Structure and reconstruction method for improving load bearing of new and old combination surface of continuous structure of bridge deck of abutment bridge

Abstract

This invention discloses a structure and reconstruction method for improving the load-bearing capacity of the interface between the old and new concrete surfaces of bridge abutments and decks. A continuous bridge deck slab is provided on the upper surface of the abutment backrest, main beam, and approach slab. The bottom surface of the portion of the continuous bridge deck slab within the vertical projection range of the main beam is integrated with the top concrete surface of the main beam, and the bottom surface of the portion within the vertical projection range of the approach slab is integrated with the top concrete surface of the approach slab, allowing the approach slab to move synchronously along the bridge direction along the main beam. During reconstruction, a core drill is used to drill holes in the concrete surrounding each anti-slip reinforcement / approach slab limiting reinforcement belonging to the approach slab, and the anti-slip reinforcement / approach slab limiting reinforcement is cut off. The drilled holes are used as openings, and a tenon-shaped shear key concrete of a certain height is poured on top. The expansion joint structure is broken, and the pre-embedded reinforcement of the expansion joint structure on the main beam is poured into the continuous bridge deck slab. This invention can accelerate the reconstruction speed of bridges and improve the shear bearing capacity and reliability of the interface between the old and new concrete surfaces.

Description

Technical Field

[0001] This invention relates to the field of existing bridge reconstruction technology, specifically to a structure and reconstruction method for improving the load-bearing capacity of the joint between the old and new bridge decks in a continuous structure. Background Technology

[0002] Bridge expansion joints are bridge expansion devices installed to eliminate displacement caused by changes in the length of the bridge beam due to temperature variations, and to maintain a smooth driving experience. Their function is to regulate the displacement between the superstructure and the connections between the superstructures caused by vehicle load environmental characteristics and the physical properties of bridge construction materials.

[0003] Bridge expansion joints transfer the load acting on them to the main bridge structure. Because they are constantly exposed to the atmosphere in harsh environments, they are among the most vulnerable and difficult-to-maintain components of the bridge structure. During construction and operation, they are affected by loads, environment, and material aging. Even slight defects or deficiencies in design, construction techniques, and welding quality can reduce driving comfort and affect vehicle lifespan.

[0004] Expansion joints and bearings in bridge structures are non-full-life components, prone to defects and requiring ongoing maintenance, which increases maintenance frequency and costs. Expansion joints, in particular, affect driving comfort and environmental noise, and their repair significantly disrupts traffic. To ensure bridge operational safety, it is essential to fundamentally eliminate defects in bridge expansion joints, reduce maintenance workload and costs, ensure safety, and extend the bridge's service life.

[0005] In existing technologies, the main defects of bridge expansion joints manifest in the following aspects:

[0006] 1. Vehicles bouncing at bridgeheads and bridge expansion joints affect road smoothness and comfort;

[0007] The term "stepping" at bridgeheads and expansion joints refers to the presence of steps at the bridgeheads and expansion joints of highways. These steps cause numerous inconveniences and even significant hazards to vehicles, and can be summarized as follows:

[0008] (1) It affects driving safety and comfort. The reason is that when a vehicle passes over a steep slope at the bridgehead, it will cause discomfort and bumpy ride, or even violent vibration and jumping. Uneven settlement will cause lateral swaying and even lead to driving accidents.

[0009] (2) Reduced road capacity; when vehicles pass over steep slopes at the bridgehead, drivers are forced to brake and slow down, which can easily cause road congestion, indirectly reducing social benefits and lowering people's overall evaluation of the road.

[0010] (3) Impact damage to bridges and vehicles; the impact force generated by the vehicle jumping causes additional impact loads on bridges and roads, which accelerates the damage to abutments, bridge approach slabs, especially supports and expansion joints, and also causes wear and tear on vehicle parts, tires, etc., reducing the service life of vehicles.

[0011] (4) It creates a vicious cycle of road damage; because the bouncing of vehicles in turn aggravates the impact on the road surface, further exacerbating the road damage, and the interaction between them forms a vicious cycle. Over time, asphalt pavements will experience an increase in the damaged area, and the defects such as undulation, cracking and subsidence will worsen, while cement concrete pavements will experience phenomena such as broken slabs, edge chipping and mud pumping.

[0012] (5) Increase highway maintenance costs; as mentioned above, bridge approach slabs affect bridges, roads and vehicles. Therefore, highway maintenance departments need to allocate certain funds for treatment and increase maintenance investment. Moreover, the treatment will affect road traffic to varying degrees.

[0013] 2. Damaged expansion joints are a source of corrosion, reducing the service life of bridges;

[0014] Bridge expansion joints are typically installed within the clear width of the bridge deck, bending vertically upwards by 5cm at the curb.

