Stone arch bridge main arch ring rib type cover arch reinforcing method

Abstract

The invention discloses a stone arch bridge main arch ring rib type cover arch reinforcing method, relates to the related field of stone arch bridge reinforcing and reconstruction, and aims at improving the bearing capacity of a bridge and enhancing the safety and durability of the bridge through a comprehensive reinforcing system combining main arch ring arch foot local increased section reinforcing, web arch cover arch reinforcing, carbon fiber grid reinforcing and bridge floor system reconstruction. The durability of the structure is improved. The reinforcing method comprises the following steps that S1, section increasing reinforcing treatment is conducted on the arch feet of the main arch ring locally; s2, a web arch close to the pier is reinforced by adopting a cover arch method; s3, other web arch rings are reinforced by adopting a carbon fiber grid hanging treatment method; s4, reinforcing the web arch ring of the bridge abutment by adopting a carbon fiber grid hanging treatment method; s5, the bridge deck pavement above the plane where the bottom face of the original guardrail outrigger is located is chiseled away; and S6, bridge deck pavement and rebuilding, bridge deck guardrail replacement and expansion joint addition.

Description

Technical Field

[0001] This invention relates to the field of stone arch bridge reinforcement and renovation, specifically a method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system. Background Technology

[0002] Stone arch bridges, an important heritage in my country's bridge engineering field, primarily use natural stone as their building material. Through their arch structure, they transform vertical loads into horizontal thrust at the arch abutments, exhibiting significant advantages such as light structural weight, strong spanning capacity, and excellent durability. A typical structure includes the main arch ring, superstructure, abutments, and foundations. The main arch ring, as the core load-bearing component, directly determines the overall safety of the bridge due to its mechanical properties.

[0003] With the continuous increase in traffic load and the extension of service life in my country, a large number of existing stone arch bridges have suffered structural damage to varying degrees. To address these problems, the engineering community has developed a series of technical systems, including arch reinforcement, steel plate bonding, and carbon fiber reinforcement. Among these, arch reinforcement is the most widely used traditional technique, which involves adding a reinforced concrete arch to the outside of the original arch ring to form a composite structure. For example, the Chinese authorized patent with publication number CN 110656590 B (A Self-Balancing Arch Reinforcement Method for Stone Arch Bridges) describes the following steps: Step 1: Excavate a set of pile holes on the inner side of each of the two abutments; Step 2: Level the site between the two sets of single-pile caps and lay a plain concrete base course on the site; Step 3: Erect several supports on the surface of the plain concrete base course, and use these supports to pour N arch ribs one-to-one above N prestressed concrete tie rods; Step 4: Grout the cracks on the main arch ring and pour a top slab between the main arch ring and the N arch ribs; Step 5: Unload the supports. This invention is applicable to the reinforcement of stone arch bridges with overlapping arches.

[0004] While the aforementioned existing technologies can reinforce arch bridges, they involve directly using a cast-in-place concrete arch under the main arch ring, which increases the self-weight of the arch bridge. Furthermore, it requires the erection of supports before casting the arch ribs, followed by the casting of the top slab, and finally grouting. This results in a long construction period, high construction costs, high implementation difficulty, and significant disturbance to the original bridge. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch-type reinforcement system. This system combines local enlargement of the main arch ring's arch foot section for reinforcement, reinforcement of the inter-arch-type arch, carbon fiber mesh reinforcement, and bridge deck system modification to improve the bridge's load-bearing capacity, enhance its safety and durability, and improve the structural durability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system, comprising the following steps: S1: Locally enlarge the cross-section and reinforce the arch foot of the main arch ring; S1-1: Clean the bridge abutment surface and remove any peeling, loose, and weathered surface layer; S1-2: Use mortar to repair cracks and honeycomb-like defects in the main arch ring; S1-3: Drilling positioning, drill holes perpendicular to the plane of the rebar structure according to the drilling diameter; S1-4: Clean and blow out the ash and debris from the hole with an air pump until the hole is clean and dry; S1-5: Insert the glue mixing tube into the bottom of the hole and inject the anchoring glue from the bottom of the hole outwards, filling 2 / 3 of the hole; S1-6: Slowly insert the reinforcing bar into the bottom of the hole while rotating it, and install it according to the specified curing time, so that the anchoring adhesive is evenly adhered to the surface of the reinforcing bar and the gaps. S1-7: Wait for the anchoring adhesive to cure; S1-8: Connect the reinforcing bars by double-sided welding or binding to form a reinforcing bar skeleton. The length of the double-sided weld is ≥5d. S1-9: Formwork construction; S1-10: Thoroughly wet the original bridge abutment surface and apply a layer of interface agent evenly, then pour C40 concrete; S2: The reinforcement of the spandrel arch near the pier is carried out by the arch-insertion method. First, the reinforcing bars are installed, then the concrete is poured, and finally the artificial stones are laid. S3: The remaining abdominal arch rings are reinforced by hanging carbon fiber mesh, with a mesh spacing of 20cm×20cm; S4: The bridge abutment arch ring is reinforced by hanging carbon fiber mesh, with a mesh spacing of 20cm×20cm; S5: Remove the bridge deck pavement above the plane where the bottom of the original guardrail cantilever beam is located, removing a thickness of 25cm, while retaining the original arch filler. S6: The bridge deck pavement will be rebuilt, the bridge railings will be replaced, and expansion joints will be added. The bridge deck pavement will be made of C40 waterproof concrete and a new 20cm thick bridge deck will be laid.

