A pre-tensioning method vertical prestressed structure

Abstract

The utility model relates to the technical fields of bridge engineering especially, more particularly to a vertical prestress structure of pretensioning method, including prestressed wire bundle, tension rod, fixed link, connecting sleeve and connecting sleeve, the vertical setting of prestressed wire bundle along concrete beam, and both ends are fixedly connected in connecting sleeve respectively, one end of connecting sleeve is movably connected with connecting sleeve, and the other end selectively connects with tension rod or fixed link, before concrete beam pouring, tension rod can drive the connecting sleeve and connecting sleeve connected with it and go up, and tension prestressed wire bundle to form prestress, the utility model discloses two ends of prestressed wire bundle are anchored on connecting sleeve, and utilize the threaded connection of connecting sleeve and connecting sleeve, realized the adjustment of the tension degree of prestressed wire bundle, effectively solved the difficulty of the connection of the both ends of prestressed wire bundle and tension pedestal or the prestress loss problem caused by the deformation of the connecting portion, and the effect of the vertical prestress of concrete beam was significantly improved.

Description

Technical Field

[0001] This utility model relates to the technical field of bridge engineering, and in particular to a pre-tensioned vertical prestressed structure. Background Technology

[0002] The fundamental characteristics of concrete are high compressive strength and low tensile strength. Therefore, applying prestress to prevent the concrete structure from being under tension is the basic principle of prestressed concrete structures. Concrete beams are structures in bridge engineering that directly support vehicles or other transportation vehicles. They are mainly subjected to bending and shearing forces. Bending forces cause tensile forces at the upper and lower edges of the concrete beam. Therefore, longitudinal prestress is generally applied to pre-load it into a longitudinal compressive state, preventing tension under vehicle loads. For large-span concrete beams, the web is subjected to significant shear forces under shearing action. These shear forces, combined with longitudinal forces, form tensile forces in the principal stress direction. Therefore, vertical prestress is generally applied to pre-load it into a vertical compressive state, preventing tension in the principal stress direction under vehicle loads.

[0003] Longitudinal prestressing is suitable for most concrete beams, while vertical prestressing is generally suitable for long-span continuous concrete beams and large-span bridges derived from them, such as arch bridges, cable-stayed bridges, and suspension bridges. The construction methods for longitudinal prestressing include pre-tensioning and post-tensioning. In the pre-tensioning process, vertical prestressing tendons are installed before pouring the concrete beam, using the upper and lower main beams of a cantilever bridge erecting machine as a platform for tensioning the prestressing. After tensioning, the concrete beam is poured; finally, the tension is released to form preload. In the post-tensioning process, vertical prestressing tendons are pre-embedded before pouring the concrete beam, with sleeves around the tendons to allow for free expansion and contraction. After pouring the concrete beam, the prestressing tendons are tensioned, anchored, and released to form preload; finally, grout is used to fill the gap between the prestressing tendons and the sleeves to form the integral structure. Compared to the pre-tensioning process, the main disadvantages of post-tensioning are lower material utilization and the risk of incomplete compaction during post-grouting.

[0004] However, the application and control of vertical prestressing is relatively complex, requiring precise calculations of the tension and location of the prestressing strands, as well as parameters such as the concrete strength. Improper application can lead to excessive deformation or cracking of the beam under vertical loads, thus affecting its load-bearing capacity and stability. The connection method at both ends of the prestressing strands plays a crucial role in the application of vertical prestress. Conventional connection methods include wedge-type anchors, compression sleeves, or upset anchors. The disadvantage of wedge-type anchors is significant prestress loss, while compression sleeves and upset anchors are difficult to use as structural interfaces for connecting to the tensioning platform. These factors all reduce the prestressing effect, thereby affecting the beam's crack resistance and stiffness. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] This utility model provides a pre-tensioned vertical prestressed structure, which aims to solve the problem of prestress loss caused by the difficulty in connecting the two ends of the prestressing bundle to the tensioning platform or the easy deformation of the connection point during the pre-tensioning process of casting concrete beams.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model proposes a pre-tensioned vertical prestressed structure, including a prestressed wire bundle, a tension rod, a fixing rod, a connecting sleeve, and a connecting bushing.

[0009] The prestressed wire bundle is arranged vertically along the concrete beam, and both ends are fixedly connected to the connecting sleeve.

[0010] One end of the connecting sleeve is movably connected to the connecting sleeve, and the other end is selectively connected to the tension rod or the fixing rod;

[0011] Before the concrete beam is poured, the tension rod can drive the connecting sleeve and connecting sleeve connected to it to move upward and tension the prestressed wire bundle to form prestress.

[0012] A further technical solution is that one end of the connecting sleeve is threadedly connected to the connecting sleeve, and the other end is fixedly connected to the tension rod or the fixing rod.

