Pier support-free standardized formwork and construction method

Abstract

The application provides a bridge pier free-supporting standardized formwork and a construction method, and belongs to the technical field of bridge pier formworks. The bridge pier free-supporting standardized formwork comprises a plurality of unit sections. Each unit section comprises a transverse plate, a longitudinal plate, and a limiting connection assembly. The limiting connection assembly comprises a longitudinal displacement seat, a limiting head, a positioning head, and a positioning seat. The bridge pier free-supporting standardized formwork and the construction method can quickly complete the splicing of the transverse plate and the longitudinal plate and preliminarily limit and connect the two plates through the positioning of the positioning head and the positioning seat. Two limiting connection points are formed between adjacent transverse plates and longitudinal plates in each unit section, which facilitates the quick and stable assembly of the unit sections. The limiting head is used to limit the unit sections preliminarily connected and limited according to the unit sections that have been spliced, thereby improving the splicing accuracy, limiting and connecting the adjacent unit sections together, reducing the use of fasteners, ensuring the strength of the overall connection structure, and effectively improving the efficiency and convenience of the splicing process and the formwork removal process.

Description

Technical Field

[0001] This invention relates to the field of bridge pier formwork technology, specifically to a standardized formwork for bridge piers that does not require support and a construction method thereof. Background Technology

[0002] Bridge pier support-free formwork is a concrete forming formwork system for bridge piers that can be stably positioned without relying on a ground support system. It mainly adopts a modular structure, which is composed of multiple standard unit sections assembled from bottom to top to form a complete formwork system. Each unit section is composed of several formwork panels. The common form is two longitudinal formwork panels and two transverse formwork panels spliced ​​together to form a casting cavity.

[0003] To meet the requirement of the formwork detaching from the concrete structure horizontally during demolding, a face-to-face direct splicing method is usually adopted. This allows each formwork panel to move outward horizontally during demolding. However, this splicing process requires not only a large number of fasteners for secure connection but also specialized auxiliary tools for positioning and adjustment to ensure accurate splicing of the formwork panels. This process is not only complex and inconvenient but also time-consuming. Especially at heights, it significantly increases the difficulty of splicing and demolding, severely reducing the efficiency and convenience of the assembly and demolding process. Summary of the Invention

[0004] This invention provides a standardized formwork for bridge piers without support and a construction method. The standardized formwork for bridge piers without support includes several unit sections, which are spliced ​​together sequentially from bottom to top. Each unit section includes a transverse plate and a longitudinal plate, which are connected end to end to form a casting cavity. A limiting connection assembly, corresponding to each unit section, includes a longitudinal sliding seat symmetrically installed on the transverse plate; a limiting head, installed on the longitudinal sliding seat, limits the movement of adjacent transverse and longitudinal plates within the unit section, and also limits the movement of adjacent transverse and longitudinal plates within the adjacent unit section above the unit section. Position; Positioning heads, respectively installed on the longitudinal plates in the unit section and on the longitudinal plates of adjacent unit sections, with the positioning heads symmetrically distributed on the longitudinal plates; Positioning seats, each corresponding to a positioning head and fixedly installed on the corresponding longitudinal sliding seats; wherein, in the initial state, the positioning seats are in the positioning state, and the longitudinal plates in the unit section are positioned based on the transverse plates of the unit section through the positioning head on it and the limiting cooperation with the corresponding positioning seats, and are in a limiting connection with the transverse plates; during the demolding process, the longitudinal sliding seats move to separate the positioning heads from the corresponding positioning seats.

[0005] In one possible implementation, the limiting head includes a plurality of wedge-shaped units, each wedge-shaped unit corresponding to an adjacent transverse plate and a longitudinal plate within a unit section, as well as an adjacent transverse plate and a longitudinal plate within an adjacent unit section above the unit section. Each wedge-shaped unit includes two wedge-shaped regions that are perpendicularly distributed to each other. Wedge-shaped portions are fixedly provided on the corresponding transverse plates and longitudinal plates, with each wedge-shaped portion corresponding to a wedge-shaped region.

