Method for reinforcing bridge through slightly bent plate curved surface steel beam

Abstract

The invention discloses a method for reinforcing a bridge by adopting a micro-bending plate curved-surface steel beam, and relates to the technical field of bridge engineering reinforcement, the method for reinforcing the bridge by adopting the micro-bending plate curved-surface steel beam comprises the following steps: step 1, designing and prefabricating a curved-surface steel beam: modeling based on curvature parameterization design of a bridge micro-bending part, processing high-strength steel by adopting a numerical control cold bending process to form a curved-surface steel beam module which is completely attached to a bridge floor; pre-stressed tendons are pre-embedded in a steel beam web, steel cable tensioning sections are arranged at the two ends of the pre-embedded pre-stressed tendons, pre-stress is applied through tensioning equipment, and the overall stress performance of the chord frame is enhanced; and thirdly, modular assembly and cooperative adjustment are conducted, a stress sensor and a displacement monitoring device are synchronously installed, and the prestress value is adjusted in real time. According to the scheme, the problems that an existing method is difficult to adapt to geometrical characteristics of a curved surface bridge, interface stripping or stress concentration is likely to be caused, and a reinforcing structure is poor in tensile property and likely to crack under long-term loads are solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering reinforcement, in particular to a method for reinforcing a bridge by using a slightly bent plate curved steel beam. Background Art

[0002] As the service life of bridges increases, a large number of rigid frame arch bridges and truss arch bridges have insufficient bearing capacity due to aging of the slightly curved plate structure or increased loads.

[0003] Traditional reinforcement methods mainly use the method of increasing the bridge cross-section or sticking steel plates to reinforce the bridge;

[0004] However, the above method is difficult to adapt to the geometric characteristics of curved bridges, which can easily lead to interface peeling or stress concentration. In addition, the reinforced structure has poor tensile properties and is prone to cracking under long-term loads. Therefore, we provide a method for strengthening bridges using slightly curved plate curved steel beams. Summary of the invention

[0005] The purpose of the present invention is to provide a method for strengthening a bridge using a slightly bent plate curved steel beam, so as to solve the problem that the existing method proposed in the above background technology is difficult to adapt to the geometric characteristics of the curved bridge, easily leads to interface peeling or stress concentration, and the reinforced structure has poor tensile properties and is prone to cracking under long-term load.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for strengthening a bridge using a slightly curved plate curved steel beam, comprising the following steps:

[0007] Step 1: Design and prefabrication of curved steel beams: Based on the parametric design modeling of the curvature of the bridge micro-bend, high-strength steel is processed using CNC cold bending technology to form a curved steel beam module that fits the bridge deck perfectly;

[0008] Step 2: Prestressing and anchoring: Prestressed tendons are embedded in the web of the steel beam. Cable tensioning sections are set at both ends of the embedded prestressed tendons. Prestress is applied through tensioning equipment to enhance the overall force-bearing performance of the chord frame.

[0009] Step 3: Modular assembly and coordinated adjustment: Use the auxiliary installation mechanism to preliminarily position the curved steel beam module, and use high-strength bolts to connect the curved steel beam with the chord frame and the original reinforcement rib frame. Simultaneously install the stress sensor and displacement monitoring device to adjust the prestress value in real time to ensure uniform load transfer;

[0010] The steel plate on the curved surface is parametrically designed based on the curvature of the micro-bend of the bridge. It is processed by CNC cold bending technology after modeling. The base is made of high-strength steel, which can form a curved surface reinforcement layer that fits the bridge deck perfectly. Its two ends are side vertical plates, and the web and side vertical plates are welded together to make the cross-section an I-shaped structure with good cross-sectional bending resistance, ensuring the stability of the structure. Because the material itself is high-strength steel, it has high strength and hardness, and can rely on the I-shaped structure to withstand greater pressure and weight loads without deformation or breakage.

[0011] Preferably, the curved steel beam module in step one comprises an upper curved steel plate, side vertical plates are provided on both sides of the upper curved steel plate, the side vertical plates are integrally formed with the upper curved steel plate and are attached to the bridge chord frame, a web is provided at the middle position of the lower end of the upper curved steel plate, and the web is welded to the upper curved steel plate and the side vertical plates, a lower steel plate is provided at the lower end of the web, and the lower steel plate is welded to the bottom surface of the web and the side vertical plates.

