Prefabricated pre-stressed anchoring block and assembling method

Abstract

The invention provides a prefabricated pre-stressed anchoring block and an assembling method, the prefabricated pre-stressed anchoring block comprises a post-tensioned pre-stressed concrete structure, and the pre-stressed anchoring block comprises an anchoring block main body prefabricated by an internal steel reinforcement framework and external high-performance concrete; protruding blocks which are evenly arranged in the arrangement direction of prestressed steel beams are arranged on the interface face of the anchoring block body and the post-tensioned prestressed concrete structure and used for forming a key groove mechanical meshing structure which is in concave-convex fit with box girder concrete outside the post-tensioned prestressed concrete structure. Extending steel bars extending out of a steel bar framework in the anchoring block body are arranged on the interface of the anchoring block body and the post-tensioned prestressed concrete structure and used for being anchored to a box girder steel bar framework in the post-tensioned prestressed concrete structure. The anchoring block main body is prefabricated in a factory, and the internal steel reinforcement framework and the external high-performance concrete are integrally formed, so that the compactness and the mechanical property of the concrete in the anchoring area are remarkably improved, and the problems that the concrete is not compact in pouring, easy to crush or split and the like due to dense steel reinforcements in the traditional cast-in-place anchoring area are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of prefabricated anchor blocks, and in particular to a prefabricated prestressed anchor block and its assembly method. Background Technology

[0002] Long-span prestressed concrete bridge structures typically have prestressed anchorage zones inside the box girder and at the girder ends to transfer and diffuse the enormous concentrated forces generated by the high-strength prestressed steel strands. Existing anchorage zones mainly consist of anchor plates, helical reinforcement under the anchor, additional anti-collapse reinforcement, locally reinforcing stirrups, and post-anchor concrete.

[0003] However, engineering practice and numerous case studies of structural defects reveal significant technical bottlenecks in traditional anchorage zones: to meet local bearing capacity and splitting resistance requirements, the reinforcement is arranged abnormally densely, with the spacing often less than the minimum allowable clear distance in the specifications. This leads to difficulties in aggregate passage and insufficient vibration during concrete pouring, easily resulting in defects such as voids, honeycombing, and segregation. Simultaneously, the combination of high stress concentration and low density causes frequent brittle failures in the anchorage zone during the prestressing tensioning stage or early operation, including localized concrete crushing, oblique splitting, and back-end cracking of the anchor plate. Such damage often necessitates the removal of damaged concrete, re-installation of reinforcement, and secondary pouring, sometimes even requiring external steel plates or carbon fiber reinforcement. This not only significantly increases construction costs and time but also severely weakens the structure's integrity, durability, and long-term service reliability. Therefore, a prefabricated prestressed anchorage block and its assembly method are proposed to address these issues. Summary of the Invention

[0004] The main objective of this invention is to provide a prefabricated prestressed anchor block and its assembly method, which solves the problems of dense reinforcement in existing cast-in-place anchor zones, difficulty in concrete pouring, and susceptibility to crushing and splitting damage, resulting in difficulty in ensuring construction quality and insufficient structural safety and durability.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a prefabricated prestressed anchor block and assembly method, including a post-tensioned prestressed concrete structure. The prestressed anchor block includes an anchor block body prefabricated from an internal steel reinforcement skeleton and an external high-performance concrete. The interface between the anchor block body and the post-tensioned prestressed concrete structure is provided with protrusions evenly arranged along the prestressed steel strand arrangement direction, which are used to form a keyway mechanical interlocking structure with the box girder concrete outside the post-tensioned prestressed concrete structure. The interface between the anchor block body and the post-tensioned prestressed concrete structure is provided with protruding steel bars extending from its internal steel reinforcement skeleton. The protruding steel bars are used to anchor with the box girder steel reinforcement skeleton inside the post-tensioned prestressed concrete structure. The anchor block body is also provided with tensioning holes for the prestressed steel strands to pass through.

[0006] In the preferred embodiment, the protruding end of the protruding reinforcing bar is also provided with an anchoring part; The bump has a conical structure.

[0007] In the preferred embodiment, the tooth height of the protrusion is 1 / 5 to 1 / 4 of the height of the concrete section of the box girder.