[0006] In one possible implementation, the positioning head is a connecting block with a limiting groove, and the corresponding positioning seat cooperates with the limiting groove to limit the longitudinal plate at least in the lateral direction.

[0007] In one possible implementation, the positioning head is provided with an association seat, and the positioning seat is provided with an association head that matches the association seat. The association seat and the association head cooperate to limit and connect adjacent unit sections together.

[0008] In one possible implementation, a docking unit is provided between the upper and lower adjacent transverse plates and longitudinal plates. The docking unit includes a slotted docking seat with an opening and a mating head that matches the slotted docking seat. The mating head cooperates with the slotted docking seat to limit the upper and lower adjacent transverse plates and longitudinal plates. The mating head is installed on the upper transverse plate and longitudinal plate respectively. The transverse plate and longitudinal plate can move in the horizontal direction to move the mating head out of the opening and separate it from the corresponding slotted docking seat.

[0009] In one possible implementation, the connector engages with a corresponding grooved mating seat in a wedge-shaped fit.

[0010] In one possible implementation, the connector head is a conical block, and the connector seat is a conical groove that mates with the corresponding connector head.

[0011] A construction method for a standardized formwork for bridge piers without support is used to assemble a standardized formwork for bridge piers without support. The method includes the following steps: S1: splicing the first unit section. First, install and fix the transverse plate to the preset position outside the steel reinforcement skeleton of the bridge pier. Then, install the longitudinal plate and achieve the initial splicing with the transverse plate through the cooperation of the corresponding positioning seat and positioning head. After correcting the position of the longitudinal plate, reinforce the transverse plate and the longitudinal plate.

[0012] S2: Based on S1, splice the first subsequent unit section. First, align the transverse plates in the new unit section with the corresponding transverse plates in the already spliced ​​unit section. Then, install the longitudinal plates in the new unit section. A preliminary connection is achieved through the cooperation of the corresponding positioning seats and positioning heads. Move the longitudinal moving seats so that the limiting heads simultaneously limit the adjacent transverse and longitudinal plates in the already installed unit section as well as the corresponding adjacent transverse and longitudinal plates in the new unit section. After correcting the position of the longitudinal and transverse plates, reinforce them.

[0013] S3: Repeat step S2 until all unit sections of the pier formwork are spliced ​​on the outside of the pier reinforcement cage.

[0014] S4: Concrete pouring and shaping operation is carried out inside the pier formwork of S3.

[0015] S5: Curing operations for cast concrete.

[0016] S6: After the curing is completed, remove all the unit sections of the pier formwork from top to bottom.

[0017] The above-mentioned one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: According to the standardized template and construction method for bridge piers without support provided by the embodiments of the present invention, the splicing of the transverse plate and the longitudinal plate is quickly completed by positioning the positioning head and the positioning seat, and the two are initially limited and connected. Two upper and lower limiting connection points are formed between adjacent transverse plates and longitudinal plates in the unit section, which facilitates the rapid and stable completion of the assembly of the unit section. Combined with the limiting head, the unit section that has been spliced ​​is limited according to the unit section that has been initially limited and connected, which improves the accuracy of splicing and limits the connection of adjacent unit sections together, reduces the use of fasteners, and ensures the strength of the overall connection structure. Overall, the efficiency and convenience of the splicing process and the demolding process are effectively improved. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the assembled structure of a standardized template for bridge piers that does not require support, provided in an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Enlarged view of point A in the middle.

[0020] Figure 3 yes Figure 1 Enlarged view of point B in the middle.

[0021] Figure 4 This is a structural schematic diagram of the horizontal and vertical plates of a standardized template for bridge piers that does not require support, provided in an embodiment of the present invention.

[0022] Figure 5 This is a structural schematic diagram of the connector and wedge-shaped area of ​​a standardized template for bridge piers that does not require support, provided in an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the structure of a local transverse plate and longitudinal plate in an adjacent unit section of a standardized template for bridge piers without support, provided by an embodiment of the present invention.

