A construction method for temporary anchoring of a cantilever cast continuous beam bridge No. 0 block
By adopting a temporary anchorage system combining steel pipe supports and prestressed steel strand bundles outside the piers in the cantilever casting of continuous beam bridges, the problem of insufficient anchorage depth under high pier conditions was solved, and the safety and stability of cantilever casting construction were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI ROAD CONSTR ENG GRP CO LTD
- Filing Date
- 2026-02-05
- Publication Date
- 2026-05-29
AI Technical Summary
In traditional continuous beam bridge cantilever construction, the temporary anchorage of block 0 is insufficient under high pier conditions, resulting in insufficient safety during the cantilever construction of the main beam. Especially when the pier top is narrow or has a tray-type pier cap, the prestressed steel reinforcement anchorage spacing is too small or the anchorage depth is insufficient, making it difficult to provide sufficient anti-overturning moment and affecting structural safety.
A top-tension combined external temporary anchoring system is adopted, which combines steel pipe supports and prestressed steel strand bundles outside the pier. By using a combination of steel pipe supports, attached steel plates, prestressed steel strand bundles and temporary supports embedded in the pier cap and pier body, a clear and reliable stress path is formed, which enhances the overturning resistance of block 0, and temporary anchoring is achieved by tensioning the prestressed steel strands.
This improved the safety of cantilever casting construction, solved the problem of excessive bending moment on the pier body under high pier conditions with traditional anchoring methods, and ensured the stability and safety of cantilever casting of the main beam.
Smart Images
Figure CN122105969A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of bridge construction, specifically a construction method for temporary anchoring of block 0 of a cantilever continuous beam bridge. Background Technology
[0002] In my country, the most common construction method for continuous beam bridges is the cantilever casting method using formwork. Because continuous beam bridges have supports at the pier tops, the unbalanced load of the T-beams during the cantilever casting of the main beam generates a significant overturning moment. Therefore, an effective temporary anchorage system is needed to ensure the overall stability of the bridge. Traditional temporary anchorage typically employs a temporary consolidation anchorage method within the pier-beam structure. This involves symmetrically placing temporary supports and embedding prestressed steel bars on both the longitudinal and lateral sides of the pier top. The prestressed steel bars extend beyond the top surface of block 0. After the construction of block 0 is completed, the prestressed steel bars are tensioned to achieve temporary anchorage. However, when the pier top is narrow or the pier has a tray-type cap, the anchorage spacing or depth of the prestressed steel bars may be too small, failing to provide sufficient anti-overturning moment and making it difficult to ensure the safety of the cantilever casting of the main beam. Furthermore, with higher piers, the traditional temporary consolidation anchorage method may result in excessive bending moments on the pier body, affecting structural safety.
[0003] In view of the above problems, it is necessary to design a construction method for temporary anchorage of block 0 of cantilever continuous beam bridge to effectively solve the problems of traditional temporary consolidation anchorage in pier and beam body under high pier conditions, insufficient anchorage depth under the condition of limited pier top structure, and difficulty in ensuring the safety of cantilever casting of main beam. Summary of the Invention
[0004] The purpose of this invention is to provide a construction method for temporary anchoring of block 0 of a cantilevered continuous beam bridge. This construction method for temporary anchoring of block 0 of a cantilevered continuous beam bridge solves the problem of insufficient overturning moment of temporary anchoring of block 0 during the cantilevered construction of a continuous beam bridge using a hanging basket, and improves the safety of temporary anchoring of block 0 and cantilevered construction using a hanging basket.
[0005] This invention achieves its objective through the following approach: A construction method for temporary anchorage of block 0 of a cantilever continuous beam bridge, characterized by the following steps: Step 1: During the construction of the pier cap, the base steel plate for installing the steel pipe support pier and the prestressed steel strand bundle outside the pier are pre-embedded according to the design position. Step 2: During the construction of the pier body, embed the attachment steel plate according to the design position for connection and fixation with the steel pipe support through the attachment rod; Step 3: During the construction of the pier cap, the structural reinforcement bars of the temporary supports are pre-embedded according to the design position, and the concrete of the temporary supports is poured during or after the construction of the pier cap. Step 4: During the construction of block 0, first connect and fix the steel pipe support on the base steel plate, and fix the steel pipe support to the attachment steel plate through the attachment rod to ensure that the steel pipe support is supported under the bottom plate of block 0; anchor the upper end of the prestressed steel strand bundle outside the pier to the bottom plate of block 0 through the pre-embedded anchor and spiral steel bar. Step 5: After tensioning according to the designed anchorage prestress value, complete the temporary anchorage of block 0.
