Prefabricating method and forming method of multifunctional beam

Abstract

The invention relates to the technical field of sea-crossing bridge construction, in particular to a prefabricating method and a forming method of a multifunctional beam, and the prefabricating method of the multifunctional beam comprises the following steps: S1, constructing a pedestal with pre-camber; s2, a multifunctional beam bottom die and reinforcing steel bars are constructed; s3, multifunctional beam prestressed pipelines are installed; S4, multifunctional beam end formworks and side formworks are installed, and concrete is poured; s5, pre-stress engineering is conducted according to the preset tensioning sequence; and S6, multifunctional beam prefabrication is completed. The prefabrication method of the multifunctional beam comprises the steps that differentiated upward pre-camber is set for a pedestal A, a pedestal B and a pedestal C, and the geometric accuracy of a formed beam block is ensured; the uncontrollable transverse bending generated in the tensioning process of the C block is effectively inhibited by finely arranging all the prestressed pipelines and matching with a specific tensioning sequence.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cross-sea bridge construction, and particularly relates to a prefabrication method and a forming method of a multifunctional beam. BACKGROUND

[0002] A special multifunctional beam (as shown in Figure 1 , Figure 2 ) has appeared in the market at present, which is applied to the erection of a cross-sea bridge, and its unique design integrates a pedestrian area (cantilever), a pipe gallery area and a green area, which not only simplifies the on-site construction process, but also reduces the pollution risk to the marine environment, and realizes the unification of functionality and aesthetics.

[0003] In the construction of the multifunctional beam, since it is a special-shaped beam and has a large self-weight (usually more than 400 tons), the traditional on-site integral pouring method is difficult to realize. Therefore, in actual construction, the multifunctional beam usually needs to be prefabricated in blocks in a beam manufacturing yard, and then transported to the construction site for assembly. The existing block division method is shown in Figure 1 , Figure 2 , which usually divides it into three blocks A, B and C, wherein the cross-sectional shapes of blocks A and B are similar to conventional “I” type beam blocks, and block C (as shown in Figure 3 , Figure 4 ) is a special-shaped block with an ultra-wide bottom plate and an ultra-heavy self-weight, and the width of the bottom plate is usually 4500mm to 5000mm, and the weight of a single block is usually more than 170 tons.

[0004] At present, when the traditional regular beam type is tensioned, the prestressed pipe (steel strand) is arranged symmetrically (for example, taking the vertical center line of the beam cross section, or the geometric center line of the cross section as the axis of symmetry). During tensioning, synchronous tensioning or symmetric batch tensioning at both ends is usually required to ensure uniform stress on the beam body, so that the lateral bending of the beam body after stress is controllable.

[0005] However, the C block of the multifunctional beam is an asymmetric special-shaped structure, and its geometric center of gravity deviates seriously from the center line of the beam body. If the traditional prestressed tensioning method is used, due to the asymmetry of the cross section of the C block, the action line of the combined force of the prestressed tendon is difficult to coincide with the structural stiffness center of the C block, which causes uncontrollable lateral bending of the beam body during tensioning, and even causes cracking or structural damage of the beam body during tensioning. SUMMARY

[0006] The present application aims to overcome the deficiency that the existing beam prestressed tensioning method is not suitable for the multifunctional beam and is prone to cause uncontrollable lateral bending of the C block after stress, and to provide a prefabrication method and a forming method of a multifunctional beam.

[0007] In a first aspect, the present application provides a prefabrication method of a multifunctional beam, comprising the following steps: S1: Constructing the pedestals of blocks A, B and C, each of which is provided with an upward pre-camber arranged in a quadratic parabola from the midspan to the beam end, the pre-camber being symmetrically arranged with the longitudinal center line of the beam, with the maximum pre-camber value in the middle; the maximum pre-camber value of the pedestal of block A is not more than 32 mm, the maximum pre-camber value of the pedestal of block B is not more than 38 mm, and the maximum pre-camber value of the pedestal of block C is not more than 40 mm; S2: Constructing the bottom form of the multifunctional beam, installing the steel bars of the multifunctional beam, and spacing the cantilever beams of block C along the length direction of block C; S3: Installing the prestressed ducts of the multifunctional beam: Two first prestressed teeth are arranged on the side of the web of block A facing block B, the first prestressed teeth are arranged on the upper part of both ends of the web of block A and symmetrically arranged with the longitudinal center line of the beam, and the ninth duct is arranged through the two first prestressed teeth; From bottom to top, the web of block A is arranged with the first duct, the second duct, the third duct, the fourth duct, the fifth duct and the sixth duct; the bottom plate of block A is arranged with the seventh duct and the eighth duct, and the seventh duct and the eighth duct are symmetrically arranged with the center line of the web of block A; Two second prestressed teeth are arranged on the side of the web of block B facing block A, the second prestressed teeth are arranged on the upper part of both ends of the web of block B and symmetrically arranged with the longitudinal center line of the beam, and the eighteenth duct is arranged through the two second prestressed teeth; From bottom to top, the web of block B is arranged with the tenth duct, the eleventh duct, the twelfth duct, the thirteenth duct, the fourteenth duct and the fifteenth duct; the bottom plate of block B is arranged with the sixteenth duct and the seventeenth duct, and the sixteenth duct and the seventeenth duct are symmetrically arranged with the center line of the web of block B; The top of the web of block C is provided with a first prestressed groove, a second prestressed groove and a third prestressed groove, the first prestressed groove, the second prestressed groove and the third prestressed groove are mirror arranged with the longitudinal center line of the beam, the twenty-ninth duct is arranged through the first prestressed groove, the thirtieth duct is arranged through the second prestressed groove, and the thirty-first duct is arranged through the third prestressed groove; From bottom to top, the web of block C is arranged with the nineteenth duct, the twentieth duct, the twenty-first duct, the twenty-second duct, the twenty-third duct and the twenty-fourth duct, and from the direction close to the web of block C to the direction away from the web of block C, the bottom plate of block C is arranged with the twenty-fifth duct, the twenty-sixth duct, the twenty-seventh duct and the twenty-eighth duct, and the cantilever beam of block C is not arranged with a prestressed duct; S4: Installing the end form and side form of the multifunctional beam, pouring the concrete of the multifunctional beam, and removing the formwork after the completion of the pouring of the concrete and carrying out the curing of the concrete; S5: Carrying out the prestressed engineering, including the following steps: S51: Forming the prestressed ducts; S52: Cutting and bundling; S53: Threaded bundle; S54: Tensioning prestressed tendons with positive bending moment: The tensioning sequence of block A is: first pipe → second pipe → third pipe → fourth pipe → fifth pipe → sixth pipe → seventh pipe → eighth pipe; The tensioning sequence for block B is as follows: pipe number 10 → pipe number 11 → pipe number 12 → pipe number 13 → pipe number 14 → pipe number 15 → pipe number 16 → pipe number 17; The tensioning sequence of block C is: pipe 19 → pipe 20 → pipe 21 → pipe 22 → pipe 23 → pipe 24 → pipe 25 → pipe 26 → pipe 27 → pipe 28; S55: Grouting of ducts; S56: Beam end sealing; S6: Complete the prefabrication of the multi-functional beam.

