A concrete sleeve reinforcement structure for a simply supported beam bridge

Abstract

The utility model discloses a concrete sleeve lining reinforcing structure for simply supported beam bridge, including setting in the sleeve lining top board of original bridge main girder below and setting in the sleeve lining side wall and sleeve lining foundation of original bridge abutment front, sleeve lining top board and original bridge main girder fixed connection, twice casting forming, lower part is the top board first stage concrete, and upper part is the top board second stage concrete, and the top board first stage concrete and sleeve lining side wall and sleeve lining foundation are integrally casted and formed, and have the gap between with original bridge main girder, and the gap is the top board second stage concrete, and is last casting forming, and sleeve lining side wall and sleeve lining foundation and original bridge abutment fixed connection, and sleeve lining top board, sleeve lining side wall and sleeve lining foundation are along bridge transverse full section arrangement, and the utility model can realize the great reduction of engineering cost, and improve economic efficiency.

Description

Technical Field

[0001] This utility model relates to the field of bridge engineering technology, specifically to a concrete lining reinforcement structure for simply supported beam bridges. Background Technology

[0002] Simply supported beam bridges, with the main girder as the primary load-bearing structure, are the earliest and most widely used type of beam bridge. With the increasing traffic volume and heavy-duty vehicles year by year, bridge maintenance projects have revealed numerous problems in early-built simply supported beam bridges, including transverse cracks at the bottom of the beams, insufficient structural stiffness, and insufficient load-bearing capacity. The main reasons for this are that these early bridges had relatively low beam heights, thinner slabs, and smaller structural dimensions. Therefore, reliable reinforcement is necessary for these bridges to address bridge defects and improve structural stiffness and load-bearing capacity.

[0003] There are various existing reinforcement techniques for the aforementioned bridge defects, including cross-section enlargement reinforcement, steel plate bonding reinforcement, fiber composite material bonding reinforcement, and external prestressing reinforcement. Cross-section enlargement reinforcement increases the main beam's stiffness and load-bearing capacity by increasing the beam height or plate thickness, but this increases the added self-weight of the structure, limiting the increase in load-bearing capacity and leading to increased stress on the substructure. Steel plate bonding and fiber composite material bonding reinforcement both increase the main beam's cross-sectional reinforcement ratio to improve load-bearing capacity and inhibit crack development, but they cannot improve the bridge's structural stiffness and have poor durability. External prestressing reinforcement balances the tensile stress at the bottom of the main beam by applying prestressing, improving load-bearing capacity and inhibiting crack development, but similarly cannot improve the bridge's structural stiffness and has poor durability. Furthermore, for short-span bridges, the actual effective reinforcement range is very small due to the need to reserve space for tensioning operations, resulting in unsatisfactory reinforcement effects and significant construction difficulties. Clad structures are often used as tunnel reinforcement structures to reinforce tunnel arches. In bridge engineering, steel frame structures or steel base plates are often required before concrete lining is poured. This method is mainly suitable for arch bridge reinforcement, but steel structures are expensive. When using concrete lining for reinforcement, the pouring of the lining concrete is affected by existing traffic on the bridge deck, often requiring long-term traffic interruptions for construction, which brings significant social impact. Therefore, we propose a concrete lining reinforcement structure for simply supported beam bridges. Utility Model Content

[0004] The purpose of this invention is to provide a concrete lining reinforcement structure for simply supported beam bridges to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a concrete lining reinforcement structure for a simply supported beam bridge, comprising a lining top plate disposed below the original bridge main beam and lining side walls and a lining foundation disposed in front of the original bridge abutment. The lining top plate is fixedly connected to the original bridge main beam and is cast in two stages. The lower part is the first-stage concrete of the top plate, and the upper part is the second-stage concrete of the top plate. The first-stage concrete of the top plate is integrally cast with the lining side walls and the lining foundation, leaving a gap between it and the original bridge main beam. The second-stage concrete of the top plate is placed in the gap and is cast last. The lining side walls and the lining foundation are fixedly connected to the original bridge abutment. The lining top plate, lining side walls, and lining foundation are arranged along the entire transverse section of the bridge.

