Bridge pier and middle beam asynchronous construction method

Abstract

The application discloses a bridge pier column and middle beam asynchronous construction method, multiple middle beams are arranged between two side pier columns in the height direction, the top of the two side pier columns is connected through an upper beam, a hydraulic creeping formwork system is used to construct the two side pier columns, when the hydraulic creeping formwork system climbs to the preset height of the middle beam, according to the cross-sectional size of the middle beam and the length of the horizontal main reinforcement of the middle beam extending into the pier column, a groove is arranged in advance at the connection position of the pier column and the middle beam, the shape of the groove is matched with the cross-sectional shape of the middle beam; after the hydraulic creeping formwork system climbs over the preset height of the middle beam, the middle beam reinforcement is installed, finally, the middle beam formwork is installed and the concrete is poured, and meanwhile, the hydraulic creeping formwork system is used to continue the pier column construction. The application effectively solves the problem of low pier column construction efficiency when the middle beams are more, and avoids the damage of the repeated disassembly and assembly of the hydraulic creeping formwork system to the formwork.

Description

Technical Field

[0001] This invention relates to the field of bridge pier construction technology. More specifically, this invention relates to a method for asynchronous construction of bridge piers and crossbeams. Background Technology

[0002] Long-span bridge piers typically employ portal frame structures. As bridge spans increase, the height and cross-sectional dimensions of the piers also gradually increase. When the pier height is significant, a crossbeam is installed between the two piers to enhance overall stability.

[0003] Currently, there are two methods for constructing piers and central crossbeams: synchronous and asynchronous. For the climbing formwork method, if the pier and crossbeam are constructed synchronously, the climbing formwork needs to be removed at the junction of the pier and crossbeam, and the crossbeam formwork installed before pouring concrete. This method is suitable for piers with relatively few crossbeams. When there are many crossbeams, it involves multiple installations and removals of the climbing formwork system, which can damage the formwork. Furthermore, high-altitude construction poses high safety risks and has low efficiency. There are also cases of asynchronous construction using the climbing formwork method for piers and central crossbeams. This method involves pre-embedding crossbeam reinforcement at the crossbeam location. The crossbeam reinforcement is pre-installed with threaded sleeves. After the climbing formwork system rises above the central crossbeam area, the inner concrete of the pier is removed until the reinforcement sleeves are exposed, and then the crossbeam reinforcement is installed. The above asynchronous construction schemes have the following problems: 1. Concrete removal is difficult: Piers generally use concrete of grade C40 or higher, which has high strength and is difficult to remove. 2. Difficulty in ensuring the quality of steel bar connection: The main reinforcement of the cross beam is connected by steel bar straight thread sleeve. The pre-embedded steel bars are pre-threaded. It is difficult to ensure the quality of the steel bar threads during concrete pouring and removal, which leads to problems with the quality of steel bar connection. 3. Low efficiency of steel bar installation: The steel bars of the middle cross beam are mostly tied manually, which involves long working time at height, high safety risks, and low tying efficiency.

[0004] Therefore, it is necessary to propose an asynchronous construction method for pier columns and crossbeams using climbing formwork to solve the above-mentioned technical problems. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0006] To achieve these objectives and other advantages according to the present invention, an asynchronous construction method for bridge piers and intermediate crossbeams is provided. Multiple intermediate crossbeams are arranged along the height direction between the piers on both sides, and the tops of the piers on both sides are connected by upper crossbeams. A hydraulic climbing formwork system is used to construct the piers on both sides. When the hydraulic climbing formwork system climbs to a preset height of the intermediate crossbeams, a groove is pre-set at the connection between the pier and the intermediate crossbeams according to the cross-sectional dimensions of the intermediate crossbeams and the length of the horizontal main reinforcement bars of the intermediate crossbeams extending into the pier. The shape of the groove matches the cross-sectional shape of the intermediate crossbeams. After the hydraulic climbing formwork system climbs above the preset height of the intermediate crossbeams, the intermediate crossbeam reinforcement bars are installed. Finally, the intermediate crossbeam formwork is installed and concrete is poured, while the pier construction continues using the hydraulic climbing formwork system.

[0007] Preferably, the internal reinforcement of the pier column includes vertical main bars and horizontal stirrups, and the horizontal stirrups are cut off at the location of the groove during construction.

[0008] Preferably, after being cut, the horizontal stirrups extend into the groove at both ends, with a length extending into the groove of not less than 45 mm. , The diameter of the horizontal stirrup is given.