[0015] In routine inspections of traditional jointed bridges, water seepage often occurs at the ends and outer sides of the expansion joints. Water on the bridge surface (especially snowmelt containing de-icing agents accumulated after snow removal in winter) seeps into the web of the main beam and the ends of the abutment (pier) cap beam, causing erosion and damage to the concrete of the beam body and the ends of the cap beam, affecting the durability of the structure.

[0016] 3. The noise level is higher than that of road sections, usually exceeding 30% of that of road sections, which affects human health;

[0017] According to data from the article "Measurement and Influencing Factor Analysis of Bridge Expansion Joint Noise" published in Environment and Development in 2017 by Shi Linze et al., combined with the sound environment quality standards, the acceptable sound environment for the human body is 60 to 70 dB, while the noise generated by vehicles passing over bridge expansion joints reaches 80 to 100 dB, which requires sufficient attention.

[0018] 4. During the operation and maintenance phase, carbon emissions account for a high proportion, usually more than one-third;

[0019] According to the publicly available literature report "Research on Carbon Emissions of Bridges with Different Structural Materials in Their Life Cycle" published by Xu Shuang of Wuhan University of Technology in 2012, the carbon emissions generated by the maintenance of expansion joints are the largest during the entire maintenance and operation phase of a bridge, accounting for more than one-third of the total carbon emissions in the entire phase.

[0020] 5. Easily damaged and difficult to repair: It affects traffic flow and safety, and the indirect costs are high and increasing day by day (daily cleaning of cracks and frequent maintenance).

[0021] According to the defect statistics in the inspection report of 40 bridges on a highway in Shanghai, 100% of the expansion joints of both elevated bridges and small and medium-sized bridges on the ground have defects.

[0022] Furthermore, damage to expansion joints could lead to vehicles losing control after a collision, causing traffic accidents and posing a threat to society.

[0023] With societal development, higher demands are being placed on bridge design. It is necessary to consider not only safety, applicability, economy, and aesthetics, but also to minimize future maintenance, or even achieve "zero maintenance." Bridge maintenance should not have a significant impact on traffic operations, and the direct and indirect costs of bridge construction and maintenance should be minimized.

[0024] Regarding the main problems with bridge expansion joints mentioned above, there are two approaches to solving them in the existing technology: one is to design and produce expansion devices with better quality and performance; the other is to reduce or eliminate expansion devices as much as possible. The concept of bridges without expansion devices is based on the latter.

[0025] Bridges without expansion joints reduce bridge maintenance during the operational period, lowering total life-cycle costs. Integral bridges, by eliminating expansion joints and supports (note: bridges retaining supports but eliminating expansion joints are called semi-integral bridges), connect the abutment slab to the main beam as a single unit (temperature deformation of the beam is transferred to the end of the abutment slab where it connects to the road). This completely eliminates the negative impacts of expansion joints and supports, fundamentally solving problems such as approach slab settlement, long-term maintenance, and periodic replacement caused by damage to bridge expansion joints. Furthermore, they offer a comfortable, smooth ride with low noise. This improves road quality, enhances the surrounding environment, and effectively improves the bridge's seismic resistance, extending its service life and yielding significant economic and social benefits.

[0026] This technology has been widely and successfully applied in developed regions abroad (tens of thousands of units). Its main advantages are as follows:

[0027] ① Significantly reduces backboard bounce: Leveling is easily achieved, resulting in a comfortable ride without bounce;

[0028] ② Noise reduction and environmental protection: Noise reduction >30%;

[0029] ③ Low maintenance: Easy to maintain, significantly reducing costs, time and complexity, and its performance and durability are no less than those of adjacent roads;

[0030] ④ Low impact: Reduces the impact of maintenance on surrounding traffic and the environment;

[0031] ⑤ Low carbon: Carbon emissions from maintenance are reduced by more than 30%;

[0032] ⑥ No increase in total life cycle cost: Although the initial investment is slightly higher than that of traditional processes, the total life cycle cost is the lowest;

[0033] ⑦ Good durability: No leakage or corrosion, which helps extend the service life of the bridge;

[0034] ⑧ Good safety performance: Increased redundancy enhances seismic resistance.

[0035] However, there are still a large number of bridges built using traditional technologies around the world. The problems with their expansion joints will not disappear with the emergence of new technologies. The problems caused by the defects of traditional technologies are constantly occurring and developing. For example, among the more than 710,000 highway bridges in service in China, small and medium-sized bridges with a total length of less than 100m account for about 93%. If existing bridges can be made without or with fewer joints, it will have important economic and social significance.

[0036] Traditional jointed bridges typically have approach slabs installed behind the abutments. Approach slabs, also known as approach ramps, are an important component of jointed bridges and bridges without expansion joints.