[0007] Preferably, in S1-3, before drilling holes for planting steel bars, the location of the defects in the old bridge should be identified. If the drilling location is near the location of the excessive cracks in the old bridge, the drilling location should be moved.

[0008] Preferably, in steps S1-5, the adhesive used for anchoring the rebar is Grade A adhesive.

[0009] Preferably, in steps S1-6, the steel bars are planted by drilling holes and planting them simultaneously. When drilling, the number of empty holes is no more than 3, and the steel bars are planted in a quincunx pattern of 30×30cm.

[0010] Preferably, in S1-10, the main arch back is reinforced with an enlarged cross-section, and the reinforcement layer is a C40 concrete structure with a thickness that gradually changes from 15cm to 30cm and a constant thickness of 15cm.

[0011] Preferably, in S2, the construction process of the rebar anchoring technology is as follows: positioning and marking - mechanical drilling - hole cleaning and inspection - injecting anchoring adhesive - inserting rebar and temporarily fixing - anchoring adhesive curing; the rebar is planted by drilling and anchoring simultaneously, and no more than 3 holes are left in the same section during the anchoring process. The length of the anchoring is 12cm, and the anchoring is arranged in a quincunx pattern of 30×30cm.

[0012] Preferably, in S2, the thickness of the cross-section of the inner arch is 20cm, and it is cast using C40 self-compacting micro-expansion concrete.

[0013] Preferably, in step S2, the false stone is laid on the outer surface of the arch and the inner arch. Before laying, the cross section of the arch and the inner arch is cleaned, then the surface is roughened evenly and mortar is applied evenly.

[0014] Preferably, in S6, the bridge deck pavement is equipped with N3 and N4 steel bars. The N3 steel bars are spaced 100cm longitudinally and 50cm laterally and are driven into the filler on the arch. The N4 steel bars are spaced 100cm longitudinally and laterally. When the bridge deck pavement is reconstructed, the longitudinal construction is symmetrical and uniform.

[0015] Preferably, in step S6, the location of the expansion joint corresponds to the original expansion joint of the existing bridge.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) In this invention, the main arch ring is reinforced by increasing the cross section at the arch foot. The reinforcement layer is designed with a combination of gradually varying thicknesses of 15cm-30cm and constant thicknesses of 15cm to form a rib-type load-bearing structure and improve the bending stiffness of the cross section. Compared with the treatment of the entire bridge with an arch ring, the construction cost is low and the implementation difficulty is relatively small. At the same time, in response to defects such as excessive expansion joints of the web arch and cracking of the bridge deck pavement, reinforcement treatments such as arch ring ring with arch ring and hanging carbon fiber mesh on the arch ring are carried out to form an active reinforcement system, improve crack control capability, improve the bridge's load-bearing capacity, and enhance its safety and durability.