[0012] Preferably, upper reinforcing ribs are welded at the connection places between the two sides of the upper end of the web and the steel plate on the curved surface, and a plurality of upper reinforcing ribs are provided.

[0013] Preferably, two lower reinforcing ribs are welded at the connections between the two ends of the lower steel plate and the side vertical plates.

[0014] Preferably, the inner side of the steel plate on the curved surface is fixedly connected to the original reinforcing rib frame by a plurality of first high-strength bolts.

[0015] Preferably, the inner side of the side vertical plate is fixedly connected to the string frame by a plurality of second high-strength bolts.

[0016] Preferably, a pre-embedded steel bar section is provided inside the web, prestressed steel bars are embedded inside the pre-embedded steel bar section, tensioning cables are provided at both ends of the prestressed steel bars, and the ends of the tensioning cables pass through and extend to the outside of the chord frame.

[0017] Preferably, reserved holes are provided inside both ends of the side vertical plates, and auxiliary installation mechanisms are installed outside the reserved holes.

[0018] Preferably, the auxiliary installation mechanism includes a positioning plate, both sides of which are threadedly connected to the reserved holes on the side vertical plates by screws, a mounting frame is welded to the rear end of the positioning plate, and guard side plates are welded to both sides of the lower end of the mounting frame, a hydraulic cylinder is installed between the guard side plates on both sides, and a push head is installed at the output end of the hydraulic cylinder.

[0019] Preferably, a rubber block is installed on the outer wall of the push head, and the surface of the rubber block is provided with anti-slip grooves, and a pressure sensor is installed at the connection between the output end of the hydraulic cylinder and the push head.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The present invention adopts a slightly curved steel plate as a reinforcement structure. The structure is based on the parametric design of the curvature of the slightly curved part of the bridge and is processed by CNC cold bending technology after modeling. The base is made of high-strength steel, which can form a curved reinforcement layer that is completely in line with the bridge deck. The two ends of the steel plate are side plates, which are welded to the web and side plates to make the cross-section an I-shaped structure with good cross-sectional bending resistance, thereby ensuring the stability of the structure. Since the material itself is high-strength steel, it has high strength and hardness. At the same time, it can rely on the I-shaped structure to withstand large pressure and weight loads without deformation or fracture. This solves the problem that the existing method is difficult to adapt to the geometric characteristics of curved bridges, which easily leads to interface peeling or stress concentration, and the reinforcement structure has poor tensile properties and is prone to cracking under long-term loads.

[0022] (2) The upper and lower connections of the curved steel beam module are both designed with reinforcing ribs, which significantly improves the overall strength and rigidity of the curved steel beam module. Due to the design of the upper and lower reinforcement structures, the thickness of the web and the lower steel plate can be reduced while ensuring the strength, thereby reducing the overall weight of the curved steel beam module and reducing the cost. It is convenient for the curved steel beam module to be transported to the reinforcement position after prefabrication. The top surface and side of the curved steel beam module are fixed to the original reinforcing rib frame and chord frame with the first high-strength bolt and the second high-strength bolt respectively, which can ensure the firmness and stability of the connection structure, enable the connection to withstand high strength and large torque, and can resist the vibration and impact generated by the bridge vehicle when it is moving, to ensure that the connection will not loosen or be damaged.

[0023] (3) By embedding prestressed steel bars in the web of the steel beam and tensioning them, pre-tensioning stress can be applied to the steel bars before the component is subjected to external loads, thereby improving the bending resistance and stiffness of the curved steel beam module, strengthening the overall stress-bearing performance of the chord frame, delaying the appearance of cracks, and increasing the durability of the structure.