[0008] In the preferred embodiment, the protruding reinforcing bars include side protruding reinforcing bars and bottom protruding reinforcing bars. The side protruding reinforcing bars are secondary connecting reinforcing bars. The reinforcing bar skeleton inside the anchor block body is provided with connecting sleeves that are compatible with the side protruding reinforcing bars. The connecting sleeves are pre-embedded in the anchor block body so that the side protruding reinforcing bars can be accurately inserted and locked during on-site installation.

[0009] In the preferred embodiment, the protrusion includes a side protrusion and a bottom protrusion. The bottom protrusion can be inserted into the gap of the steel mesh in the bottom plate of the box girder steel reinforcement skeleton, and its conical profile is used to automatically center and guide the positioning during the lowering process.

[0010] In the preferred embodiment, the anchoring part includes side anchors and bottom anchors. The bottom anchor is a pre-embedded anchor frame, which is fixedly installed on the lower layer of steel mesh on the bottom plate of the box girder steel reinforcement skeleton. It is provided with a hole corresponding to each bottom protruding steel bar. The bottom of the bottom protruding steel bar is provided with a locking component that can pass through the hole and form a locking structure with the bottom anchor.

[0011] In the preferred embodiment, the locking assembly includes a locking sleeve provided at the bottom end of the reinforcing bar extending from the bottom surface. The top of the locking sleeve is provided with a limiting top plate, and the bottom is provided with an elastic locking part. The size of the limiting top plate is larger than the size of the insertion hole. The elastic locking part can retract when it is inserted through the insertion hole and reset to form a locking structure after it passes through. The gap between the elastic locking part and the limiting top plate is adapted to the width of the side anchor, and the side anchor can be embedded in the gap.

[0012] In the preferred embodiment, the elastic locking part specifically includes an installation cavity that runs through the lower part of the locking sleeve. Both the upper and lower ends of the installation cavity are provided with limiting grooves. Two symmetrically arranged locking blocks are movably installed in the installation cavity. The outer ends of the locking blocks extend to the outside of the installation cavity. Their tops are used to form a locking fit with the edge of the insertion hole of the bottom anchor. The bottom is provided with a retraction guide slope so that it can slide and retract inward when squeezed when inserted into the insertion hole. The inner end of the locking block is provided with a limiting slider that slides and engages with the limiting groove. A telescopic spring is provided between the two locking blocks, which pushes the two locking blocks to open outward under normal conditions.

[0013] In the preferred embodiment, the locking sleeve is provided with a telescopic locking part, which includes a sliding cavity. The locking sleeve is slidably fitted onto the bottom of the bottom protruding steel bar through the sliding cavity. Two limiting grooves are symmetrically arranged on the inner wall of the sliding cavity. A limiting block that slides with the limiting groove is provided at the bottom of the bottom protruding steel bar. An opening is provided between the sliding cavity and the mounting cavity. A locking plug that can pass through the opening and exit the mounting cavity is provided at the bottom end of the bottom protruding steel bar. The locking plug is used to lock the two locking blocks in the open state. A tension spring is provided in the sliding cavity and fitted outside the locking plug. The tension spring is located between the bottom wall of the sliding cavity and the bottom end of the bottom protruding steel bar, so that the locking plug is normally kept in the retracted state. The insertion hole is an elongated hole, and the bottom end of the locking sleeve is equipped with a tapered head.

[0014] The method includes: S1. Prefabrication of the anchor block main body; S2, Assembly of the steel reinforcement cage for the box girder; S3. Prefabricated connection: The main body of the anchor block is hoisted to the installation area of ​​the box girder reinforcement cage, and the protruding steel bars of the main body of the anchor block are connected to the box girder reinforcement cage. S4. Install the box girder formwork system and pour the box girder concrete.