[0013] A further technical solution is that one end of the connecting sleeve is threadedly connected to the connecting sleeve, and the other end is threadedly connected to the tension rod or the fixing rod.

[0014] A further technical solution is that one end of the connecting sleeve is threadedly connected to the connecting sleeve, and the other end is movably connected to the tension rod or the fixing rod.

[0015] A further technical solution is that the connecting sleeve includes an upper connecting sleeve and a lower connecting sleeve, and the connecting sleeve includes an upper connecting sleeve and a lower connecting sleeve;

[0016] The upper end of the prestressed wire harness is fixedly connected to the upper connecting sleeve, and the lower end is fixedly connected to the lower connecting sleeve.

[0017] The end of the upper connecting sleeve away from the upper connecting sleeve is rotatably connected to the tension rod, and the end of the lower connecting sleeve away from the lower connecting sleeve is rotatably connected to the tension rod.

[0018] A further technical solution is that a pad is provided between the connecting sleeve and the concrete beam. The pad is fixedly connected to the connecting sleeve, and a spiral reinforcement is fixed on the side facing the concrete beam. The spiral reinforcement is coaxially arranged with the prestressed wire bundle. A through hole is opened on the pad, through which the prestressed wire bundle passes.

[0019] A further technical solution is that the prestressed wire bundle is selected from either steel strand or reinforcing bar.

[0020] A further technical solution is that the bottom end of the fixing rod is fixedly connected to the lower main longitudinal beam of the bridge building machine, and the top end of the tensioning rod is fixedly connected to the upper main longitudinal beam of the bridge building machine.

[0021] A further technical solution is that the fixing rod and the tensioning rod are made of threaded steel bars.

[0022] (III) Beneficial Effects

[0023] This invention employs a threaded connection on the connecting sleeve, achieving anchorage of the prestressed wire harness and connection with the tension rod, resulting in minimal prestress loss and high connection reliability. Both ends of the prestressed wire harness are anchored to the connecting sleeve, and the threaded connection between the connecting sleeve and the connecting sleeve allows for adjustment of the prestressed wire harness tension. This effectively prevents deformation of the connecting sleeve and the anchorage point of the prestressed wire harness due to tensile extension, significantly improving the effect of applying vertical prestress to the concrete beam. The threaded connection between the connecting sleeve and the connecting sleeve not only enhances the stability of the connection but also makes the installation and disassembly process exceptionally simple, allowing construction personnel to easily install and adjust, reducing operational difficulty and greatly improving construction efficiency. Simultaneously, the precision of the threaded connection ensures accurate adjustment of the prestressed wire harness tension, improving construction safety. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the pre-tensioned vertical prestressed structure in the following embodiments.

[0025] [Explanation of Labels in the Attached Image]

[0026] 1: Prestressed wire bundle; 2: Spiral reinforcement; 3: Pad; 4: Connecting sleeve; 5: Connecting sleeve; 6: Fixing rod; 7: Tensioning rod. Detailed Implementation

[0027] To better explain and facilitate understanding of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment provides a pre-tensioned vertical prestressed structure, such as... Figure 1As shown, the structure includes a prestressed wire bundle 1, a tension rod 7, a fixing rod 6, a connecting sleeve 4, and a connecting sleeve 5. The prestressed wire bundle 1 is arranged vertically along the concrete beam, and both ends are fixedly connected to the connecting sleeve 4. One end of the connecting sleeve 5 is movably connected to the connecting sleeve 4, and the other end is selectively connected to either the tension rod 7 or the fixing rod 6. Before the concrete beam is poured, the tension rod 7 can drive the connecting sleeve 5 and the connecting sleeve 4 connected to it to move upward and tension the prestressed wire bundle 1 to form prestress. This method of tensioning the prestressed wire bundle 1 first and then pouring concrete will make the prestressed wire bundle 1 and the concrete beam form an integral structure, which can more effectively exert the tensioning effect of the prestressed wire bundle 1.

[0029] Specifically, the prestressed wire bundle 1 is stretched before concrete pouring. Based on its material properties, it forms an elastic force within itself, creating internal stress that enhances the structural strength of the concrete beam and reduces cracking. Tensioning rod 7 is used to fix the top of the prestressed wire bundle 1, providing tension. Fixing rod 6 is used to fix the bottom of the prestressed wire bundle 1, providing a fixing function. Both fixing rod 6 and tensioning rod 7 need to have a certain degree of rigidity to reduce deformation after tensioning. Connecting sleeve 4 is used to anchor both ends of the prestressed wire bundle 1, providing a fixed connection. Connecting sleeve 4 and prestressed wire bundle 1 can be reliably fixed using riveting, welding, or other methods to accommodate larger tension forces. A movable connection is used between connecting sleeve 4 and connecting sleeve 5. This movable connection means that connecting sleeve 4 and connecting sleeve 5 are detachably threaded. Specifically, the connecting sleeve 4 is threaded after being engraved, achieving both anchoring of the prestressed wire bundle 1 and connection to the tensioning platform, resulting in minimal prestress loss and high connection reliability. By using this threaded connection method, a certain relative movement can be formed between the connecting sleeve 4 and the connecting sleeve 5. This relative movement can further adjust the tension of the prestressed wire harness 1, and ultimately achieve the effect of precise control of prestress.