[0024] Figure 7 This is a structural schematic diagram of a standardized template positioning seat, an associated head, and an associated seat for bridge piers without support, provided in an embodiment of the present invention.

[0025] Figure 8 This is a structural schematic diagram of a standardized template limiting groove for bridge piers that does not require support, provided in an embodiment of the present invention.

[0026] In the diagram: 1. Horizontal plate; 2. Vertical plate; 3. Limiting connection assembly; 31. Longitudinal sliding seat; 32. Limiting head; 321. Wedge unit; 322. Wedge area; 33. Positioning head; 331. Limiting groove; 332. Connecting block; 34. Positioning seat; 35. Wedge part; 36. Associate seat; 37. Associate head; 38. Docking unit; 381. Opening; 382. Groove docking seat; 383. Butt joint; 39. Mounting seat; 4. Threaded fastener. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described below, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Please see Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 A standardized formwork for bridge piers without supports comprises several unit sections, which are assembled sequentially from bottom to top. Each unit section includes two transverse plates 1 that are symmetrical front to back and two longitudinal plates 2 that are symmetrical left to right. Figure 4 As shown, the transverse plate 1 and the longitudinal plate 2 are connected end to end to form a casting cavity. Each unit section is equipped with a set of limiting connection components 3, which include mounting seats 39. Each unit section is provided with four mounting seats 39, which are divided into two groups and fixedly installed on the transverse plate 1, as shown. Figure 4 As shown, the mounting seats 39 on the transverse plate 1 are symmetrically distributed on the left and right and located at the corners above the corresponding transverse plates 1. Each mounting seat 39 has a longitudinal sliding seat 31 slidably mounted on it. The longitudinal sliding seat 31 is controlled and locked by threaded fasteners 4. A limit head 32 is installed on the longitudinal sliding seat 31. After the lower unit section is assembled and the adjacent upper unit section is initially assembled, the limit head 32 moves towards the unit section under the control of the longitudinal sliding seat 31, simultaneously limiting the movement of the two adjacent sets of transverse plates 1 and longitudinal plates 2 at the corners (e.g., ...). Figure 6 As shown, the two adjacent sets of transverse plates 1 and longitudinal plates 2 at the corner are adjacent transverse plates 1 and longitudinal plates 2 in the lower unit section and adjacent and corresponding transverse plates 1 and longitudinal plates 2 in the upper section, so that the adjacent transverse plates 1 and longitudinal plates 2 in the unit section and the adjacent unit sections above and below are connected together. On the one hand, the unit section to be spliced ​​is aligned with the unit section to be spliced, thereby improving the splicing accuracy of the two. On the other hand, the adjacent unit sections are connected together to reduce the amount of fasteners used and ensure the connection strength of the overall structure.

[0029] See Figure 2 , Figure 4 , Figure 5 , Figure 7 and Figure 8 Each longitudinal sliding seat 31 is fixedly equipped with two positioning seats 34, which are distributed front to back. Positioning heads 33 are installed on the longitudinal plates 2 adjacent to the transverse plate 1 where the longitudinal sliding seat 31 is located, as well as on the longitudinal plates 2 adjacent above the transverse plate 2. The positioning heads 33 correspond one-to-one with the two positioning seats 34 on the longitudinal sliding seat 31 and cooperate with each other. They limit the longitudinal plates 2 according to the transverse plate 1, thus initially connecting the longitudinal plates 2 and the transverse plate 1 together. Figure 4 and Figure 8 As shown, during the splicing of the longitudinal plates 2 within the unit section, after aligning the positioning head 33 with the corresponding positioning seat 34, it is placed from top to bottom, thereby limiting and connecting the positioning head 33 and the corresponding positioning seat 34 together (e.g. Figure 4 As shown, the longitudinal plate 2 is limited by the position of the transverse plate 1, so that the two are initially limited and connected together. Similarly, during the installation of the corresponding longitudinal plate 2 in the adjacent unit section above, the corresponding positioning head 33 is also aligned with the corresponding positioning head 33. The longitudinal plate 2 in this unit section is limited by the transverse plate 1 in the lower unit section, so that the longitudinal plate 2 in this unit section is simultaneously limited and connected with the transverse plate 1 in this unit section and the transverse plate 1 in the lower unit section. Two limiting connection points are formed in the vertical direction, which improves the stability of the limiting connection. In the subsequent demolding process, it is only necessary to move the longitudinal sliding seat 31 in the reverse direction to separate and offset the positioning seat 34 from the corresponding positioning head 33, so as to release the limiting connection state between the transverse plate 1 and the longitudinal plate 2. Then, the longitudinal plate 2 can be removed by translating it, and then the transverse plate 1 can be removed. It is very convenient.

