A construction method for large-span special-shaped slow-bonding prestressed concrete beams

Abstract

The invention discloses a construction method for a large-span special-shaped slow-bonding prestressed concrete beam, which belongs to the technical field of building construction, and comprises the following steps: 1) local factory prefabrication; 2) transportation and on-site hoisting; 3) prefabricated component elevation and shape control; 4) supplementing the missing anchoring section steel bars to complete the concrete pouring between the prefabricated component and the anchoring structure; 5) after the strength of the concrete poured on-site reaches the design strength requirement and meets the slow-bonding prestressed tendon tensioning requirement, tensioning the prestress according to the design requirement; 6) dismantling the temporary support system at the lower end of the prefabricated component to complete the construction; the purpose of the invention is to solve the problems that the traditional construction of the slow-bonding prestressed beam has a complicated on-site construction process, a long time consumption and low construction efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and in particular relates to a construction method of a large-span special-shaped slow-bonding prestressed concrete beam. Background Art

[0002] Compared with traditional reinforced concrete structures, prestressed concrete structures have the advantages of strong bearing capacity, high rigidity, and light force, and are widely used in various projects such as bridges and buildings. The general construction methods of prestressed concrete structures are divided into two categories: cast-in-place and factory prefabrication. For slow-bonding prestressed beams, traditional construction mainly focuses on cast-in-place construction, that is, on-site tying of steel bars, arrangement of slow-bonding bars, support of formwork, pouring of concrete, and tensioning of prestressed bars after the concrete strength reaches the design requirements. This type of cast-in-place construction has problems such as cumbersome on-site construction process, long time consumption, and low construction efficiency, which is especially true for large-span special-shaped slow-bonding prestressed concrete beams. Summary of the invention

[0003] In view of this, the present invention discloses a construction method for a large-span special-shaped slow-bonding prestressed concrete beam, which aims to solve the problems of complicated on-site construction process, long time consumption and low construction efficiency in traditional construction of slow-bonding prestressed concrete beams.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A construction method for a large-span special-shaped slow-bonding prestressed concrete beam comprises the following steps:

[0006] 1) Partial factory prefabrication: Comprehensively consider the lifting capacity and transportation capacity requirements, as well as the anchorage area of ​​the prestressed beam end, determine the factory prefabrication location of the large-span special-shaped slow-bonding prestressed beam components; on the prefabrication stand, arrange the bottom membrane, tie the steel bars, arrange the slow-bonding prestressed tendons, seal the side formwork, and ensure that one end of the slow-bonding prestressed tendons extends out of the side formwork, then pour concrete and maintain according to the design requirements;

[0007] 2) Transportation and on-site hoisting: After the prefabricated components reach the required strength, they are demoulded and transported to the site; on-site installation: a temporary support system is set up under the prefabricated components before installation; a scaffold is installed, the formwork of the cast-in-place section is laid between the existing building foundation and the prefabricated components, and the steel bars are tied; the ends of the slow-bonding prestressed bars are installed in the cast-in-place section;

[0008] 3) Control of elevation and shape of prefabricated components: To ensure that the elevation and spatial shape of large-span special-shaped prestressed beams meet the design requirements during the construction process, the vertical elevation and cross-sectional level of the prefabricated beam components are regulated through a temporary support system;

[0009] 4) Fill in the missing anchoring section steel bars and complete the concrete pouring between the prefabricated components and the anchoring structure;

[0010] 5) When the strength of the concrete poured on site reaches the design strength requirement and meets the tensioning requirements of the slow-bonding prestressed tendons, the prestressing is tensioned according to the design requirements;

[0011] 6) Remove the temporary support system at the lower end of the prefabricated components and complete the construction.