[0006] Further preferred: The temporary supports are symmetrically arranged on both sides of the permanent supports at the top of the pier. The temporary supports are supported at the bottom of block 0. Multiple temporary supports are arranged side by side on each side. The temporary supports are higher than the permanent supports. During the construction of the pier cap, the structural reinforcement of the temporary supports is accurately pre-embedded. The structural reinforcement extends into the pier cap by no less than 50cm, and the longitudinal and transverse spacing of the structural reinforcement is no more than 20cm.
[0007] A further preferred embodiment: the temporary support is internally arranged with a steel mesh, the layer spacing of the steel mesh is 10cm, and the steel mesh is connected and fixed to the structural reinforcement; after the steel mesh is connected and fixed to the structural reinforcement, the temporary support concrete is poured, and the concrete strength grade is the same as that of the permanent support.
[0008] Further preferred configuration: The steel pipe supports are symmetrically arranged away from the pier while supporting block 0. Multiple steel pipe supports are arranged side by side on each side. The bottom of the steel pipe supports is connected to the pier cap, and the top of the steel pipe supports is connected to the bottom of block 0. The upper and lower ends of the steel pipe supports are fixed with upper and lower bearing plates, respectively. The lower bearing plate is fixedly connected and supported on the top surface of the base steel plate, which is embedded in the pier cap. The top surface of the base steel plate is flush with the top surface of the pier cap, and the upper bearing plate is connected to the bottom of block 0. The steel pipe supports on the same side are connected by horizontal and diagonal connecting rods to form a whole.
[0009] A further preferred embodiment: multiple sets of U-shaped anchor bars are welded to the bottom surface of the base steel plate, with an anchoring depth of not less than 50cm. Within the bearing platform within the anchoring depth range of the U-shaped anchor bars, steel mesh sheets are arranged at 10cm intervals, with the size of the steel mesh sheets being larger than that of the base steel plate.
[0010] A further preferred embodiment: the attached steel plate is welded with a second U-shaped anchor bar, and the second U-shaped anchor bar is anchored into the concrete of the pier body to a depth of not less than 30cm.
[0011] A further preferred embodiment: The prestressed steel strand bundles outside the piers are symmetrically arranged next to the steel pipe supports on both sides of the piers. During the construction of the pier cap, the prestressed steel strand bundles outside the piers are pre-cut and bundled on site. The prestressed steel strand bundles outside the piers are accurately pre-embedded at the designed pre-embedded positions, and a stiffening skeleton is set to guide the vertical direction. The prestressed steel strand bundles outside the piers are reinforced and connected to the pier cap through spiral steel bars II and anchoring steel plates. Spiral steel bars II are sleeved on the prestressed steel strand bundles outside the piers. The bottom steel strands at the lower end of the prestressed steel strand bundles outside the piers are dispersed and fixed through the anchoring steel plates. Multiple layers of steel mesh III are pre-embedded in the No. 0 block at the anchoring point of the prestressed steel strand bundles for reinforcement at a layer spacing of 10cm. The prestressed steel strand bundles outside the piers are anchored and connected to the No. 0 block through pre-embedded anchors and spiral steel bars I.
[0012] A further preferred embodiment: the prestressed steel strand bundle outside the pier is covered with a PVC pipe 304 for protection. The prestressed steel strand bundle outside the pier is tensioned synchronously according to the principle of symmetry in the left and right directions of the transverse bridge and the forward and backward directions of the longitudinal bridge. The prestress is controlled according to the design anchorage prestress value. After tensioning is completed, cement mortar is pressed into the outer PVC pipe 304 to protect the steel strands, and the temporary anchorage of block 0 is completed.