[0006] Furthermore, the lining top plate is fixedly connected to the original bridge main beam through L-shaped rebar anchoring on the top plate. A layer of steel mesh is arranged at the bottom of both the first-stage concrete and the second-stage concrete of the top plate, and the steel mesh is tied to the L-shaped rebar anchoring on the top plate.

[0007] Furthermore, the lining sidewall is fixedly connected to the original bridge abutment through L-shaped rebar anchors on the sidewall, and the lining foundation is fixedly connected to the original bridge abutment through L-shaped rebar anchors on the foundation. Two layers of steel mesh are arranged inside the lining sidewall, and one layer of steel mesh is arranged in a ring inside the lining foundation. The steel mesh is tied to the L-shaped rebar anchors on the sidewall and the L-shaped rebar anchors on the foundation.

[0008] Furthermore, the first-stage concrete of the roof slab, the side walls of the lining, and the foundation of the lining are all made of ordinary concrete, while the second-stage concrete of the roof slab is made of fine aggregate quick-hardening concrete.

[0009] Furthermore, the thickness of the first-stage concrete of the roof slab is [20, 40] cm, the thickness of the second-stage concrete of the roof slab is [10, 20] cm, the thickness of the lining sidewall is [20, 60] cm, the width of the lining foundation is [40, 80] cm, and the height is [50, 100] cm.

[0010] Furthermore, the implantation depth of the L-shaped rebar in the top slab is not less than 10 times the diameter of the rebar, and the implantation depth of the L-shaped rebar in the side wall and the L-shaped rebar in the foundation is not less than 15 times the diameter of the rebar.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] 1. The concrete lining reinforcement structure, consisting of a lining top plate, lining side walls, and lining foundation, not only increases the cross-sectional height and structural dimensions of the original bridge main beam, but also increases the reinforcement ratio of the cross-section by arranging multiple layers of steel mesh. This significantly improves the bridge's load-bearing capacity and structural stiffness, and effectively inhibits the development of transverse cracks at the bottom of the original bridge main beam. The concrete lining reinforcement structure is arranged along the entire transverse section of the bridge, which greatly increases the overall transverse stiffness of the bridge, making the stress on each main beam of the entire bridge more uniform and avoiding the formation of a single-slab stress state.

[0013] 2. By using the lining sidewalls and lining foundations, the additional self-weight of the reinforced structure is transferred to the foundation, forming a clear force transmission path. This ensures that the structural stiffness and bearing capacity are improved without increasing the burden on the original structure or increasing the stress on the original bridge substructure.

[0014] 3. By pouring the top slab of the lining in two stages, the first stage involves pouring the first phase of concrete for the top slab, the side walls of the lining, and the foundation of the lining in one integrated manner. Ordinary concrete is used to reduce the project cost. Since it is not fully connected to the original main beam of the bridge, there is no need to interrupt the traffic on the bridge during construction. The second stage involves pouring the second phase of concrete for the top slab, using fine aggregate quick-hardening concrete to ensure the density of the concrete pouring in the confined space. At the same time, it also significantly shortens the concrete setting time. Only a brief interruption of traffic on the bridge is required, which greatly reduces the impact of construction on the existing traffic on the bridge. In addition, this utility model does not use steel structure, which greatly reduces the project cost and improves economic efficiency. Attached Figure Description

[0015] Figure 1 This is an elevation view of the concrete lining reinforcement structure of this utility model;

[0016] Figure 2 This is a detailed drawing of the connection between the concrete lining reinforcement structure of this utility model and the original bridge main beam.

[0017] Figure 3 This is a detailed drawing of the connection between the concrete lining reinforcement structure of this utility model and the original bridge abutment.