[0037] Using approach slabs offers numerous advantages. The approach slab effectively spans the abutment and the backfill, reducing the impact of vehicles on the backfill and the passive earth pressure on the abutment. If the approach slab is long enough, it can completely eliminate the backfill earth pressure caused by vehicles. When the roadbed settles, the approach slab acts as a transition between the bridge and the adjacent roadbed, resulting in smoother traffic and reducing the impact force on the bridge. Approach slabs also provide a more even load distribution at the bridge ends, reducing damage to the abutments, especially from overloaded vehicles. Furthermore, approach slabs with drainage systems help regulate roadbed drainage, preventing rainwater erosion of the backfill or damage caused by freezing and thawing of the backfill due to water accumulation.

[0038] In bridges without expansion joints, part of the temperature deformation is absorbed by the elastic deformation of the main beam, while the other part is transferred to the junction of the approach slab and the connecting road through the approach slab. In other words, the approach slab is a crucial component for transferring temperature displacement in the bridge structure. However, in traditional jointed bridges, to limit the longitudinal and lateral horizontal displacement of the approach slab, anti-slip steel bars are typically embedded in the abutment body below the end of the approach slab near the main beam. These bars are usually placed at a certain height above the abutment body and wrapped with insulating material, generally spaced approximately 500mm apart transversely. During the pouring of the approach slab concrete, these reinforcing bars are encased within the approach slab. Specifically... Figure 1 As shown.

[0039] To address the defects in existing bridges constructed using traditional techniques, the only solutions are reconstruction or renovation. However, the time and economic costs of rebuilding bridges are too high, especially for small and medium-sized bridges with a total length of less than 100 meters. It is difficult to recoup the investment after reconstruction. This has created an urgent need for society to renovate existing bridges to eliminate the defects caused by their construction using traditional techniques.

[0040] When carrying out seamless reconstruction of existing bridges, it is necessary to first partially remove the concrete at the back of the abutment between the existing main beam and the approach slab. By using the new UHPC material, a continuous reinforcement structure for the bridge deck is added within the abutment area, which can easily achieve the integration of the bridge deck structure system.

[0041] However, on the one hand, the approach slab is constrained by the skin friction from the base soil when deforming together with the main beam. This means that the newly added continuous bridge deck structure at the abutment needs to be reliably integrated with the approach slab to effectively resist the large new external inter-layer shear forces. On the other hand, after the approach slab and main beam are integrated through the continuous bridge deck structure system, the different support systems of the approach slab and main beam lead to inconsistent deformation of their top surfaces under external loads, resulting in inconsistent deformation of the continuous bridge deck structure on their top surfaces. Therefore, compared to the continuous bridge deck structure at the piers, the reliability requirements for the integration of the continuous bridge deck structure at the abutments with the new and old concrete on the top surface of the approach slab are higher.

[0042] However, in existing technologies, if only the top concrete of the approach slab within the continuous bridge deck structure and its height is removed, reinforcing members of the continuous bridge deck structure are installed, and concrete is poured to integrate the continuous bridge deck structure with the approach slab concrete, the thickness of the continuous bridge deck structure is relatively thin (generally around 8cm), and the overlap height with the top surface of the approach slab is generally less than 8cm, or even as small as 2cm. After deducting the protective layer thickness (generally around 2-5cm), the effective embedment depth of the original reinforcing steel in the continuous bridge deck structure is shallow, or even zero. This means that the continuous bridge deck structure mainly relies on the interlocking, adhesion, or friction of the new and old concrete interface to allow the approach slab to slide synchronously with the main beam. When the deformation of the approach slab and the main beam ends is not coordinated, leading to inconsistent deformation of the continuous bridge deck structure on their top surfaces, interlayer tearing easily occurs at the interface between the new and old concrete on the top surface of the approach slab. This causes the continuous bridge deck structure to fail, the approach slab to be unable to slide synchronously with the main beam, and asphalt pavement cracking at the longitudinal boundary between the continuous bridge deck structure and the approach slab. However, if reinforcement bars are installed on the top surface of the approach slab or the concrete of the entire height range of the approach slab near the main beam is removed, the newly added continuous structural reinforcement bars of the bridge deck are embedded in the approach slab and the anchorage length requirements of the reinforcement bars are met, and then the approach slab concrete is re-poured to restore strength, on the one hand, the project cost and construction period will be increased, and on the other hand, it will have a significant impact on the environment and existing traffic, especially on roads with high environmental requirements and heavy traffic.

[0043] Therefore, how to accelerate the reconstruction of bridges during their service life and improve the structural shear bearing capacity and reliability of the interface between new and old concrete has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0044] In view of the above-mentioned deficiencies of the prior art, the present invention provides a structure and reconstruction method for improving the load-bearing capacity of the interface between the new and old concrete in the continuous structure of the bridge deck at the abutment. The purpose is to improve the shear bearing capacity and reliability of the interface between the new and old concrete in the continuous structure of the bridge deck at the abutment, accelerate the reconstruction speed of the bridge, and improve the structural shear resistance and reliability of the interface between the new and old concrete.