[0017] (2) In this invention, after the main arch and the web arch are reinforced, the bridge deck pavement is replaced, bridge deck traffic safety measures are implemented, and expansion joints are added to improve the durability of the structure. When paving the bridge deck, the concrete pouring adopts a longitudinal symmetrical uniform material distribution process to reduce the generation of temperature cracks. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall bridge reinforcement method according to the present invention; Figure 2 For the present invention Figure 1Sectional view at point I-I; Figure 3 This is a partial schematic diagram of the bridge reinforcement method according to the present invention; Figure 4 This is a schematic diagram of the partial reinforcement of the arch foot in this invention; Figure 5 For the present invention Figure 4 A schematic diagram of the structure at point A; Figure 6 For the present invention Figure 4 A schematic diagram of the structure at point B; Figure 7 For the present invention Figure 5 and Figure 6 Sectional views at various points; Figure 8 This is a schematic diagram of the artificial stone paving method of the present invention; Figure 9 This is a diagram showing the reinforcement layout of the bridge deck panel according to the present invention; Figure 10 This is a schematic diagram of the expansion joint of the present invention. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] 1. Project Overview 1.1 Bridge Conditions Hutian Bridge is located on the C014 road from Hutian to Zhengyuan Village in Dongping Town, Zhenghe County, with a center chainage of K0+330. It was completed and opened to traffic in 1991. Hutian Bridge is a stone arch bridge spanning the Songxi River. The total length of the bridge is 200m, with a span combination of (6m clear + 4m clear × 40m clear + 6m clear)m solid-web + open-web slab arches. The total width of the bridge deck is 7.1m, with a transverse arrangement of 0.8m (pedestrian walkway) + 5.5m (driving road) + 0.8m (pedestrian walkway). The substructure piers are gravity-type piers made of masonry blocks. The bridge deck pavement is a later-added reinforced concrete layer, and the bridge railings are stone railings. The original design load rating was Class 10 for automobiles; the current bridge load limit is 10t.

[0021] 1.2 Disease Status According to the "Inspection and Evaluation Report of Hutian Bridge in Dongping Town, Zhenghe County" and based on the on-site conditions, the following defects exist: (1) Defects in the superstructure: Excessive deformation joints in the ventral arch, cracks in the arch top, water seepage and white crystals in the main arch, holes in the bottom of the main arch, and detachment of the masonry joints.

[0022] (2) Substructure defects: water seepage in the pier masonry joints and local grouting failure.

[0023] (3) Bridge deck defects: There are many regular transverse and longitudinal cracks in the bridge deck pavement, and the concrete of the railings is corroded, peeling, rusted and swollen, and the height is insufficient.

[0024] According to the inspection results of the "Inspection and Evaluation of Hutian Bridge in Dongping Town, Zhenghe County", the technical condition of Hutian Bridge is rated as Class 4. Specific defects are detailed in Table 1.1.

[0025] Table 1.1 Overview of Diseases

[0026] 1.3 Disease Situation Analysis Analysis of the inspection report and on-site survey revealed that vehicles with load capacities of 30t / 40t crossed the bridge, with the maximum axle load ranging from 12t to 14t. These loads exceeded the original design range, which was a low design load level (vehicle load -10). According to the bridge inspection report, the main arch ring showed no obvious external defects. However, the secondary arch ring exhibited significant external defects due to insufficient load-bearing capacity. Long-term overloading caused frequent bridge deck vibrations, leading to the gradual loosening and loss of mortar between the masonry blocks under vibration and impact. Excessive expansion joint capacity prevented effective release of structural deformation stress, ultimately resulting in transverse fracture at the arch crown. The bridge deck pavement also showed numerous regular cracks, with longer longitudinal cracks along the rut direction. This was attributed to insufficient load-bearing capacity and stiffness of the secondary arch rings, causing excessive deflection and damage when heavy vehicles passed over it.

[0027] 2. Structural Analysis 2.1 Verification Calculation In accordance with the specifications issued by the Ministry of Transport during the bridge construction, the original design load of Hutian Bridge was recalculated.

[0028] (1) Parameter values Vehicle load rating: Vehicle-10; Mortar grade: M10; Stone blocks: No. 50, compressive strength 9.0 MPa, density 24 kN / m³ 3 ; Elastic modulus: 6.24 × 10 6 kN / m 2 .

[0029] Weight of arch fill and bridge deck: 20kN / m 3 ; The density of the arch structure material is 24 kN / m. 3 .

[0030] (2) Verification process In accordance with the specifications issued by the Ministry of Transport during the bridge construction (JTJ022-85 Specifications for Design of Highway Masonry and Concrete Bridges and Culverts, JTJ021-89 General Specifications for Design of Highway Culverts), the original design load of Hutian Bridge was recalculated. The calculation results of the original bridge section strength verification and "strength-stability" verification are shown in Table 2.1.