[0030] In summary, the above scheme, by anchoring both ends of the prestressed wire harness 1 to the connecting sleeve 4 and utilizing the threaded connection between the connecting sleeve 4 and the connecting sleeve 5, achieves adjustment of the tension of the prestressed wire harness 1. This effectively avoids deformation of the connecting sleeve 4 and the anchoring point of the prestressed wire harness 1 due to tensile extension, significantly improving the efficiency of applying vertical prestress to the concrete beam. The threaded connection between the connecting sleeve 5 and the connecting sleeve 4 not only enhances the stability of the connection but also makes the installation and disassembly process exceptionally simple, allowing construction personnel to easily install and adjust, reducing operational difficulty and greatly improving construction efficiency. Simultaneously, the precision of the threaded connection ensures that the tension of the prestressed wire harness 1 can be accurately adjusted, improving construction safety.

[0031] In this embodiment, one end of the connecting sleeve 5 is threaded to the connecting sleeve 4, and the other end is movably connected to the tension rod 7 or the fixing rod 6. This connection method allows the prestressed wire harness 1 to disperse and relieve stress when it is under tension through the relative rotation between the connecting sleeve 5 and the tension rod 7 or the fixing rod 6, thereby preventing the structure from being damaged due to stress concentration.

[0032] Specifically, the connecting sleeve 4 includes an upper connecting sleeve and a lower connecting sleeve, and the connecting sleeve 5 includes an upper connecting sleeve and a lower connecting sleeve. The upper end of the prestressed wire harness 1 is fixedly connected to the upper connecting sleeve, and the lower end is fixedly connected to the lower connecting sleeve. The end of the upper connecting sleeve away from the upper connecting sleeve is rotatably connected to the tension rod 7, and the end of the lower connecting sleeve away from the lower connecting sleeve is rotatably connected to the tension rod 7. Both the connection between the upper connecting sleeve and the tension rod 7, and the connection between the lower connecting sleeve and the fixed rod 6, use a pin and hole mating rotatable connection. This allows for better rotation of the upper or lower connecting sleeve to further adjust the tension of the prestressed wire harness 1. Furthermore, this design has good adaptability and can adapt to various complex construction environments. This connection method demonstrates its advantages whether in confined spaces or in situations requiring frequent tension adjustments.

[0033] In this embodiment, a pad 3 is also provided between the connecting sleeve 4 and the concrete beam. The pad 3 is fixedly connected to the connecting sleeve 4, and a spiral reinforcement 2 is fixed on the side facing the concrete beam. The spiral reinforcement 2 is coaxially arranged with the prestressed wire bundle 1. A through hole is opened on the pad 3, through which the prestressed wire bundle 1 passes.

[0034] A pad 3 is added to the connecting sleeve 4 to allow the prestress to be transferred more evenly to the concrete beam. This avoids relative slippage between the prestressing strand 1 and the concrete caused by the retraction of the prestressing strand 1 after tensioning, thus enhancing the overall structural integrity. Specifically, the pad 3 is made of steel plate and welded to the connecting sleeve 4. The pad 3 enhances the connection strength between the connecting sleeve 4 and the concrete beam, making the entire structure more stable. As a transition component between the connecting sleeve 4 and the concrete beam, the pad 3 effectively disperses and alleviates the stress generated by the tensioning of the prestressing strand 1, thereby preventing structural damage due to stress concentration. Secondly, the spiral reinforcement 2 is coaxially arranged with the prestressing strand 1, which further improves the prestress transfer efficiency. The presence of the spiral reinforcement 2 increases the bond strength between the prestressing strand 1 and the concrete beam, allowing the prestress to be transferred more evenly to the concrete beam, thereby improving the load-bearing capacity of the entire structure.

[0035] Specifically, the prestressed wire harness 1 is preferably made of steel strand, which has good bonding performance with concrete. Of course, prestressed steel bars, prestressed steel rods, carbon fiber composite cables, etc. can also be used.

[0036] In this embodiment, the bottom end of the fixing rod 6 is fixedly connected to the lower main longitudinal beam of the bridge-building machine, and the top end of the tensioning rod 7 is fixedly connected to the upper main longitudinal beam of the bridge-building machine. Specifically, the upper and lower main longitudinal beams of the bridge-building machine serve as tensioning platforms for the prestressed wire harness 1, providing support and fixation.

