A post-earthquake resetting and reinforcing system for reinforced concrete bridge piers and a method thereof

Abstract

This invention discloses a post-earthquake recovery and reinforcement system for reinforced concrete bridge piers, comprising a pier cap, steel sleeves, a cap beam anchor plate, an upper steel anchor cylinder, a lower steel anchor cylinder, and cables. The pier cap is set on the pier base under the concrete pier column. At least four steel sleeves are installed along the edge of the pier cap. The cap beam anchor plate is installed on the bridge cap beam located at the top of the concrete pier column. The lower steel anchor cylinder is hinged to the steel sleeves, and the upper steel anchor cylinder is installed on the cap beam anchor plate. Cables are installed and anchored between the upper and lower steel anchor cylinders. This invention also discloses a method for post-earthquake recovery and reinforcement of reinforced concrete bridge piers. This invention's post-earthquake recovery and reinforcement system and method for reinforced concrete bridge piers are simple and practical, and can improve the self-resetting capacity of piers in a large number of small- and medium-span simply supported beam bridges and continuous beam bridges already built in my country, reduce residual displacement after earthquakes, ensure normal operation, improve post-earthquake reinforcement efficiency, reduce reinforcement costs, and are quick and convenient to install with a short construction period.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a post-earthquake repositioning and reinforcement system and method for reinforced concrete bridge piers. Background Technology

[0002] Small- and medium-span simply supported beam bridges and continuous beam bridges are the most prevalent bridge types in my country. Previous seismic design primarily focused on the displacement ductility of bridge piers, aiming to ensure the bridge structure would not collapse during earthquakes by designing the seismic displacement demand of the piers to be less than their displacement capacity. However, after actual earthquakes, it was found that some bridges based on ductility design, while avoiding collapse, faced repair difficulties due to excessive residual displacement at the pier tops, ultimately requiring post-earthquake demolition and reconstruction. In the Hanshin earthquake, in addition to the 250 collapsed piers, approximately 100 of the 591 slightly damaged piers had to be demolished and rebuilt due to excessive residual displacement at the pier tops (residual drift rate exceeding 1.75%).

[0003] Currently, the most studied self-resetting bridge pier structures include swaying piers, unbonded vertical prestressed piers, and steel-superelastic nickel-titanium reinforced concrete piers. However, swaying piers require the establishment of a pier-cap contact surface before pier construction; unbonded vertical prestressed piers require the pre-reservation of prestressing ducts and cap bottom anchoring devices before pouring pier concrete; and steel-superelastic nickel-titanium reinforced concrete piers require the use of superelastic nickel-titanium reinforcement as longitudinal reinforcement in the plastic hinge area at the pier bottom before pouring pier concrete. None of these self-resetting pier structures can be directly used to improve the post-earthquake self-resetting capability of existing reinforced concrete bridge piers. Summary of the Invention

[0004] The purpose of this invention is to provide a post-earthquake repositioning and reinforcement system and method for reinforced concrete bridge piers to solve the above-mentioned defects.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers includes a pier cap, steel sleeves, a cap beam anchor plate, upper steel anchor cylinders, lower steel anchor cylinders, and cables. The pier cap is located on the pier base under the concrete pier column. At least four steel sleeves are provided and installed at the edges of the pier cap. The cap beam anchor plate is installed on the bridge cap beam located at the top of the concrete pier column. The lower steel anchor cylinders correspond one-to-one with the steel sleeves and are hinged to the steel sleeves. At least four upper steel anchor cylinders are provided and installed on the cap beam anchor plate. The cables are installed between the upper and lower steel anchor cylinders and anchored thereto.

[0007] Preferably, the steel boot is fitted with a lower ear plate by bolts or welding, and the cap beam anchor plate is fitted with an upper ear plate in the same number as the lower ear plate by bolts or welding. Several upper and lower steel anchor cylinders are provided and are respectively installed on the upper and lower ear plates.

[0008] Preferably, the cap beam anchor plate is provided in two parts, and both are fixed to the outer surface of the middle part of the bridge cap beam by interlocking with each other using expansion bolts and adhesive.

[0009] Preferably, four steel boots are provided and are fixedly installed at the four corner edges of the support platform by expansion bolts and adhesive.

[0010] Preferably, both the upper and lower steel anchor cylinders include an anchor cylinder body and anchor bearing plates and anchor rollers installed at the front and rear ends of the anchor cylinder body. The anchor cylinder body is provided with a tensioning space. The anchor rollers of the upper and lower steel anchor cylinders pass through the ear holes provided in the upper and lower ear plates, respectively. The two ends of the cable pass through the anchor bearing plates of the upper and lower steel anchor cylinders and are fixed in their tensioning spaces. The tension of the cable can be adjusted by tensioning jacks in the tensioning spaces of the upper and lower steel anchor cylinders.

