A device for preventing formwork deformation of extruded prestressed pier and its design method

Abstract

The present invention relates to the technical field of pier body formwork fixing, and provides an extruded prestressed pier body formwork deformation prevention device and a design method thereof, comprising a prestressed beam and a connector corresponding to the side wall of the pier body formwork, wherein two adjacent prestressed beams are detachably fixedly connected via the connector; the prestressed beam is in an arc-shaped structure, and both ends of the prestressed beam extend in a direction away from the outer wall of the pier body formwork; a pressure plate is provided on one side of the prestressed beam close to the outer wall of the pier body formwork, and the prestressed beam abuts against the outer wall of the pier body formwork via the pressure plate. The present invention connects and fixes two adjacent prestressed beams via a connector, and under the cooperation of the prestressed beam in an arc-shaped structure and the connector, a stable prestress can be provided for the pier body formwork to offset the lateral pressure applied to the pier body formwork by concrete when pouring concrete, thereby preventing the pier body formwork from deforming during pouring and causing concrete slurry to leak out.

Description

Technical Field

[0001] The invention relates to the technical field of pier body formwork fixing, and in particular to a device for preventing an extruded prestressed pier body formwork from being deformed and a design method thereof. Background Art

[0002] A bridge pier is a substructure that supports the bridge span structure and transfers dead loads and vehicle live loads to the foundation, usually consisting of a top cap and a pier body.

[0003] The existing pier body is often poured from bottom to top in sections, and the shape of the pier body is often limited by the pier body formwork when pouring each section of the pier body. In the existing construction method, after the pier body formwork is installed, the pier body formwork is often further reinforced by installing wooden boards on the outer wall of the pier body formwork. However, in the actual concrete pouring process, in order to speed up the construction progress, after the pouring of the lower section of the pier body is completed and before the concrete is completely solidified, the pier body formwork of the upper section will be installed on the basis of the pier body formwork of the pier body section without removing it, and then the concrete will be poured. However, since the pier body formworks of two adjacent sections of the pier body are often installed independently, and the concrete will exert a large lateral pressure on the pier body formwork when pouring concrete, it is very likely that the pier body formwork will be deformed. Once the pier body formwork is deformed, a large gap will appear between the two adjacent pier body formworks, so that the concrete slurry will leak out from the gap, affecting the construction quality and construction period. Summary of the invention

[0004] The first object of the present invention is to provide an extruded prestressed pier body formwork deformation prevention device, which can apply a prestress to the pier body formwork to offset the lateral pressure applied to the pier body formwork by using prestressed beams and their connecting parts corresponding to the side walls of the pier body formwork.

[0005] The second object of the present invention is to provide a design method for an extruded prestressed pier body anti-formwork deformation device, wherein the designed prestressed beam can effectively apply a prestress to the pier body formwork to offset the lateral pressure applied by concrete to the pier body formwork.

[0006] The embodiments of the present invention are implemented by the following technical solutions:

[0007] On the one hand, the present invention provides an extruded prestressed pier body template deformation prevention device, comprising a prestressed beam corresponding to the side wall of the pier body template and a connecting piece, two adjacent prestressed beams are detachably fixedly connected by the connecting piece; the prestressed beam is an arc-shaped structure, and both ends of the prestressed beam extend in a direction away from the outer wall of the pier body template;

[0008] A pressure plate is provided on one side of the prestressed beam close to the outer wall of the pier body formwork, and the prestressed beam abuts against the outer wall of the pier body formwork through the pressure plate.

[0009] Optionally, the connecting member includes a wire pull rod, and connecting holes are provided on both sides of the prestressed beam. The wire pull rod sequentially passes through the connecting holes opened at adjacent ends of two adjacent prestressed beams.

[0010] Furthermore, the connecting member also includes a limit plate and a limit nut corresponding to the connecting holes one by one. The limit plate is arranged on the side of the prestressed beam away from the pier body formwork. The wire pull rod passes through the limit plate and then passes through the connecting hole. The outer side of the limit plate is fixed by the limit nut, and the wire pull rod is threadedly connected to the limit nut.