[0012] In this scheme, the combination of prefabrication and cast-in-place solves the problem of complicated and time-consuming on-site construction procedures of traditional large-span special-shaped slow-bonding prestressed beams. The present invention has a high level of industrialized construction, convenient construction, and controllable quality. In addition, the cast-in-place at the end of the prefabricated component solves the anchoring problem of the large-span special-shaped slow-bonding prestressed beam and the surrounding structure, and the anchoring effect can be reliable. At the same time, the combination of prefabrication and cast-in-place solves the hoisting and transportation problems caused by the full-size prefabrication of large-span special-shaped slow-bonding prestressed beams. The temporary support system can be used for the vertical elevation and cross-sectional leveling of the prefabricated components to ensure that the structural form after forming meets the design requirements.

[0013] A temporary support system involved in a construction method of a large-span special-shaped slow-bonding prestressed concrete beam, the temporary support system comprising a base detachably connected to the ground, a vertically arranged load-bearing rod fixed on the base, the height of the load-bearing rod being adjustable; the top end of the load-bearing rod is connected to a mounting seat by a ball joint, the top end of the mounting seat is coaxially rotatably connected to a horizontally arranged guide rail, the mounting seat is provided with a rotating structure for driving the guide rail to rotate; a connecting seat is slidably connected to the guide rail, and a power structure for driving the connecting seat is provided on the guide rail; an embedded part detachably rotatably connected to the connecting seat is embedded in the prefabricated component, and the embedded part and the connecting seat are locked by a latch.

[0014] In this scheme, the vertical elevation of the prefabricated component is adjusted by adjusting the height of the load-bearing rod; when the prefabricated component needs to be adjusted horizontally, the lock between the embedded part and the connecting seat is released, and the guide rail is driven to rotate by the rotating structure until the guide rail is parallel to the horizontal adjustment direction of the prefabricated component, and then the connecting seat is driven by the power structure to drive the horizontal displacement of the prefabricated component, so as to adjust the horizontal position of the prefabricated component, and then the embedded part and the connecting seat are locked by the latch; when the horizontal direction needs to be adjusted, one of the support systems is used as the rotation center, the connection between the base of the support system at the rotation center and the ground is released, the guide rail is driven in the reverse direction by the power structure, so that the connecting seat and the load-bearing rod are coaxial, and then the base is fixed to the ground, the lock between the corresponding embedded part and the connecting seat at the rotation center is maintained, and the lock between the remaining embedded parts and the connecting seat is released, and the guide rail and the connecting seat are driven by the rotating structure in the support system at the rotation center to drive the prefabricated component to rotate synchronously, and the rotating structures of the remaining support systems drive the corresponding guide rails to rotate, and the corresponding connecting seat is driven to move by the driving structure, so as to apply a driving force to the prefabricated component to help the prefabricated component rotate.

[0015] Furthermore, a plurality of connecting grooves are provided on both sides of the inner wall of the guide rail, and limit blocks for carding and connecting seats are slidably connected in the connecting grooves, the ends of the limit blocks are arc-shaped, and a return spring is provided between the limit blocks and the connecting grooves; a plurality of suction cups are provided on the top of the guide rail, and through holes are provided on the tops of the connecting grooves to communicate with the corresponding suction cups, a sealing plate is vertically slidably connected in the connecting groove, a sealing block extending into the through hole is fixed on the sealing plate, a plurality of protrusions are provided on the bottom of the sealing plate, and a plurality of grooves cooperating with the protrusions are provided on the upper end of the limit block; the connecting grooves are connected to each other, and a suction machine for generating negative pressure in the connecting grooves is provided on the guide rail.

[0016] In this solution, after the prefabricated component is adjusted into place, a vacuum is generated in the connection groove through suction by a vacuum machine, so that the sealing plate moves downward, and the protrusion on the sealing plate is embedded in the groove on the limit block, thereby limiting the movement of the limit block, so that the limit block remains stuck on the connection seat, thereby preventing the prefabricated component from being displaced during construction; at the same time, when the sealing plate moves downward, it drives the sealing block to move synchronously, resulting in negative pressure in the suction cup, so that the suction cup is adsorbed on the lower end of the prefabricated component, thereby enhancing the connection stability between the support system and the prefabricated component.