[0008] The prefabrication method for the multifunctional beam provided by this invention sets differentiated upward precamber for the three platforms A, B, and C (no more than 32mm for platform A, no more than 38mm for platform B, and no more than 40mm for platform C), all set according to a quadratic parabola. Due to the excessive self-weight of platform C, it is set with the largest precamber value (no more than 40mm). This precise differentiation can accurately offset the deflection of each beam block caused by its own weight, prestress, and subsequent loads, control the longitudinal alignment of the beam, ensure the geometric accuracy of the beam blocks after forming, and lay a good foundation for subsequent assembly.

[0009] The prestressed teeth and prestressed grooves on the upper part of the multi-functional beam are used to apply negative bending moments, while the various prestressed ducts at the lower part of the multi-functional beam are used to apply positive bending moments subsequently. By arranging each prestressed duct in a precise manner and coordinating with the specific tensioning sequence in S54, the resultant force line of the prestressing tendons can be precisely controlled, making it closer to the structural stiffness center of block C. This effectively suppresses the uncontrollable transverse bending generated by block C during tensioning, avoids cracking or structural damage to the beam during the tensioning stage, and ensures the structural safety and construction quality of the irregular beam block.

[0010] Above the cantilever beams of block C is a pedestrian area with relatively low load, and the cantilever beams are spaced apart. Prestressed ducts are not placed at the cantilever beams, which simplifies the prefabrication process, reduces construction costs, and improves work efficiency.

[0011] Preferably, the pre-camber value of the A-block pedestal satisfies: Y a =64×f×X a (L a -X a ) / L a 2 ; In the formula Y a is the pre-camber value of platform A; f is a control parameter, taken as 2.0; Xa A is the distance from the first end of the A block; L a is the length of the A block; The pre-camber value of the B block pedestal satisfies: Y b = 76 x f x X b (L b -X b ) / L b 2 ; In the formula, Y b is the pre-camber value of the B block pedestal; X b is the distance from the first end of the B block; L b is the length of the B block; The pre-camber value of the C block pedestal satisfies: Y c = 80 x f x X c (L c -X c ) / L c 2 ; In the formula, Y c is the pre-camber value of the C block pedestal; X c is the distance from the first end of the C block; L c is the length of the C block.

[0012] By fine design of the pre-camber of the A block, the B block and the C block pedestal, it is ensured that the pre-camber line shape is highly consistent with the deflection curve generated by the beam body under the action of uniform load (such as self weight and uniform prestress), so that the pre-camber setting can effectively offset the deflection generated by the beam body, and accurate linear control is realized.

[0013] Preferably, the distance between the first pipe and the second pipe is 800±50mm, the distance between the second pipe, the third pipe, the fourth pipe, the fifth pipe and the sixth pipe is 240±20mm; the distance between the seventh pipe and the eighth pipe and the center line of the A block web is 225±15mm, the seventh pipe and the eighth pipe are located in the same horizontal plane, and the vertical distance between the seventh pipe and the eighth pipe and the first pipe is 315±15mm.

[0014] The first duct and the second duct are spaced apart and located at the bottom region of the web, and jointly constitute a prestressed core of the bottom main tension zone. The larger spacing helps to move the action line of the prestressed resultant force downward, so as to be close to the bottom of the section, so as to maximize the prestressed eccentricity, thereby efficiently resisting the larger bending moment. The spacing of the second duct to the sixth duct is uniform and small, and these ducts are located in the middle and lower part of the web of the beam body, which is the key area of resisting shear and controlling web diagonal cracks. The uniform and dense arrangement ensures that the stress gradient of the prestress in the vertical direction of the web changes smoothly, effectively inhibiting the possible diagonal cracking. The seventh duct and the eighth duct are symmetrically arranged at the bottom of the A block with the center line of the web, ensuring that the prestress is uniformly distributed on the cross section of the beam body, effectively resisting the transverse bending stress that may be generated in the bottom plate.

[0015] Preferably, the tenth duct and the eleventh duct are spaced apart by 800±50mm, the spacing between the eleventh duct, the twelfth duct, the thirteenth duct, the fourteenth duct, and the fifteenth duct is 240±20mm; the distance between the sixteenth duct and the seventeenth duct from the center line of the web of the B block is 225±15mm, the sixteenth duct and the seventeenth duct are located on the same horizontal plane, and the vertical distance between the sixteenth duct and the seventeenth duct and the tenth duct is 315±15mm.

[0016] Since the cross-sectional shape of the B block is similar to that of the A block, the B block is arranged with prestressed pipes similar to the A block, which can improve the stability of the B block.

[0017] Preferably, the spacing between the nineteenth duct, the twentieth duct, the twenty-first duct, the twenty-second duct, the twenty-third duct, and the twenty-fourth duct is 240±20mm; The spacing between the twenty-fifth duct and the twenty-sixth duct is 640±20mm, and the spacing between the twenty-sixth duct, the twenty-seventh duct, and the twenty-eighth duct is 240±20mm; The twenty-fifth duct, the twenty-sixth duct, the twenty-seventh duct, and the twenty-eighth duct are located on the same horizontal plane, the horizontal distance between the twenty-fifth duct and the nineteenth duct is 300±10mm, and the vertical distance between the twenty-fifth duct and the nineteenth duct is 550±5mm.

[0018] The C block bottom plate is arranged with four ducts (25, 26, 27, 28 ducts) for applying positive bending moment. The four ducts are located on the same horizontal plane, which ensures that the prestressed force of the C block bottom plate has a stable eccentricity, and can efficiently resist the bending moment generated by the self-weight and the upper load of the structure.

[0019] The distance between the No. 25 and No. 26 pipes is large, and the distance between the No. 26, No. 27 and No. 28 pipes is small. The non-uniform transverse spacing design can adapt to the non-uniform stress distribution on the super-wide bottom plate of the C block and balance the eccentric load caused by the web. Through accurate positioning of the prestressed pipes of the C block, the deviation between the actual prestress resultant force action line and the theoretical design position is small, the effectiveness of the prestress application of the C block is ensured, and the reliability of the stress of the C block structure is ensured.