[0011] Furthermore, the limiting plate includes a first panel, a second panel and a reinforcing plate, the second panel is vertically arranged on one side of the first panel, the number of the reinforcing plates is two, the two reinforcing plates are relatively arranged between the first panel and the second panel, the first panel is provided with a through hole for the wire pull rod to pass through, and the through hole is located between the two reinforcing plates.

[0012] Optionally, the prestressed beam comprises a first flange plate, a second flange plate and a web plate, the first flange plate and the second flange plate are arranged opposite to each other, the web plate is arranged between the first flange plate and the second flange plate, and the first flange plate and the second flange plate are connected via the web plate;

[0013] The number of the webs is two, and the two webs are arranged opposite to each other.

[0014] On the other hand, the present invention provides a design method for the above-mentioned extruded prestressed pier body anti-formwork deformation device, the design process comprising:

[0015] a. Calculate the lateral pressure F applied by the newly poured concrete to the pier formwork;

[0016] b. Calculate the linear load Q applied to the prestressed beam by the newly poured concrete according to the lateral pressure F. The linear load Q is calculated using the following formula:

[0017] Q = FLμ;

[0018] Wherein, L is the distance from the bottom end reinforcement beam of the newly poured concrete to the prestressed beam, and μ is the load correction coefficient;

[0019] c. Establish a coordinate system with the axis of the wire drawing rod and the axis of the prestressed beam as the coordinate origin; wherein, the distance from the end face of the prestressed beam close to the coordinate origin to the coordinate origin is set as U1, the distance from the coordinate origin to the end face of the pressure plate close to the coordinate origin is set as U2, and half of the length of the pressure plate is set as U3; at the same time, U1, U2 and U3 correspond to the horizontal coordinates in the coordinate system;

[0020] d. Calculate the stress σ of the prestressed beam, the prestress S formed by the wire tie rod and the linear shape Y of the prestressed beam according to the line load Q;

[0021] Optionally, the stress σ of the prestressed beam is calculated using the following formula:

[0022]

[0023] Wherein, w is the bending modulus of the prestressed beam.

[0024] Optionally, the prestress S formed by the wire pull rod is calculated using the following formula:

[0025] S=1.414QU3.

[0026] Optionally, the line shape Y of the prestressed beam is calculated using the following formula:

[0027] in,

[0028] U1 segment line type:

[0029] U2 segment line type:

[0030] U3 segment line type:

[0031] Wherein, E is the elastic modulus of the prestressed beam, and I is the section modulus of the prestressed beam.

[0032] Optionally, the design process further includes calculating the strength P of the newly poured concrete according to the prestress S formed by the wire tie rod; the specific calculation formula is as follows:

[0033]

[0034] Wherein, a is the length of the short side of the pier body formwork, t1 is the thickness of the end rib of the pier body formwork, and t2 is the thickness of the panel of the pier body formwork.

[0035] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0036] The present invention has a reasonable design and a simple structure. Two adjacent prestressed beams are connected and fixed by a connecting piece. Under the cooperation of the prestressed beam with an arc structure and the connecting piece, a stable prestress can be provided for the pier body formwork to offset the lateral pressure applied to the pier body formwork by the concrete when pouring concrete, thereby preventing the pier body formwork from being deformed during pouring and causing leakage of concrete slurry. The quality of the pier body pouring construction is ensured while avoiding delays in the construction period. There is no need to manually clean up the leaked concrete slurry at a later stage, thereby reducing labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A schematic diagram of the structure of a device for preventing formwork deformation of an extruded prestressed pier body provided in an embodiment of the present invention;

[0039] Figure 2 A side view of a prestressed beam provided in Example 1 of the present invention;

[0040] Figure 3 A front view of a limit plate provided in Example 1 of the present invention;

[0041] Figure 4 A side view of the limiting plate provided in Example 1 of the present invention;

[0042] Figure 5 A schematic diagram of the structure of the device for preventing the deformation of the formwork of the extruded prestressed pier body provided in Example 1 of the present invention when in use;

[0043] Figure 6 A geometric relationship diagram of the device for preventing the formwork from being deformed by an extruded prestressed pier body provided in Example 2 of the present invention;

[0044] Figure 7 A schematic diagram of the structure for establishing a coordinate system on a prestressed beam provided in Example 2 of the present invention.