[0009] Preferably, during the reinforcement construction of the middle crossbeam, the cut horizontal stirrups are spliced ​​using reinforcing bars of the same type, and the weld length between the two ends of the spliced ​​reinforcing bar and the two ends of the corresponding horizontal stirrup is not less than 10 mm. .

[0010] Preferably, the top and bottom surfaces of the middle crossbeam are chamfered at the connection points with the pier, and chamfered reinforcing bars are provided at the corresponding chamfers; when constructing the groove, the chamfered reinforcing bars are pre-embedded in the pier, and the portion extending out of the pier is bent toward one side of the pier until the entire chamfered reinforcing bar is located inside the pier; after the hydraulic climbing formwork system climbs above the preset height of the middle crossbeam, the chamfered reinforcing bars are straightened first, and then the reinforcing bar construction of the middle crossbeam is carried out.

[0011] Preferably, the groove is constructed using a quick-closing mesh as the groove template.

[0012] Preferably, the internal reinforcement of the middle crossbeam includes a middle reinforcement component and loosely tied reinforcement at both ends of the middle reinforcement component; after the middle reinforcement component is prefabricated, it is hoisted onto the crossbeam construction support, and then the loosely tied reinforcement at both ends is tied onto the crossbeam construction support.

[0013] Preferably, both the intermediate reinforcing bar component and the loosely tied reinforcing bars include horizontal main bars and vertical stirrups. The horizontal main bars of the intermediate reinforcing bar component and the horizontal main bars of the loosely tied reinforcing bars are connected by straight threaded sleeves to form joints. The joints of the upper and lower adjacent rows of horizontal main bars are staggered, and the horizontal distance between the joints of the upper and lower adjacent rows of horizontal main bars is not less than 35 degrees. , The diameter of the horizontal main reinforcement bar is given.

[0014] Preferably, it includes the following steps: S1. The hydraulic climbing formwork system is used to simultaneously construct the piers on both sides; S2. When the construction reaches the preset position of the middle crossbeam, the groove is reserved. At this time, the vertical main reinforcement of the pier is constructed normally, and the horizontal stirrups of the pier are cut off at the groove. At the same time, the chamfered steel bars at the top and bottom chamfers of the middle crossbeam are pre-embedded, and the part of the chamfered steel bars extending out of the pier is bent into the interior of the pier. S3. After the hydraulic climbing formwork system has climbed above the preset height of the middle crossbeam, clean the surface laitance of the groove until the concrete surface strength meets the requirements, and straighten the chamfered steel bars at the same time; then hoist the middle steel bar component of the middle crossbeam, and manually tie the loose steel bars at both ends of the middle steel bar component; and reconnect the horizontal stirrups cut off at the groove. S4. Install the pouring formwork for the middle crossbeam and carry out the concrete pouring construction for the middle crossbeam; S5. Repeat steps S1 to S4 to complete the construction of the remaining crossbeams between the two piers.

[0015] Preferably, in steps S3 and S4, the hydraulic climbing formwork system is used simultaneously to continue the construction of the piers on both sides.

[0016] The present invention has at least the following beneficial effects: 1. The asynchronous construction method for bridge piers and central crossbeams provided by this invention avoids the repeated disassembly and assembly of the hydraulic climbing formwork system and climbing frame, effectively improving the construction efficiency of piers and reducing damage to the formwork. By pre-reserving a groove at the connection between the pier and the central crossbeam, there is no need to pre-embed the horizontal main reinforcement of the central crossbeam, avoiding the need for extensive concrete removal; only the surface laitance at the groove needs to be removed, thus reducing construction costs.

[0017] 2. The asynchronous construction method for bridge piers and crossbeams provided by this invention allows for the prefabrication of the intermediate steel reinforcement components of the crossbeam, improving the efficiency of crossbeam reinforcement construction, shortening the time for high-altitude operations, and reducing the safety risks of high-altitude operations.

[0018] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the pier and the middle crossbeam of the present invention; Figure 2 This is a schematic diagram showing the location of the groove described in this invention; Figure 3 This is a schematic diagram of the internal steel reinforcement structure of the pier column at the groove described in this invention; Figure 4 This is a schematic diagram of the chamfered steel bar in the bent state according to the present invention; Figure 5 This is a schematic diagram of the internal steel reinforcement structure of the crossbeam described in this invention; Figure 6 This is a schematic diagram showing the location of the connector of the horizontal main reinforcement bar according to the present invention. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0021] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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.