[0020] Preferably, in the same A block, the distance between the two first prestressed teeth blocks is 20600±50mm, and the distance between the edge of the first prestressed teeth block and the beam end is 5000±50mm. In the same B block, the distance between the two second prestressed teeth blocks is 20600±50mm, and the distance between the edge of the second prestressed teeth block and the beam end is 5000±50mm. The C block is sequentially provided with a first prestressed groove, a second prestressed groove and a third prestressed groove from the beam end to the longitudinal center line of the beam, and in the same C block, the distance between the two first prestressed grooves is 26000±100mm, the distance between the two second prestressed grooves is 21000±100mm, and the distance between the two third prestressed grooves is 16000±100mm.

[0021] Through accurate design of the positions of the prestressed teeth blocks and the prestressed grooves, it can be ensured that the negative bending moment prestressed tendons can be accurately arranged in the ninth pipe, the eighteenth pipe, the twenty-ninth pipe, the thirtieth pipe and the thirty-first pipe during subsequent on-site assembly of the multifunctional beam, so that the prestressed tendons can be accurately anchored and applied with negative bending moment at the predetermined positions, and the effectiveness of the prestress application is ensured.

[0022] Preferably, the angle between the anchoring end of the first prestressed teeth block and the web of the A block is 100°~110°, the angle between the anchoring end of the second prestressed teeth block and the web of the B block is 100°~110°, and the angle between the anchoring end of the first prestressed groove, the second prestressed groove and the third prestressed groove and the horizontal plane is 105°~115°.

[0023] Through accurate design of the angle of the anchoring end of the prestressed teeth block and the prestressed groove, it can be ensured that the anchoring end is flat during tensioning, and the friction loss of the steel strand in the hole is reduced.

[0024] Preferably, in S52, the prestressed steel strand adopts a steel strand with a standard tensile strength pkf=1860MPa and a nominal diameter d=15.2mm.

[0025] Preferably, the prestressed steel strand is a low-relaxation high-strength steel strand, which can more long-term maintain the crack resistance and structural stiffness of the beam body, and improve the long-term durability and safety of the multifunctional beam.

[0026] Preferably, in S55, when grouting the ducts, the bleeding rate of the grout is ≤3%, the bleeding rate is controlled at 2% after 3 hours of mixing, and the consistency of the grout is ≤25s.

[0027] By strictly controlling the bleeding rate, the "water pockets" or voids at the top of the duct can be effectively reduced, ensuring the density of the slurry and the durability of the structure. The consistency of the slurry is controlled at ≤25s, which can ensure that the slurry fills the entire pipe smoothly and avoids blockage or voids in long-distance pipes. It can also ensure that the slurry has sufficient strength and adhesion, thus enhancing the reliability of the prestressed system.

[0028] In a second aspect, the present invention provides a method for forming a multifunctional beam, used to form a multifunctional beam prefabricated by the above-mentioned method for forming a multifunctional beam, comprising the following steps: Hoist block C to its support at the beam to be erected, then hoist block B to its support at the beam to be erected. Install temporary scissor bracing between blocks B and C. Then hoist block A to its support at the beam to be erected, and install temporary scissor bracing between blocks A and B. After the bridge erecting machine has passed the span, pour the wet joint between blocks B and C, as well as the wet joint between blocks A and B.

[0029] The multi-functional beam forming method provided by this invention pre-connects three independent beam blocks (C, B, and A) using temporary scissor bracing. Before the wet joint is poured, the originally scattered and uncontrolled beam blocks form a relatively stable whole, providing a stable standing space for the bridge erecting machine's central support leg. When the lateral track of the bridge erecting machine's central support leg is laid out and sits on top of the multi-functional beam, the pre-connected multi-functional beam will not easily become unstable or displaced, thus greatly improving the stability and safety of the bridge erecting machine during operation. This effectively avoids safety hazards such as the bridge erecting machine overturning due to scattered beam blocks, achieving "beam erection first, joint pouring later." During construction, there is no need to wait for the wet joint to solidify; the wet joint of the next span is poured after the bridge erecting machine passes through the hole, without affecting the construction rhythm, greatly shortening the overall bridge construction period and improving construction efficiency.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a method for prefabricating a multifunctional beam, which sets differentiated upward precamber for three platforms A, B, and C, and all of them are set according to a quadratic parabola. This precise differentiation can accurately offset the deflection of each beam block caused by its own weight, prestress, and subsequent loads, control the longitudinal alignment of the beam body, ensure the geometric accuracy of the beam block after forming, and lay a good foundation for subsequent assembly. 2. This invention provides a method for prefabricating a multifunctional beam. The prestressed tooth blocks and prestressed grooves at the top of the multifunctional beam are used to apply negative bending moments, while the prestressed ducts at the bottom of the multifunctional beam are used to apply positive bending moments subsequently. By finely arranging the prestressed ducts and coordinating with the specific tensioning sequence in S54, the resultant force line of the prestressing tendons can be precisely controlled, making it closer to the structural stiffness center of block C. This effectively suppresses uncontrollable transverse bending generated by block C during tensioning, avoids cracking or structural damage to the beam during the tensioning stage, and ensures the structural safety and construction quality of the irregularly shaped beam blocks.

[0031] 3. This invention provides a method for forming a multi-functional beam. By temporarily using scissor bracing to pre-connect three independent beam blocks (C, B, and A), the previously scattered and uncontrolled beam blocks are formed into a relatively stable whole before the wet joint is poured. This provides a stable standing space for the middle support leg of the bridge erecting machine. When the lateral track of the middle support leg of the bridge erecting machine is laid out and sits on top of the multi-functional beam, the pre-connected multi-functional beam will not easily become unstable or displaced, thus greatly improving the stability and safety of the bridge erecting machine during operation. This effectively avoids safety hazards such as the bridge erecting machine overturning due to scattered beam blocks, achieving "beam erection first, joint pouring later." During construction, there is no need to wait for the wet joint to solidify; the wet joint of the next span is poured after the bridge erecting machine passes through the hole, without affecting the construction rhythm, greatly shortening the overall bridge construction period and improving construction efficiency. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a multi-functional beam structure; Figure 2 Top view of a multi-functional beam; Figure 3 This is a schematic diagram of the C-block structure; Figure 4 This is a top view of block C; Figure 5 The pre-arched curve of platform A; Figure 6 The pre-arched curve of the B block platform; Figure 7 The pre-arch curve of block C pedestal; Figure 8 Schematic diagram of prestressed duct layout in Block A Figure 1 ; Figure 9 Schematic diagram of prestressed duct layout in Block A Figure 2 ; Figure 10 Schematic diagram of prestressed duct layout in block B Figure 1 ; Figure 11 Schematic diagram of prestressed duct layout in block B Figure 2 ; Figure 12 Schematic diagram of prestressed duct layout in block C Figure 1 ; Figure 13 Schematic diagram of prestressed duct layout in block C Figure 2 ; Figure 14 for Figure 13 Enlarged diagram of section A in the middle; Figure 15 This is a schematic diagram showing the layout of the 29th, 30th, and 31st pipelines in the two adjacent blocks C along the longitudinal bridge. Figure 16 A schematic diagram showing the prestressed duct layout of two adjacent multi-functional beams in the longitudinal direction of the bridge. Figure 17 for Figure 16 Enlarged schematic diagram of section B in the middle; Figure 18 A schematic diagram showing the pre-connection status of blocks C, B, and A of the temporary scissor bracing.