[0045] Icons: 1- pier body formwork, 2- prestressed beam, 201- first flange plate, 202- second flange plate, 203- web plate, 204- connecting hole, 3- pressure plate, 4- wire pull rod, 5- limit plate, 501- first panel, 502- second panel, 503- reinforcement plate, 504- through hole, 6- limit nut. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0050] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] Example 1

[0052] Please refer to Figures 1 to 4 The existing pier body formwork 1 is a frame with a rectangular symmetrical structure, wherein each side of the rectangular frame includes a straight line segment and an arc segment. In order to fix this type of pier body formwork 1, the present embodiment provides an extruded prestressed pier body formwork deformation prevention device, including a prestressed beam 2 corresponding to the side wall of the pier body formwork 1 and a connecting piece, at least one side of the prestressed beam 2 abuts against the outer wall of the pier body formwork 1, and two adjacent prestressed beams 2 are detachably fixedly connected by a connecting piece; the prestressed beam 2 is an arc-shaped structure, and both ends of the prestressed beam 2 extend in a direction away from the outer wall of the pier body formwork 1.

[0053] At the same time, a pressing plate 3 is provided on the side of the prestressed beam 2 close to the outer wall of the pier body formwork 1, and the prestressed beam 2 is in contact with the outer wall of the pier body formwork 1 through the pressing plate 3. The pressing plate 3 is provided to achieve a more uniform distribution of the prestress applied by the prestressed beam 2 to the pier body formwork 1. It should be noted that the pressing plate 3 of this embodiment can be, but is not limited to, a nylon plate made of polyamide-6 material with a thickness of 1 cm; at the same time, the length of the pressing plate 3 of this embodiment is equal to the length of the straight line segment of each side of the pier body formwork 1.

[0054] In this embodiment, the inner side surface of the prestressed beam 2 is abutted against the outer wall of the pier body formwork 1 through the pressure plate 3. Through the cooperation of the prestressed beam 2 and the connecting piece, and the use of an arc-shaped prestressed beam 2, when the connecting piece tightens the prestressed beam 2, it can provide a stable prestress for the pier body formwork 1 to offset the lateral pressure applied to the pier body formwork 1 by the concrete when pouring concrete, thereby preventing the pier body formwork 1 from deforming during pouring and causing leakage of concrete slurry, thereby ensuring the quality of the pier body pouring construction and avoiding delays in the construction period, and eliminating the need for manual cleaning of the leaked concrete slurry at a later stage, thereby reducing labor costs.

[0055] In this embodiment, the connecting member includes a wire tie rod 4, and connection holes 204 are provided on both sides of the prestressed beam 2. The wire tie rod 4 passes through the connection holes 204 opened at the adjacent ends of two adjacent prestressed beams 2 in sequence, and the two adjacent prestressed beams 2 are fixedly connected by the wire tie rod 4. It should be noted that in actual implementation, the angle between the axis of the wire tie rod 4 and the horizontal line is 45°, so that the prestress formed by the wire tie rod 4 can be better applied to the prestressed beam 2.

[0056] At the same time, the connecting piece also includes a limit plate 5 and a limit nut 6 corresponding to the connection holes 204. The limit plate 5 is arranged on the side of the prestressed beam 2 away from the pier body formwork 1. The wire tie rod 4 passes through the limit plate 5 and then passes through the connection hole 204. The outer side of the limit plate 5 is fixed by the limit nut 6. The wire tie rod 4 and the limit nut 6 are threadedly connected. After the prestressed beam 2 is set at the predetermined position of the pier body formwork 1, the wire tie rod 4 is respectively passed through the connection holes 204 at the adjacent ends of two adjacent prestressed beams 2, and the limit plate 5 is sleeved on the wire tie rod 4. By continuously twisting the limit nut 6, the fixation of the two adjacent prestressed beams 2 is achieved; at the same time, the prestressed beam 2 is tightened by the wire tie rod 4 and the limit plate 5, which can provide a prestress for the prestressed beam 2, so as to realize the use of the prestressed beam 2 to apply prestress to the pier body formwork 1, so as to use the prestress to offset the lateral pressure applied to the pier body formwork 1 by the concrete, and prevent the pier body formwork 1 from deforming during the pouring process. At the same time, considering that the extruded prestressed pier body formwork deformation prevention device needs to be reused during the pier body casting process, the use of a limit nut 6 to fix the prestressed beam 2 also facilitates the disassembly of the extruded prestressed pier body formwork deformation prevention device after a certain section of the pier body is cast, so as to be used for the casting of the next section of the pier body.