[0031] Table 2.1 Calculation of original bridge section strength (Automotive-10 grade) and "Strength-Stability" Calculation Table

[0032] (3) Summary In accordance with the specifications issued by the Ministry of Transport during the bridge construction, the original design load of Hutian Bridge was re-verified and verified. It was found that the strength calculation of the original bridge section and the "strength-stability" calculation met the requirements of the specifications, thus verifying that the original bridge met the design requirements.

[0033] 2.2 Verification based on actual traffic conditions (construction specifications) According to the inspection report and on-site survey analysis, vehicles with a load capacity of 30t to 40t cross the bridge, corresponding to vehicle load ratings of Class-20 and Class-Exceeding Class-20. Given the specifications issued during the bridge's construction, and considering that the road where Hutian Bridge is located is classified as a village road with low traffic volume, the calculation was performed using a Class-20 vehicle load rating.

[0034] (1) Parameter values Vehicle load rating: Vehicle-20; Mortar grade: M10; Stone blocks: No. 50, compressive strength 9.0 MPa, density 24 kN / m³ 3 ; Elastic modulus: 6.24 × 10 6 kN / m 2 .

[0035] Weight of arch fill and bridge deck: 20kN / m 3 ; The density of the arch structure material is 24 kN / m. 3 .

[0036] (2) Verification process In accordance with the specifications issued by the Ministry of Transport (JTJ022-85 Specifications for Design of Highway Masonry and Concrete Bridges and Culverts, JTJ021-89 General Specifications for Design of Highway Culverts) during the bridge construction, the original design load of Hutian Bridge was recalculated. The calculation results of the original bridge section strength verification and "strength-stability" verification are shown in Table 2.2.

[0037] Table 2.2 Calculation of original bridge section strength (Automotive-20 grade) and "Strength-Stability" Calculation Table

[0038] (3) Summary According to the specifications issued by the Ministry of Transport when the old bridge was built, the Hutian Bridge was subjected to a vehicle-20 load calculation. It was found that the original bridge section strength met the specification requirements. However, during the "strength-stability" calculation, the arch foot section did not meet the specification requirements, and local sections of the arch foot need to be reinforced.

[0039] 2.3 Verification based on actual traffic conditions (current specifications) The vehicle-20 load standard used in bridge construction is equivalent to the current highway-II vehicle load standard. Therefore, this section will verify the load according to the current highway-II vehicle load standard.

[0040] (1) Parameter values Vehicle load rating: Highway-II; Mortar grade: M10; Stone blocks: No. 50, compressive strength 9.0 MPa, density 24 kN / m³ 3 ; Elastic modulus: 6.24 × 10 6 kN / m 2 .

[0041] Weight of arch fill and bridge deck: 20kN / m 3 ; The density of the arch structure material is 24 kN / m. 3 .

[0042] (2) Verification process According to the current Ministry-issued standard (JTGD61-2005 Highway Masonry Bridge and Culvert Design Specification), using Highway-II vehicle load, the Hutian Bridge was recalculated. The calculation results of the original bridge section strength verification and "strength-stability" verification are shown in Table 2.3.

[0043] Table 2.3 Original Bridge Section Strength (Automotive-Class II) Verification and "Strength-Stability" Verification Table

[0044] (3) Summary According to the current ministerial standards, the Hutian Bridge was recalculated and it was found that the strength of the original bridge arch foot section did not meet the standard requirements, and the strength-stability calculation of each section of the entire bridge did not meet the standard requirements. Therefore, the main arch ring needs to be reinforced with a full-bridge arch.

[0045] 2.4 Reinforcement Calculation Based on the above calculation results, reinforcement calculations were performed on the original bridge according to the standards issued by the Ministry of Transport during its construction and the current standards issued by the Ministry of Transport.

[0046] (1) Calculation of reinforcement of arch foot section The thickness of the section on the back of the arch foot is increased by 0.3m. The calculation results of the "strength-stability" verification are shown in Table 2.4.

[0047] Table 2.4 Strength-Stability Verification Table after Reinforcement of the Back Section of the Arch Foot

[0048] The thickness of the cross section on the back of the arch foot is increased by 0.3m. According to the current specifications, the strength-stability verification of the original bridge cross section meets the requirements of the specifications.