[0030] See Figure 2 , Figure 4 , Figure 5 and Figure 6 The limiting head 32 includes four wedge-shaped units 321. Each wedge-shaped unit 321 corresponds to an adjacent transverse plate 1 and a longitudinal plate 2 within a unit section, as well as an adjacent transverse plate 1 and a longitudinal plate 2 within an adjacent unit section above that unit section. Each wedge-shaped unit 321 includes two mutually perpendicularly distributed wedge-shaped regions 322. Wedge-shaped portions 35 are fixedly disposed on the corresponding transverse plate 1 and longitudinal plate 2, with each wedge-shaped portion 35 corresponding one-to-one with a wedge-shaped region 322. Figure 6As shown, two mutually perpendicular wedge-shaped parts 35 are provided at the corner of the horizontal plate 1 and at the corner of the adjacent horizontal plate 1 and two vertical plates 2. The wedge-shaped parts 35 are wedge-shaped blocks. When the lower unit section is completed and the horizontal plate 1 and vertical plate 2 of the upper unit section are initially limited and spliced, the longitudinal moving seat 31 moves towards the unit section until the wedge area 322 in its upper positioning head 32 wedges and the corresponding wedge-shaped parts 35 wedge together, limiting the horizontal plate 1 and vertical plate 2 in the horizontal and vertical directions, so that the adjacent horizontal plate 1 and vertical plate 2 in the unit section and the adjacent unit sections above and below are limited and connected together. During the demolding process, the longitudinal moving seat 31 can be moved in the opposite direction to release the limiting connection state. In the disassembly process, after the longitudinal moving seat 31 releases the limiting connection state of the limiting head 32, it is necessary to continue to move to release the positioning state of the positioning head 33 and the positioning seat 34.

[0031] See Figure 2 , Figure 5 and Figure 8 The positioning head 33 is a connecting block 332 with a limiting groove 331. The corresponding positioning seat 34 wedges with the limiting groove 331 to limit the longitudinal plate 2 in the lateral direction. Figure 8 As shown, the limiting groove 331 moves down after aligning with the positioning seat 34 until it fits with the positioning seat 34, thus limiting the connecting block 332 in the lateral direction. Since the connecting block 332 is fixedly installed on the longitudinal plate 2, the lateral direction limitation of the longitudinal plate 2 is thus completed.

[0032] See Figure 2 , Figure 5 and Figure 7 The positioning head 33 is provided with an association seat 36, and the positioning seat 34 is provided with an association head 37 that matches the association seat 36. The association seat 36 and the association head 37 cooperate to limit and connect adjacent unit sections together. The association head 37 is a conical block (e.g., Figure 5 As shown), the connecting seat 36 is a conical groove that fits into the wedge shape of the connecting head 37 (as shown). Figure 7 As shown, when the longitudinal shift seat 31 moves toward the unit section, until the wedge-shaped area 322 in its upper limit head 32 engages with the corresponding wedge portion 35, the positioning seat 34 moves along with it, and the associated head 37 is inserted into the corresponding associated seat 36, further limiting the connection between the transverse plate 1 and the longitudinal plate 2, thereby improving the stability and reliability of the overall structure.

