One-off pouring method for variable cross-section bridge pier column

Abstract

The application relates to the technical field of pier construction, in particular to a one-time pouring method for a variable cross-section bridge pier, which comprises the following steps: S1, construction of a bearing platform: constructing the bearing platform at a specified position in a construction site; S2, binding of pier reinforcement: after the center of the pier is measured and laid out, the pier reinforcement is bound according to the measurement result; S3, assembly of a forming template: assembling the forming template outside the pier reinforcement to form a pouring cavity; S4, fixing of a force-bearing outer plate: fixing the force-bearing outer plate on the outer circumferential side of the forming template, so that a placing cavity is formed between the force-bearing outer plate and the forming template; S5, pouring and water injection: injecting concrete into the pouring cavity and vibrating, meanwhile, putting a water bag into the placing cavity and injecting water into the water bag, and controlling the upper surface of the concrete and the liquid level in the water bag to be level; and S6, drainage and template removal: after the concrete is solidified, the water in the water bag is drained, and the force-bearing outer plate and the forming template are removed in sequence; the application has the effects of shortening the construction period of the pier and guaranteeing the safety of the template structure in the construction process.

Description

Technical Field

[0001] This application relates to the field of pier construction technology, and in particular to a method for one-time casting of variable cross-section bridge piers. Background Technology

[0002] Bridges generally consist of a superstructure, a substructure, and ancillary structures. The superstructure mainly refers to the bridge span structure and bearing system; the substructure includes abutments, piers, and ground foundations. The construction of piers can be divided into two methods: cast-in-place and precast pier installation.

[0003] The prior art discloses a construction method for bridge piers, which includes the following steps: 1) completing the construction of grouted foundation piles, the upper surface of which is flush with the ground and has several reserved vertical pile foundation reinforcements; 2) placing the tower cage unit on the ground; the tower cage includes several vertically spaced annular construction platforms, the middle of which is a hollow internal space; the reserved pile foundation reinforcements are all fitted into the hollow internal space in the middle of each annular construction platform; 3) binding the reinforcement cage; 4) removing the tower cage unit from the reinforcement cage; 5) erecting the cylindrical formwork body, the cylindrical formwork body is vertical and fits on the outside of the reinforcement cage, and a horizontal platform protrudes from the upper part of the outer side of the cylindrical formwork body; 6) pouring concrete grout; the operators perform vibration work on the horizontal platform; the top of the reserved pile foundation reinforcements should be able to expose the cast-in-place part; 7) placing the tower cage unit on the horizontal platform; binding the next section of the reinforcement cage; repeating the operation until the pier elevation is reached.

[0004] Regarding the aforementioned technologies, constructing piers by segmented casting requires waiting for the lower cast section to solidify before the formwork can be flipped up and the next segment can be cast, resulting in a long construction period. For piers of road overpass beam bridges, the construction period needs to be controlled, but casting in one go poses a safety hazard because the formwork is subjected to great pressure. Therefore, a new pier construction method is urgently needed. Summary of the Invention

[0005] In order to shorten the construction period of the pier and ensure the safety of the formwork structure during construction, this application provides a method for one-time casting of variable cross-section bridge piers.

[0006] The technical solution for a one-time casting method for variable cross-section bridge piers provided in this application is as follows:

[0007] A method for one-time casting of variable cross-section bridge piers, including

[0008] S1: Foundation construction: Construction of the foundation at the designated location on the construction site;

[0009] S2: Pier column reinforcement binding: After the center of the pier column is measured and laid out, the pier column reinforcement is bound according to the measurement results;

[0010] S3: Formwork assembly: Assemble the formwork outside the pier column reinforcement to form a casting cavity;

[0011] S4: Load-bearing outer plate fixing: Fix the load-bearing outer plate to the outer periphery of the forming template, forming a placement cavity between the load-bearing outer plate and the forming template;

[0012] S5: Pouring and water injection: Inject concrete into the pouring cavity and vibrate it. At the same time, place a water bag in the placement cavity and inject water into the water bag to control the concrete surface and the liquid level in the water bag to be level.

[0013] S5: Drainage and formwork removal: After the concrete has solidified, drain the water from the water bag and remove the load-bearing outer plate and the formwork in sequence.