[0022] like Figure 1 and Figure 2 As shown, this invention provides a method for asynchronous construction of bridge piers and crossbeams, such as... Figure 1As shown, multiple middle crossbeams 1 are arranged along the height direction between the two piers 2. The tops of the two piers 2 are connected by upper crossbeams 3. The two piers 2 are constructed using a hydraulic climbing formwork system. When the hydraulic climbing formwork system climbs to the preset height of the middle crossbeam 1, a groove 4 is pre-set at the connection between the pier 2 and the middle crossbeam 1 according to the cross-sectional dimensions of the middle crossbeam 1 and the length of the horizontal main reinforcement of the middle crossbeam 1 extending into the pier 2. The shape of the groove 4 matches the cross-sectional shape of the middle crossbeam 1. After the hydraulic climbing formwork system climbs above the preset height of the middle crossbeam 1, the middle crossbeam reinforcement is installed. Finally, the middle crossbeam formwork is installed and concrete is poured. At the same time, the pier construction continues using the hydraulic climbing formwork system.

[0023] In this technical solution, the hydraulic climbing formwork system is a conventional climbing formwork construction structure used in the field, and its specific configuration is existing technology. During the construction of the pier 2, the groove 4 is first reserved at the connection between the central crossbeam 1 and the pier 2. The shape of the groove 4 matches the cross-sectional shape of the central crossbeam 1, and its depth is determined by the length of the horizontal main reinforcement 1 of the central crossbeam 1 extending into the pier 2. Then, the pier construction continues until the hydraulic climbing formwork system has climbed above the central crossbeam 1, at which point the construction of the central crossbeam 1 is carried out. Simultaneously, the construction of the pier 2 does not need to be interrupted, avoiding repeated disassembly and reassembly of the hydraulic climbing formwork system's template and climbing frame, effectively improving the pier construction efficiency while reducing damage to the template. By reserving the groove 4, a large amount of concrete removal is avoided; this solution only requires removing the surface laitance of the concrete, reducing construction costs.

[0024] In another technical solution, refer to Figure 3 The internal reinforcement of the pier column 2 includes vertical main bars 21 and horizontal stirrups 22. When constructing the groove 4, the horizontal stirrups 22 are cut off at the location of the groove.

[0025] Furthermore, after being cut, the horizontal stirrup 22 extends into the groove 4 at both ends, and the length extending into the groove 4 is not less than 45 mm. , The diameter of the horizontal stirrup 22 is given.

[0026] During the construction of the groove 4, the vertical main reinforcement 21 of the pier column 2 is constructed normally, while the horizontal stirrups 22 are cut off to facilitate the subsequent reinforcement construction of the middle crossbeam 1. The two ends of the cut horizontal stirrups 22 extend into the groove 4, i.e., protrude from the pier column 2, for subsequent splicing; and the length d of the exposed portion, i.e., the distance between the end of the horizontal stirrup 22 and the sidewall of the groove 4, satisfies d≥45. .

[0027] In another technical solution, during the reinforcement construction of the middle crossbeam 1, the cut horizontal stirrups 22 are spliced ​​using reinforcing bars of the same type, and the weld length between the two ends of the spliced ​​reinforcing bars and the two ends of the corresponding horizontal stirrups 22 is not less than 10 mm. By welding and ensuring sufficient weld length, the overlap area is made large enough to bear the load, so that the horizontal stirrup 22 after welding can achieve a strength similar to that of the whole stirrup when under tension or compression, thus ensuring the shear resistance of the section.

[0028] In another technical solution, refer to Figure 4 The top and bottom surfaces of the middle crossbeam 1 are chamfered at the connection points with the pier column 2, and chamfered reinforcing bars are correspondingly installed at these chamfered locations. During the construction of the groove 4, the chamfered reinforcing bars 11 are pre-embedded within the pier column 2, and the portion extending beyond the pier column 2 is bent towards one side of the pier column 2 until the entire chamfered reinforcing bar 12 is located inside the pier column 2. After the hydraulic climbing formwork system has climbed above the preset height of the middle crossbeam 1, the chamfered reinforcing bars 12 are straightened before the reinforcement construction of the middle crossbeam 1 is carried out. During the construction of the groove 4, only the chamfered reinforcing bars 11 are pre-embedded and bent into the interior of the pier column 2 to avoid hindering the climbing of the hydraulic climbing formwork system. After the hydraulic climbing formwork system has climbed above the preset height of the middle crossbeam 1, the chamfered reinforcing bars 11 bent into the pier column 2 are straightened and then reinforced with the same type of reinforcing bar with hooks, with a weld length of not less than 10 mm. , The diameter of the chamfered steel bar 11.