[0033] Marked in the image: 1-First pipe, 2-Second pipe, 3-Third pipe, 4-Fourth pipe, 5-Fifth pipe, 6-Sixth pipe, 7-Seventh pipe, 8-Eighth pipe, 9-Ninth pipe, 10-Tenth pipe, 11-Eleventh pipe, 12-Twelfth pipe, 13-Thirteenth pipe, 14-Fourteenth pipe, 15-Fifteenth pipe, 16-Sixteenth pipe, 17-Seventeenth pipe, 18-Eighteenth pipe, 19-Nineteenth pipe, 20-Twentieth pipe, 21-Twenty-first pipe, 22-Twenty-second pipe Pipeline 23, Pipeline 24, Pipeline 25, Pipeline 25, Pipeline 26, Pipeline 27, Pipeline 27, Pipeline 28, Pipeline 29, Pipeline 29, Pipeline 30, Pipeline 30, Pipeline 31, Pipeline 31, Block C, Block C, Block D, Pipeline 101, Pipeline 102, Pipeline 2, Pipeline 103, Pipeline 3, Block D, Block B, Block D, Block D, Block E ... Detailed Implementation

[0034] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0035] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0036] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0037] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0038] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0039] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0040] Example 1 like Figure 1 , Figure 2 The structure of the multifunctional beam is shown. Due to its enormous size and weight, it can only be fabricated using a segmented prefabrication method during actual construction. Segment A (300mm), Segment B (200mm), and Segment C (100mm) are connected by wet joints cast on-site.

[0041] like Figure 3 , Figure 4 The specific structure of the aforementioned multifunctional beam C block 100 is shown, and the definition is as follows: Figure 3 The portion above the horizontal dashed line is defined as the web of block C100, the left side of the vertical dashed line is defined as the bottom plate of block C100, and the right side is defined as the cantilever beam of block C.

[0042] In the actual construction of the cross-sea bridge using this multi-functional beam, the middle part of the bridge consists of several T-beams, the top of which is covered with a motor vehicle lane slab. One of these multi-functional beams is erected on each side of the motor vehicle lane, and the pedestrian area of ​​the two multi-functional beams is located on the outermost side of the cross-sea bridge.

[0043] This embodiment provides a method for prefabricating multifunctional beams, used for prefabricating beams such as... Figures 1-4 The multifunctional beam shown includes the following steps: S1: Construct 300 piers in Block A, 200 piers in Block B, and 100 piers in Block C. Each pier has an upward pre-camber at the mid-span, set according to a quadratic parabola from the mid-span to the beam end. The pre-camber is symmetrically arranged with respect to the longitudinal (longitudinal) centerline of the beam, with the maximum pre-camber value in the middle.

[0044] Taking a multi-functional beam with a single beam length of 36.4m as an example, the maximum pre-camber value of its section A (300 piers) does not exceed 32mm, the maximum pre-camber value of section B (200 piers) does not exceed 38mm, and the maximum pre-camber value of section C (100 piers) does not exceed 40mm. The pre-camber values ​​of section A (300 piers) are shown in Table 1, and the pre-camber curve of section A (300 piers) is shown in... Figure 5 As shown in Table 2, the pre-camber values ​​for 200 piers in Block B are shown in Table 2, and the pre-camber curves for 200 piers in Block B are shown in Table 2. Figure 6 As shown in Table 3, the pre-camber values ​​for 100 pedestals in block C are shown in Table 3, and the pre-camber curve for 100 pedestals in block C is shown in Table 4. Figure 7 As shown.

[0045] Table 1 Design Table of Pre-arch Values ​​for Block A A Foundation

[0046] Table 2 Design Table of Pre-arch Values ​​for Block B Abutment

[0047] Table 3 Design Table of Pre-arch Values ​​for Block C Abutment

[0048] In this embodiment, the pre-camber value of block A with 300 pedestals satisfies: Y a =64×f×X a (L a -X a ) / L a 2 ; In the formula Y a is the pre-camber value for 300 pedestals in block A; f is a control parameter, taken as 2.0; X a L is the distance from the beginning of block A (300 units). a Block A is 300mm long. The pre-camber value of the 200mm pedestal in Block B satisfies: Y b =76×f×X b (L b -X b ) / L b 2 ; In the formula Y b is the pre-camber value for 200 pedestals in block B; f is a control parameter, taken as 2.0; X b L is the distance from the beginning of block B, which is 200 units away. b The length of block B is 200. The pre-camber value of the 100 pedestal in block C satisfies: Y c =80×f×X c (L c -X c ) / L c 2 ; In the formula Y c is the pre-camber value for 100 pedestals in block C; f is a control parameter, taken as 2.0; X c L is the distance from the beginning of block C (100 units). c Block C is 100 units long.

[0049] By meticulously designing the precamber of the A block (300), B block (200), and C block (100) pedestals, the precamber alignment is ensured to closely match the deflection curve of the beam under uniform loads (such as self-weight and uniform prestress). This allows the precamber setting to effectively counteract the deflection of the beam and achieve precise alignment control.

[0050] S2: For the construction of the multi-functional beam bottom formwork, clean the bottom formwork thoroughly, ensuring there is no concrete residue on the surface, and that the lines are smooth and the surface is flat. Apply release agent evenly to the bottom formwork, ensuring there is no oil accumulation contaminating the reinforcing bars. Install soft plastic pipes or rubber strips with a diameter of not less than 3cm on both sides of the bottom formwork where they contact the side formwork. The plastic pipes or rubber strips should be parallel to the top surface of the bottom formwork, with smooth joints to prevent grout leakage. Install the multi-functional beam reinforcing bars. Specifically, the 300mm reinforcing bars for block A and the 200mm reinforcing bars for block B are tied on a jig, and after tying, are lifted into the formwork using two gantry cranes. For block C (100mm), mark the positions and spacing of the main reinforcing bars on the bottom formwork according to the design requirements, and mark the position of each stirrup on the main reinforcing bars according to the designed stirrup spacing, then tie and install them one by one. Figure 4 As shown, in order to reduce the self-weight of the beam, the cantilever beams of block C100 are spaced apart along the length of block C100.