[0018] In the diagram: 1. Original bridge main beam; 2. Original bridge abutment; 3. Top slab lining; 4. First-stage concrete of the top slab; 5. Second-stage concrete of the top slab; 6. Side walls lining; 7. Foundation lining; 8. L-shaped rebars in the top slab; 9. L-shaped rebars in the side walls; 10. L-shaped rebars in the foundation; 11. Steel mesh. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] Please see Figures 1-3 A concrete lining reinforcement structure for a simply supported beam bridge includes a lining top plate 3 located below the original main beam 1, and lining side walls 6 and lining foundation 7 located in front of the original abutment 2. The lining top plate 3 is fixedly connected to the original main beam 1 and is cast in two stages. The lower part is the first-stage concrete 4 of the top plate, and the upper part is the second-stage concrete 5 of the top plate. The first-stage concrete 4 of the top plate, the lining side walls 6 and the lining foundation 7 are cast as a whole, leaving a gap between it and the original main beam 1. The second-stage concrete 5 of the top plate is cast in the gap and is the last to be cast. The lining side walls 6 and the lining foundation 7 are fixedly connected to the original abutment 2. The lining top plate 3, the lining side walls 6 and the lining foundation 7 are arranged along the entire transverse section of the bridge. The lining top plate 3 is fixedly connected to the original main beam 1 by L-shaped rebars 8. A layer of steel mesh 11 is arranged at the bottom of both the first-stage concrete 4 and the second-stage concrete 5 of the top plate. The steel mesh 11 is tied to the L-shaped rebars 8 of the top plate.

[0021] Before use, clean the bottom of the original bridge main beam 1 and the front surface of the original bridge abutment 2. For example, wipe off the dust and knock off loose concrete fragments to ensure that the original structure surface is flat and free of debris. This will ensure that the new structure and the original bridge can be tightly bonded without gaps when installing reinforcement bars and pouring concrete. Use professional measuring tools to mark the laying range of the top plate 3 under the original bridge main beam 1, and mark the masonry position of the side wall 6 and the excavation range of the foundation 7 in front of the original bridge abutment 2. At the same time, determine the drilling points of the L-shaped reinforcement bars 8 on the top plate, the L-shaped reinforcement bars 9 on the side wall, and the L-shaped reinforcement bars 10 on the foundation to ensure that all reinforcement parts are aligned.

[0022] In this embodiment, the lining sidewall 6 is fixedly connected to the original bridge abutment 2 via L-shaped rebars 9, and the lining foundation 7 is fixedly connected to the original bridge abutment 2 via L-shaped rebars 10. Two layers of steel mesh 11 are arranged inside the lining sidewall 6, and one layer of steel mesh 11 is arranged in a ring inside the lining foundation 7. The steel mesh 11 is tied to the L-shaped rebars 9 and the L-shaped rebars 10. Ordinary concrete is used for the first-stage concrete 4 of the roof slab, the lining sidewall 6, and the lining foundation 7. Ordinary concrete is used for the second-stage concrete 5 of the roof slab. The first-stage concrete of the top slab (4) is [20, 40] cm thick, the second-stage concrete of the top slab (5) is [10, 20] cm thick, the side wall of the lining (6) is [20, 60] cm thick, the foundation of the lining (7) is [40, 80] cm wide and [50, 100] cm high, the L-shaped rebar of the top slab (8) is implanted to a depth of not less than 10 times the diameter of the rebar, and the L-shaped rebar of the side wall (9) and the L-shaped rebar of the foundation (10) are implanted to a depth of not less than 15 times the diameter of the rebar.