[0017] Furthermore, a plurality of adjusting rods are connected to ball joints on both sides of the guide rails, the ends of the adjusting rods are coaxially slidably connected to fixed rods, the load-bearing rods are rotatably connected to an annular seat on the circumference, and the ends of the fixed rods are ball-jointed to the annular seat; a locking structure for locking the coaxial sliding of the adjusting rods is provided on the fixed rods.

[0018] When the locking structure is used to lock the fixed rod and the movable rod, the fixed rod and the movable rod form a stable support for the guide rail; when the vertical angle of the prefabricated component is adjusted, the guide rail tilts, and the lock between the fixed rod and the movable rod is released, so that the movable rod can move relative to the fixed rod as the guide rail tilts, and always maintains the connection with the guide rail.

[0019] Furthermore, the locking structure includes a locking ring rotatably connected to the end of the fixed rod, a plurality of limit rods are arranged inside the locking ring, a plurality of guide grooves parallel to the adjusting rod are arranged around the adjusting rod, and a plurality of limit grooves are arranged on one side of the guide groove.

[0020] When the moving rod needs to be locked, the locking ring only needs to be rotated so that the limiting rod on the locking ring slides from the guide groove into the limiting groove to lock the moving rod; when the moving rod needs to slide, the locking ring only needs to be rotated in the opposite direction.

[0021] Furthermore, a plurality of anti-overturning rods detachably connected to the ground are arranged around the load-bearing rod.

[0022] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0024] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0025] Figure 2 It is a schematic diagram of the structure after the slow-bonding prestressed tendons are tensioned in an embodiment of the present invention;

[0026] Figure 3 A longitudinal cross-sectional view of an embodiment of the present invention;

[0027] Figure 4 for Figure 3 The enlarged schematic diagram of point A in the middle;

[0028] Figure 5 for Figure 3 A magnified schematic diagram of point B in the middle.

[0029] The markings in the attached drawings are as follows: prefabricated component 1, slow-bonding prestressed tendons 2, base 3, load-bearing rod 4, mounting seat 5, guide rail 6, connecting seat 7, embedded part 8, suction cup 9, limit block 10, return spring 11, sealing plate 12, sealing block 13, adjusting rod 14, fixing rod 15, annular seat 16, locking ring 17, guide groove 18, limit groove 19, anti-overturning rod 20, cast-in-place section 21. DETAILED DESCRIPTION

[0030] like Figures 1 to 5 As shown:

[0031] A construction method for a large-span special-shaped slow-bonding prestressed concrete beam comprises the following steps:

[0032] 1) Partial factory prefabrication: Comprehensively consider the lifting capacity and transportation capacity requirements, as well as the anchorage area of ​​the prestressed beam end, determine the factory prefabrication location of the large-span special-shaped slow-bonding prestressed beam components; on the prefabrication stand, arrange the bottom membrane, tie the steel bars, arrange the slow-bonding prestressed tendons 2, seal the side form, and ensure that one end of the slow-bonding prestressed tendons extends out of the side form, then pour concrete and maintain according to the design requirements;

[0033] 2) Transportation and on-site hoisting: After the prefabricated component 1 reaches the required strength, it is demoulded and transported to the site; on-site installation: a temporary support system is set up under the prefabricated component 1 before installation; a scaffold is installed, the template of the cast-in-place section 21 is laid between the existing building foundation and the prefabricated component 1, and the steel bars are tied, and the end of the slow-bonding prestressed tendon 2 is installed in the cast-in-place section 21;

[0034] 3) Control of elevation and shape of prefabricated components 1: To ensure that the elevation and spatial shape of the large-span special-shaped prestressed beams meet the design requirements during the construction process, the vertical elevation and cross-sectional level of the prefabricated beam components are regulated through a temporary support system;

[0035] 4) Fill in the missing anchoring section steel bars and complete the concrete pouring between the prefabricated component 1 and the anchoring structure;

[0036] 5) When the strength of the concrete poured on site reaches the design strength requirement and meets the tensioning requirements of the slow-bonding prestressed tendons 2, the prestressing is tensioned according to the design requirements;

[0037] 6) Remove the temporary support system at the lower end of prefabricated component 1 and complete the construction.