[0051] S3: Install prestressed ducts for multi-functional beams: such as Figure 1 , Figure 2 , Figure 8 , Figure 9 , Figure 16 , Figure 17 As shown, two first prestressed tooth blocks 301 are provided on the side of the web of block A 300 facing block B 200. The first prestressed tooth blocks 301 are located at both ends of the web of block A 300, and the first prestressed tooth blocks 301 are located on the upper part of the web of block A 300, and as shown... Figure 2 As shown, the two first prestressed teeth 301 are arranged symmetrically with respect to the longitudinal centerline of the beam, and the ninth pipe 9 passes through the two first prestressed teeth 301. The ninth pipe 9 is mainly used for the later installation of negative bending moment prestressing tendons. The ninth pipe 9 can be a metal corrugated pipe with an inner diameter of 95mm or 105mm.

[0052] like Figure 8 As shown, from bottom to top, pipes 1, 2, 3, 4, 5, and 6 are arranged on the web of block A 300. The distance H1 between pipes 1 and 2 is 800±50mm. The distance H2 between pipes 2, 3, 4, 5, and 6 is 240±20mm. Pipes 7 and 8 are arranged on the bottom plate of block A 300, symmetrically arranged about the center line of the web of block A 300. The distance H3 between pipes 7 and 8 and the center line of the web of block A 300 is 225±15mm. Pipes 7 and 8 are located on the same horizontal plane, and the vertical distance H4 between pipes 7 and 8 and pipe 1 is 315±15mm.

[0053] The first duct 1 and the second duct 2 are spaced relatively far apart and located at the bottom of the web, together forming the prestressing core of the bottom main tension zone. The larger spacing helps to shift the line of action of the prestressing resultant force downwards, bringing it closer to the bottom of the section, maximizing the prestressing eccentricity and thus effectively resisting large bending moments. The second duct 2 to the sixth duct 6 are spaced relatively evenly and are located in the lower middle part of the beam web, a key area for shear resistance and controlling diagonal cracks in the web. Their uniform and dense arrangement ensures a smooth change in the vertical stress gradient of the prestress in the web, effectively suppressing potential diagonal cracking. The seventh duct 7 and the eighth duct 8 are symmetrically arranged around the web centerline on the 300mm bottom plate of block A, ensuring uniform distribution of prestress across the beam cross-section and effectively resisting potential transverse bending stresses in the bottom plate. Figure 9 As shown, in the same block A 300, the distance L1 between the two first prestressed tooth blocks 301 is (for example, it can be as follows) Figure 9 The spacing between the anchoring ends is 20600±50mm, and the distance L2 between the edge of the first prestressed tooth block 301 and the beam end is 5000±50mm.

[0054] like Figure 1 , Figure 2 , Figure 10 , Figure 11 , Figure 16 , Figure 17 As shown, two second prestressed tooth blocks 201 are installed on the side of the web of block B 200 facing block A 300. The second prestressed tooth blocks 201 are located at both ends of the web of block B 200 and are located on the upper part of the web of block B 200. The two second prestressed tooth blocks 201 are symmetrically arranged with respect to the longitudinal centerline of the beam. The eighteenth duct 18 passes through the two second prestressed tooth blocks 201. The eighteenth duct 18 is mainly used for the later placement of negative moment prestressing tendons. The eighteenth duct 18 can be a metal corrugated pipe with an inner diameter of 95mm or 105mm. Figure 10 As shown, from bottom to top, the web of block B 200 has the following pipes arranged: the tenth pipe 10, the eleventh pipe 11, the twelfth pipe 12, the thirteenth pipe 13, the fourteenth pipe 14, and the fifteenth pipe 15. The distance H5 between the tenth pipe 10 and the eleventh pipe 11 is 800±50mm. The distance H6 between the eleventh pipe 11, the twelfth pipe 12, the thirteenth pipe 13, the fourteenth pipe 14, and the fifteenth pipe 15 is 240±20mm.

[0055] The base plate of block B 200 is equipped with the sixteenth pipe 16 and the seventeenth pipe 17, which are symmetrically arranged about the center line of the web of block B 200. The distance H7 between the sixteenth pipe 16 and the center line of the web of block B 200 is 225±15mm. The sixteenth pipe 16 and the seventeenth pipe 17 are located on the same horizontal plane. The vertical distance H8 between the sixteenth pipe 16 and the seventeenth pipe 17 and the tenth pipe 10 is 315±15mm. Since the cross-sectional shape of block B 200 is similar to that of block A 300, arranging prestressed pipes in block B 200 that are similar to those in block A 300 can improve the stability of block B 200. Figure 11 As shown, in the same block B 200, the distance L3 between the two second prestressed tooth blocks 201 is (for example, it can be as follows) Figure 10 The spacing between the anchoring ends is 20600±50mm, and the distance L4 between the edge of the second prestressed tooth block 201 and the beam end is 5000±50mm.

[0056] like Figure 1 , Figure 2 , Figure 12 , Figure 13 , Figure 15 As shown, the top of the web of block C 100 is provided with two sets of first prestressing grooves 101, second prestressing grooves 102, and third prestressing grooves 103; and the two sets of first prestressing grooves 101, second prestressing grooves 102, and third prestressing grooves 103 are located at both ends of the web of block C 100. The two sets of first prestressing grooves 101, second prestressing grooves 102, and third prestressing grooves 103 are arranged in a mirror image of the longitudinal centerline of the beam. The twenty-ninth duct 29 passes through the first prestressing groove 101, the thirtieth duct 30 passes through the second prestressing groove 102, and the thirty-first duct 31 passes through the third prestressing groove 103. The twenty-ninth duct 29, the thirtieth duct 30, and the thirty-first duct 31 are mainly used for the later placement of negative moment prestressing tendons, and they can all be made of corrugated metal pipes with an inner diameter of 95mm or 105mm. Figure 12 As shown, from bottom to top, the web of block C 100 is arranged with the nineteenth pipe 19, the twentieth pipe 20, the twenty-first pipe 21, the twenty-second pipe 22, the twenty-third pipe 23, and the twenty-fourth pipe 24. The spacing H9 between the nineteenth pipe 19, the twentieth pipe 20, the twenty-first pipe 21, the twenty-second pipe 22, the twenty-third pipe 23, and the twenty-fourth pipe 24 is 240±20mm.