[0023] According to the previously marked locations, drill holes at the bottom of the original main beam 1 for inserting L-shaped rebar 8 into the top slab. The hole depth must be ≥10 times the rebar diameter. For example, if the rebar diameter is 20mm, the hole depth should be at least 200mm. Then drill holes for L-shaped rebar 9 on the side wall of the original abutment 2 and holes for L-shaped rebar 10 in the foundation at the bottom. The depth of these two types of holes must be ≥15 times the rebar diameter. Insufficient hole depth will cause the rebar to be unstable and may fall off later. After drilling the holes, use a blower to blow away the dust and debris in the holes. Clean the holes thoroughly, then inject a special rebar adhesive—a strong bonding agent—into the holes. The adhesive must be fully injected, without any gaps. This adhesive is the "binder" that firmly bonds the rebar to the original bridge. Incomplete cleaning will affect the adhesive's stickiness. Insert the L-shaped rebars (8 for the top slab, 9 for the side walls, and 10 for the foundation) into their corresponding holes. Gently rotate them to ensure the adhesive and rebar are in full contact. Then let them stand and wait for the adhesive to cure. This usually takes several hours; refer to the adhesive instructions for details. Do not touch the rebars before they cure, otherwise they will become misaligned.

[0024] Next, within the construction area of ​​the side wall 6, tie two layers of steel mesh 11, one layer on the top and one layer on the bottom, with spacing according to design requirements. Then, within the construction area of ​​the foundation 7, tie a ring of steel mesh 11 to form a circle, conforming to the shape of the foundation. When tying, these steel meshes 11 must be tied together with the corresponding L-shaped rebars 9 on the side wall and L-shaped rebars 10 on the foundation, and tied tightly with tie wire. This ensures that they are not loose. After the concrete of the side wall and foundation solidifies, the steel mesh and the rebars can work together to bear the load. This will be achieved on the top slab of the lining. At the lower part of 3, which is the location of the first-stage concrete 4 of the top slab, a layer of steel mesh 11 is tied. This steel mesh 11 is then tightly bound to the previously installed L-shaped rebar 8 of the top slab using tie wire. This ensures that the first-stage concrete 4 of the top slab and the original main beam 1 are connected through the steel mesh and rebar. Steel plates or wooden boards are used to support the formwork on the outside of the lining sidewalls 6 and the lining foundation 7. A bottom formwork is then erected below the lining top slab 3. The formwork must be firmly fixed, for example, with steel pipe supports, to prevent grout leakage or deformation during pouring. The shape of the formwork is determined by the concrete... The shape of the solidified concrete will affect the dimensions of the reinforced structure if it is crooked. Ordinary concrete is poured into the formwork because these three parts do not have high requirements for solidification speed and ordinary concrete is inexpensive. When pouring, use a vibrator to compact the concrete to avoid honeycomb, pitting and other voids. Special note: When pouring the first phase of the top slab concrete 4, leave a gap with the bottom of the original bridge main beam 1. The width is the thickness of the subsequent second phase of the top slab concrete 5, 10-20cm. It cannot be directly attached to the original bridge main beam 1. This gap is left as a "connection space" for the second pour. After pouring, cover the concrete surface with a layer of geotextile and water it every day to keep it moist. Cure for 7-14 days, depending on the temperature, to allow the concrete to slowly solidify and harden. Poor curing will lead to insufficient concrete strength and easy cracking. This pour does not need to interrupt bridge traffic because the first phase of the top slab concrete 4 is not completely bonded to the original bridge main beam 1. The vibration of vehicles on the bridge will not affect the concrete solidification, which can minimize the interference with traffic.

[0025] After the first concrete pour reaches the required strength, it generally needs to be cured to more than 70% of the design strength before pouring the second-stage concrete (5) for the roof slab. This completely connects the roof slab (3) and the original main beam (1). First, use a high-pressure water gun to clean the dust and debris from the gaps left earlier, then wipe them dry with a dry cloth. Impurities in the gaps can cause the second-stage concrete to not bond tightly with the original bridge and the first-stage concrete. Fill the gaps with fine aggregate, which is quick-setting concrete. Fine aggregate can fill narrow gaps. Quick-setting concrete sets quickly, so it should be poured slowly while gently vibrating with a small vibrator to ensure that the concrete fills the entire gap without any voids. Fine aggregate ensures density, and quick-setting concrete shortens the setting time. During pouring, bridge traffic should be temporarily interrupted for several hours to a day, depending on the concrete setting speed, to avoid vehicle vibration affecting the bond between the concrete and the original bridge. After pouring, cover with geotextile and water for curing. Because it is quick-setting concrete, it can reach the design strength in 3-5 days. The temporary traffic interruption reduces social impact, and quick-setting concrete can speed up the construction progress.