[0015] This invention provides a prefabricated prestressed anchor block and its assembly method. By prefabricating the main body of the anchor block in a factory, integrating the internal steel reinforcement skeleton with the external high-performance concrete, the density and mechanical properties of the concrete in the anchor zone are significantly improved. This effectively avoids problems such as insufficient concrete density, easy crushing, or splitting caused by dense reinforcement in traditional cast-in-place anchor zones. The protrusions evenly distributed along the direction of the prestressed steel strands at the interface between the anchor block and the box girder form a keyway structure with the subsequently poured box girder concrete, greatly enhancing the interface shear bearing capacity and overall synergistic performance. At the same time, the protruding steel bars extending from the anchor block can reliably connect with the box girder reinforcement skeleton, ensuring continuous force transmission, while the built-in tensioning holes provide precise channels for the prestressed steel strands, facilitating tensioning construction. The overall structure combines the precision of industrial prefabrication with the convenience of on-site assembly, simplifying the construction process of complex high-altitude nodes and significantly improving the structural safety, durability, and construction quality control of the prestressed anchor zone. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a structural diagram of the anchor block in Embodiment 1 of the present invention; Figure 2 This is a structural diagram showing the connection between the anchor block body and the post-tensioned prestressed concrete structure base plate in Embodiment 1 of the present invention. Figure 3This is a structural diagram of the anchor block body and the end section of the post-tensioned prestressed concrete structure according to Embodiment 1 of the present invention; Figure 4 This is an assembly flowchart of Embodiment 1 of the present invention; Figure 5 This is a cross-sectional view of the anchor block body in Embodiment 3 of the present invention; Figure 6 This is a diagram illustrating the interlocking structure between the bottom protrusion and the bottom reinforcing bars of the box girder reinforcement skeleton in Embodiment 3 of the present invention. Figure 7 This is a structural diagram of the anchor block in Embodiment 4 of the present invention; Figure 8 This is a structural diagram of the bottom anchor of Embodiment 4 of the present invention; Figure 9 This is a half-sectional view of the locking component according to Embodiment 4 of the present invention; Figure 10 This is a half-sectional view of the locking assembly and bottom anchor of Embodiment 4 of the present invention; Figure 11 This is an assembly flowchart of Embodiment 4 of the present invention.

[0017] In the diagram: Anchor block body 1; Protrusion 2; Side protrusion 21; Bottom protrusion 22; Extended reinforcing bar 3; Bottom extended reinforcing bar 31; Side extended reinforcing bar 32; Connecting sleeve 320; Anchoring part 4; Side anchor 41; Bottom anchor 42; Insertion hole 420; Tensioning hole 5; Box girder reinforcing bar skeleton 6; Post-tensioned prestressed concrete structure 7; Locking assembly 8; Locking sleeve 80; Elastic locking part 81; Installation cavity 810; Limiting groove 811; Locking block 812; Telescopic spring 813; Limiting slider 814; Limiting top plate 82; Telescopic locking part 83; Sliding cavity 830; Limiting groove 831; Limiting block 832; Tension spring 833; Locking plug 834; Opening 835; Conical head 84. Detailed Implementation

[0018] Example 1 like Figure 1-3 As shown, a prefabricated prestressed anchor block includes a post-tensioned prestressed concrete structure 7 and an anchor block body 1. The post-tensioned prestressed concrete structure 7 is composed of an internal box girder steel reinforcement skeleton 6 and an externally cast box girder concrete. In this embodiment, the post-tensioned prestressed concrete structure 7 is a concrete box girder structure.

[0019] After the box girder reinforcement cage 6 is tied, the anchor block body 1 is installed in the preset position of the box girder reinforcement cage 6 before the box girder concrete is poured. The anchor block body 1 is prefabricated from the internal reinforcement cage and the external high-performance concrete. Its specific shape can be adjusted according to the needs of use. The high-performance concrete can be ultra-high performance concrete (UHPC) or fiber-reinforced concrete, with a compressive strength of not less than 100 MPa. Multiple protrusions 2 are provided at the interface between the anchor block body 1 and the post-tensioned prestressed concrete structure 7. The protrusions 2 are evenly arranged along the arrangement direction of the prestressed steel strands, so that a keyway mechanical interlocking structure with the post-tensioned prestressed concrete structure 7 can be formed. The protrusions 2 and the anchor block body 1 are integrally formed. At the interface between the anchor block body 1 and the post-tensioned prestressed concrete structure 7, there are protruding steel bars 3 extending from its internal reinforcement cage. The protruding steel bars 3 extend into the box girder reinforcement cage 6 and are anchored thereto, so as to ensure the shear bearing capacity of the interface. The anchor block body 1 is also provided with tensioning holes 5 for the prestressed steel strands to pass through.

[0020] In this embodiment, the interface between the anchor block body 1 and the post-tensioned prestressed concrete structure 7 includes the ground and one side.

[0021] Furthermore, the tooth height of protrusion 2 is 1 / 5 to 1 / 4 of the height of the concrete section of the box girder. By increasing the mechanical interlocking effect of the joint surface, the shear bearing capacity of the interface is significantly improved, ensuring that there is no relative slippage between the precast anchor block and the cast-in-place box girder under the load of prestressing tension and service stage, thus meeting the overall stress and safety requirements of the structure.

