerts significant tensile stress on the first steel plate 2. Under the action of n jacks, the second steel plate 3 undergoes fully elastic deformation. When the second steel plate 3 undergoes fully elastic deformation, its length shortens, thereby causing the first steel plate to press tightly against the cap beam 1. This results in the first steel plate 2 exerting active pressure on the cap beam 1. The first steel plate 2, subjected to prestress on both sides of the cap beam 1, significantly improves its utilization efficiency and saves material usage. Simultaneously, due to the pre-pressure from the first and second steel plates 2 and 3, the stress on the cap beam 1 increases by more than 50%, which has a certain repairing effect on existing structural cracks and greatly improves the steel-bonded reinforcement effect. This method of steel-bonded reinforcement for bridge pier cap beams becomes an active reinforcement method, with the bonded steel plates having a large effective load-bearing capacity.

[0079] The above embodiments are merely illustrative examples of the present invention and do not limit its scope of protection. Those skilled in the art can make partial changes to them, as long as they do not exceed the spirit and essence of the present invention, they are all within the scope of protection of the present invention.

Claims

1. A method for reinforcing bridge cap beams against overturning, wherein the cap beam (1) is set on the left and right sides, characterized in that, Includes the following steps: Step 1: Repair the existing cracks in the cap beam (1); Step 2: Roughen the areas to be bonded on the front and rear sides and left and right ends of the cap beam (1) to expose the aggregate of the cap beam (1), and clean the surface dust of the cap beam (1) with an iron brush or compressed air. Step 3, Rebar Installation: Detect the main reinforcement of the cap beam (1), drill several types of reinforcement holes on the front and rear sides and left and right ends of the cap beam (1) to be bonded, avoiding the main reinforcement. First, inject the rebar adhesive into each type of reinforcement hole, and then insert several chemical anchors (7) into the corresponding type of reinforcement holes one by one. Wait for the rebar adhesive to solidify so that the chemical anchors (7) are bonded to the cap beam (1) as one. Step 4: Fabricate the first steel plate (2), the second steel plate (3), the stiffening rib (4), the tension nut (5), and the reinforced semi-frame (8), and perform surface rust removal and cleaning treatment. The first steel plate (2), the second steel plate (3), and the stiffening rib (4) are all rectangular steel plates. The length of the stiffening rib (4) is set according to the width of the cap beam (1). The length of the first steel plate (2) is equal to the sum of the length of the cap beam (1) and the width of the two stiffening ribs (4). The length of the second steel plate (3) is equal to the sum of the width of the cap beam (1) and the thickness of the two first steel plates (2). Set the cross-sectional area of ​​the first steel plate (2) as S, with the unit being m. 2 S is determined by the following formula: S= ； In the formula: F represents the pressure that needs to be applied to the end face of the cap beam (1), in N; L is the length of the first steel plate (2), in meters; ΔL is the elongation elastic deformation of the first steel plate (2) when the tensile stress at both ends is F after the two first steel plates (2) are superimposed and combined, and the unit is m; ΔL is determined by the following formula: ΔL = (σ / E)×L=[(F / S) / E]×L; In the formula: σ is the allowable tensile stress of the first steel plate (2), in MPa; E is the elastic modulus of the first steel plate (2), in MPa; Step Five: Two stiffening ribs (4) are horizontally arranged at the left and right ends of the cap beam (1). A number of leakage ports (41) are provided on the stiffening ribs (4). The front and rear ends of the stiffening ribs (4) are respectively aligned with the front and rear side faces of the cap beam (1). The inner side edges of the stiffening ribs (4) are abutted against the bonding area of the corresponding end face of the cap beam (1). The stiffening ribs (4) are located in the middle of the corresponding bonding area in the vertical direction. Two first steel plates (2) are respectively arranged in parallel on the front and rear sides of the cap beam (1). The inner end faces of the first steel plates (2) are abutted against the bonding area of the corresponding side faces of the cap beam (1). A number of long circular holes (21) through which a number of chemical anchor bolts (7) on the corresponding side faces of the cap beam (1) can pass are formed in the first steel plates (2). The long circular holes (21) are arranged horizontally. The left and right ends of the first steel plates (2) are respectively aligned with the outer side edges of the two stiffening ribs (4). Two second steel plates (3) are arranged in parallel on the