[0011] Preferably, the upper ear plate and the lower ear plate are perpendicular to each other.

[0012] Preferably, a method for post-earthquake repositioning and reinforcement of reinforced concrete bridge piers specifically includes the following steps:

[0013] S1. Based on the pier dimensions, reinforcement details, and self-weight load, design appropriate specifications and quantities of steel purlins, cap beam anchor plates, upper steel anchor cylinders, lower steel anchor cylinders, and cables;

[0014] S2. Install the bearing platform on the pier base under the concrete pier column, excavate the corners of the bearing platform, and then use expansion bolts and adhesive to fix several steel boots to the corners of the bearing platform.

[0015] S3. Interlock the two cap beam anchor plates and fix them to the outer surface of the middle part of the bridge cap beam with expansion bolts and adhesive.

[0016] S4. Hinge and fix several upper steel anchor cylinders and lower steel anchor cylinders to the cap beam anchor plate and steel sleeve shoe respectively, and ensure that the number of upper steel anchor cylinders, lower steel anchor cylinders and steel sleeve shoes is consistent, and that the upper steel anchor cylinders correspond one-to-one with the lower steel anchor cylinders.

[0017] S5. Install the two ends of several cables onto the upper and lower steel anchor cylinders respectively and tension and anchor them.

[0018] S6. Tensioning jacks can be used to tension both ends of the cable in the upper and lower steel anchor cylinders. By selectively tensioning several cables, the concrete pier can be reset and reinforced after an earthquake.

[0019] The beneficial effects of this invention are as follows:

[0020] This invention relates to a post-earthquake repositioning and reinforcement system and method for reinforced concrete bridge piers. It is simple and practical, and can improve the self-repositioning capacity of the numerous small-to-medium span simply supported beam bridges and continuous beam bridges already built in China, reducing residual displacement after an earthquake and ensuring the normal operation of the road network during earthquake relief efforts. Furthermore, when repositioning the bridge, the foundation of the pier base serves as the anchoring end for the cables, eliminating the need for ground anchors, thus improving post-earthquake reinforcement efficiency and reducing costs. Simultaneously, all components are prefabricated in a factory, ensuring processing precision and component quality, and enabling quick and convenient on-site installation, reducing the construction period. Attached Figure Description

[0021] Figure 1 : A schematic diagram of the post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers of the present invention. Detailed Implementation

[0022] Combined with appendix Figure 1 The specific embodiments of the present invention are described below:

[0023] like Figure 1 As shown, a post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers includes a pier cap 1, a steel sleeve 2, a cap beam anchor plate 3, an upper steel anchor cylinder 4, a lower steel anchor cylinder 5, and a cable 6. The pier cap 1 is fixedly installed on the pier base under the concrete pier column 200 by bolts.

[0024] At least four steel boots 2 are provided and are fixed to the edge of the foundation 1 using expansion bolts and adhesive. If only four steel boots 2 are provided, it is best to fix them to the four corners of the foundation 1 for better stress distribution and stability. The internal height of the steel boots 2 on the foundation 1 is slightly greater than the height of the foundation 1, so that the corners of the foundation 1 can be easily embedded into the steel boots 2 after excavation.

[0025] The cap beam anchor plate 3 is installed on the bridge cap beam 100 located at the top of the concrete pier 200. Specifically, two cap beam anchor plates 3 are provided, and both are interlocked and fixed to the outer surface of the middle part of the bridge cap beam 100 by expansion bolts and adhesive. The installation is convenient and the fixation is firm. The cap beam anchor plates 3 are set in two parallel interlocking configurations. During the reinforcement construction, since the beam body is already installed above the bridge cap beam 100, it is not possible to lift them by crane. Generally, the cap beam anchor plates 3 are hoisted to the height of the bridge cap beam 100 on site using a pull hoist, and then the two cap beam anchor plates 3 are spliced ​​together by bolts, thereby covering the middle area of ​​the bridge cap beam 100 above the concrete pier 200.

[0026] The steel boot 2 is fitted with a lower ear plate 7 by bolts or welding, and the cap beam anchor plate 3 is fitted with an upper ear plate 8 of the same number as the lower ear plate 7 by bolts or welding. The upper ear plate 8 and the lower ear plate 7 are perpendicular to each other.