[0013] The construction method for temporary anchorage of block 0 of this cantilever continuous beam bridge has the following advantages: 1. In this construction method, steel pipe supports are symmetrically set away from the pier while supporting block 0. Multiple steel pipe supports are set up side by side on each side. The bottom of the steel pipe supports is connected to the abutment, and the top of the steel pipe supports is connected to the bottom of block 0. Steel pipe supports on the same side are connected by horizontal and diagonal connecting rods. The steel pipe supports are connected to the attachment steel plates embedded in the pier body by attachment rods. By setting the steel pipe supports away from the pier to increase the resistance moment, the overturning resistance of the temporary anchorage of block 0 is improved, thereby improving the safety of the cantilever casting construction of the continuous beam bridge.
[0014] 2. The external temporary anchoring system formed by combining steel pipe supports and prestressed steel strand bundles outside the pier can effectively solve the problems of excessive bending moment that the pier body may bear under high pier conditions and insufficient anchoring depth under the condition of limited pier top structure in the traditional internal temporary fixed anchoring method. Moreover, the external temporary anchoring system has a clear and reliable force path and high safety. Attached Figure Description
[0015] Figure 1 This is a schematic diagram showing the arrangement of the temporary anchorage of block 0 of a cantilevered continuous beam bridge. Figure 2 yes Figure 1 A schematic diagram of the left-side cross-sectional structure; Figure 3 yes Figure 1 Detailed schematic diagram of point A in the middle; Figure 4 yes Figure 1A detailed schematic diagram of point B in the middle; Figure 5 yes Figure 1 A detailed schematic diagram of point C in the middle; Figure 6 yes Figure 2 Detailed schematic diagram at point D; Figure 7 yes Figure 2 Detailed schematic diagram at point E; The component names corresponding to the serial numbers in the diagram are: 1. Temporary support; 2. Steel pipe pier; 3. Prestressed steel strand bundle outside the pier; 4. Horizontal and diagonal connecting rods; 5. Attachment rods; 6. Permanent support; 101. Structural reinforcement; 102. Steel mesh sheet one; 201. Upper end bearing steel plate; 202. Lower end bearing steel plate; 203. Base steel plate; 204. U-shaped anchor bar one; 205. Steel mesh sheet two; 301. Anchor; 302. Spiral reinforcement bar one; 303. Steel mesh sheet three; 304. PVC pipe 304; 305. Spiral reinforcement bar two; 306. Anchoring steel plate; 501. Attachment steel plate; 502. U-shaped anchor bar two. Detailed Implementation
[0016] The specific embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. It should be noted that the described embodiments are merely a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0017] In the description of this invention, it should be noted that the terms "upper", "lower", "middle", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0018] Example 1
[0019] The following construction steps were used to complete the temporary anchorage of block 0 of the cantilever continuous beam bridge: Step 1: During the construction of the pier cap, the base steel plate 203 for installing the steel pipe support pier 2 and the prestressed steel strand bundle 3 outside the pier are pre-embedded according to the design position. Step 2: During the construction of the pier body, the attachment steel plate 501 is pre-embedded at the design position for connection and fixation with the steel pipe support pier 2 through the attachment rod 5; Step 3: During the construction of the pier cap, the structural reinforcement 101 of the temporary support 1 is pre-embedded at the design position. During or after the construction of the pier cap, the concrete of the temporary support 1 is poured. The concrete strength grade is the same as that of the permanent support 6. Step 4: During the construction of block 0, first connect and fix the steel pipe support 2 on the base steel plate 203, and fix the steel pipe support 2 to the attachment steel plate 501 through the attachment rod 5 to ensure that the steel pipe support 2 is supported under the bottom plate of block 0; anchor the upper end of the prestressed steel strand bundle 3 outside the pier to the bottom plate of block 0 through the pre-embedded anchor 301 and spiral steel bar. Step 5: After tensioning according to the designed anchorage prestress value, complete the temporary anchorage of block 0.
[0020] The temporary supports 1 are symmetrically arranged on both sides of the permanent supports 6 at the top of the pier. The temporary supports 1 are supported at the bottom of block 0. There are multiple temporary supports 1 arranged side by side on each side. The temporary supports 1 are higher than the permanent supports 6. During the construction of the pier cap, the structural reinforcement 101 of the temporary supports 1 is accurately pre-embedded. The structural reinforcement 101 extends into the pier cap by not less than 50cm and the longitudinal and transverse spacing of the structural reinforcement 101 is not greater than 20cm.