[0014] By adopting the above technical solution, a load-bearing outer plate is constructed on the outside of the pier forming template, and a water bag is placed between the load-bearing outer plate and the forming template. By controlling the concrete pouring speed and the water injection speed in the water bag, the surface of the concrete and the liquid level in the water bag are made level, thus achieving synchronous support for the forming template under stress. By applying a force to the forming template in the opposite direction to the force exerted by the concrete on the forming template through the water bag, the possibility of deformation of the forming template due to excessive stress during the pier pouring process can be reduced, ensuring the safety of the template structure during construction, and enabling the pier to be poured in one go, thereby shortening the pier construction cycle.

[0015] In one specific implementation scheme, in step S5, the water in the water bag is gradually drained over time until the concrete has completely solidified, at which point the water bag is completely emptied.

[0016] By adopting the above technical solution, as the concrete in the pouring cavity gradually solidifies over time, the force acting on the forming template gradually decreases. Therefore, the water in the water bag is gradually drained to prevent the water in the water bag from exerting a force on the forming template, which could cause the forming template to shift and affect the pouring accuracy of the pier column.

[0017] In one specific implementation, in step S5, there are multiple water bags distributed along the height direction.

[0018] By adopting the above technical solution, it is possible to apply force to the forming template while reducing the material strength requirements of the water bag, and to mitigate the risk of water bag breakage during construction.

[0019] In one specific implementation scheme, in step S5, the water bag is hung on the load-bearing outer plate by multiple handles, and after the water bag is filled with water, the handles are in a taut state.

[0020] By adopting the above technical solution, the water bag can exert a force on the forming template while simultaneously applying its own weight to the load-bearing outer plate, thereby increasing the positional stability of the load-bearing outer plate.

[0021] In one specific implementation scheme, in step S5, the water bag has a ring structure, and the pier forming template is set through the hollow of the ring water bag.

[0022] By adopting the above technical solution, a circumferential force can be applied to the pier column forming template using a water bag, reducing the possibility of expansion of the pier column forming template.

[0023] In one specific implementation, in step S5, a vibrator is used to vibrate the concrete, and the vibrator is suspended by a traction cable, which pulls the vibrator up as the concrete pouring height increases.

[0024] By adopting the above technical solutions, the use of vibrating rods can reduce undesirable phenomena such as cavities and air holes after concrete solidification.

[0025] In one specific implementation scheme, multiple hollow rings are connected along the height direction of the load-bearing outer plate, the traction cable passes over the upper edge of the pier forming template and enters the hollow rings, the water bag is located between the load-bearing outer plate and the traction cable, and one end of the traction cable is connected to the side of the load-bearing outer plate near the pier cap.

[0026] By adopting the above technical solution, when concrete is injected into the pouring cavity, the height of the upper surface of the concrete gradually rises. At the same time, water is injected into the water bag, and as the water bag expands, it will also cause the traction cable to deform. Since the total length of the traction cable remains unchanged, it will gradually pull up the vibrator.

[0027] In one specific implementation scheme, step S3, the assembly of the molding template includes...

[0028] S31: Pier formwork assembly: After applying release agent to the working surface of the pier formwork, the pier formwork is assembled on the pier platform. After the assembly is completed, the formwork dimensions are remeasured.

[0029] S32: Top cap formwork assembly: Apply release agent to the working surface of the top cap formwork, then install the top cap formwork on the foundation of the pier formwork. After installation, remeasure the formwork dimensions.

[0030] S33: Formwork structure reinforcement: Internal reinforcement is carried out by through-through tie rods, and external reinforcement is carried out by external back tie rods to improve the stability of the pier formwork structure.

[0031] By adopting the above technical solution, the pier body and the top cap can be cast in one go, shortening the construction cycle.

[0032] In one specific implementation, in step S2, the surface of the pier cap is roughened before the reinforcement of the pier column is tied.

[0033] By adopting the above technical solutions, the connection strength between the pier and the foundation can be increased.