[0026] After all inspections are passed, normal traffic on the bridge can be fully restored. The entire reinforced structure, including the top slab, side walls, and foundation, will form a whole with the original main beam and abutments to jointly bear vehicle loads, improve the bridge's rigidity and load-bearing capacity, and inhibit the development of cracks at the bottom of the beams.

[0027] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A concrete jacketing reinforcement structure for a simply supported beam bridge, characterized by, The utility model relates to a bridge sleeve lining structure, including the sleeve lining roof (3) set below the original bridge main girder (1) and the sleeve lining side wall (6) and sleeve lining foundation (7) set in front of the original bridge abutment (2), the sleeve lining roof (3) with the original bridge main girder (1) fixed connection, two times pouring forming, the lower part is roof first stage concrete (4), and the upper part is roof second stage concrete (5), and the roof first stage concrete (4) with the sleeve lining side wall (6) and the sleeve lining foundation (7) are integrally poured and formed, and the gap is left between the roof first stage concrete (4) with the original bridge main girder (1), and the gap is the roof second stage concrete (5) for last pouring forming, the sleeve lining side wall (6) and the sleeve lining foundation (7) with the original bridge abutment (2) fixed connection, the sleeve lining roof (3), the sleeve lining side wall (6) and the sleeve lining foundation (7) are along the bridge transverse full section arrangement.

2. The concrete encasement reinforcement structure for a simply supported beam bridge according to claim 1, characterized in that: The sleeve lining roof (3) with the original bridge main girder (1) is fixedly connected through roof L type planting reinforcement (8), the roof first stage concrete (4) and the roof second stage concrete (5) bottom are arranged a layer of steel bar net (11), and the steel bar net (11) is tied and connected with the roof L type planting reinforcement (8).

3. The concrete encasement reinforcement structure for a simply supported beam bridge according to claim 2, characterized in that: The sleeve lining side wall (6) with the original bridge abutment (2) is fixedly connected through side wall L type planting reinforcement (9), and the sleeve lining foundation (7) with the original bridge abutment (2) is fixedly connected through foundation L type planting reinforcement (10), two layers of steel bar net (11) are arranged in the sleeve lining side wall (6), and a layer of steel bar net (11) is arranged in the sleeve lining foundation (7) in annular, and the steel bar net (11) is tied and connected with the side wall L type planting reinforcement (9) and the foundation L type planting reinforcement (10).

4. The concrete encasement reinforcement structure for a simply supported beam bridge according to claim 3, characterized in that: The roof first stage concrete (4), the sleeve lining side wall (6) and the sleeve lining foundation (7) all adopt ordinary concrete, and the roof second stage concrete (5) adopts fine stone fast hard concrete.

5. The concrete encasement reinforcement structure for a simply supported beam bridge according to claim 4, characterized in that: The roof first stage concrete (4) thickness is [20, 40] cm, the roof second stage concrete (5) thickness is [10, 20] cm, the sleeve lining side wall (6) thickness is [20, 60] cm, the sleeve lining foundation (7) width is [40, 80] cm, and height is [50, 100] cm.

6. The concrete encasement reinforcement structure for a simply supported beam bridge according to claim 5, characterized by: The implantation depth of the roof L type planting reinforcement (8) is not less than 10 times of the diameter of the steel bar, and the implantation depth of the side wall L type planting reinforcement (9) and the foundation L type planting reinforcement (10) is not less than 15 times of the diameter of the steel bar.

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