[0038] In this scheme, the combination of prefabrication and cast-in-place solves the problem of complicated and time-consuming on-site construction procedures of traditional large-span special-shaped slow-bonding prestressed beams. The present invention has a high level of industrialized construction, convenient construction, and controllable quality. In addition, the cast-in-place at the end of the prefabricated component 1 solves the anchoring problem of the large-span special-shaped slow-bonding prestressed beam and the surrounding structure, and the anchoring effect can be reliable. At the same time, the combination of prefabrication and cast-in-place solves the hoisting and transportation problems caused by the full-size prefabrication of large-span special-shaped slow-bonding prestressed beams. The temporary support system can be used for the vertical elevation and cross-sectional leveling of the prefabricated component 1 to ensure that the structural form after forming meets the design requirements.

[0039] A temporary support system involved in a construction method of a large-span special-shaped slow-bonding prestressed concrete beam, the temporary support system comprising a base 3 detachably connected to the ground, a vertically arranged load-bearing rod 4 fixed to the base 3 (in this embodiment, a hydraulic cylinder drive in conventional technology is adopted, so it is not drawn in the figure), and the height of the load-bearing rod 4 is adjustable; the top of the load-bearing rod 4 is connected to a mounting seat 5 by a ball joint, and the top of the mounting seat 5 is coaxially rotatably connected to a horizontally arranged guide rail 6, and the mounting seat 5 is provided with a rotating structure for driving the guide rail 6 to rotate (in this embodiment, a motor drive in conventional technology is adopted, so it is not drawn in the figure); a connecting seat 7 is slidably connected to the guide rail 6, and a power structure for driving the connecting seat 7 is provided on the guide rail 6 (in this embodiment, a hydraulic cylinder drive in conventional technology is adopted, so it is not drawn in the figure); an embedded part 8 detachably rotatably connected to the connecting seat 7 is embedded in the prefabricated component 1, and the embedded part 8 and the connecting seat 7 are locked by a latch (not drawn in the figure).

[0040] In this solution, the vertical elevation of the prefabricated component 1 is adjusted by adjusting the height of the load-bearing rod 4; when the prefabricated component 1 needs to be adjusted horizontally, the lock between the embedded part 8 and the connecting seat 7 is released, and the guide rail 6 is driven to rotate by the rotating structure until the guide rail 6 is parallel to the horizontal adjustment direction of the prefabricated component 1, and then the connecting seat 7 is driven by the power structure to drive the horizontal displacement of the prefabricated component 1, so as to adjust the horizontal position of the prefabricated component 1, and then the embedded part 8 and the connecting seat 7 are locked by the latch; when the horizontal direction needs to be adjusted, one of the support systems is used as the rotation center, and the support system at the rotation center is released. The base 3 of the system is connected to the ground, and the guide rail 6 is driven in reverse by the power structure to make the connecting seat 7 coaxial with the load-bearing rod 4, and then the base 3 is fixed to the ground, the locking between the corresponding embedded parts 8 and the connecting seat 7 at the rotation center is maintained, and the locking between the remaining embedded parts 8 and the connecting seat 7 is released, and the guide rail 6 and the connecting seat 7 are driven by the rotating structure in the support system at the rotation center to drive the prefabricated component 1 to rotate synchronously, and the rotating structure of the remaining support systems drives the corresponding guide rail 6 to rotate, and the driving structure is used to drive the corresponding connecting seat 7 to move, thereby applying a driving force to the prefabricated component 1 to help the prefabricated component 1 rotate.