[0021] The temporary support 1 is internally arranged with a steel mesh 102, the layer spacing of the steel mesh 102 is 10cm, and the steel mesh 102 is connected and fixed to the structural reinforcement 101. After the steel mesh 102 is connected and fixed to the structural reinforcement 101, concrete is poured for the temporary support 1, and the concrete strength grade is the same as that of the permanent support 6.
[0022] The steel pipe supports 2 are symmetrically arranged away from the pier while supporting block 0. Multiple steel pipe supports 2 are arranged side by side on each side. The bottom of the steel pipe supports 2 is connected to the pier cap, and the top of the steel pipe supports 2 is connected to the bottom of block 0. The upper and lower ends of the steel pipe supports 2 are respectively fixed with an upper bearing steel plate 201 and a lower bearing steel plate 202. The lower bearing steel plate 202 is fixedly connected and supported on the top surface of the base steel plate 203. The base steel plate 203 is embedded in the pier cap, and the top surface of the base steel plate 203 is flush with the top surface of the pier cap. The upper bearing steel plate 201 is connected to the bottom of block 0. The steel pipe supports 2 on the same side are connected by horizontal and diagonal connecting rods 4 to form a whole.
[0023] Multiple sets of U-shaped anchor bars 204 are welded to the bottom surface of the base steel plate 203. The anchoring depth of the U-shaped anchor bars 204 is not less than 50cm. Within the bearing platform within the anchoring depth range of the U-shaped anchor bars 204, steel mesh 205 is arranged at 10cm layer intervals. The size of the steel mesh 205 is larger than the size of the base steel plate 203.
[0024] The attached steel plate 501 is welded with U-shaped anchor bars 502, and the U-shaped anchor bars 502 are anchored into the concrete of the pier body to a depth of not less than 30cm.
[0025] The prestressed steel strand bundles 3 outside the pier are symmetrically arranged next to the steel pipe supports 2 on both sides of the pier. During the construction of the pier cap, the prestressed steel strand bundles 3 outside the pier are cut and bundled in advance on site. The prestressed steel strand bundles 3 outside the pier are accurately embedded at the designed pre-embedded positions, and a stiffening skeleton is set to guide the vertical direction. The prestressed steel strand bundles 3 outside the pier are reinforced and connected to the pier cap through spiral steel bars 2 305 and anchoring steel plates 306. Spiral steel bars 2 305 are sleeved on the prestressed steel strand bundles 3 outside the pier. The bottom steel strands of the lower end of the prestressed steel strand bundles 3 outside the pier are dispersed and fixed through the anchoring steel plates 306. In the No. 0 block at the anchoring of the prestressed steel strand bundle, multiple layers of steel mesh 303 are pre-embedded at a layer spacing of 10cm for reinforcement. The prestressed steel strand bundles 3 outside the pier are anchored and connected to the No. 0 block through pre-embedded anchors 301 and spiral steel bars 1 302.
[0026] The prestressed steel strand bundle 3 outside the pier is covered with a PVC pipe 304 for protection. The prestressed steel strand bundle 3 outside the pier is tensioned according to the principle of symmetrical and synchronous tensioning in the transverse direction of the bridge and in the longitudinal direction of the bridge. The tensioning is controlled according to the design anchorage prestress value. After tensioning is completed, cement mortar is pressed into the outer PVC pipe 304 to protect the steel strands, and the temporary anchorage of block 0 is completed.
[0027] The above description is not intended to limit this application, nor is this application limited to the examples described above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of this application should fall within the protection scope of this application.