[0022] Furthermore, the protruding end of the protruding reinforcing bar 3 is also provided with an anchoring part 4. In this embodiment, the anchoring part 4 is a steel plate, which is welded to the end of the protruding reinforcing bar 3. This improves the anchoring effect and reduces the anchoring length, making it easier to assemble the whole. In addition, by hooking it with the box girder reinforcing bar skeleton 6, it can temporarily fix the anchoring block body 1. The size of the steel plate is smaller than the grid formed by the box girder reinforcing bar skeleton 6, so it can be directly inserted into the box girder reinforcing bar skeleton 6.

[0023] Furthermore, the protrusion 2 has a conical structure, and the sloping surface formed around it facilitates interface shaping.

[0024] It should be noted that the anchor block body 1 is formed by first binding a customized steel reinforcement skeleton in the factory, then pouring high-performance concrete into an adjustable mold, and after curing and demolding, it forms a precast component with flexible shape and reliable performance. The mold meets the requirements of the steel reinforcement 3 passing through and the tensioning hole 5 being formed, and its interior is provided with a concave-convex structure to form the protrusion 2.

[0025] This design avoids the problem of difficult concrete pouring in areas with dense steel reinforcement on site by using separately prefabricated anchor block body 1. At the same time, it simplifies the steel reinforcement layout in the anchoring area, optimizes the force transmission path, significantly improves the construction quality of the anchoring area, avoids the risk of tension bursting and rework, and can also greatly reduce costs through the standardized design and production of anchor block body 1.

[0026] Example 2 Further explanation in conjunction with Example 1, such as Figure 4 The structure shown illustrates a method for assembling a prefabricated prestressed anchor block, the method comprising: S1. Anchor block body 1 is prefabricated. According to the design requirements, the steel reinforcement skeleton of anchor block body 1 is precisely arranged in the prefabrication yard. The steel reinforcement skeleton is fixed in the mold using positioning clamps to ensure accurate positioning of the protruding steel bars 3 of anchor block body 1. Then, high-performance concrete is poured into the mold in layers and fully vibrated to ensure that the inside of the toothed block is dense and free of voids. It is cured according to the standard curing system. After the concrete strength reaches the design requirements, it is transported to the construction site.

[0027] S2. Assemble the box girder steel reinforcement cage in 6 groups according to the design drawings. Reserve installation space in advance in the installation area of ​​the corresponding anchor block body 1, and appropriately reduce the local steel reinforcement configuration. After the anchor block body 1 is in place, the missing steel reinforcement will be added to ensure reliable connection and structural integrity.

[0028] S3. Prefabricated connection: The prefabricated anchor block body 1 is hoisted to the installation area of ​​the box girder reinforcement cage 6. After the reinforcement in the installation area is completed, the protruding reinforcement 3 of the anchor block body 1 is reliably connected to the main reinforcement of the box girder reinforcement cage 6 by welding or mechanical connection to ensure continuous force flow. Before the connection is completed, temporary supports can be set to ensure the stability of the connection. The position, elevation and size of the prefabricated anchor block body 1 after installation are checked, and fine adjustments are made if necessary to ensure that the design and specification requirements are met.

[0029] S4. Install the box girder formwork system, pour the box girder concrete in layers and vibrate it thoroughly to ensure good bonding between the old and new concrete and no cold joints. After pouring, cover and moisturize or steam curing as required to ensure the overall structural quality.

[0030] With this design, the anchor block body 1 and the box girder steel reinforcement skeleton 6 can be manufactured simultaneously, shortening the construction cycle. Furthermore, the binding and forming of the box girder steel reinforcement skeleton 6 is not affected by the anchoring zone, making the assembly and construction simple and quick, and significantly improving construction efficiency.