[0027] The lower steel anchor cylinder 5 corresponds one-to-one with the steel boot 2 and is hinged to the lower ear plate 7 of the steel boot 2. At least four upper steel anchor cylinders 4 are provided and are respectively installed on the upper ear plate 8 of the cap beam anchor plate 3. There are several upper steel anchor cylinders 4 and lower steel anchor cylinders 5, which correspond one-to-one.

[0028] Both the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5 include an anchor cylinder body and anchor bearing plates and anchor rollers installed at the front and rear ends of the anchor cylinder body. The anchor cylinder body is provided with a tensioning space. The anchor rollers of the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5 pass through the ear holes provided with the upper ear plate 8 and the lower ear plate 7, respectively. The two ends of the cable 6 pass through the anchor bearing plates of the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5, respectively, and are fixed in their tensioning spaces. The tension of the cable 6 can be adjusted by tensioning jacks in the tensioning spaces of the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5. After the tension adjustment is completed, the tensioning jacks can be removed.

[0029] In this invention, by setting the connection between the upper ear plate 8, the lower ear plate 7 and the anchor roller, the bending moment at both ends of the cable 6 can be released, and by setting the upper ear plate 8 and the lower ear plate 7 to be spatially perpendicular, the bending moment in both directions of the cable 6 can be released.

[0030] A method for post-earthquake repositioning and reinforcement of reinforced concrete bridge piers, specifically including the following steps:

[0031] S1. Based on the pier dimensions, reinforcement details, and self-weight load, design appropriate specifications and quantities of steel jacks 2, cap beam anchor plates 3, upper steel anchor cylinders 4, lower steel anchor cylinders 5, and cables 6.

[0032] S2. Install the bearing cap 1 on the pier base under the concrete pier 200, and excavate the corners of the bearing cap 1. When excavating the corners of the bearing cap 1, attention should be paid to excavating symmetrically at the same time to prevent uneven settlement of the bearing cap due to changes in the soil around the bearing cap 1. Then, use expansion bolts and adhesive to fix several steel boots 2 at the corners of the bearing cap 1.

[0033] S3. The two cap beam anchor plates 3 are interlocked and fixed to the outer surface of the middle part of the bridge cap beam 100 using expansion bolts and adhesive. Since the beam body is already installed above the bridge cap beam 100, it is not possible to lift them by crane. Generally, the cap beam anchor plates 3 are lifted to the height of the bridge cap beam 100 on site using a pull hoist, and then the two cap beam anchor plates 3 are spliced ​​together with bolts, thereby wrapping the outer surface of the middle area of ​​the bridge cap beam 100 above the concrete pier 200 and fixing it with expansion bolts and adhesive.

[0034] S4. Hinge and fix the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5 to the cap beam anchor plate 3 and the steel sleeve 2 respectively, and ensure that the number of upper steel anchor cylinder 4, lower steel anchor cylinder 5 and steel sleeve 2 is consistent, and that the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5 correspond one-to-one.

[0035] S5. After passing through the anchor bearing plates of the upper steel anchor cylinder 4 and the lower steel anchor cylinder 5, the two ends of several cables 6 are fixed in their tensioning space and anchored.

[0036] S6. When tension adjustment of cable 6 is required, a tensioning jack can be installed in the tensioning space of the upper steel anchor cylinder 4 or the lower steel anchor cylinder 5, and the tensioned end of cable 6 can be fixed to the tensioning jack. The tension of cable 6 can then be adjusted using the tensioning jack. After the tension adjustment is completed, the tensioning jack can be removed. By selectively tensioning part or all of cable 6, the post-earthquake reset and reinforcement of the concrete pier column 200 can be achieved.

[0037] In this invention, the tension of cable 6 should take into account the following two factors: (1) The concrete pier 200 provides self-resetting force due to gravity and the axial pressure of prestressed steel bars, and the ordinary steel bars in the plastic hinge area at the bottom of the concrete pier 200 provide hysteretic energy dissipation capacity. In order to ensure the self-resetting capacity of the concrete pier 200 in an earthquake, the axial pressure of the concrete pier 200 should be greater than the yield force of the longitudinal reinforcement at the bottom of the pier. Therefore, when determining the cable force, it should be ensured that the sum of the vertical component of several cables 6 and the pressure caused by the gravity of the concrete pier 200 is greater than the yield force of the longitudinal reinforcement at the bottom section of the concrete pier 200. (2) When the displacement at the top of the concrete pier 200 reaches the ultimate displacement, the cable 6 on the tension side should still remain elastic to provide a restoring force for the pier.