outer sides of the two stiffening ribs (4). The upper and lower side edges of the first steel plates (2) and the second steel plates (3) are respectively aligned. The inner end faces of the second steel plates (3) are connected to the outer side edges of the stiffening ribs (4) on the same side. The front and rear ends of the second steel plates (3) are respectively aligned with the outer end faces of the two first steel plates (2). The tension nut (5) includes an internal thread section (51). One end of the internal thread section (51) is provided with a backing plate (52). Each chemical anchor bolt (7) on the left and right end faces of the cap beam (1) is in threaded fit with a tension nut (5) and a lock nut (6). A number of tension nuts (5) are respectively abutted against the inner end faces of the second steel plates (3) on the same side through the backing plates (52). The two first steel plates (2) and the two second steel plates (3) are sequentially connected end to end to form an enclosing plate frame. The reinforcing semi-frame (8) is in a "C" shape. The two reinforcing semi-frames (8) are respectively wrapped on the outer sides of the two second steel plates (3). The two ends of the reinforcing semi-frame (8) are respectively connected to the two first steel plates (2); Step Six: Select the type of the jack (9) according to the compressive stress F applied to the end face of the cap beam (1) so that F = f * n, where f is the working force output by the jack (9) and n is the number of jacks; Step 7: Set n jacks (9) between the end face of the cap beam (1) and the second steel plate (3) on the same side. When the jacks (9) are pressed between the inner end face of the corresponding second steel plate (3) and the cap beam (1), the two second steel plates (3) apply tension to the two first steel plates (2) to the left and right sides respectively. Attach several strain gauges (22) horizontally at intervals to the outer end faces of the two first steel plates (2) respectively, and press out the piston rods of n jacks (9) at each end in the order of first the middle and then the sides. Based on the output data of several strain gauges (22), each jack provides a tension force of 40%f to the first steel plate (2). Then, in the order of first the middle and then the two sides, the piston rods of n jacks (9) at each end are pressed out. Based on the output data of several strain gauges (22), each jack provides a tension force of f to the first steel plate (2). Then, several tension nuts (5) are screwed in the opposite direction, so that several tension nuts (5) abut against the inner end face of the second steel plate (3) on the same side through the pad (52). Step 8: After tensioning the two first steel plates (2), apply epoxy resin adhesive with a thickness of ≥2mm to the bonding areas on the sides of the first steel plate (2) and the cap beam (1), and use pressure injection to bond the first steel plate (2) and the cap beam (1). Step 9: Before the epoxy resin adhesive solidifies, fastening nuts (71) are respectively installed on several chemical anchors (7) on the front and rear sides of the cap beam (1), and several fastening nuts (71) are tightened to fix the two first steel plates (2) on several chemical anchors (7) on the front and rear sides of the cap beam (1). Several back nuts (6) are screwed in the opposite direction so that the back nuts (6) and the corresponding tension nuts (5) are pressed against each other. Step 10: Scrape off any excess epoxy resin that has been squeezed out from the edge of the first steel plate (2) in a timely manner; Step 11: After the epoxy resin has solidified, install the bottom mold between the lower edge of the second steel plate (3) and the cap beam (1), and fill the cavity between the second steel plate (3) and the cap beam (1) with grout so that the grout covers the stiffening rib plate (4). Step 12: After the grout has solidified, remove the bottom formwork and apply anti-corrosion coating to the exposed surfaces of the first steel plate (2), the second steel plate (3), and the reinforced semi-enclosure (8).

2. The method for reinforcing bridge cap beams against overturning according to claim 1, characterized in that: The first steel plate (2) is a Q355 steel plate.

3. The method for reinforcing bridge cap beams against overturning according to claim 2, characterized in that: The first steel plate (2) is 400mm high.

4. The method for reinforcing bridge cap beams against overturning according to claim 1, characterized in that: The second steel plate (3) is a Q355 steel plate.

5. The method for reinforcing bridge cap beams against overturning according to claim 1, characterized in that: The stiffening rib (4) is made of Q355 steel plate.

6. A method for reinforcing bridge cap beams against overturning according to any one of claims 1-5, characterized in that: The two first steel plates (2) and the two second steel plates (3) are welded together end to end in sequence.

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