[0057] The base plate of block C100 extends from near the web of block C100 to away from the web of block C100 (e.g.) Figure 12From the web to the left, pipes 25 (25), 26 (26), 27 (27), and 28 (28) are arranged. No prestressed ducts are arranged on the 100mm cantilever beam in block C. The distance H10 between pipes 25 and 26 is 640±20mm. The distance H11 between pipes 26, 27, and 28 is 240±20mm. Pipes 25, 26, 27, and 28 are all located on the same horizontal plane. The horizontal distance H13 between pipe 25 and pipe 19 is 300±10mm, and the vertical distance H12 between pipe 25 and pipe 19 is 550±5mm.

[0058] Four pipes (pipes 25, 26, 27, and 28) are arranged on the C-block 100 base slab to apply positive bending moments. These four pipes are located on the same horizontal plane, ensuring that the resultant prestressing force of the C-block 100 base slab has a stable eccentricity, which can effectively resist the bending moments generated by the structure's self-weight and the superstructure load.

[0059] The spacing between pipes 25 and 26 is relatively large, while the spacing between pipes 26, 27, and 28 is relatively small. This non-uniform lateral spacing design can accommodate the non-uniform stress distribution on the ultra-wide base plate of Block C100 and balance the eccentric load brought by the web. Precise positioning of the prestressed pipes in Block C100 ensures that the actual prestressing resultant force line of action deviates little from the theoretical design position, guaranteeing the effectiveness of prestressing application in Block C100 and ensuring the structural reliability of Block C100.

[0060] like Figure 13 As shown, block C 100 consists of a first prestressing groove 101, a second prestressing groove 102, and a third prestressing groove 103, arranged sequentially from the beam end towards the longitudinal centerline of the beam. Within the same block C 100, the distance L5 between the two first prestressing grooves 101 is 26000±100mm, the distance L6 between the two second prestressing grooves 102 is 21000±100mm, and the distance L7 between the two third prestressing grooves 103 is 16000±100mm.

[0061] This embodiment achieves this by precisely designing the positions of the prestressed tooth blocks and prestressed grooves, such as... Figure 15 , Figure 16 As shown, this ensures that when assembling the multi-functional beam along the longitudinal direction of the bridge at the subsequent construction site, prestressing tendons can be accurately inserted into the ninth pipe 9, the eighteenth pipe 18, the twenty-ninth pipe 29, the thirtieth pipe 30, and the thirty-first pipe 31, ensuring that the prestressing tendons can be accurately anchored at the predetermined positions and apply bending moment, thus guaranteeing the effectiveness of prestressing application.

[0062] like Figure 17As shown, the angle α1 between the anchoring end of the first prestressed tooth block 301 and the web of block A 300 is 100°~110°; the angle α2 between the anchoring end of the second prestressed tooth block 201 and the web of block B 200 is 100°~110°. Figure 13 , 14 As shown, the angle α3 between the anchoring ends of the first prestressing groove 101, the second prestressing groove 102, and the third prestressing groove 103 and the horizontal plane is 105°~115°. By accurately designing the angles of the prestressing teeth and the anchoring ends of the prestressing grooves, it is possible to ensure that the anchoring ends are flat during tensioning, thereby reducing the frictional losses generated by the steel strands in the duct.

[0063] S4: Install the end and side forms of the multi-functional beam, pour the concrete for the multi-functional beam, and remove the formwork and perform concrete curing after the concrete pouring is completed. Specifically, in this embodiment, the end formwork of the multi-functional beam adopts an integral formwork, and the side formwork can be a segmented assembly steel formwork made of steel profiles commonly used in industrial production. When pouring concrete, A block 300 and B block 200 are poured in one go, while C block 100 can be poured in two stages. First, the bottom slab and cantilever beam of C block 100 are poured, and finally, the web of C block 100 is poured starting from the beginning of the beam slab. The concrete is poured from one end to the other, using a diagonal segmented and horizontal layered method. When removing the formwork of the multi-functional beam, the concrete strength should not be less than 5MPa, and the temperature difference between the core and surface of the beam concrete, and between the surface and the ambient temperature, should not exceed 15℃. After removing the formwork, the multi-functional beam can be watered for curing and covered with geotextile up to the bottom of the beam to maintain sufficient humidity and temperature. The wet curing period should not be less than 7 days.

[0064] S5: Conduct prestressed engineering, including the following steps: S51: Prestressed pipe forming.

[0065] S52: Material cutting and bundling. In this embodiment, the prestressed steel strands are low-relaxation high-strength steel strands with a tensile strength standard value of pkf=1860MPa and a nominal diameter of d=15.2mm. The preferred prestressed steel strands are low-relaxation high-strength steel strands, which can maintain the beam's crack resistance and structural stiffness for a longer period, thus improving the long-term durability and safety of this multi-functional beam.

[0066] Opening the steel strand: Place the steel strand reel vertically into the opening frame, take out the steel strand head from the center of the reel, cut the steel strand with a grinding wheel and then braid it into bundles. When braiding, keep each steel strand parallel and do not tangle. Tie a lead wire every 1~1.5m.

[0067] S53: Threading the prestressed steel strands. After the multi-functional beam concrete is poured and reaches 80% of its design strength, the prestressed steel strands can be threaded. Before threading, remove moisture and other contaminants from the prestressing ducts. The steel strand bundles are threaded into the ducts according to their length and hole number. Threading can be done manually. When threading, the ends of the steel strand bundles can be wrapped with tape to prevent them from puncturing the ducts and to reduce threading resistance.

[0068] S54: Tensioning prestressed tendons with positive bending moment: The tensioning sequence of Block A (300) is as follows: Pipe 1 → Pipe 2 → Pipe 3 → Pipe 4 → Pipe 5 → Pipe 6 → Pipe 7 → Pipe 8; The tensioning sequence of Block B, 200, is as follows: 10th pipe 10 → 11th pipe 11 → 12th pipe 12 → 13th pipe 13 → 14th pipe 14 → 15th pipe 15 → 16th pipe 16 → 17th pipe 17; The tensioning sequence of block C, number 100, is as follows: pipe 19 → pipe 20 → pipe 21 → pipe 22 → pipe 23 → pipe 24 → pipe 25 → pipe 26 → pipe 27 → pipe 28.

[0069] In this embodiment, prestressing tensioning can be performed using a prestressing CNC tensioning instrument, or the tensioning stress and elongation of the steel strand can be controlled manually. During the tensioning process, technicians must strictly control the tensioning force at each stage and measure and calculate the elongation according to the design tensioning procedure and the oil gauge reading after the jack calibration conversion.