[0029] In another technical solution, the groove 4 uses a quick-closing mesh 5 as a groove template during construction. The quick-closing mesh 5 is lightweight, easy to install and process, and does not need to be removed after pouring, being permanently embedded in the concrete; the protruding teeth of the mesh are embedded in the concrete, forming a mechanical interlocking surface between the old and new concrete, which can eliminate the need for manual roughening and greatly simplify the interface treatment of construction joints and post-pouring strips.

[0030] In another technical solution, such as Figure 5As shown, the internal reinforcement of the central crossbeam 1 includes a central reinforcement component 15 and loosely tied reinforcement bars 16 located at both ends of the central reinforcement component 15. After the central reinforcement component 15 is prefabricated, it is hoisted onto the crossbeam construction support 17, and then the loosely tied reinforcement bars 16 at both ends are tied onto the crossbeam construction support 17. The central reinforcement component 15 is fabricated on a steel platform at the bottom of the pier. The reinforcement unit is placed inside the crossbeam reinforcement jig and positioned using a comb plate to ensure the spacing between the reinforcement bars. The fabricated central reinforcement component 15 is hoisted onto the crossbeam construction support 17 using a special hoisting tool for precise positioning, and then the loosely tied reinforcement bars 16 at both ends of the central crossbeam 1 are manually tied. The crossbeam construction support 17 is erected at the same height as the central crossbeam 1.

[0031] Furthermore, both the intermediate reinforcing bar component 15 and the loosely tied reinforcing bars 16 include the horizontal main bars 13 and vertical stirrups. The horizontal main bars 13 of the intermediate reinforcing bar component 15 and the horizontal main bars 13 of the loosely tied reinforcing bars 16 are connected by straight threaded sleeves to form connectors 14. The connectors 14 of two adjacent rows of horizontal main bars 13 are staggered, and the horizontal distance between the connectors of two adjacent rows of horizontal main bars 13 is not less than 35. , The diameter of the horizontal main reinforcement 13 is, for example... Figure 6 As shown. By staggering the arrangement, the connectors 14 are distributed at different horizontal positions, which can eliminate stress concentration and allow the internal shear flow to pass around the connector area more smoothly; at the same time, it ensures that each row of straight threaded sleeves has sufficient construction space.

[0032] The asynchronous construction method for bridge piers and crossbeams described in this invention specifically includes the following steps: S1. The hydraulic climbing formwork system is used to simultaneously construct the piers 2 on both sides; S2. When the construction reaches the preset position of the middle crossbeam 1, the groove 4 is reserved. At this time, the vertical main reinforcement 21 of the pier column 2 is constructed normally, and the horizontal stirrups 22 of the pier column 2 are cut off at the groove 4. At the same time, the chamfered steel bars 11 at the top and bottom chamfers of the middle crossbeam 1 are pre-embedded, and the part of the chamfered steel bars 11 extending out of the pier column 2 is bent into the interior of the pier column 2. S3. After the hydraulic climbing formwork system has climbed above the preset height of the middle crossbeam 1, clean the surface laitance of the groove 4 until the concrete surface strength meets the requirements, and straighten the chamfered steel bar 11; and further reinforce it by welding with steel bars of the same type with hooks; then hoist the middle steel bar component 15 of the middle crossbeam 2, and manually tie the loose steel bars 16 at both ends of the middle steel bar component 15; and reconnect the horizontal stirrups 13 cut off at the groove 4. S4. Install the pouring template of the middle crossbeam 1 and carry out the concrete pouring construction of the middle crossbeam; the concrete placement of the middle crossbeam is assisted by the tremie pipe to avoid segregation of the concrete due to the large drop.

[0033] S5. Repeat steps S1 to S4 to complete the construction of the remaining crossbeams 1 between the two piers 2.

[0034] In steps S3 and S4, the hydraulic climbing formwork system is used simultaneously to continue the construction of the pier columns on both sides. The upper crossbeam 3 is constructed synchronously with the pier body, and the groove 4 is no longer installed.

[0035] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for asynchronous construction of bridge piers and intermediate crossbeams, wherein multiple intermediate crossbeams are arranged along the height direction between the piers on both sides, and the tops of the piers on both sides are connected by an upper crossbeam, characterized in that, The piers on both sides are constructed using a hydraulic climbing formwork system. When the hydraulic climbing formwork system climbs to the preset height of the middle crossbeam, a groove is pre-set at the connection between the pier and the middle crossbeam according to the cross-sectional dimensions of the middle crossbeam and the length of the horizontal main reinforcement of the middle crossbeam extending into the pier. The shape of the groove matches the cross-sectional shape of the middle crossbeam. After the hydraulic climbing formwork system climbs above the preset height of the middle crossbeam, the middle crossbeam reinforcement is installed. Finally, the middle crossbeam formwork is installed and concrete is poured. At the same time, the pier construction continues using the hydraulic climbing formwork system.