[0049] (2) Calculation of the main arch ring The main arch ring is 0.6m in diameter, and the calculation results of the section strength verification and the "strength-stability" verification are shown in Table 2.5.

[0050] Table 2.5 Strength-Stability Verification Table After Integrating the Main Arch Ring with the Arch

[0051] By insulating the main arch ring with an arch of 0.6m, calculations according to current specifications show that the strength of the original bridge arch foot section meets the specifications, and the "strength-stability" verification of the section meets the specifications.

[0052] 2.5 Summary Based on the above calculations, if the calculations are performed according to the departmental specifications issued at the time of construction, the main arch ring needs to be reinforced at a local section at the arch foot, which has low construction costs and is relatively easy to implement. However, if the calculations are performed according to the current departmental specifications, to meet the specifications, the main arch ring needs to be treated with a full-bridge arch system, which has high construction costs and is difficult to implement. Combined with the results of static and dynamic load tests, the actual stiffness of the completed bridge is slightly greater than the theoretical stiffness, and the measured fundamental frequency is greater than the theoretically calculated value. Existing operational bridges and culverts on national and provincial highways contain vehicles with loads of 30t to 40t, designed based on the old specifications. Therefore, considering the economy, practicality, and feasibility of the bridge reinforcement, this bridge will be designed according to the departmental specifications issued at the time of the original bridge construction, using the vehicle-20 load as the design basis. After reinforcement, the load limit of 30t can be used as a reference for the old bridges on national and provincial highways.

[0053] 3. Reinforcement Design 3.1 Reinforcement Strategy and Objectives The main arch ring undergoes localized cross-sectional reinforcement at the arch foot based on calculation results. For defects such as excessive expansion joints in the inter-arch and cracked pavement, reinforcement schemes such as inter-arch ring with an arch and carbon fiber mesh on the arch ring are implemented to improve the bridge's load-bearing capacity and enhance its safety and durability. Simultaneously, schemes including replacing the pavement, implementing traffic safety measures, and adding expansion joints are used to improve the structure's durability.

[0054] 3.2 Reinforcement Measures (1) Local reinforcement of the arch foot: In response to the problem of insufficient bearing capacity of the bridge, the cross section of the main arch foot is increased and reinforced.

[0055] (1-1) Rebar installation ① Process Flow Drilling → Cleaning the hole → Blowing the hole → Injecting adhesive → Installing rebar → Curing.

[0056] ② Key Technological Points Before drilling holes for planting steel bars, first find out the location of the defects in the old bridge. If the drilling location is near the location of the excessive cracks in the old bridge, the drilling location should be moved. Drill holes perpendicular to the plane of the rebar structure according to the specified drilling diameter, and set the scale to the hole depth; Clean and blow out the ash and debris from the hole with an air pump. At the same time, you must use a brush or other equipment to remove the dust adhering to the hole wall until the hole is clean and dry. Insert the adhesive mixing tube into the bottom of the hole and inject the adhesive from the bottom of the hole outwards, filling 2 / 3 of the hole to ensure fullness after the rebar is installed; The steel bars are planted by drilling holes and planting bars at the same time. Holes cannot be drilled at the same time within a 1m interval. When drilling, ensure that there are no more than 3 empty holes. The steel bars are planted in a quincunx pattern of 30×30cm. The prepared steel bars are slowly inserted into the bottom of the hole while rotating, and the installation is carried out according to the time specified in the curing schedule, so that the anchoring agent is evenly attached to the surface and gaps of the steel bars. After it has cured, the steel bars are tied and other work is carried out.

[0057] Table 3.1 Substrate Temperature and Curing Schedule

[0058] (1-2) Reinforcing bar connection For reinforcement connections using the enlarged cross-section method, double-sided welding or binding is employed, with the double-sided weld length ≥ 5d. When splicing reinforcement, areas of high stress should be avoided, and joints should be staggered strictly according to construction specifications.

[0059] (1-3) Concrete pouring Concrete pouring is carried out using scaffolding, and the scaffolding must be kept stable and free from deformation during construction. To ensure a tight bond between the new and old concrete, the abutment surface should be cleaned and any loose, weathered, or peeling layers removed before pouring. Before enlarging the cross-section, other defects in the arch bridge, such as cracks, should be repaired. Before pouring concrete, the original abutment surface should be thoroughly moistened and a bonding agent should be applied evenly to ensure a reliable bond between the new and old structures.