[0033] See Figure 1 and Figure 3Each of the adjacent horizontal plates 1 and vertical plates 2 is provided with a docking unit 38. The docking unit 38 includes a groove-shaped docking seat 382 with an opening 381 and a mating connector 383 that matches the groove-shaped docking seat 382. The mating connector 383 cooperates with the groove-shaped docking seat 382 to limit the movement of the adjacent horizontal plates 1 and vertical plates 2. The mating connector 383 is correspondingly installed on the upper horizontal plate 1 and vertical plate 2. The horizontal plates 1 and vertical plates 2 can move horizontally to allow the mating connector 383 to move out of the opening 381 and separate from the corresponding groove-shaped docking seat 382. Figure 3 As shown, the connector 383 is fixedly installed on the longitudinal plate 2, and the corresponding slotted mating seat 382 is fixedly installed on the lower longitudinal plate 2. The longitudinal plate 2 moves downwards, causing the connector 383 to insert into the corresponding slotted mating seat 382, ​​thus limiting the vertical alignment of the adjacent longitudinal plates 2 and ensuring precise mating. During demolding, the upper longitudinal plate 2 can be directly moved and removed. The connector 383 and the corresponding slotted mating seat 382 have a wedge-shaped fit, as shown... Figure 3 As shown, the two wedge-shaped parts fit together vertically to limit the longitudinal plate 2.

[0034] The present invention also provides a construction method for a standardized formwork for bridge piers without support, which is used to assemble a standardized formwork for bridge piers without support, including the following steps: S1: splicing the first unit section, first installing and fixing the transverse plate 1 to the preset position outside the steel reinforcement skeleton of the bridge pier, then installing the longitudinal plate 2, and achieving the initial splicing with the transverse plate 1 through the cooperation of the corresponding positioning seat 34 and the positioning head 33, and then reinforcing the transverse plate 1 and the longitudinal plate 2 after correcting the position of the longitudinal plate 2.

[0035] S2: Based on S1, the first subsequent unit section is spliced. First, the transverse plate 1 in the new unit section is placed in conjunction with the corresponding transverse plate 1 in the spliced ​​unit section. Then, the longitudinal plate 2 in the new unit section is installed. The initial connection is achieved through the cooperation of the corresponding positioning seat 34 and the positioning head 33. The longitudinal moving seat 31 is moved so that the limiting head 32 simultaneously limits the adjacent transverse plate 1 and longitudinal plate 2 in the installed unit section and the corresponding adjacent transverse plate 1 and longitudinal plate 2 in the new unit section. After the position of the longitudinal plate 2 and the transverse plate 1 is corrected, reinforcement is performed.

[0036] S3: Repeat step S2 until all unit sections of the pier formwork are spliced ​​on the outside of the pier reinforcement cage.

[0037] S4: Concrete pouring and shaping operation is carried out inside the pier formwork of S3.

[0038] S5: Curing operations for cast concrete.

[0039] S6: After the curing is completed, remove all the unit sections of the pier formwork from top to bottom.