2. The asynchronous construction method for bridge piers and crossbeams as described in claim 1, characterized in that, The internal reinforcement of the pier column includes vertical main bars and horizontal stirrups. During the construction of the groove, the horizontal stirrups are cut off at the location of the groove.

3. The asynchronous construction method for bridge piers and crossbeams as described in claim 2, characterized in that, After being cut, the horizontal stirrups extend into the grooves at both ends, with a length extending into the grooves of not less than 45 mm. , The diameter of the horizontal stirrup is given.

4. The asynchronous construction method for bridge piers and crossbeams as described in claim 3, characterized in that, During the reinforcement construction of the middle crossbeam, the cut horizontal stirrups are spliced ​​using reinforcing bars of the same type. The weld length between the two ends of the spliced ​​reinforcing bar and the two ends of the corresponding horizontal stirrup is not less than 10 mm. .

5. The asynchronous construction method for bridge piers and crossbeams as described in claim 1, characterized in that, The top and bottom surfaces of the middle crossbeam are chamfered at the connection points with the pier column, and chamfered reinforcing bars are correspondingly installed at the chamfered locations. During the construction of the groove, the chamfered reinforcing bars are pre-embedded in the pier column, and the portion extending beyond the pier column is bent toward one side of the pier column until the entire chamfered reinforcing bar is located inside the pier column. After the hydraulic climbing formwork system climbs above the preset height of the middle crossbeam, the chamfered reinforcing bars are straightened before the reinforcement construction of the middle crossbeam is carried out.

6. The asynchronous construction method for bridge piers and crossbeams as described in claim 1, characterized in that, The groove is constructed using a quick-closing mesh as the groove template.

7. The asynchronous construction method for bridge piers and crossbeams as described in claim 1, characterized in that, The internal reinforcement of the middle crossbeam includes a middle reinforcement component and loosely tied reinforcement at both ends of the middle reinforcement component; after the middle reinforcement component is prefabricated, it is hoisted onto the crossbeam construction support, and then the loosely tied reinforcement at both ends is tied onto the crossbeam construction support.

8. The asynchronous construction method for bridge piers and crossbeams as described in claim 7, characterized in that, Both the intermediate reinforcing bar component and the loosely tied reinforcing bars include the horizontal main bars and vertical stirrups. The horizontal main bars of the intermediate reinforcing bar component and the horizontal main bars of the loosely tied reinforcing bars are connected by straight threaded sleeves to form joints. The joints of the upper and lower adjacent rows of horizontal main bars are staggered, and the horizontal distance between the joints of the upper and lower adjacent rows of horizontal main bars is not less than 35 degrees. , The diameter of the horizontal main reinforcement bar is given.

9. The asynchronous construction method for bridge piers and crossbeams as described in claim 1, characterized in that, Includes the following steps: S1. The hydraulic climbing formwork system is used to simultaneously construct the piers on both sides; S2. When the construction reaches the preset position of the middle crossbeam, the groove is reserved. At this time, the vertical main reinforcement of the pier is constructed normally, and the horizontal stirrups of the pier are cut off at the groove. At the same time, the chamfered steel bars at the top and bottom chamfers of the middle crossbeam are pre-embedded, and the part of the chamfered steel bars extending out of the pier is bent into the interior of the pier. S3. After the hydraulic climbing formwork system has climbed above the preset height of the middle crossbeam, clean the surface laitance of the groove until the concrete surface strength meets the requirements, and straighten the chamfered steel bars at the same time; then hoist the middle steel bar component of the middle crossbeam, and manually tie the loose steel bars at both ends of the middle steel bar component; and reconnect the horizontal stirrups cut off at the groove. S4. Install the pouring formwork for the middle crossbeam and carry out the concrete pouring construction for the middle crossbeam; S5. Repeat steps S1 to S4 to complete the construction of the remaining crossbeams between the two piers.

10. The asynchronous construction method for bridge piers and crossbeams as described in claim 9, characterized in that, In steps S3 and S4, the hydraulic climbing formwork system is used simultaneously to continue the construction of the piers on both sides.

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