[0057] In order to improve the structural strength of the limit plate 5, the limit plate 5 includes a first panel 501, a second panel 502 and a reinforcing plate 503. The second panel 502 is vertically arranged on one side of the first panel 501. There are two reinforcing plates 503. The two reinforcing plates 503 are relatively arranged between the first panel 501 and the second panel 502. The first panel 501 is provided with a through hole 504 for the wire rod 4 to pass through. The through hole 504 is located between the two reinforcing plates 503. The first panel 501, the second panel 502 and the reinforcing plate 503 form a reinforcing structure similar to a triangle to prevent the limit nut 6 from loosening when pouring concrete, so as to ensure that the prestressed beam 2 can continuously apply a stable prestress to the pier body formwork 1.

[0058] In this embodiment, in order to improve the structural strength of the prestressed beam 2, the prestressed beam 2 includes a first flange plate 201, a second flange plate 202 and a web plate 203. The first flange plate 201 and the second flange plate 202 are arranged opposite to each other, and the web plate 203 is arranged between the first flange plate 201 and the second flange plate 202. The first flange plate 201 and the second flange plate 202 are connected by the web plate 203. By arranging the first flange plate 201, the second flange plate 202 and the web plate 203, the prestressed beam 2 is in an "I" shape as a whole, ensuring that the prestressed beam 2 has sufficient strength to cope with the stress generated during concrete pouring. At the same time, the number of webs 203 in this embodiment is two, and the two webs 203 are arranged relative to each other to improve the structural strength of the prestressed beam 2, and the connecting hole 204 for the wire tie rod 4 to pass through is arranged between the two webs 203, and the connecting hole 204 passes through the first flange plate 201 and the second flange plate 202 respectively, ensuring that the prestress generated by the wire tie rod 4 can be effectively transferred to the prestressed beam 2, thereby forming prestress through the prestressed beam 2 to be applied to the pier body formwork 1.

[0059] It should be noted that when the extruded prestressed pier body anti-formwork deformation device is actually used to fix the pier body formwork 1, the extruded prestressed pier body anti-formwork deformation device can be selectively used only between the pier body formwork 1 of the upper and lower adjacent pier body casting sections. Figure 5 Specifically, when the pouring of the lower pier body casting section is completed and the pier body formwork 1 of the upper pier body casting section is installed, the prestressed beam 2 in the extruded prestressed pier body anti-formwork deformation device is set at the connecting position between two adjacent pier body formworks 1, and the upper half of the prestressed beam 2 is used to abut against the end rib of the pier body formwork 1 of the upper pier body casting section, and the lower half of the prestressed beam 2 is used to abut against the end rib of the pier body formwork 1 of the lower pier body casting section. When the position of the prestressed beam 2 is determined, the prestressed beam 2 is fixed by the wire pull rod 4, the limit plate 5 and the limit nut 6, so that a prestress is applied to the pier body formworks 1 of the upper and lower pier body casting sections through the prestressed beam 2 to offset the lateral pressure applied to the pier body formwork 1 by the concrete, effectively preventing deformation at the connecting position between two adjacent pier body formworks 1 and avoiding leakage of concrete slurry.

[0060] Example 2

[0061] Based on Example 1, this embodiment provides a design method for the device for preventing the deformation of the formwork of the extruded prestressed pier body as described in Example 1, which mainly includes a design method for the prestressed beam 2, and the design process includes:

[0062] a. Calculate the lateral pressure F exerted by the newly poured concrete on the pier formwork 1;

[0063] The side pressure F can be calculated using a calculation formula in the prior art, and specific reference may be made to Formula 1 and Formula 2.

[0064] Formula 1: Among them, γ c is the gravity density of concrete, t0 is the initial setting time of newly poured concrete, β1 is the correction coefficient for the influence of admixture (when no admixture is added, it is 1.0), β2 is the correction coefficient for the influence of concrete slump (when the slump is less than 30 mm, it is 0.85; when the slump is 50-90 mm, it is 1.0; when the slump is 110-150, it is 1.15);

[0065] Formula 2: F = γ c H; where γ c is the gravity density of concrete, and H is the total height from the calculation position of concrete lateral pressure to the top surface of the newly poured concrete.