[0034] In summary, this application includes at least one of the following beneficial technical effects:

[0035] 1. The designed method for one-time casting of variable cross-section bridge piers involves constructing a load-bearing outer plate on the outside of the pier's forming template, and placing a water bag between the load-bearing outer plate and the forming template. By controlling the concrete pouring speed and the water injection speed in the water bag, the surface of the concrete and the liquid level in the water bag are kept level, achieving synchronous support for the forming template. The water bag applies a force to the forming template in the opposite direction to the force exerted by the concrete on the forming template, which can reduce the possibility of deformation of the forming template due to excessive stress during the pier casting process, ensure the safety of the template structure during construction, and achieve one-time casting of the pier, thereby shortening the pier construction cycle.

[0036] 2. The designed method for one-time casting of variable cross-section bridge piers can increase the positional stability of the load-bearing outer plate by applying force to the forming template through water bags and applying force to the load-bearing outer plate through its own weight.

[0037] 3. The designed method for one-time casting of variable cross-section bridge piers involves gradually raising the upper surface of the concrete as it is poured into the casting cavity. Simultaneously, water is injected into the water bag, and as the water bag expands, it also causes the traction cable to deform. Since the total length of the traction cable remains unchanged, it will gradually pull up the vibrator. Attached Figure Description

[0038] Figure 1 This is a structural schematic diagram of the one-time casting method for variable cross-section bridge piers according to an embodiment of this application.

[0039] Figure 2 yes Figure 1 A sectional view.

[0040] Figure 3 yes Figure 1 A partial structural diagram.

[0041] Figure 4 yes Figure 2 A schematic diagram of the structure after the addition of traction cables and vibrating rods.

[0042] Explanation of reference numerals in the attached drawings: 1. Pier cap; 2. Forming template; 21. Pier body template; 22. Top cap template; 23. Tie rod; 24. Outer back rib; 3. Load-bearing outer plate; 4. Water bag; 5. Hanging handle; 6. Vibrator; 7. Traction cable; 8. Hollow ring. Detailed Implementation

[0043] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0044] This application discloses a method for one-time casting of variable cross-section bridge piers.

[0045] Example 1

[0046] Reference Figure 1 and Figure 2 A method for one-time casting of variable cross-section bridge piers includes

[0047] S1: Construction of Pier 1: Excavate a foundation pit at the designated location on the construction site, install structural steel reinforcement in the foundation pit, cast in place the pile foundation column, and then construct Pier 1 on the pile foundation column.

[0048] S2: Pier column reinforcement binding: The surface of the pier cap 1 is roughened, and then the center position data of the pier column is obtained by measuring and setting out on the pier cap 1. Then, the pier column reinforcement is bound at the designated position according to the measurement data. Quality spot check is carried out before the pier column reinforcement is bound.

[0049] S3: Assembly of Forming Template 2: Calculate the number of template blocks according to the pier column size, and erect and assemble the Forming Template 2 in sequence on the outside of the pier column reinforcement according to the principle of template correspondence and uniform staggering of the joint template and wedge template to form the pouring cavity.

[0050] S4: Fixing the load-bearing outer plate 3: Fix the load-bearing outer plate 3 to the outer periphery of the forming template 2, and set the load-bearing outer plate 3 above the support platform 1, forming a placement cavity between the load-bearing outer plate 3 and the forming template 2;

[0051] S5: Pouring and water injection: Concrete is injected into the pouring cavity from top to bottom using a concrete pump truck and vibrated. At the same time, water bag 4 is placed in the placement cavity and water is injected into water bag 4. By controlling the injection speed of concrete and the injection speed of water bag 4, the surface of concrete and the liquid level inside water bag 4 are made level.

[0052] S5: Drainage and formwork removal: After the concrete has solidified, drain the water from the water bag 4, and remove the load-bearing outer plate 3 and the forming template 2 in sequence. Then, perform surface grinding and curing operations on the cast-in-place pier column.

[0053] Example 2

[0054] Reference Figure 2 As the concrete gradually solidifies over time, the force acting on the molding template 2 gradually decreases. Therefore, the water in the water bag 4 is gradually drained over time until the concrete is completely solidified, at which point the water in the water bag 4 is completely drained, so that the external force on the molding template 2 is always kept within a reliable range.