[0045] To achieve the above objectives, the present invention discloses a structure for improving the load-bearing capacity of the joint surface between the old and new bridge decks in a continuous bridge abutment structure, including a bridge abutment and an approach slab; the upper end of the bridge abutment is provided with a bridge abutment backrest; a main beam is provided on one side of the bridge abutment backrest facing the middle of the bridge span, and the approach slab is provided on the other side.

[0046] The upper surface of the abutment backrest is flush with the upper surface of the approach plate near the abutment backrest after the main beam and the top surface are partially broken, and is provided with a bridge deck continuous structural slab made of ultra-high performance concrete, abbreviated as UHPC material.

[0047] The thickness of the continuous structural slab of the bridge deck is the same as the thickness of the concrete pavement on the main beam. It is connected by steel bars and cast UHPC to form a whole. The bottom surface of the part located within the vertical projection range of the main beam and the top surface of the main beam are bonded together by roughening the interface between the old and new concrete and secondary casting. The bottom surface of the part located within the vertical projection range of the approach slab and the top surface of the approach slab are also bonded together by roughening the interface between the old and new concrete and secondary casting. Multiple pairs of matching tenon-shaped shear keys and holes are provided between them. When the main beam expands and contracts with heat, the approach slab and the main beam will move synchronously in the longitudinal direction of the bridge.

[0048] Each of the tenon-shaped shear keys is located below the overlapping part of the bridge deck continuous structural slab and the approach slab. The reinforcing bars in each of the tenon-shaped shear keys are embedded in the bridge deck continuous structural slab after being poured. The concrete of each of the tenon-shaped shear keys is combined with the approach slab and the bridge deck continuous structural slab through secondary pouring, so that the new and old concrete are integrated into one.

[0049] Each of the aforementioned holes is located on the upper surface of the overlapping part of the approach slab and the continuous structural slab of the bridge deck, and is located within the entire height range of the approach slab; each of the aforementioned tenon-shaped shear keys is embedded in the corresponding hole, and the new and old concrete are bonded together with the matching hole in the approach slab through secondary pouring.

[0050] Preferably, a rubber material isolation layer is provided between the lower surface of the continuous bridge deck slab and the upper surface of the abutment backrest.

[0051] Preferably, multiple interlayer concrete self-tapping reinforcing bolts are provided between the continuous bridge deck slab and the main beam and the approach slab;

[0052] The shaft of each of the interlayer concrete special self-tapping reinforcing bolts penetrates the continuous structural slab of the bridge deck, the main beam, or the approach slab;

[0053] Alternatively, a portion of the shaft of each of the interlayer concrete-specific self-tapping reinforcing bolts is drilled and screwed into the main beam or the approach slab, while the remaining portion is embedded in the subsequently cast bridge deck continuous structural slab.

[0054] Preferably, the continuous bridge deck structural plate is a new structure added to the abutment area after the bridge has been reconstructed to be seamless or with fewer joints;

[0055] The abutment backrest, the approach slab, and the main beam are existing structures of the bridge, and the main beam is equipped with an expansion joint structure.

[0056] The pre-embedded reinforcement bars of the expansion joint structure on the main beam are retained and cast into the continuous structural slab of the bridge deck during the reconstruction process, and are fixed with the pre-embedded steel mesh of the continuous structural slab of the bridge deck.

[0057] Preferably, the continuous bridge deck structural plate is a new structure added to the abutment area after the bridge has been reconstructed to be seamless or with fewer joints;

[0058] The abutment and the approach slab are existing structures of the bridge;

[0059] The holes on the approach plate for setting each tenon-shaped shear key serve as anti-slip constraints on the approach plate by the bridge abutment. When the concrete surrounding each anti-slip steel bar in the approach plate is broken, an opening is formed over the entire height range of the approach plate.

[0060] The present invention also provides a method for reconstructing a bridge abutment and bridge deck continuous structure at the interface between the old and new sections to improve load-bearing capacity, comprising the following steps:

[0061] Step 1: Remove the concrete and asphalt pavement above the abutment, approach slab, and main beam for setting the continuous structural slab of the bridge deck, as well as the expansion joint structure on the back of the main beam and abutment, so that the embedded reinforcement of the expansion joint structure on the main beam is exposed, and the reinforcement in the existing concrete pavement of the bridge is exposed.

[0062] Step 2: Determine the location of each anti-slip steel bar between the bridge abutment and the approach slab;

[0063] Step 3: Use a core drill to make holes in the concrete surrounding each anti-slip steel bar that belongs to the approach slab, breaking the concrete surrounding each anti-slip steel bar that belongs to the approach slab down to the upper surface of the bridge abutment, so that the part of each anti-slip steel bar above the upper surface of the bridge abutment is exposed in the corresponding holes.

[0064] Step 4: Cut off the portion of each anti-slip steel bar located above the upper surface of the bridge abutment;

[0065] Step 5: Each of the openings from which the corresponding anti-slip steel bars have been cut is used as the hole, and the corresponding tenon-shaped shear key steel bars are installed.