[0040] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral connection, or a sliding connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made based on the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A standardized formwork for bridge piers without supports, characterized in that: It comprises several unit sections, which are assembled together from bottom to top; the unit section includes: The horizontal and vertical plates are connected end to end to form the casting cavity; Limiting connection components, corresponding one-to-one with unit sections, include: The longitudinal sliding seat is symmetrically installed on the transverse plate; The limiting connection assembly includes a mounting base. Each unit section is provided with four mounting bases. The mounting bases are divided into two groups and fixedly installed on the transverse plates respectively. The mounting bases on the transverse plates are symmetrically distributed on the left and right and located at the corners above the corresponding transverse plates. Each mounting base has a longitudinal sliding seat that slides back and forth. The longitudinal sliding seat is controlled and locked by threaded fasteners. The limiting head is installed on the longitudinal shift seat. The limiting head limits the adjacent transverse and longitudinal plates within the unit section, and also limits the adjacent transverse and longitudinal plates within the adjacent unit section above the unit section. Positioning heads are respectively installed on the longitudinal plates in the unit section and on the longitudinal plates of the adjacent unit sections, and the positioning heads on the longitudinal plates are symmetrically distributed. The positioning seats are set one-to-one with the positioning heads and are fixedly installed on the corresponding longitudinal sliding seats; In the initial state, the positioning seat is in a positioning state, and the longitudinal plate in the unit section is positioned based on the transverse plate of the unit section through the positioning head on it and the corresponding positioning seat limit engagement, and is in a limit connection with the transverse plate; during the demolding process, the longitudinal moving seat moves to separate the positioning head from the corresponding positioning seat; The positioning head is provided with an association seat, and the positioning seat is provided with an association head that matches the association seat. The association seat and the association head cooperate to limit and connect adjacent unit sections together. A docking unit is provided between the adjacent horizontal plates and the vertical plates.

2. The standardized formwork for bridge piers without supports according to claim 1, characterized in that: The limiting head includes several wedge-shaped units, each corresponding to an adjacent transverse plate and a longitudinal plate within a unit section, as well as an adjacent transverse plate and a longitudinal plate within an adjacent unit section above the unit section. Each wedge-shaped unit includes two wedge-shaped areas that are perpendicularly distributed to each other. Wedge-shaped portions are fixedly provided on the corresponding transverse plates and longitudinal plates, with each wedge portion corresponding to a wedge-shaped area.

3. The standardized formwork for bridge piers without supports according to claim 1, characterized in that: The positioning head is a connecting block with a limiting groove, and the corresponding positioning seat cooperates with the limiting groove to limit the longitudinal plate at least in the lateral direction.

4. The standardized formwork for bridge piers without supports according to claim 1, characterized in that: The docking unit includes a slotted docking seat with an opening and a mating head that matches the slotted docking seat. The mating head cooperates with the slotted docking seat to limit the movement of adjacent horizontal plates and adjacent vertical plates. The mating head is installed on the upper horizontal plate and vertical plate respectively. The horizontal plate and vertical plate can move in the horizontal direction to allow the mating head to move out of the opening and separate from the corresponding slotted docking seat.

5. The standardized formwork for bridge piers without supports according to claim 4, characterized in that: The connector engages with the corresponding grooved mating seat in a wedge shape.

6. The standardized formwork for bridge piers without supports according to claim 1, characterized in that: The connecting head is a conical block, and the connecting seat is a conical groove that mates with the corresponding connecting head.

7. A method for constructing a standardized formwork for bridge piers without supports, used for assembling the standardized formwork for bridge piers without supports as described in claim 1, characterized in that: Includes the following steps: S1: The first unit section is spliced. First, the transverse plate is installed and fixed to the preset position outside the steel reinforcement cage of the pier. Then, the longitudinal plate is installed, and the initial splicing with the transverse plate is achieved through the cooperation of the corresponding positioning seat and positioning head. After the position of the longitudinal plate is corrected, the transverse plate and the longitudinal plate are reinforced. S2: Based on S1, splice the first subsequent unit section. First, place the transverse plate in the new unit section with the corresponding transverse plate in the spliced ​​unit section. Then, install the longitudinal plate in the new unit section. A preliminary connection is achieved through the cooperation of the corresponding positioning seat and positioning head. Move the longitudinal moving seat so that the limiting head simultaneously limits the adjacent transverse and longitudinal plates in the installed unit section as well as the corresponding adjacent transverse and longitudinal plates in the new unit section. After correcting the position of the longitudinal and transverse plates, reinforce them. S3: Repeat step S2 until all unit sections of the pier formwork are spliced ​​on the outside of the pier reinforcement cage; S4: Concrete pouring and shaping operation is carried out inside the pier formwork of S3; S5: Curing operations for cast concrete; S6: After the curing is completed, remove all the unit sections of the pier formwork from top to bottom.

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