[0038] This invention relates to a post-earthquake repositioning and reinforcement system and method for reinforced concrete bridge piers. It is simple and practical, and can improve the self-repositioning capacity of the numerous small-to-medium span simply supported beam bridges and continuous beam bridges already built in China, reducing residual displacement after an earthquake and ensuring the normal operation of the road network during earthquake relief efforts. Furthermore, when repositioning the bridge, the foundation of the pier base serves as the anchoring end for the cables, eliminating the need for ground anchors, thus improving post-earthquake reinforcement efficiency and reducing costs. Simultaneously, all components are prefabricated in a factory, ensuring processing precision and component quality, and enabling quick and convenient on-site installation, reducing the construction period.

[0039] The invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the invention, or the direct application of the inventive concept and technical solution to other situations without modification, is within the protection scope of the invention.

Claims

1. A post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers, characterized in that, The bridge includes a pier cap (1), steel boots (2), a cap beam anchor plate (3), an upper steel anchor cylinder (4), a lower steel anchor cylinder (5), and a cable (6). The pier cap (1) is set on the pier base under the concrete pier (200). At least four steel boots (2) are provided and installed at the edge of the pier cap (1). The cap beam anchor plate (3) is installed on the bridge cap beam (100) located at the top of the concrete pier (200). The lower steel anchor cylinder (5) corresponds to the steel boots (2) and is hinged to the steel boots (2). At least four upper steel anchor cylinders (4) are provided and installed on the cap beam anchor plate (3). The cable (6) is installed between the upper steel anchor cylinder (4) and the lower steel anchor cylinder (5) and anchored. The steel boot (2) is fitted with a lower ear plate (7) by bolts or welding. The cap beam anchor plate (3) is fitted with an upper ear plate (8) of the same number as the lower ear plate (7) by bolts or welding. Several upper steel anchor cylinders (4) and lower steel anchor cylinders (5) are provided and installed on the upper ear plate (8) and lower ear plate (7) respectively. The upper ear plate (8) and lower ear plate (7) are perpendicular to each other.

2. The post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers according to claim 1, characterized in that, The cap beam anchor plate (3) has two parts, both of which are fixed to the outer surface of the middle part of the bridge cap beam (100) by expansion bolts and adhesive.

3. The post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers according to claim 1, characterized in that, The steel boots (2) are provided in four parts and are fixedly installed at the four corners of the support platform (1) by expansion bolts and adhesive.

4. The post-earthquake repositioning and reinforcement system for reinforced concrete bridge piers according to claim 1, characterized in that, The upper steel anchor cylinder (4) and the lower steel anchor cylinder (5) both include an anchor cylinder body and anchor bearing plates and anchor rollers installed at the front and rear ends of the anchor cylinder body. The anchor cylinder body is provided with a tensioning space. The anchor rollers of the upper steel anchor cylinder (4) and the lower steel anchor cylinder (5) are respectively installed through the ear holes provided in the upper ear plate (8) and the lower ear plate (7). The two ends of the cable (6) are respectively fixed in the tensioning space after passing through the anchor bearing plates of the upper steel anchor cylinder (4) and the lower steel anchor cylinder (5). The cable (6) can be tensioned and adjusted by tensioning jacks in the tensioning space of the upper steel anchor cylinder (4) and the lower steel anchor cylinder (5).

5. A method for repositioning and strengthening a reinforced concrete bridge pier post-earthquake repositioning and strengthening system according to any one of claims 1-4, characterized in that, Specifically, the steps include the following: S1. Based on the pier dimensions, reinforcement details, and self-weight load, design appropriate specifications and quantities of steel jacks (2), cap beam anchor plates (3), upper steel anchor cylinders (4), lower steel anchor cylinders (5), and cables (6). S2. Install the foundation (1) on the pier base under the concrete pier (200), and excavate the corners of the foundation (1). Then use expansion bolts and adhesive to fix several steel boots (2) at the corners of the foundation (1). S3. Interlock the two cap beam anchor plates (3) and fix them to the outer surface of the middle part of the bridge cap beam (100) with expansion bolts and adhesive; S4. Several upper steel anchor cylinders (4) and lower steel anchor cylinders (5) are hinged and fixed to the cap beam anchor plate (3) and steel boot (2) respectively, and ensure that the number of upper steel anchor cylinders (4), lower steel anchor cylinders (5) and steel boot (2) is consistent, and that the upper steel anchor cylinders (4) and lower steel anchor cylinders (5) correspond one-to-one. S5. Install the two ends of several cables (6) onto the upper steel anchor cylinder (4) and the lower steel anchor cylinder (5) respectively, and then tension and anchor them. S6. Tensioning jacks can be used to tension both ends of the cable (6) in the upper steel anchor tube (4) and lower steel anchor tube (5). By selectively tensioning several cables (6), the concrete pier (200) can be reset and reinforced after the earthquake.

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