Claims
1. A construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge, characterized in that, The construction includes the following steps: Step 1: During the construction of the pier cap, the base steel plate for installing the steel pipe support pier and the prestressed steel strand bundle outside the pier are pre-embedded according to the design position. Step 2: During the construction of the pier body, embed the attachment steel plate according to the design position for connection and fixation with the steel pipe support through the attachment rod; Step 3: During the construction of the pier cap, the structural reinforcement bars of the temporary supports are pre-embedded according to the design position, and the concrete of the temporary supports is poured during or after the construction of the pier cap. Step 4: During the construction of block 0, first connect and fix the steel pipe support on the base steel plate, and fix the steel pipe support to the attachment steel plate through the attachment rod to ensure that the steel pipe support is supported under the bottom plate of block 0; anchor the upper end of the prestressed steel strand bundle outside the pier to the bottom plate of block 0 through the pre-embedded anchor and spiral steel bar. Step 5: After tensioning according to the designed anchorage prestress value, complete the temporary anchorage of block 0.
2. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1, characterized in that, The temporary supports are symmetrically arranged on both sides of the permanent supports at the top of the pier. The temporary supports are supported at the bottom of block 0. There are multiple temporary supports arranged side by side on each side. The temporary supports are higher than the permanent supports. During the construction of the pier cap, the structural reinforcement of the temporary supports is accurately pre-embedded. The structural reinforcement extends into the pier cap by no less than 50cm and the longitudinal and transverse spacing of the structural reinforcement is no more than 20cm.
3. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1 or 2, characterized in that, The temporary support is internally arranged with a steel mesh, the layer spacing of which is 10cm. The steel mesh is connected and fixed to the structural reinforcement. After the steel mesh is connected and fixed to the structural reinforcement, the temporary support concrete is poured. The concrete strength grade is the same as that of the permanent support.
4. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1, characterized in that, The steel pipe supports are symmetrically arranged away from the piers while supporting block 0. Multiple steel pipe supports are arranged side by side on each side. The bottom of the steel pipe supports is connected to the pier cap, and the top of the steel pipe supports is connected to the bottom of block 0. The upper and lower ends of the steel pipe supports are fixed with upper and lower bearing steel plates respectively. The lower bearing steel plate is fixedly connected and supported on the top surface of the base steel plate, which is embedded in the pier cap. The top surface of the base steel plate is flush with the top surface of the pier cap, and the upper bearing steel plate is connected to the bottom of block 0. The steel pipe supports on the same side are connected by horizontal and diagonal connecting rods to form a whole.
5. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 4, characterized in that, Multiple sets of U-shaped anchor bars are welded to the bottom surface of the base steel plate. The anchoring depth of the U-shaped anchor bars is not less than 50cm. Within the bearing platform within the anchoring depth range of the U-shaped anchor bars, steel mesh is arranged at 10cm intervals. The size of the steel mesh is larger than that of the base steel plate.
6. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1, characterized in that, The attached steel plate is welded with U-shaped anchor bars, which are anchored into the concrete of the pier body to a depth of not less than 30cm.
7. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1, characterized in that, The aforementioned prestressed steel strand bundles are symmetrically arranged next to the steel pipe supports on both sides of the pier. During the construction of the pier cap, the prestressed steel strand bundles are pre-cut and bundled on site. The prestressed steel strand bundles are accurately embedded at the designed pre-embedded positions, and a stiffening skeleton is set to guide the vertical alignment. The prestressed steel strand bundles are reinforced to the pier cap through spiral steel bars II and anchoring steel plates. Spiral steel bars II are fitted onto the prestressed steel strand bundles. The bottom strands of the prestressed steel strand bundles are dispersed and fixed through the anchoring steel plates. Multiple layers of steel mesh III are pre-embedded in the No. 0 block at the anchoring location of the prestressed steel strand bundles at 10cm intervals for reinforcement. The prestressed steel strand bundles are anchored to the No. 0 block through pre-embedded anchors and spiral steel bars I.
8. The construction method for temporary anchorage of block 0 of a cantilevered continuous beam bridge according to claim 1 or 6, characterized in that, The prestressed steel strand bundles outside the pier are covered with PVC pipes 304 for protection. The prestressed steel strand bundles outside the pier are tensioned synchronously according to the principle of symmetry in the left and right directions of the transverse bridge and the forward and backward directions of the longitudinal bridge. The prestress value of the anchorage is controlled according to the design. After the tensioning is completed, cement mortar is pressed into the outer PVC pipe 304 to protect the steel strands, and the temporary anchorage of block 0 is completed.