[0066] b. Based on the calculated lateral pressure F, the linear load Q applied by the newly poured concrete to the prestressed beam 2 is calculated according to the lateral pressure F. The linear load Q is calculated using the following formula:

[0067] Q = FLμ;

[0068] Wherein, L is the distance from the bottom reinforcement beam of the newly poured concrete to the prestressed beam 2, and μ is the load correction factor; it should be noted that when the distance from the bottom reinforcement beam of the newly poured concrete to the prestressed beam 2 is less than 0.8m, L is taken as 0.8; at the same time, please refer to Figure 6 The pier body formwork 1 described in this embodiment is a rectangular structure. It is assumed that the short side length of the pier body formwork 1 is a, the long side length is b, and a and b are the distances between the intersection points of the axes of the wire tie rods 4 on both sides of the prestressed beam 2 and the axes of the prestressed beam 2 respectively; when calculating the linear load Q of the prestressed beam 2 corresponding to the short side, μ=b / a; and when calculating the linear load Q of the prestressed beam 2 corresponding to the long side, μ=1.0.

[0069] c.Please refer to Figure 7 , establish a coordinate system with the axis of the wire tie rod 4 and the axis of the prestressed beam 2 as the coordinate origin; wherein, the distance from the end face of the prestressed beam 2 close to the coordinate origin to the coordinate origin is set as U1, the distance from the coordinate origin to the end face of the pressure plate 3 close to the coordinate origin is set as U2, and half of the length of the pressure plate 3 is set as U3; at the same time, U1, U2 and U3 correspond to the horizontal coordinates in the coordinate system.

[0070] d. Calculate the stress σ of the prestressed beam 2, the prestress S formed by the wire tie rod 4, and the linear shape Y of the prestressed beam 2 based on the linear load Q.

[0071] The stress σ of the prestressed beam 2 is calculated using the following formula:

[0072]

[0073] Wherein, w is the bending modulus of the prestressed beam 2. In actual calculation, the corresponding bending modulus can be directly queried based on existing data.

[0074] The prestress S formed by the wire tie rod 4 is calculated using the following formula:

[0075] S=1.414QU3; the prestress is the prestress applied by the wire tie rod 4 to the prestressed beam 2, and finally applied to the pier body formwork 1 through the prestressed beam 2.

[0076] The linear shape Y of prestressed beam 2 is calculated using the following formula:

[0077] in,

[0078] U1 segment line type:

[0079] U2 segment line type:

[0080] U3 segment line type:

[0081] Wherein, E is the elastic modulus of the prestressed beam 2, and I is the section modulus of the prestressed beam 2.

[0082] It should be noted that, based on the fact that the prestressed beam 2 is a bilaterally symmetrical structure, the line shape obtained by the calculation formula of the line shape Y of the prestressed beam 2 is only half of the line shape of the prestressed beam 2. After obtaining the line shape of half of the prestressed beam 2, only mirror symmetry is required to obtain the line shape of the entire prestressed beam 2.

[0083] For the calculation formula of the above-mentioned line type Y, the value of χ is selected as needed in the actual calculation. When χ falls within the numerical range of the U1 segment, χ is substituted into the formula Y1 for calculation to obtain the corresponding ordinate value; similarly, when χ falls within the numerical range of the U2 segment, χ is substituted into the formula Y2 for calculation to obtain the corresponding ordinate value; when χ falls within the numerical range of the U2 segment, χ is substituted into the formula Y2 for calculation to obtain the corresponding ordinate value. Repeat the above operation until enough points are calculated to form a smooth curve, which is the linear curve of half of the prestressed beam 2.

[0084] By calculating various parameters of the prestressed beam 2 as described above, a prestressed beam 2 that meets the requirements can be designed.

[0085] In addition, the design process also includes calculating the strength P of the newly poured concrete based on the prestress S formed by the wire tie rod 4; the specific calculation formula is as follows:

[0086]

[0087] Wherein, a is the length of the short side of the pier body formwork 1, t1 is the thickness of the end rib of the pier body formwork 1, and t2 is the thickness of the panel of the pier body formwork 1. The values ​​of t1 and t2 are obtained according to actual measurements.