[0066] The upper end of the reinforcing bar of each tenon-shaped shear key extends beyond the corresponding hole and into the range of the continuous structural slab of the bridge deck;

[0067] Step 6: Pour a certain height of concrete material at the top of each hole to form a tenon-shaped shear key with its upper surface flush with the upper surface of the slab.

[0068] Step 7: Embed multiple interlayer concrete self-tapping reinforcing bolts that extend into the continuous structural slab of the bridge deck on the upper surface of the approach slab and the main beam; install the rubber material isolation layer on the top surface of the abutment back;

[0069] Step 8: Lay the reinforcing embedded steel mesh of the continuous bridge deck slab;

[0070] Step 9: Pour UHPC material to form the continuous structural slab of the bridge deck, which is combined with the concrete and steel reinforcement of all the tenon-shaped shear keys to form a T-shaped integral structure.

[0071] Preferably, when the concrete pavement on the main beam is broken, a slope is formed towards the direction of the continuous structural slab of the bridge deck.

[0072] Preferably, when pouring the continuous structural slab of the bridge deck, a slope is formed facing the direction of the approach slab.

[0073] Preferably, after the continuous bridge deck slab is poured, asphalt pavement is laid on the continuous bridge deck slab and the approach slab.

[0074] Preferably, before drilling holes in the concrete surrounding each of the anti-slip steel bars that belongs to the slab, the local asphalt pavement at the location where the holes need to be drilled in the slab is first broken up.

[0075] In step 3, an oxygen and acetylene cutting gun is used to cut off the portion of each anti-slip steel bar located above the upper surface of the bridge abutment.

[0076] The beneficial effects of this invention are:

[0077] This invention utilizes the temporary holes opened inside the approach slab during reconstruction. By installing steel bars and pouring concrete in batches, multiple tenon-shaped shear keys are formed on the bottom surface of the newly added bridge deck continuous structure. These keys are embedded inside the approach slab and integrated with the surrounding approach slab concrete, serving a similar function to the welding studs in the connectors of steel-concrete composite structures.

[0078] The tenon-shaped shear key in this invention can not only significantly improve the structural shear resistance of the interface between new and old concrete, but also constrain the deformation of the bridge deck continuous structure on the top surface of the approach slab when the deformation of the end of the approach slab and the main beam is not coordinated, thus preventing interlayer tearing at the interface between the new and old concrete and ensuring that the approach slab can slide synchronously with the main beam.

[0079] Meanwhile, this invention can flexibly and rationally utilize existing structures, accelerate the reconstruction speed of bridges during their service life, improve the shear bearing capacity and reliability of the new and old concrete interface of the bridge deck continuous structure, reduce the investment scale, and minimize the construction cycle of the conversion between the old and new systems and the impact on the existing traffic.

[0080] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0081] Figure 1 This diagram illustrates the connection structure between the abutment, main beam, and approach slab of an existing bridge in one embodiment of the present invention.

[0082] Figure 2 This diagram shows a partial cross-sectional view of the structure after the anti-slip constraint between the abutment and the approach slab has been removed, according to an embodiment of the present invention.

[0083] Figure 3 This diagram illustrates the structure after modification in one embodiment of the present invention.

[0084] Figure 4 This diagram illustrates a continuous structural slab and tenon-shaped shear key reinforcement structure of the bridge deck after reconstruction, according to one embodiment of the present invention. Detailed Implementation

[0085] Example: Figure 1 and Figure 2 As shown, a specific embodiment of the structure for improving the load-bearing capacity of the new and old joint surfaces of the bridge deck continuous structure of the present invention includes a bridge abutment 1 and an approach slab 3; a bridge abutment backrest 7 is provided at the upper end of the bridge abutment 1; a main beam 5 is provided on one side of the bridge abutment backrest 7 facing the middle of the bridge span, and an approach slab 3 is provided on the other side.

[0086] Among them, the upper surface of the abutment back 7 is flush with the upper surface of the main beam 5 and the part of the approach plate 3 after partial removal of the top surface near the abutment back 7, and is provided with a bridge deck continuous structure plate 8 made of ultra-high performance concrete (UHPC material).

[0087] The thickness of the continuous structural slab 8 on the bridge deck is the same as the thickness of the concrete pavement 9 on the main beam 5. It is connected by steel bars and cast UHPC to form a whole. The bottom surface of the part within the vertical projection range of the main beam 5 and the top surface of the main beam 5 are bonded together by roughening the interface between the new and old concrete and secondary casting. The bottom surface of the part within the vertical projection range of the approach slab 3 and the top surface of the approach slab 3 are also bonded together by roughening the interface between the new and old concrete and secondary casting. Multiple pairs of matching tenon-shaped shear keys 10 and holes 16 are provided between them. When the main beam 5 expands and contracts with heat, the approach slab 3 and the main beam 5 will move synchronously in the bridge direction.