[0041] When the prefabricated component 1 needs to be adjusted in vertical angle, one of the rows of support systems is used as the rotation center, the guide rail 6 in the support system at the rotation center is adjusted to be parallel to the rotation center, and the guide rails 6 in the remaining support systems are adjusted to be perpendicular to the rotation center. The prefabricated component 1 is pushed to deflect by adjusting the length of the load-bearing rod 4 in the remaining support systems. At the same time, the driving structure in the remaining support systems drives the connecting seat 7 to move synchronously to maintain the connection relationship between the connecting seat 7 and the guide rail 6.

[0042] In this embodiment, a plurality of connecting grooves are provided on both sides of the inner wall of the guide rail 6, and a limit block 10 for carding and connecting seat 7 is slidably connected in the connecting grooves, the end of the limit block 10 is arc-shaped, and a return spring 11 is provided between the limit block 10 and the connecting groove; a plurality of suction cups 9 are provided on the top of the guide rail 6, and a through hole is provided on the top of the connecting groove to communicate with the corresponding suction cup 9, and a sealing plate 12 is vertically slidably connected in the connecting groove, and a sealing block 13 extending into the through hole is fixed on the sealing plate 12, and a plurality of protrusions are provided on the bottom of the sealing plate 12, and a plurality of grooves cooperating with the protrusions are provided on the upper end of the limit block 10; the connecting grooves are connected to each other, and a suction machine for generating negative pressure in the connecting groove is provided on the guide rail 6.

[0043] In this solution, after the prefabricated component 1 is adjusted into place, a vacuum is generated in the connection groove by suction from a vacuum machine, causing the sealing plate 12 to move downward, thereby causing the protrusion on the sealing plate 12 to embed into the groove on the limit block 10, thereby limiting the movement of the limit block 10 and allowing the limit block 10 to maintain its engagement with the connection seat 7, thereby preventing the prefabricated component 1 from being displaced during construction; at the same time, when the sealing plate 12 moves downward, it drives the sealing block 13 to move synchronously, causing a negative pressure to be formed in the suction cup 9, causing the suction cup 9 to be adsorbed on the lower end of the prefabricated component 1, thereby enhancing the connection stability between the support system and the prefabricated component 1.

[0044] In this embodiment, a plurality of adjusting rods 14 are ball-jointedly connected on both sides of the guide rail 6, the ends of the adjusting rods 14 are coaxially slidably connected to fixed rods 15, the load-bearing rods 4 are rotatably connected to an annular seat 16, the ends of the fixed rods 15 are ball-jointedly connected to the annular seat 16; the fixed rods 15 are provided with a locking structure for locking the coaxial sliding of the adjusting rods 14.

[0045] When the fixed rod 15 and the movable rod are locked by the locking structure, the fixed rod 15 and the movable rod form a stable support for the guide rail 6; when the prefabricated component 1 is adjusted in vertical angle, the guide rail 6 is tilted, and the lock between the fixed rod 15 and the movable rod is released, so that the movable rod can move relative to the fixed rod 15 as the guide rail 6 tilts, and always maintains the connection with the guide rail 6.

[0046] In this embodiment, the locking structure includes a locking ring 17 rotatably connected to the end of the fixed rod 15, and a plurality of limit rods are arranged inside the locking ring 17. A plurality of guide grooves 18 parallel to the adjusting rod 14 are arranged on the circumference of the adjusting rod 14, and a plurality of limit grooves 19 are arranged on one side of the guide groove 18.

[0047] When the moving rod needs to be locked, the locking ring 17 only needs to be rotated so that the limiting rod on the locking ring 17 slides from the guide groove 18 into the limiting groove 19 to lock the moving rod; when the moving rod needs to slide, the locking ring 17 only needs to be rotated in the opposite direction.

[0048] In this embodiment, a plurality of anti-overturning rods 20 detachably connected to the ground are arranged around the load-bearing rod 4 to prevent the support system from overturning.