[0088] By calculating the strength P of concrete and pouring according to the strength P during actual pouring, it can be further ensured that the pier body formwork 1 will not be deformed.

[0089] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A design method for a device for preventing a prestressed pier body from being deformed by a prestressed pier body, the device comprising a prestressed beam and a connecting piece corresponding to the side wall of the pier body formwork, wherein two adjacent prestressed beams are detachably fixedly connected by the connecting piece; the prestressed beam is an arc-shaped structure, and both ends of the prestressed beam extend in a direction away from the outer wall of the pier body formwork; A pressing plate is provided on one side of the prestressed beam close to the outer wall of the pier body formwork, and the prestressed beam abuts against the outer wall of the pier body formwork through the pressing plate; The connecting member comprises a wire rod, and both sides of the prestressed beam are provided with connecting holes, and the wire rod sequentially passes through the connecting holes opened at the adjacent ends of two adjacent prestressed beams; It is characterized in that Design methods include: a. Calculate the lateral pressure F applied by the newly poured concrete to the pier formwork; b. Calculate the linear load Q applied to the prestressed beam by the newly poured concrete according to the lateral pressure F. The linear load Q is calculated using the following formula: Q = FLμ; Wherein, L is the distance from the bottom end reinforcement beam of the newly poured concrete to the prestressed beam, and μ is the load correction coefficient; c. Establish a coordinate system with the axis of the wire rod and the axis of the prestressed beam as the coordinate origin; wherein, the distance from the end face of the prestressed beam close to the coordinate origin to the coordinate origin is set as U1, the distance from the coordinate origin to the end face of the pressure plate close to the coordinate origin is set as U2, and half of the length of the pressure plate is set as U3; at the same time, U1, U2 and U3 correspond to the horizontal coordinates in the coordinate system; d. Calculate the stress σ of the prestressed beam, the prestress S formed by the wire tie rod and the linear shape Y of the prestressed beam according to the line load Q; The stress σ of the prestressed beam is calculated using the following formula: ; in, is the bending modulus of the prestressed beam; The prestress S formed by the wire pull rod is calculated using the following formula: ； The linear shape Y of the prestressed beam is calculated using the following formula: in, U1 segment line type: ; U2 segment line type: ; U3 segment line type: ; Wherein, E is the elastic modulus of the prestressed beam, and I is the section modulus of the prestressed beam; 2. The design method of the device for preventing the formwork from deforming when extruding a prestressed pier according to claim 1 is characterized in that: The connecting member also includes a limit plate and a limit nut corresponding to the connecting holes one by one. The limit plate is arranged on the side of the prestressed beam away from the pier body formwork. The wire pull rod passes through the limit plate and then passes through the connecting hole. The outer side of the limit plate is fixed by the limit nut, and the wire pull rod is threadedly connected to the limit nut.

3. The design method of the device for preventing the formwork from deforming when extruding a prestressed pier according to claim 2 is characterized in that: The limiting plate includes a first panel, a second panel and a reinforcing plate. The second panel is vertically arranged on one side of the first panel. There are two reinforcing plates. The two reinforcing plates are relatively arranged between the first panel and the second panel. The first panel is provided with a through hole for the wire pull rod to pass through, and the through hole is located between the two reinforcing plates.

4. The design method of the device for preventing the formwork from deforming when extruding a prestressed pier according to claim 1 is characterized in that: The prestressed beam comprises a first flange plate, a second flange plate and a web plate, the first flange plate and the second flange plate are arranged opposite to each other, the web plate is arranged between the first flange plate and the second flange plate, and the first flange plate and the second flange plate are connected by the web plate; The number of the webs is two, and the two webs are arranged opposite to each other.

5. The design method of the device for preventing the formwork from deforming when extruding a prestressed pier according to claim 1 is characterized in that: The design process also includes calculating the strength P of the newly poured concrete based on the prestress S formed by the wire tie rod; the specific calculation formula is as follows: ； Wherein, a is the length of the short side of the pier body formwork, t1 is the thickness of the end rib of the pier body formwork, and t2 is the thickness of the panel of the pier body formwork.

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