[0088] Each tenon-shaped shear key 10 is located below the overlapping part of the bridge deck continuous structural slab 8 and the approach slab 3. The reinforcing bars in each tenon-shaped shear key 10 are embedded in the later-cast bridge deck continuous structural slab 8. The concrete of each tenon-shaped shear key 10 is combined with the approach slab 3 and the bridge deck continuous structural slab 8 through secondary casting, so that the new and old concrete are integrated into one.

[0089] Each hole 16 is located on the upper surface of the overlapping part of the approach slab 3 and the continuous structural slab 8 of the bridge deck, and is located within the entire height range of the approach slab 3; each tenon-shaped shear key 10 is embedded in the corresponding hole 16, and the new and old concrete are combined into one by secondary pouring with the matching hole 16 in the approach slab 3.

[0090] This invention provides multiple pairs of matching tenon-shaped shear keys 10 and holes 16 between the continuous structural slab 8 and the approach slab 3. When the main beam 5 expands and contracts with heat, the approach slab 3 and the main beam 5 are displaced synchronously in the bridge direction. The concrete and steel bars of the continuous structural slab 8 and the tenon-shaped shear keys 10 are combined to form a T-shaped whole. The concrete of the tenon-shaped shear keys 10 is combined with the side concrete of the holes 16 on the approach slab 3 and they share the force, which improves the shear bearing capacity and reliability of the interface between the new and old concrete of the continuous structural slab 8 and the approach slab 3.

[0091] In some embodiments, a rubber material isolation layer 11 is provided between the lower surface of the bridge deck continuous structural plate 8 and the upper surface of the abutment backing 7.

[0092] In some embodiments, multiple interlayer concrete self-tapping reinforcing bolts 13 are provided between the bridge deck continuous structural slab 8 and the main beam 5 and the approach slab 3;

[0093] The shaft of the concrete-specific self-tapping reinforcing bolt 13 between each layer penetrates the continuous structural slab 8 of the bridge deck, the main beam 5, or the approach slab 3.

[0094] Alternatively, part of the shaft of the concrete-specific self-tapping reinforcing bolt 13 between each layer is drilled and screwed into the main beam 5 or the approach slab 3, while the rest is embedded in the post-cast bridge deck continuous structural slab 8.

[0095] In some embodiments, the continuous bridge deck slab 8 is a new structure added to the abutment area after the bridge has been reconstructed to be seamless or with fewer seams.

[0096] The abutment backrest 7, approach slab 3 and main beam 5 are existing structures of the bridge, and the main beam 5 is equipped with an expansion joint structure 6.

[0097] The pre-embedded reinforcement 12 of the expansion joint structure 6 on the main beam 5 is retained and cast into the continuous structural slab 8 of the bridge deck during the reconstruction process, and is fixed with the pre-embedded steel mesh of the continuous structural slab 8 of the bridge deck.

[0098] In some embodiments, the continuous bridge deck slab 8 is a new structure added to the abutment area after the bridge has been reconstructed to be seamless or with fewer seams.

[0099] Abutment 1 and approach slab 3 are existing structures of the bridge;

[0100] The holes 16 on the approach slab 3 for setting each tenon-shaped shear key 10 are anti-slip constraints of the bridge abutment 1 on the approach slab 3. When the concrete around each anti-slip steel bar 4 in the approach slab 3 is broken, it forms an opening in the entire height range of the approach slab 3.

[0101] like Figures 1 to 4 As shown, the present invention also provides a method for reconstructing a bridge abutment deck continuous structure at the interface between the old and new sections to improve the load-bearing capacity, comprising the following steps:

[0102] Step 1: Remove the concrete pavement 9 and asphalt pavement 2 above the bridge abutment 1, approach slab 3 and main beam 5 for setting the bridge deck continuous structural slab 8, as well as the expansion joint structure 6 on the main beam 5 and the bridge abutment back 7, so that the embedded reinforcement 12 of the expansion joint structure 6 on the main beam 5 is exposed, as well as the reinforcement in the existing concrete pavement 9 of the bridge is exposed.

[0103] Step 2: Locate the position of each anti-slip steel bar 4 between abutment 1 and approach slab 3;

[0104] Step 3: Use a core drill to make holes in the concrete surrounding the approach slab 3 of each anti-slip steel bar 4, breaking the concrete surrounding the approach slab 3 of each anti-slip steel bar 4 down to the upper surface of the bridge abutment 1, so that the part of each anti-slip steel bar 4 above the upper surface of the bridge abutment 1 is exposed in the corresponding holes.

[0105] Step 4: Cut off the portion of each anti-slip steel bar 4 above the upper surface of the bridge abutment 1;

[0106] Step 5: Each opening from which the corresponding anti-slip steel bar 4 has been cut is designated as a hole 16, and a corresponding tenon-shaped shear key 10 is installed.

[0107] The upper end of the reinforcing bar of each tenon-shaped shear key 10 extends beyond the corresponding hole 16 and into the range of the continuous structural slab 8 of the bridge deck.