[0049] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A construction method for a large-span special-shaped slow-bonding prestressed concrete beam, characterized in that: The steps include: 1) Partial factory prefabrication: Comprehensively consider the lifting capacity and transportation capacity requirements, as well as the anchorage area of ​​the prestressed beam end, determine the factory prefabrication location of the large-span special-shaped slow-bonding prestressed beam components; on the prefabrication stand, arrange the bottom membrane, tie the steel bars, arrange the slow-bonding prestressed tendons, seal the side formwork, and ensure that one end of the slow-bonding prestressed tendons extends out of the side formwork, then pour concrete and maintain according to the design requirements; 2) Transportation and on-site hoisting: After the prefabricated components reach the required strength, they are demoulded and transported to the site. Before installation on site, a temporary support system is set up under the prefabricated components. Install the stand, lay the formwork of the cast-in-place section between the existing building foundation and the prefabricated component and tie the steel bars, and install the end of the slow-bonding prestressed tendon in the cast-in-place section; the temporary support system includes a base detachably connected to the ground, a vertically arranged load-bearing rod is fixed on the base, and the height of the load-bearing rod is adjustable; the top of the load-bearing rod is connected to a mounting seat by a ball joint, the top of the mounting seat is coaxially rotatably connected to a horizontally arranged guide rail, and the mounting seat is provided with a rotating structure for driving the guide rail to rotate; a connecting seat is slidably connected to the guide rail, and a power structure for driving the connecting seat is provided on the guide rail; an embedded part detachably rotatably connected to the connecting seat is embedded in the prefabricated component, and the embedded part and the connecting seat are locked by a latch; 3) Control of elevation and shape of prefabricated components: To ensure that the elevation and spatial shape of large-span special-shaped prestressed beams meet the design requirements during the construction process, the vertical elevation and cross-sectional level of the prefabricated beam components are regulated through a temporary support system; 4) Fill in the missing anchoring section steel bars and complete the concrete pouring between the prefabricated components and the anchoring structure; 5) When the strength of the concrete poured on site reaches the design strength requirement and meets the tensioning requirements of the slow-bonding prestressed tendons, the prestressing is tensioned according to the design requirements; 6) Remove the temporary support system at the lower end of the prefabricated components and complete the construction.

2. The temporary support system involved in the construction method of a large-span special-shaped slow-bonding prestressed concrete beam according to claim 1 is characterized by: A plurality of connecting grooves are provided on both sides of the inner wall of the guide rail, and limit blocks for carding and connecting seats are slidably connected in the connecting grooves, the ends of the limit blocks are arc-shaped, and a return spring is provided between the limit blocks and the connecting grooves; a plurality of suction cups are provided on the top of the guide rail, and through holes are provided on the tops of the connecting grooves to communicate with the corresponding suction cups, a sealing plate is vertically slidably connected in the connecting groove, a sealing block extending into the through hole is fixed on the sealing plate, a plurality of protrusions are provided on the bottom of the sealing plate, and a plurality of grooves cooperating with the protrusions are provided on the upper end of the limit block; the connecting grooves are connected to each other, and a suction machine for generating negative pressure in the connecting grooves is provided on the guide rail.

3. The temporary support system according to claim 2, characterized in that: A plurality of adjusting rods are connected with ball joints on both sides of the guide rails, the ends of the adjusting rods are coaxially slidably connected with fixed rods, the load-bearing rods are rotatably connected with an annular seat on the circumference, and the ends of the fixed rods are ball-jointed with the annular seat; a locking structure for locking the coaxial sliding of the adjusting rods is provided on the fixed rods.

4. The temporary support system according to claim 3, characterized in that: The locking structure includes a locking ring rotatably connected to the end of the fixed rod, a plurality of limiting rods are arranged inside the locking ring, a plurality of guide grooves parallel to the adjusting rod are arranged around the adjusting rod, and a plurality of limiting grooves are arranged on one side of the guide groove.

5. The temporary support system according to claim 4, characterized in that: A plurality of anti-overturning rods detachably connected to the ground are arranged around the load-bearing rod.

Images