[0055] Example 3

[0056] Reference Figure 3 In order to achieve one-time casting of the variable cross-section pier column and shorten the construction period, step S3 includes the assembly of the forming template 2.

[0057] S31: Pier formwork 21 assembly: After applying release agent to the working surface of pier formwork 21, pier formwork 21 is assembled on pier cap 1. After assembly, the formwork dimensions are remeasured.

[0058] S32: Assembly of top cap template 22: Apply release agent to the working surface of top cap template 22, and then install top cap template 22 on the foundation of pier template 21. After installation, remeasure the template dimensions.

[0059] S33: Template structure reinforcement: internal reinforcement is achieved by using tie rods 23 through the formwork, and external reinforcement is achieved by using tie bars 24 to improve the structural stability of the pier formwork 21.

[0060] Example 4

[0061] Reference Figure 4 To further reduce the risk of water bag 4 rupture after being filled with water, and to reduce the strength requirements of the material used to make water bag 4 to lower costs, multiple water bags 4 are used, distributed along the height direction, and the water bags 4 are set as a ring structure. The pier forming template 2 is set through the hollow hole of the ring water bag 4. In this application, the ring structure of the water bag 4 can be a circular ring or a square ring, that is, the solution of this application can be applied to both circular and square piers. In this application, multiple water bags 4 can be stacked or spaced apart. The water bags 4 further restrict the deformation of the forming template 2. Furthermore, in order to increase the positional stability of the load-bearing outer plate 3, the water bags 4 are hung on the load-bearing outer plate 3 by multiple hanging handles 5. After the water bags 4 are filled with water, the hanging handles 5 are in a taut state. The weight of the water bags 4 presses the load-bearing outer plate 3 upright on the pier 1, reducing the possibility of the load-bearing outer plate 3 moving outward after being subjected to force.

[0062] Example 5

[0063] Reference Figure 4To reduce quality defects such as air bubbles and shrinkage cavities in the pier column after concrete solidification, vibration is required during the pouring process. Therefore, in step S5, a vibrator 6 is used to vibrate the concrete, and the vibrator 6 is suspended by a traction cable 7, which pulls the vibrator 6 up as the concrete pouring height increases. Multiple hollow rings 8 are connected along the height direction on the load-bearing outer plate 3. The traction cable 7 passes over the upper edge of the pier column forming template 2 and passes through the hollow rings 8. A water bag 4 is located between the load-bearing outer plate 3 and the traction cable 7, with one end of the traction cable 7 connected to the side of the load-bearing outer plate 3 near the foundation 1. By injecting water into the water bag 4, the expansion of the water bag 4 will cause the traction cable 7 to deform. Since the length of the traction cable 7 remains constant, the height of the vibrator 6 will gradually increase during the deformation of the water bag 4, thereby achieving uniform and timely vibration of the concrete.

[0064] The implementation principle of the one-time casting method for variable cross-section bridge piers in this application embodiment is as follows: a foundation pit is excavated at a designated location on the construction site, and structural steel reinforcement is installed in the foundation pit before the pile foundation column is cast in place. Then, the pier cap 1 is constructed on the pile foundation column. The surface of the pier cap 1 is then roughened, and the center position data of the pier column is obtained by measuring and setting out on the pier cap 1. Then, the pier column reinforcement is tied at a designated location according to the measurement data, and the quality of the pier column reinforcement is sampled before tying.

[0065] After the pier column reinforcement is tied, the number of template blocks is calculated according to the pier column size. Template 2 is erected and assembled sequentially on the outside of the pier column reinforcement according to the principle of template correspondence and staggered joint templates and wedge templates, forming a casting cavity. The assembly of the pier column forming template 2 includes the assembly of the pier body template 21 and the top cap template 22. After applying a release agent to the working surface of the pier body template 21, it is assembled on the foundation 1. After assembly, the template dimensions are remeasured. A release agent is applied to the working surface of the top cap template 22, and then the top cap template 22 is installed on the pier body template 21. After installation, the template dimensions are remeasured. Then, tie rods 23 are used for internal reinforcement, and external reinforcing ribs 24 are used for external reinforcement to improve the structural stability of the pier body template 21 and the top cap template 22. The load-bearing outer plate 3 is fixed to the outer periphery of the forming template 2, and the load-bearing outer plate 3 is positioned above the foundation 1, forming a placement cavity between the load-bearing outer plate 3 and the forming template 2.