[0024] (4) When installing the curved steel beam module, firstly, an auxiliary installation mechanism is installed on the inner side of both ends of the side vertical plate, and then the curved steel beam module is lifted to the bottom surface of the bridge by manual or mechanical equipment to make it fit the curved surface of the bridge. After completion, the hydraulic cylinder on the auxiliary installation mechanism operates under the action of the hydraulic station, driving the push head at the output end to extend, and using the rubber block at the end of the push head to squeeze the string frame. During the squeezing process, the pressure sensor at the output end of the hydraulic cylinder can detect the pressure condition. When the pressure reaches the preset threshold, the force is stopped, so that the curved steel beam module and the string frame are self-positioned and supported. In this state, the curved steel beam module can be positioned without the need for an additional supporting mechanism. During the process, the personnel drive high-strength bolts into the corresponding positions in sequence. After all the high-strength bolts are driven in, the auxiliary installation mechanism can be removed one by one, thereby improving the convenience of installation.

[0025] (5) The curved steel beam module adopts a prefabricated component structure, and the production process is relatively centralized, which reduces the time and complexity of on-site operations and reduces the impact on the environment. Only installation is required on site, which greatly shortens the construction time and can save a lot of manpower and material costs.

[0026] (6) When the auxiliary installation mechanism is used to preliminarily position the curved steel beam module and high-strength bolts are used to connect the curved steel beam to the chord frame and the original reinforcing rib frame, the stress sensor and the displacement monitoring device can be installed simultaneously to adjust the prestress value in real time to ensure uniform load transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 It is a front structural schematic diagram of the present invention;

[0029] Figure 3 It is a schematic diagram of a top cross-sectional structure of the present invention;

[0030] Figure 4 It is a schematic diagram of the cross-sectional structure of the present invention when viewed from above;

[0031] Figure 5 It is a schematic diagram of the structure of the installation state of the present invention;

[0032] Figure 6 It is a structural schematic diagram of the auxiliary installation mechanism of the present invention;

[0033] In the figure: 1. curved steel plate; 2. side vertical plate; 3. web plate; 4. embedded steel bar section; 5. upper reinforcing rib; 6. lower steel plate; 7. lower reinforcing rib; 8. first high-strength bolt; 9. second high-strength bolt; 10. tensioning steel cable; 11. reserved hole; 12. prestressed steel bar; 13. auxiliary installation mechanism; 131. positioning plate; 132. mounting frame; 133. side guard plate; 134. hydraulic cylinder; 135. push head; 136. rubber block; 14. string frame; 15. original reinforcing rib frame. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] See also Figure 1-6 The present invention provides an embodiment: a method for strengthening a bridge using a slightly curved plate curved steel beam, comprising the following steps:

[0036] Step 1: Design and prefabrication of curved steel beams: Based on the parametric design modeling of the curvature of the bridge micro-bend, high-strength steel is processed using CNC cold bending technology to form a curved steel beam module that fits the bridge deck perfectly;

[0037] Step 2: Prestressing and anchoring: Prestressed tendons are embedded in the web of the steel beam. Cable tensioning sections are set at both ends of the embedded prestressed tendons. Prestress is applied through tensioning equipment to enhance the overall force-bearing performance of the chord frame.

[0038] Step 3: Modular assembly and coordinated adjustment: Use the auxiliary installation mechanism to preliminarily position the curved steel beam module, and use high-strength bolts to connect the curved steel beam to the chord frame 14 and the original reinforcing rib frame 15. Simultaneously install stress sensors and displacement monitoring devices, adjust the prestress value in real time, and ensure uniform load transfer.

[0039] See also Figure 1-4 The curved steel beam module in step 1 comprises a curved steel plate 1, side vertical plates 2 are arranged on both sides of the curved steel plate 1, the side vertical plates 2 are integrally formed with the curved steel plate 1 and are attached to the bridge chord frame 14, a web 3 is arranged at the middle position of the lower end of the curved steel plate 1, and the web 3 is welded to the curved steel plate 1 and the side vertical plates 2, a lower steel plate 6 is arranged at the lower end of the web 3, and the lower steel plate 6 is welded to the bottom surface of the web 3 and the side vertical plates 2;

[0040] The steel plate 1 on the curved surface is parametrically designed based on the curvature of the micro-bend of the bridge, and is processed by CNC cold bending technology after modeling. The base is made of high-strength steel, which can form a curved surface reinforcement layer that is completely in line with the bridge deck. The two ends are side vertical plates 2, and the web plate 3 and the side vertical plates 2 are welded together to make the cross-section an I-shaped structure with good cross-section bending resistance, ensuring the stability of the structure. Because the material itself is high-strength steel, it has high strength and hardness, and can rely on the I-shaped structure to withstand large pressure and weight loads without deformation or breakage;