[0070] S55: Grouting of ducts. During grouting, the bleeding rate of the grout should be ≤3%, and the bleeding rate should be controlled at 2% after 3 hours of mixing. The consistency of the grout should be ≤25s. By strictly controlling the bleeding rate, "water pockets" or voids at the top of the ducts can be effectively reduced, ensuring the density of the grout and the durability of the structure. Controlling the consistency of the grout to ≤25s ensures that the grout can smoothly fill the entire pipe, avoiding blockages or voids in long-distance pipes, and also ensures that the grout has sufficient strength and bonding force, enhancing the reliability of the prestressed system.

[0071] S56: Beam end sealing.

[0072] S6: Complete the prefabrication of the multi-functional beam.

[0073] The prefabrication method for the multifunctional beam provided in this embodiment sets differentiated upward precamber for the three platforms A, B, and C (A block 300 not exceeding 32mm, B block 200 not exceeding 38mm, and C block 100 not exceeding 40mm), all set according to a quadratic parabola. Due to the excessive self-weight of block C 100, it is set with the maximum precamber value (not exceeding 40mm). This precise differentiation accurately offsets the deflection of each beam block caused by its own weight, prestress, and subsequent loads, controls the longitudinal alignment of the beam, ensures the geometric accuracy of the formed beam blocks, and lays a good foundation for subsequent assembly.

[0074] The prestressed teeth and prestressed grooves on the upper part of the multi-functional beam are used to apply negative bending moments, while the various prestressed ducts at the lower part of the multi-functional beam are used to apply positive bending moments subsequently. By arranging each prestressed duct in a precise manner and coordinating with the specific tensioning sequence in S54, the resultant force line of the prestressing tendons can be precisely controlled, making it closer to the structural stiffness center of block C100. This effectively suppresses the uncontrollable transverse bending generated by block C100 during the tensioning process, fundamentally avoiding cracking or structural damage to the beam during the tensioning stage, and ensuring the structural safety and construction quality of the irregular beam blocks.

[0075] The area above the 100mm cantilever beam in Block C is a pedestrian area with a relatively low load. The cantilever beams are spaced out, and no prestressed ducts are installed at the cantilever beams, which simplifies the prefabrication process, reduces construction costs, and improves work efficiency.

[0076] Example 2 like Figure 1 , Figure 2 As shown, prefabricated blocks A300, B200, and C100 at the beam fabrication plant are scattered during construction site erection. When using a bridge erecting machine to erect the beam, the transverse track of the machine's central support leg needs to be stably positioned on top of the multi-functional beam (specifically, on top of the web of blocks A300, B200, and C100). If the wet joints between the multi-functional beam blocks are poured first, and then the transverse track of the bridge erecting machine is laid, the beam erection efficiency will be greatly slowed down. If the wet joints between the multi-functional beam blocks are not poured, blocks A300, B200, and C100 will be scattered and uncontrolled. The bridge erecting machine moving directly on the web of the multi-functional beam can easily lead to instability of the machine, posing a high safety hazard. Therefore, this embodiment provides a method for forming a multi-functional beam, mainly used for forming multi-functional beams prefabricated by the method provided in Embodiment 1, including the following steps: Hoist block C100 to its support at the beam to be erected, then hoist block B200 to its support at the beam to be erected. Install temporary scissor bracing 400 between block B200 and block C100. Then hoist block A300 to its support at the beam to be erected. Install temporary scissor bracing 400 between block A300 and block B200. After the bridge erecting machine has passed the span, remove the temporary scissor bracing 400 and pour the wet joint between block B200 and block C100, as well as the wet joint between block A300 and block B200.

[0077] The multi-functional beam forming method provided in this embodiment pre-connects three independent beam blocks—C block 100, B block 200, and A block 300—using temporary scissor bracing 400. Before the wet joint is poured, the originally scattered and uncontrolled beam blocks form a relatively stable whole, providing a stable standing space for the bridge erecting machine's central support leg. When the lateral track of the bridge erecting machine's central support leg is laid out and sits on top of the multi-functional beam, the pre-connected multi-functional beam will not easily become unstable or displaced, thus greatly improving the stability and safety of the bridge erecting machine during operation. This effectively avoids safety hazards such as the bridge erecting machine overturning due to scattered beam blocks, achieving "beam erection first, joint pouring later." During construction, there is no need to wait for the wet joint to solidify; the wet joint of the next span is poured after the bridge erecting machine passes through the hole, without affecting the construction rhythm, greatly shortening the overall bridge construction period and improving construction efficiency.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of prefabricating a multi-functional beam, characterized by, The method comprises the following steps: S1: Constructing the pedestals of the A block (300), the B block (200) and the C block (100), and arranging upward pre-arches symmetrically with respect to the longitudinal center line of the beam, with the maximum pre-arch value in the middle; the maximum pre-arch value of the A block (300) is not more than 32 mm, the maximum pre-arch value of the B block (200) is not more than 38 mm, and the maximum pre-arch value of the C block (100) is not more than 40 mm; S2: Constructing the multifunctional beam bottom mold and installing the multifunctional beam steel bars, and arranging the cantilever beams of the C block (100) along the length direction of the C block (100) at intervals; S3: Installing the multifunctional beam prestressed pipe: The A block (300) web is arranged, from bottom to top, with the first pipe (1), the second pipe (2), the third pipe (3), the fourth pipe (4), the fifth pipe (5) and the sixth pipe (6); the A block (300) bottom plate is arranged with the seventh pipe (7) and the eighth pipe (8), which are arranged symmetrically with respect to the center line of the A block (300) web; The B block (200) web is arranged, from bottom to top, with the tenth pipe (10), the eleventh pipe (11), the twelfth pipe (12), the thirteenth pipe (13), the fourteenth pipe (14) and the fifteenth pipe (15); the B block (200) bottom plate is arranged with the sixteenth pipe (16) and the seventeenth pipe (17), which are arranged symmetrically with respect to the center line of the B block (200) web; The top of the C block (100) web is provided with the first prestressed groove (101), the second prestressed groove (102) and the third prestressed groove (103) at both ends, which are arranged symmetrically with respect to the longitudinal center line of the beam; the twenty-ninth pipe (29) is arranged in the first prestressed groove (101), the thirtieth pipe (30) is arranged in the second prestressed groove (102), and the thirty-first pipe (31) is arranged in the third prestressed groove (103); ​ ​ The C block (100) web is arranged from bottom to top with a nineteenth pipeline (19), a twentieth pipeline (20), a twenty-first pipeline (21), a twenty-second pipeline (22), a twenty-third pipeline (23), and a twenty-fourth pipeline (24). The C block (100) bottom plate is arranged from close to the C block (100) web to away from the C block (100) web direction with a twenty-fifth pipeline (25), a twenty-sixth pipeline (26), a twenty-seventh pipeline (27), and a twenty-eighth pipeline (28). The C block (100) cantilever beam is not arranged with a prestressed pipeline. S4: Install the multifunctional beam end mold and side mold, pour the multifunctional beam concrete, and remove the mold after the concrete pouring is completed and carry out concrete curing; S5: Perform prestressed engineering, including the following steps: S51: Prestressed pipeline forming; S52: Downstream bundle; S53: Thread bundle; S54: Tensioning normal bending moment prestressed reinforcement: The A block (300) tensioning sequence is: first pipeline (1) → second pipeline (2) → third pipeline (3) → fourth pipeline (4) → fifth pipeline (5) → sixth pipeline (6) → seventh pipeline (7) → eighth pipeline (8); The B block (200) tensioning sequence is: tenth pipeline (10) → eleventh pipeline (11) → twelfth pipeline (12) → thirteenth pipeline (13) → fourteenth pipeline (14) → fifteenth pipeline (15) → sixteenth pipeline (16) → seventeenth pipeline (17); The C block (100) tensioning sequence is: nineteenth pipeline (19) → twentieth pipeline (20) → twenty-first pipeline (21) → twenty-second pipeline (22) → twenty-third pipeline (23) → twenty-fourth pipeline (24) → twenty-fifth pipeline (25) → twenty-sixth pipeline (26) → twenty-seventh pipeline (27) → twenty-eighth pipeline (28); S55: Hole grouting; S56: Beam end sealing; S6: Complete the multifunctional beam prefabrication.