[0066] At this time, a concrete pump truck is used to inject concrete into the pouring cavity from top to bottom and vibrate it. At the same time, a water bag 4 is placed in the placement cavity and water is injected into the water bag 4. By controlling the injection speed of the concrete and the injection speed of the water bag 4, the surface of the concrete and the liquid level in the water bag 4 are made level. The water bag 4 applies a force to the forming template 2 in the opposite direction to the force exerted by the concrete on the forming template 2. This can reduce the possibility of deformation of the forming template 2 due to excessive force during the pier pouring process, ensure the safety of the template structure during construction, and achieve one-time pouring of the pier, thereby shortening the construction cycle of the pier.

[0067] After the concrete has solidified, drain the water from the water bag 4, and then remove the load-bearing outer plate 3 and the forming template 2. Finally, perform surface grinding and curing operations on the cast-in-place pier column.

[0068] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for one-time casting of variable cross-section bridge piers, characterized in that: include S1: Construction of the foundation (1): Construction of the foundation (1) at the designated location on the construction site; S2: Pier column reinforcement binding: After the center of the pier column is measured and laid out, the pier column reinforcement is bound according to the measurement results; S3: Assembly of the forming template (2): Assemble the forming template (2) on the outside of the pier column reinforcement to form a casting cavity; S4: Fixing the load-bearing outer plate (3): Fix the load-bearing outer plate (3) to the outer periphery of the forming template (2), and a placement cavity is formed between the load-bearing outer plate (3) and the forming template (2); S5: Pouring and water injection: Inject concrete into the pouring cavity and vibrate it. At the same time, put a water bag (4) into the placement cavity and inject water into the water bag (4) to control the concrete surface and the liquid level in the water bag (4) to be level. S5: Drainage and formwork removal: After the concrete has solidified, drain the water from the water bag (4) and remove the load-bearing outer plate (3) and the forming template (2) in sequence. In step S5, there are multiple water bags (4), and the multiple water bags (4) are distributed along the height direction; In step S5, the water bag (4) is a ring structure, and the pier forming template (2) passes through the hollow of the ring water bag (4); In step S5, a vibrating rod (6) is used to vibrate the concrete, and the vibrating rod (6) is suspended by a traction cable (7). As the concrete pouring height increases, the vibrating rod (6) is pulled up. Multiple hollow rings (8) are connected along the height direction of the load-bearing outer plate (3). The traction cable (7) passes over the upper edge of the pier forming template (2) and enters the hollow ring (8). The water bag (4) is located between the load-bearing outer plate (3) and the traction cable (7). One end of the traction cable (7) is connected to the side of the load-bearing outer plate (3) near the pier (1).

2. The method for one-time casting of variable cross-section bridge piers according to claim 1, characterized in that: In step S5, the water in the water bag (4) is gradually drained over time until the concrete is completely solidified and the water in the water bag (4) is completely drained.

3. The method for one-time casting of variable cross-section bridge piers according to claim 1, characterized in that: In step S5, the water bag (4) is hung on the load-bearing outer plate (3) by multiple handles (5), and after the water bag (4) is filled with water, the handles (5) are in a taut state.

4. The method for one-time casting of variable cross-section bridge piers according to claim 1, characterized in that: In step S3, the assembly of the molding template (2) includes S31: Pier formwork (21) assembly: After applying release agent to the working surface of pier formwork (21), pier formwork (21) is assembled on the pier cap (1). After assembly, the formwork dimensions are remeasured. S32: Assembly of top cap template (22): Apply release agent to the working surface of top cap template (22), and then install top cap template (22) on the basis of pier template (21). After installation, remeasure the template size. S33: Template structure reinforcement: internal reinforcement is carried out by using tie rods (23) through the formwork, and external reinforcement is carried out by using back bracing (24) to improve the structural stability of the pier template (21).

5. The method for one-time casting of variable cross-section bridge piers according to claim 1, characterized in that: In step S2, the surface of the pier cap (1) is roughened before the reinforcement of the pier column is tied.

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