[0041] Upper reinforcing ribs 5 are welded at the connection between the two sides of the upper end of the web 3 and the steel plate 1 on the curved surface, and there are multiple upper reinforcing ribs 5. Two lower reinforcing ribs 7 are welded at the connection between the two ends of the lower steel plate 6 and the side vertical plate 2. The inner side of the steel plate 1 on the curved surface is fixedly connected to the original reinforcing rib frame 15 by multiple first high-strength bolts 8, and the inner side of the side vertical plate 2 is fixedly connected to the chord frame 14 by multiple second high-strength bolts 9;

[0042] The design of the upper reinforcing ribs 5 and the lower reinforcing ribs 7 significantly improves the overall strength and rigidity of the curved steel beam module. Due to the design of the upper and lower reinforcement structures, the thickness of the web 3 and the lower steel plate 6 can be reduced while ensuring the strength, thereby reducing the overall weight of the curved steel beam module and reducing the cost. It is convenient for the curved steel beam module to be transported to the reinforcement position after prefabrication. The top surface and side edges of the curved steel beam module are fixed to the original reinforcing rib frame 15 and the chord frame 14 with the first high-strength bolts 8 and the second high-strength bolts 9 respectively, which can ensure the firmness and stability of the connection structure, enable the connection to withstand high strength and large torque, and can resist the vibration and impact generated by the bridge vehicle when traveling, to ensure that the connection will not loosen or be damaged.

[0043] A pre-embedded steel bar section 4 is arranged inside the web 3, and a pre-stressed steel bar 12 is pre-embedded inside the pre-embedded steel bar section 4. Tensioning steel cables 10 are arranged at both ends of the pre-stressed steel bar 12, and the ends of the tensioning steel cables 10 penetrate and extend to the outside of the string frame 14;

[0044] By embedding prestressed steel bars 12 in the web 3 of the steel beam and tensioning them, pre-tensioning stress can be applied to the steel bars before the component is subjected to external loads, thereby improving the bending resistance and rigidity of the curved steel beam module, strengthening the overall bearing performance of the chord frame, delaying the appearance of cracks, and increasing the durability of the structure.

[0045] See also Figure 5-6 , both ends of the side vertical plate 2 are provided with reserved holes 11 inside, and an auxiliary installation mechanism 13 is installed outside the reserved hole 11, and the auxiliary installation mechanism 13 includes a positioning plate 131, and both sides of the positioning plate 131 are threadedly connected with the reserved holes 11 on the side vertical plate 2 by screws, and a mounting frame 132 is welded to the rear end of the positioning plate 131, and both sides of the lower end of the mounting frame 132 are welded with guard side plates 133, and a hydraulic cylinder 134 is installed between the guard side plates 133 on both sides, and a push head 135 is installed at the output end of the hydraulic cylinder 134, and a rubber block 136 is installed on the outer wall of the push head 135, and the surface of the rubber block 136 is provided with anti-slip grooves, and a pressure sensor is installed at the connection between the output end of the hydraulic cylinder 134 and the push head 135;

[0046] When installing the curved steel beam module, the auxiliary installation mechanism 13 is first installed on the inner side of the two ends of the side vertical plate 2, and then the curved steel beam module is lifted to the bottom surface of the bridge by manual or mechanical equipment to make it fit the curved surface of the bridge. After completion, the hydraulic cylinder 134 on the auxiliary installation mechanism 13 operates under the action of the hydraulic station, driving the push head 135 at the output end to extend, and the rubber block 136 at the end of the push head 135 is used to squeeze the string frame 14. During the squeezing process, the pressure sensor at the output end of the hydraulic cylinder 134 can detect the pressure condition. When the pressure reaches the preset threshold, the force is stopped, so that the curved steel beam module and the string frame 14 are self-positioned and supported. In this state, the curved steel beam module can be positioned without the need for an additional supporting mechanism. During the process, the personnel drive high-strength bolts into the corresponding positions in sequence. After all the high-strength bolts are driven in, the auxiliary installation mechanism 13 can be removed one by one, thereby improving the convenience of installation.