[0060] This cross-section enlargement reinforcement method uses C40 concrete for pouring. Appropriate measures should be taken in accordance with the construction specifications to ensure the compactness of the concrete. The volume of concrete poured at one time should not be too large, and the continuous pouring of concrete should be ensured. The main arch back is reinforced with an enlarged cross section, and the reinforcement layer is a C40 concrete structure with a thickness that varies from 15cm to 30cm and a constant thickness of 15cm.

[0061] (2) Reinforcement of the abdominal arch: (2-1) The reinforcement of the ventral arches near the piers (such as 2-1#, 2-2#, 2-5#, 2-6#, etc.) is carried out by the arch-in-arch method. The arch-in-arch section thickness is 20cm. C40 self-compacting micro-expansion concrete is used for pouring. Finally, artificial stones are laid on the outer surface of the arch-in-arch. Before laying, the arch-in-arch section is cleaned, roughened evenly, and mortar is evenly applied.

[0062] The rebar installation process before concrete pouring is the same as described above.

[0063] (2-2) The remaining abutment arches (such as 2-3#, 2-4#, etc.) and the abutment abutment arches are reinforced by hanging carbon fiber mesh.

[0064] ① Surface treatment After the rebar is installed, a high-pressure water gun is used to roughen the surface to remove all dirt, oil, cement slurry and oxidized compounds from the concrete, mortar and stone, exposing the rough concrete surface or masonry surface.

[0065] ②Polymer-modified mortar mixing Add the mortar mix and water to the mortar mixer according to the appropriate water-cement ratio, and mix using a low-speed drill bit and blades. Mix for 3-5 minutes until the mortar is evenly mixed.

[0066] ③ First layer of mortar spraying construction Spray the first layer of polymer-modified mortar onto the rough structural surface. The thickness of the first layer of polymer-modified mortar is 2cm. Ensure the smoothness of the mortar after spraying.

[0067] ④ Cutting and laying of carbon fiber mesh After spraying the first layer of polymer-modified mortar, cut the carbon fiber mesh to the required dimensions. Hang the carbon fiber mesh on the surface of the first layer of mortar and anchor it to the rebar. The overlap length of the carbon fiber mesh should be 20cm to ensure that the surface of the carbon fiber mesh is flat after installation.

[0068] ⑤ Surface brushing Three hours later, the surface of the carbon fiber mesh was pressed to ensure the bonding strength between the layers.

[0069] ⑥ Second layer spray After brushing, the second layer of polymer-modified mortar can be mixed and sprayed. The thickness of the sprayed concrete is 2cm. Ensure that there is no exposed mesh and the entire surface is flat after spraying.

[0070] (3) Bridge deck system renovation: After the main body of the arch bridge is reinforced, measures such as demolition and reconstruction of the bridge deck pavement, replacement of bridge deck guardrails and addition of expansion joints will be taken to address the problems of damaged concrete pavement and aging guardrails.

[0071] When the bridge deck pavement is demolished and rebuilt, the bridge deck pavement above the plane where the bottom of the original guardrail cantilever beam is located needs to be removed, with a thickness of 25cm, while retaining the original arch filler.

[0072] The bridge deck pavement uses C40 waterproof concrete, with a new bridge deck thickness of 20cm. The bridge deck pavement is reinforced with N3 and N4 steel bars. The N3 steel bars are spaced 100cm longitudinally and 50cm laterally and are driven into the filler material on the arch. The N4 steel bars are spaced 100cm longitudinally and 100cm laterally. When rebuilding the bridge deck pavement, the construction is carried out symmetrically and evenly in the longitudinal direction.

[0073] The location of the expansion joint corresponds to the original expansion joint of the existing bridge.

[0074] 4. Materials used for repair and reinforcement 4.1 Concrete The arch foot section is locally enlarged using C40 concrete, and the inner arch of the spandrel arch uses C40 self-compacting micro-expansion concrete; the bridge deck pavement uses C40 waterproof concrete.

[0075] 4.2 Rebar Adhesive All anchoring adhesives used in this reinforcement project should be Grade A adhesives.

[0076] Table 4.1 Safety Performance Indicators of Adhesives for Rebar Anchoring

[0077] 4.3 Steel The design adopts HRB400 and HPB300 grade steel bars; the quality of the steel bars shall comply with the provisions of the current national standard "Steel for Reinforced Concrete Part 2: Specification for Hot-Rolled Ribbed Steel Bars" GB / T1499.2-2018; the basic performance indicators of ordinary steel bars shall comply with the relevant provisions of the industry standard "Design Specification for Highway Reinforced Concrete and Prestressed Concrete Bridges and Culverts" (JTG3362-2018).