[0031] Example 3 Further explanation in conjunction with Examples 1 and 2, such as Figure 5The structure shown includes protruding reinforcing bars 32 on the sides and protruding reinforcing bars 31 on the bottom. To address the problem of difficulty in aligning with the box girder's reinforcing cage and inconvenience in installation caused by the protruding reinforcing bars 3 on both the bottom and sides of the anchor block body 1 and the fixed, non-adjustable internal reinforcing cage, the protruding reinforcing bars 32 on the sides are designated as secondary connecting reinforcing bars. Connecting sleeves 320 adapted to the protruding reinforcing bars 32 are installed on the internal reinforcing cage of the anchor block body 1. The connecting sleeves 320 are pre-embedded in the anchor block body 1. Before the anchor block body 1 is cast, the connecting sleeves 320 are fitted onto the designated position of the reinforcing cage of the anchor block body 1, ensuring that their axis is consistent with the designed insertion direction of the reinforcing bars. During the concrete pouring process, the connecting sleeves 320 are completely embedded in the high-performance concrete, forming a reliable pre-embedded connection node, so that the protruding reinforcing bars 32 on the sides can be accurately inserted and locked during on-site installation, achieving an efficient, adjustable, and clearly defined prefabricated connection.

[0032] The bottom protruding steel bar 31 and the steel bar skeleton inside the anchor block body 1 are integrally molded, that is, they are tied together and poured into high-performance concrete as a whole during the prefabrication stage to form a rigid and reliable connection structure. This method simplifies the on-site installation process and improves the convenience of positioning while ensuring the continuity of structural stress. It can also effectively reduce the use of connecting sleeves 320, thereby effectively reducing costs.

[0033] This design allows for the direct binding and shaping of the entire box girder steel reinforcement skeleton 6 without reserving installation gaps in the installation area of ​​the anchor block body 1 during the assembly of the 6 groups of the box girder steel reinforcement skeleton. When installing the anchor block body 1, the bottom protruding steel bar 31 is aligned with the gaps in the bottom plate steel reinforcement mesh of the box girder steel reinforcement skeleton 6, and the anchor block body 1 is vertically lowered so that the bottom protruding steel bar 31 can be smoothly inserted between the bottom plate steel reinforcement mesh until the anchor block body 1 is at the preset elevation and position. Subsequently, the end of the side protruding steel bar 32 is inserted from the side of the box girder steel reinforcement skeleton 6 and screwed into the pre-embedded connecting sleeve 320 inside the anchor block body 1 to complete a reliable connection. This method takes into account both construction efficiency and installation accuracy, and realizes efficient prefabricated construction by binding the entire structure first and then embedding it for installation.

[0034] In the preferred solution, such as Figure 6As shown in the diagram, the protrusion 2 includes a side protrusion 21 and a bottom protrusion 22. To further improve the installation accuracy of the anchor block body 1, the bottom protrusion 22 can be inserted into the gaps in the bottom plate steel mesh of the box girder steel skeleton 6. Its tapered profile automatically centers and guides positioning during the lowering process, effectively reducing deviation and further improving the shear resistance of the interface. Furthermore, to avoid affecting the aforementioned convenient installation method, the side protrusion 21 is located on the side of the web steel reinforcement of the box girder steel skeleton 6, avoiding the main web reinforcement, ensuring that the anchor block can be smoothly lowered into place. During subsequent cast-in-place concrete pouring, a reliable mechanical interlocking interface is formed with it, thereby synergistically improving the shear bearing capacity of the interface and the overall workability. Secondly, with this design, the anchor block body 1 can be directly placed on the bottom plate steel mesh of the box girder steel skeleton 6. Stable support is achieved by the interlocking of the bottom protrusion 22 with the steel mesh and the insertion and limiting effect of the bottom protruding steel bar 31. This method does not require additional temporary support structure to complete the temporary fixation of the anchor block body 1, which simplifies the construction process and ensures the stability and accuracy of the installation position.

[0035] Example 4 Further explanation in conjunction with Example 3, such as Figure 7-11 As shown in the structure, the anchoring part 4 includes a side anchor 41 and a bottom anchor 42. The structure of the side anchor 41 is the same as described in Embodiment 1, and it is welded to the end of the side protruding steel bar 32. Since the anchoring block body 1 is installed and its own structure blocks the bottom, it is not convenient to fix the bottom protruding steel bar 31 to the box girder steel reinforcement skeleton 6. Therefore, the bottom anchor 42 is a pre-embedded anchoring frame, which is fixedly installed on the lower layer of steel mesh on the bottom plate of the box girder steel reinforcement skeleton 6. It is provided with a socket 420 corresponding to each bottom protruding steel bar 31. The socket 420 is an elongated hole. The bottom of the bottom protruding steel bar 31 is provided with a locking component 8 that can pass through the socket 420 and form a locking structure with the bottom anchor 42.