2. A method of prefabricating a multi-functional beam according to claim 1, wherein The A block (300) pedestal pre-arch value satisfies: Y a = 64 x f x X a (L a -X a ) / L a 2 ; wherein Y a is the pre-arch value of the A-block (300) pedestal; f is a control parameter, taken as 2.0; X a is the distance from the first end of the A-block (300); L a is the length of the A-block (300); The B block (200) pedestal pre-arch value satisfies: Y b = 76 x f x X b (L b -X b ) / L b 2 ; where Y b is the pre-arch value of the B-block (200) pedestal; X b is the distance from the first end of the B-block (200); L b is the length of the B-block (200); The C block (100) pedestal pre-arch value satisfies: Y c = 80 x f x X c (L c -X c ) / L c 2 ; where Y c is the pre-arch value of the C-block (100) pedestal; X c is the distance from the first end of the C-block (100); L c is the length of the C-block (100).

3. The method of claim 1, wherein, The first pipeline (1) and the second pipeline (2) are spaced 800±50mm apart, the second pipeline (2), the third pipeline (3), the fourth pipeline (4), the fifth pipeline (5), and the sixth pipeline (6) are spaced 240±20mm apart; the seventh pipeline (7) and the eighth pipeline (8) are spaced 225±15mm apart from the center line of the A block (300) web, the seventh pipeline (7) and the eighth pipeline (8) are located on the same horizontal plane, and the vertical distance between the seventh pipeline (7) and the eighth pipeline (8) and the first pipeline (1) is 315±15mm.

4. The method of claim 1, wherein, The tenth pipe (10) and the eleventh pipe (11) are spaced apart by 800±50mm, the eleventh pipe (11), the twelfth pipe (12), the thirteenth pipe (13), the fourteenth pipe (14), the fifteenth pipe (15) are spaced apart by 240±20mm; the sixteenth pipe (16) and the seventeenth pipe (17) are spaced apart from the center line of the web of the B block (200) by 225±15mm, the sixteenth pipe (16) and the seventeenth pipe (17) are located on the same horizontal plane, and the vertical distance between the sixteenth pipe (16) and the seventeenth pipe (17) and the tenth pipe (10) is 315±15mm.

5. The method of claim 1, wherein, The nineteenth pipe (19), the twentieth pipe (20), the twenty-first pipe (21), the twenty-second pipe (22), the twenty-third pipe (23), and the twenty-fourth pipe (24) are spaced apart by 240±20mm; The twenty-fifth pipe (25) and the twenty-sixth pipe (26) are spaced apart by 640±20mm, and the twenty-sixth pipe (26), the twenty-seventh pipe (27), and the twenty-eighth pipe (28) are spaced apart by 240±20mm; The twenty-fifth pipe (25), the twenty-sixth pipe (26), the twenty-seventh pipe (27), and the twenty-eighth pipe (28) are located on the same horizontal plane, the horizontal distance between the twenty-fifth pipe (25) and the nineteenth pipe (19) is 300±10mm, and the vertical distance between the twenty-fifth pipe (25) and the nineteenth pipe (19) is 550±5mm.

6. The method of claim 1, wherein, In the same A block (300), the distance between the two first prestressed teeth blocks (301) is 20600±50mm, and the distance between the edge of the first prestressed teeth block (301) and the beam end is 5000±50mm; In the same B block (200), the distance between the two second prestressed teeth blocks (201) is 20600±50mm, and the distance between the edge of the second prestressed teeth block (201) and the beam end is 5000±50mm; The C block (100) is sequentially provided with a first prestressed slot (101), a second prestressed slot (102), and a third prestressed slot (103) from the beam end to the longitudinal center line of the beam, and in the same C block (100), the distance between the two first prestressed slots (101) is 26000±100mm, the distance between the two second prestressed slots (102) is 21000±100mm, and the distance between the two third prestressed slots (103) is 16000±100mm.

7. The method of claim 1, wherein, The angle between the anchoring end of the first prestressed teeth block (301) and the web of the A block (300) is 100°~110°; the angle between the anchoring end of the second prestressed teeth block (201) and the web of the B block (200) is 100°~110°; and the angle between the anchoring end of the first prestressed slot (101), the second prestressed slot (102), and the third prestressed slot (103) and the horizontal plane is 105°~115°.

8. The method of claim 1, wherein, In S52, the prestressed steel strand adopts a steel strand with a standard tensile strength pkf=1860MPa and a nominal diameter d=15.2mm.

9. The method of claim 1, wherein, In S55, the bleeding rate of the slurry is ≤3% when the hole is grouted, and the bleeding rate is controlled at 2% after 3h of mixing, and the consistency of the slurry is ≤25s.

10. A method of forming a multi-functional beam, characterized by, The prefabricated multifunctional beam is prepared by the prefabrication method for forming the multifunctional beam of any one of claims 1-9. The C block (100) is hoisted to the support of the position where the beam is to be erected, then the B block (200) is hoisted to the support of the position where the beam is to be erected, the temporary scissors brace (400) is installed between the B block (200) and the C block (100), then the A block (300) is hoisted to the support of the position where the beam is to be erected, the temporary scissors brace (400) is installed between the A block (300) and the B block (200), after the bridge erecting machine passes through the hole, the wet joints between the B block (200) and the C block (100) and the wet joints between the A block (300) and the B block (200) are poured.

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