[0078] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system, characterized in that, Includes the following steps: S1: Locally enlarge the cross-section and reinforce the arch foot of the main arch ring; S1-1: Clean the bridge abutment surface and remove any peeling, loose, and weathered surface layer; S1-2: Use mortar to repair cracks and honeycomb-like defects in the main arch ring; S1-3: Drilling positioning, drill holes perpendicular to the plane of the rebar structure according to the drilling diameter; S1-4: Clean and blow out the ash and debris from the hole with an air pump until the hole is clean and dry; S1-5: Insert the glue mixing tube into the bottom of the hole and inject the anchoring glue from the bottom of the hole outwards, filling 2 / 3 of the hole; S1-6: Slowly insert the reinforcing bar into the bottom of the hole while rotating it, and install it according to the specified curing time, so that the anchoring adhesive is evenly adhered to the surface of the reinforcing bar and the gaps. S1-7: Wait for the anchoring adhesive to cure; S1-8: Connect the reinforcing bars by double-sided welding or binding to form a reinforcing bar skeleton. The length of the double-sided weld is ≥5d. S1-9: Formwork construction; S1-10: Thoroughly wet the original bridge abutment surface and apply a layer of interface agent evenly, then pour C40 concrete; S2: The reinforcement of the spandrel arch near the pier is carried out by the arch-insertion method. First, the reinforcing bars are installed, then the concrete is poured, and finally the artificial stones are laid. S3: The remaining abdominal arch rings are reinforced by hanging carbon fiber mesh, with a mesh spacing of 20cm×20cm; S4: The bridge abutment arch ring is reinforced by hanging carbon fiber mesh, with a mesh spacing of 20cm×20cm; S5: Remove the bridge deck pavement above the plane where the bottom of the original guardrail cantilever beam is located, removing a thickness of 25cm, while retaining the original arch filler. S6: The bridge deck pavement will be rebuilt, the bridge railings will be replaced, and expansion joints will be added. The bridge deck pavement will be made of C40 waterproof concrete and a new 20cm thick bridge deck will be laid.

2. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch reinforcement method according to claim 1, characterized in that: In S1-3, before drilling holes for planting steel bars, the location of the defects in the old bridge should be identified. If the drilling location is near the location of the excessive cracks in the old bridge, the drilling location should be moved.

3. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S1-5, the adhesive used for anchoring rebar is Grade A adhesive.

4. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S1-6, the steel bars are planted by drilling holes and planting them simultaneously. When drilling, the number of empty holes should not exceed 3, and the steel bars are planted in a quincunx pattern of 30×30cm.

5. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S1-10, the main arch back is reinforced with an enlarged cross-section, and the reinforcement layer is a C40 concrete structure with a thickness that gradually changes from 15cm to 30cm and a constant thickness of 15cm.

6. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S2, the construction process of the rebar anchoring technology is as follows: positioning and setting out - mechanical drilling - hole cleaning and inspection - injecting anchoring adhesive - inserting rebar and temporarily fixing - anchoring adhesive curing; the rebar is planted by drilling and anchoring simultaneously, and no more than 3 holes are left in the same section during the anchoring process. The length of the anchoring is 12cm, and the anchoring is arranged in a quincunx pattern of 30×30cm.

7. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S2, the cross-sectional thickness of the inner arch is 20cm, and it is cast using C40 self-compacting micro-expansion concrete.

8. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S2, the false stone is laid on the outer surface of the arch and the inner arch. Before laying, the cross section of the arch and the inner arch is cleaned, then the surface is roughened evenly and mortar is applied evenly.

9. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S6, the bridge deck pavement is equipped with N3 and N4 steel bars. The N3 steel bars are spaced 100cm longitudinally and 50cm laterally and are driven into the filler on the arch. The N4 steel bars are spaced 100cm longitudinally and 100cm laterally. When the bridge deck pavement is reconstructed, the longitudinal construction is symmetrical and uniform.

10. The method for reinforcing the main arch ring of a stone arch bridge using a ribbed arch system according to claim 1, characterized in that: In S6, the location of the expansion joint corresponds to the original expansion joint of the existing bridge.

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