[0036] The locking assembly 8 includes a locking sleeve 80 provided at the bottom end of the protruding reinforcing bar 31 on the bottom surface. The top of the locking sleeve 80 is provided with a limiting top plate 82, and the bottom is provided with an elastic locking part 81. The size of the limiting top plate 82 is larger than the size of the insertion hole 420. The elastic locking part 81 can retract when it is inserted through the insertion hole 420 and reset after passing through to form a locking structure. The gap between the elastic locking part 81 and the limiting top plate 82 is adapted to the width of the side anchor 41. The side anchor 41 can be embedded in the gap, thereby forming a clamping structure between the limiting top plate 82 and the elastic locking part 81, forming a reliable anti-disengagement locking structure.

[0037] It should be noted that the elastic locking part 81 and the insertion hole 420 are arranged in a cross shape, that is, the unfolding direction of the elastic locking part 81 is perpendicular to the elongated extension direction of the insertion hole 420; the elongated hole design of the insertion hole 420 is convenient to adapt to the positional deviation of the bottom protruding steel bar 31 during the installation and alignment process, and provides adjustment margin along the length of the hole.

[0038] In addition, the bottom end of the locking sleeve 80 is provided with a conical head 84, which has a guiding function. During the process of the locking assembly 8 being inserted into the elongated insertion hole 420 of the bottom anchor 42, it can smoothly guide the elastic locking part 81 to align and pass smoothly through the insertion hole, reducing the risk of jamming or deflection. At the same time, the conical head 84 can also automatically correct the insertion angle when initially contacting the edge of the insertion hole, further improving the installation tolerance and construction convenience.

[0039] Specifically, the elastic locking part 81 includes a mounting cavity 810 that extends through the lower part of the locking sleeve 80. Both the upper and lower ends of the mounting cavity 810 are provided with limiting grooves 811. Two symmetrically arranged locking blocks 812 are movably installed in the mounting cavity 810. The outer ends of the locking blocks 812 extend outside the mounting cavity 810, and their tops are used to form a locking fit with the edge of the insertion hole 420 of the bottom anchor 42. The bottom is provided with a retraction guide slope so that it slides inward under pressure when inserted into the insertion hole 420. The inner end of the locking block 812 is provided with a limiting groove 811. The sliding limit slider 814 ensures that the locking block 812 can only reciprocate in the horizontal direction without disengaging. A telescopic spring 813 is provided between the two locking blocks 812. Under normal conditions, the spring pushes the two locking blocks 812 outward, so that their outer ends protrude from the outer wall of the locking sleeve 80. When passing through the insertion hole 420, the retraction guide slope is squeezed by the edge of the hole, and the locking block 812 overcomes the spring force and retracts inward. After passing through smoothly, it automatically resets and opens under the action of the telescopic spring 813, and is locked to the bottom surface of the bottom anchor 42, thus forming a reliable and self-locking mechanical anchoring structure.

[0040] In a preferred embodiment, in order to further lock the elastic locking part 81 and prevent the elastic locking part 81 from accidentally retracting during vibration or stress, a telescopic locking part 83 is provided in the locking sleeve 80. The telescopic locking part 83 includes a sliding cavity 830, and the locking sleeve 80 is slidably fitted onto the bottom of the bottom of the protruding steel bar 31 through the sliding cavity 830.

[0041] Two limiting grooves 831 are symmetrically arranged on the inner wall of the sliding cavity 830. A limiting block 832 that slides in conjunction with the limiting groove 831 is provided at the bottom of the bottom of the protruding steel bar 31. The two work together to restrict the locking sleeve 80 to slide only along the axial direction, thus preventing rotational deviation.

[0042] An opening 835 is provided between the sliding cavity 830 and the mounting cavity 810. The bottom end of the bottom protruding steel bar 31 is provided with a locking plug 834 that can pass through the opening 835 into and out of the mounting cavity 810. The locking plug 834 is used to lock the two locking blocks 812 in the open state. When the two locking blocks 812 of the elastic locking part 81 are opened to the position under the action of the telescopic spring 813, the bottom protruding steel bar 31 continues to be pressed down during the installation process. The limiting top plate 82 at its bottom end contacts the upper surface of the bottom anchor 42 and generates a squeezing force. This reaction force pushes the locking sleeve 80 upward along the bottom protruding steel bar 31. During this process, the locking sleeve 80 moves upward relative to the steel bar, so that the originally retracted locking plug 834 passes through the opening 835 into the mounting cavity 810 and is precisely inserted into the gap between the two opened locking blocks 812. It mechanically prevents the locking blocks 812 from retracting inward from the inside, thereby achieving reliable secondary locking of the elastic locking part 81 in the open state.