[0047] It will be apparent to those skilled in the art that the 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 the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for strengthening a bridge using a slightly curved steel beam, characterized in that: The following steps are involved: Step 1: Design and prefabrication of curved steel beams: Based on the parametric design modeling of the curvature of the bridge micro-bend, high-strength steel is processed using CNC cold bending technology to form a curved steel beam module that fits the bridge deck perfectly; Step 2: Prestressing and anchoring: Prestressed tendons are embedded in the web of the steel beam. Cable tensioning sections are set at both ends of the embedded prestressed tendons. Prestress is applied through tensioning equipment to enhance the overall force-bearing performance of the chord frame. Step 3: Modular assembly and coordinated adjustment: Use the auxiliary installation mechanism to preliminarily position the curved steel beam module, and use high-strength bolts to connect the curved steel beam to the chord frame (14) and the original reinforcing rib frame (15). Simultaneously install the stress sensor and displacement monitoring device to adjust the prestress value in real time to ensure uniform load transmission.

2. The method for strengthening a bridge using a slightly curved steel beam according to claim 1, characterized in that: The curved steel beam module in step 1 comprises a curved steel plate (1), side vertical plates (2) are arranged on both sides of the curved steel plate (1), the side vertical plates (2) are integrally formed with the curved steel plate (1) and are attached to the bridge chord frame (14), a web (3) is arranged at the middle position of the lower end of the curved steel plate (1), and the web (3) is welded to the curved steel plate (1) and the side vertical plates (2), a lower steel plate (6) is arranged at the lower end of the web (3), and the lower steel plate (6) is welded to the bottom surface of the web (3) and the side vertical plates (2).

3. The method for strengthening a bridge using a slightly curved steel beam according to claim 2, characterized in that: Upper reinforcing ribs (5) are welded at the connection points between the two sides of the upper end of the web (3) and the steel plate (1) on the curved surface, and a plurality of upper reinforcing ribs (5) are provided.

4. The method for strengthening a bridge using a slightly curved steel beam according to claim 3, characterized in that: Two lower reinforcing ribs (7) are welded at the connection points between the two ends of the lower steel plate (6) and the side vertical plate (2).

5. The method for strengthening a bridge using a slightly curved steel beam according to claim 4, characterized in that: The inner side of the steel plate (1) on the curved surface is fixedly connected to the original reinforcing rib frame (15) via a plurality of first high-strength bolts (8).

6. The method for strengthening a bridge using a slightly curved steel beam according to claim 5, characterized in that: The inner side of the side vertical plate (2) is fixedly connected to the string frame (14) via a plurality of second high-strength bolts (9).

7. The method for strengthening a bridge using a slightly curved steel beam according to claim 6, characterized in that: A pre-embedded steel bar section (4) is arranged inside the web (3), and pre-stressed steel bars (12) are pre-embedded inside the pre-embedded steel bar section (4). Tensioning steel cables (10) are arranged at both ends of the pre-stressed steel bars (12), and the ends of the tensioning steel cables (10) penetrate and extend to the outside of the string frame (14).

8. The method for strengthening a bridge using a slightly curved steel beam according to claim 7, characterized in that: Reserved holes (11) are provided inside both ends of the side vertical plate (2), and auxiliary installation mechanisms (13) are installed outside the reserved holes (11).

9. The method for strengthening a bridge using a slightly curved steel beam according to claim 8, characterized in that: The auxiliary mounting mechanism (13) comprises a positioning plate (131), both sides of which are threadedly connected to the reserved holes (11) on the side vertical plate (2) by means of screws, a mounting frame (132) is welded to the rear end of the positioning plate (131), both sides of the lower end of the mounting frame (132) are welded to guard side plates (133), a hydraulic cylinder (134) is installed between the guard side plates (133) on both sides, and a push head (135) is installed at the output end of the hydraulic cylinder (134).

10. The method for strengthening a bridge using a slightly curved steel beam according to claim 9, characterized in that: A rubber block (136) is installed on the outer wall of the push head (135), and the surface of the rubber block (136) is provided with anti-slip grooves. A pressure sensor is installed at the connection between the output end of the hydraulic cylinder (134) and the push head (135).

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