[0108] Step 6: Pour a certain height of concrete material at the top of each hole 16 to form a tenon-shaped shear key 10 with its upper surface flush with the upper surface of the slab.

[0109] Step 7: Embed multiple interlayer concrete self-tapping reinforcing bolts 13 that extend into the continuous structural slab 8 of the bridge deck on the upper surface of the approach slab 3 and the main beam 5; install a rubber material isolation layer 11 on the top surface of the abutment back 7;

[0110] Step 8: Lay the reinforcing embedded steel mesh for the continuous bridge deck slab 8;

[0111] Step 9: Pour UHPC material to form the continuous bridge deck slab 8, which is combined with the concrete and steel reinforcement of all tenon-shaped shear keys 10 to form a T-shaped integral structure.

[0112] This invention utilizes a core drill to drill holes in the concrete surrounding each anti-slip steel bar 4, forming the entire height of the slab 3. The holes from which the anti-slip steel bars 4 are cut are used as templates for casting tenon-shaped shear keys 10. The steel bars of the tenon-shaped shear keys 10 are installed in the holes, protruding a certain height from the top surface of the slab. Then, concrete is poured into the holes to form the tenon-shaped shear keys 10.

[0113] In some embodiments, when the concrete pavement 9 on the main beam 5 is broken, a slope is formed toward the direction of the continuous structural slab 8 of the bridge deck.

[0114] In some embodiments, a slope is formed towards the approach slab 3 when the continuous structural slab 8 of the bridge deck is poured.

[0115] In some embodiments, after the continuous structural slab 8 of the bridge deck is poured, asphalt pavement 2 is laid on the continuous structural slab 8 and the approach slab 3.

[0116] In some embodiments, before drilling holes in the concrete surrounding each anti-slip steel bar 4 that belongs to the slab 3, the local asphalt pavement 2 at the location where the hole needs to be drilled in the slab 3 is first broken.

[0117] In step 3, an oxygen and acetylene cutting gun is used to cut off the portion of each anti-slip steel bar 4 located above the upper surface of the bridge abutment 1.

[0118] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A structure for improving the load-bearing capacity of the new and old joint surfaces of a bridge deck and abutment, comprising abutment (1) and approach slab (3); the abutment (1) is provided with a backrest (7) at its upper end; the backrest (7) is provided with a main beam (5) on one side facing the middle of the bridge span, and the approach slab (3) on the other side; characterized in that: The upper surface of the abutment backrest (7) is flush with the upper surface of the main beam (5) and the part of the approach plate (3) after the top surface is partially broken, which is close to the abutment backrest (7), and is provided with a bridge deck continuous structural plate (8) made of ultra-high performance concrete. The thickness of the continuous structural slab (8) of the bridge deck is the same as the thickness of the concrete pavement (9) on the main beam (5). It is connected by steel bars and ultra-high performance concrete to form a whole. The bottom surface of the part within the vertical projection range of the main beam (5) and the top surface of the main beam (5) are connected by roughening the interface between the old and new concrete and secondary pouring to form a whole. The bottom surface of the part within the vertical projection range of the approach slab (3) and the top surface of the approach slab (3) are also connected by roughening the interface between the old and new concrete and secondary pouring to form a whole. Multiple pairs of matching tenon-shaped shear keys (10) and holes (16) are provided between them. When the main beam (5) expands and contracts with heat, the approach slab (3) and the main beam (5) are displaced synchronously in the bridge direction. Each of the tenon-shaped shear keys (10) is located below the overlapping part of the bridge deck continuous structural slab (8) and the approach slab (3). The reinforcing bars in each of the tenon-shaped shear keys (10) are embedded in the bridge deck continuous structural slab (8) after being poured. The concrete of each of the tenon-shaped shear keys (10) is combined with the approach slab (3) and the bridge deck continuous structural slab (8) through secondary pouring, so that the new and old concrete are integrated into one. Each of the holes (16) is located on the upper surface of the overlapping part of the approach plate (3) and the bridge deck continuous structural plate (8), and is located within the entire height range of the approach plate (3); each of the tenon-shaped shear keys (10) is embedded in the corresponding hole (16), and the new and old concrete are combined into one by secondary pouring with the matching hole (16) in the approach plate (3).

2. The structure for improving the load-bearing capacity of the new and old joint surfaces of the bridge abutment and bridge deck as described in claim 1, characterized in that, A rubber material isolation layer (11) is provided between the lower surface of the continuous bridge deck slab (8) and the upper surface of the abutment backrest (7).

3. The structure for improving the load-bearing capacity of the new and old joint surfaces of the bridge abutment and bridge deck as described in claim 1, characterized in that, Multiple interlayer concrete special self-tapping reinforcing bolts (13) are provided between the bridge deck continuous structural plate (8), the main beam (5), and the approach plate (3). The shaft of each of the interlayer concrete special self-tapping reinforcing bolts (13) penetrates the bridge deck continuous structural plate (8), the main beam (5), or the approach plate (3). Alternatively, a portion of the shaft of each of the interlayer concrete-specific self-tapping reinforcing bolts (13) is drilled and screwed into the main beam (5) or the approach plate (3), while the remaining portion is embedded in the post-cast bridge deck continuous structural slab (8).