[0037] Specifically, in this embodiment, the fixing rod 6 and the tensioning rod 7 are made of threaded steel bars.

[0038] The specific construction steps in this embodiment are as follows:

[0039] The working length of the prestressed wire harness 1 (steel strand) is determined according to the height of the beam segment. The factory cuts the material and marks the anchoring position. The steel strand is anchored using connecting sleeve 4. After anchoring, the connecting sleeve 4 is threaded and shipped from the factory. After the cantilever bridge-building machine is in place on site, the prestressed wire harness 1, pad 3, and spiral reinforcement 2 are installed and temporarily fixed. The lower end of the prestressed wire harness 1 is connected to the lower main longitudinal beam of the bridge-building machine through connecting sleeve 5 and fixing rod 6 to complete the fixing operation. The upper end of the prestressed steel strand is connected to the upper main longitudinal beam of the bridge-building machine through connecting sleeve 5 and tension rod 7 to complete the tensioning operation. The beam segment concrete is poured. The prestress is released, and the tension rod 7, fixing rod 6, and connecting sleeve 5 are removed. The cantilever bridge-building machine is moved forward, and the above steps are repeated.

[0040] In another embodiment, one end of the connecting sleeve 5 is threadedly connected to the connecting sleeve 4, and the other end is fixedly connected to the tension rod 7 or the fixing rod 6.

[0041] In another embodiment, one end of the connecting sleeve 5 is threaded to the connecting sleeve 4, and the other end is threaded to the tension rod 7 or the fixing rod 6.

[0042] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicator will also change accordingly.

[0043] In this embodiment, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this embodiment according to the specific circumstances.

[0044] It should be understood that the above description of the specific embodiments of this utility model is only for illustrating the technical route and features of this utility model, and its purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. However, this utility model is not limited to the specific embodiments described above. All changes or modifications made within the scope of the claims of this utility model should be covered by the protection scope of this utility model.

Claims

1. A pre-tensioned vertical prestressed structure, characterized in that, It includes a prestressed wire harness (1), a tension rod (7), a fixing rod (6), a connecting sleeve (4), and a connecting sleeve (5); The prestressed wire bundle (1) is arranged vertically along the concrete beam, and both ends are fixedly connected to the connecting sleeve (4); One end of the connecting sleeve (5) is movably connected to the connecting sleeve (4), and the other end is selectively connected to the tension rod (7) or the fixing rod (6); Before the concrete beam is poured, the tension rod (7) can drive the connecting sleeve (5) and connecting sleeve (4) connected to it to move upward and tension the prestressed wire bundle (1) to form prestress.

2. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, One end of the connecting sleeve (5) is threadedly connected to the connecting sleeve (4), and the other end is fixedly connected to the tension rod (7) or the fixing rod (6).

3. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, One end of the connecting sleeve (5) is threaded to the connecting sleeve (4), and the other end is threaded to the tension rod (7) or the fixing rod (6).

4. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, One end of the connecting sleeve (5) is threadedly connected to the connecting sleeve (4), and the other end is movably connected to the tension rod (7) or the fixing rod (6).

5. The pre-tensioned vertical prestressed structure as described in claim 4, characterized in that, The connecting sleeve (4) includes an upper connecting sleeve and a lower connecting sleeve, and the connecting sleeve (5) includes an upper connecting sleeve and a lower connecting sleeve; The upper end of the prestressed wire harness (1) is fixedly connected to the upper connecting sleeve, and the lower end is fixedly connected to the lower connecting sleeve. The end of the upper connecting sleeve away from the upper connecting sleeve is rotatably connected to the tension rod (7), and the end of the lower connecting sleeve away from the lower connecting sleeve is rotatably connected to the tension rod (7).

6. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, A pad (3) is also provided between the connecting sleeve (4) and the concrete beam. The pad (3) is fixedly connected to the connecting sleeve (4), and a spiral reinforcement (2) is fixed on the side facing the concrete beam. The spiral reinforcement (2) is coaxially arranged with the prestressed wire bundle (1). A through hole is opened on the pad (3), through which the prestressed wire bundle (1) passes.

7. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, The prestressed wire bundle (1) is selected from either steel strand or steel bar.

8. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, The bottom end of the fixed rod (6) is fixedly connected to the lower main longitudinal beam of the bridge building machine, and the top end of the tension rod (7) is fixedly connected to the upper main longitudinal beam of the bridge building machine.

9. The pre-tensioned vertical prestressed structure as described in claim 1, characterized in that, The fixing rod (6) and the tensioning rod (7) are made of threaded steel bars.

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