4. The structure for improving the load-bearing capacity of the new and old joint surfaces of the bridge deck and abutment continuous construction as described in claim 1, characterized in that, The continuous bridge deck slab (8) is a new structure added to the abutment after the bridge is reconstructed to be seamless or with fewer joints. The abutment backrest (7), the approach plate (3) and the main beam (5) are the existing structures of the bridge, and the main beam (5) is provided with an expansion joint structure (6). The pre-embedded reinforcement (12) of the expansion joint structure (6) on the main beam (5) is retained and cast into the continuous structural slab (8) of the bridge deck during the reconstruction process, and is fixed with the pre-embedded steel mesh of the continuous structural slab (8).

5. The structure for improving the load-bearing capacity of the new and old joint surfaces of the continuous bridge deck and abutment construction as described in claim 1, characterized in that, The continuous bridge deck slab (8) is a new structure added to the abutment after the bridge is reconstructed to be seamless or with fewer joints. The abutment (1) and the approach slab (3) are existing structures of the bridge; The holes (16) on the approach plate (3) for setting each tenon-shaped shear key (10) are all anti-slip constraints of the bridge abutment (1) on the approach plate (3). When the concrete around each anti-slip steel bar (4) in the approach plate (3) is broken, the openings in the approach plate (3) are formed in the full height range of the approach plate (3).

6. The reconstruction method for improving the load-bearing capacity of the new and old joint surfaces of the bridge abutment and deck through continuous construction as described in claim 1, characterized in that, Includes the following steps: Step 1: Remove the concrete pavement (9) and asphalt pavement (2) above the abutment (1), the approach slab (3) and the main beam (5) for setting the continuous structural slab (8) of the bridge deck, as well as the expansion joint structure (6) on the main beam (5) and the abutment backrest (7), so that the embedded reinforcement (12) of the expansion joint structure (6) on the main beam (5) is exposed, as well as the reinforcement in the existing concrete pavement (9) of the bridge is exposed; Step 2: Determine the position of each anti-slip steel bar (4) between the bridge abutment (1) and the approach slab (3); Step 3: Use a core drill to make holes in the concrete around each of the anti-slip steel bars (4) that belongs to the approach slab (3), and break the concrete around each of the anti-slip steel bars (4) that belongs to the approach slab (3) down to the upper surface of the bridge abutment (1), so that the part of each of the anti-slip steel bars (4) above the upper surface of the bridge abutment (1) is exposed in the corresponding holes. Step 4: Cut off the portion of each of the anti-slip steel bars (4) above the upper surface of the bridge abutment (1); Step 5: Each of the openings from which the corresponding anti-slip steel bars (4) have been cut is taken as the hole (16), and the corresponding tenon-shaped shear key (10) steel bars are set. The upper end of the reinforcing bar of each of the tenon-shaped shear keys (10) extends above the corresponding hole (16) and into the range of the continuous structural slab (8) of the bridge deck; Step 6: Pour a certain height of concrete material on the top of each hole (16) to form the tenon-shaped shear key (10) with its upper surface flush with the upper surface of the slab. Step 7: Embed multiple interlayer concrete self-tapping reinforcing bolts (13) that extend into the continuous structural plate (8) of the bridge deck on the upper surface of the approach slab (3) and the main beam (5); install a rubber material isolation layer (11) on the top surface of the abutment back (7); Step 8: Lay the reinforcing pre-embedded steel mesh of the continuous bridge deck slab (8); Step 9: Pour UHPC material to form the continuous structural slab (8) of the bridge deck, which is combined with the concrete and steel reinforcement of all the tenon-shaped shear keys (10) to form a T-shaped integral structure.

7. The reconstruction method as described in claim 6, characterized in that, When the concrete pavement (9) on the main beam (5) is broken, a slope is formed in the direction of the continuous structural slab (8) of the bridge deck.

8. The reconstruction method as described in claim 6, characterized in that, When the continuous structural slab (8) of the bridge deck is poured, a slope is formed in the direction of the approach slab (3).

9. The reconstruction method as described in claim 6, characterized in that, After the continuous structural slab (8) of the bridge deck is poured, asphalt pavement (2) is laid on the continuous structural slab (8) and the approach slab (3).

10. The reconstruction method as described in claim 6, characterized in that, Before drilling holes in the concrete surrounding each of the anti-slip steel bars (4) belonging to the slab (3) using a core drill, the local asphalt pavement (2) at the location where the holes need to be drilled in the slab (3) is broken. In step 3, an oxygen and acetylene cutting gun is used to cut off the portion of each of the anti-slip steel bars (4) above the upper surface of the bridge abutment (1).

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