[0043] A tension spring 833 is provided in the sliding cavity 830 and is fitted outside the locking plug 834. The tension spring 833 is located between the bottom wall of the sliding cavity 830 and the bottom end of the bottom protruding steel bar 31. Under normal conditions, the tension spring 833 provides downward preload to keep the locking plug 834 in the retracted state and avoid prematurely interfering with the retraction action of the locking block 812.

[0044] It should be noted that the elastic coefficient of the tension spring 833 is greater than that of the extension spring 813. During the initial insertion stage, the locking block 812 can be smoothly compressed by the edge of the insertion hole 420 because the required force is small.

[0045] With this design, when assembling the box girder steel reinforcement skeleton 6, the bottom anchor 42 is fixedly installed at the designated position of the lower layer of steel reinforcement mesh on the bottom plate, ensuring that it corresponds precisely with the installation coordinates of the subsequent anchor block body 1; the anchor block body 1 is lowered vertically, and its bottom protrusion 22 is inserted into the gap of the bottom plate steel reinforcement mesh to achieve guidance; the bottom protruding steel bar 31 then passes through the insertion hole 420, so that the limiting top plate 82 and the elastic locking part 81 form a clamping structure, forming a reliable anti-disengagement locking structure. Continuing to press down, the limiting top plate 82 contacts the upper surface of the bottom anchor 42, and the reaction force pushes the locking sleeve 80 upward, triggering the locking plug 824 to be inserted between the two locking blocks 812, completing the double mechanical locking of the elastic locking part 81.

[0046] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A precast prestressed anchor block, comprising a post-tensioned prestressed concrete structure (7), characterized in that: The prestressed anchor block includes an anchor block body (1) made of an internal steel reinforcement skeleton and an external high-performance concrete precast. The interface between the anchor block body (1) and the post-tensioned prestressed concrete structure (7) is provided with protrusions (2) evenly arranged along the prestressed steel strand arrangement direction, which are used to form a keyway mechanical interlocking structure with the box girder concrete outside the post-tensioned prestressed concrete structure (7). The interface between the anchor block body (1) and the post-tensioned prestressed concrete structure (7) is provided with protruding steel bars (3) extending from its internal steel reinforcement skeleton. The protruding steel bars (3) are used to anchor with the box girder steel reinforcement skeleton (6) inside the post-tensioned prestressed concrete structure (7). The anchor block body (1) is also provided with tensioning holes (5) for the prestressed steel strands to pass through.

2. The prefabricated prestressed anchor block according to claim 1, characterized in that: The protruding end of the protruding steel bar (3) is also provided with an anchoring part (4); The bump (2) is a cone-shaped structure.

3. A prefabricated prestressed anchor block according to claim 1 or 2, characterized in that: The tooth height of the protrusion (2) is 1 / 5 to 1 / 4 of the height of the concrete section of the box girder.

4. The prefabricated prestressed anchor block according to claim 2, characterized in that: The protruding reinforcing bars (3) include side protruding reinforcing bars (32) and bottom protruding reinforcing bars (31). The side protruding reinforcing bars (32) are secondary connecting reinforcing bars. The reinforcing bar skeleton inside the anchor block body (1) is provided with a connecting sleeve (320) that is compatible with the side protruding reinforcing bars (32). The connecting sleeve (320) is embedded in the anchor block body (1) so that the side protruding reinforcing bars (32) can be accurately inserted and locked during on-site installation.

5. The prefabricated prestressed anchor block according to claim 4, characterized in that: The protrusion (2) includes a side protrusion (21) and a bottom protrusion (22). The bottom protrusion (22) can be inserted into the gap of the bottom plate steel mesh of the box girder steel skeleton (6) and automatically center and guide the positioning during the lowering process by utilizing its conical profile.

6. The prefabricated prestressed anchor block according to claim 5, characterized in that: The anchoring part (4) includes a side anchor (41) and a bottom anchor (42). The bottom anchor (42) is a pre-embedded anchoring frame and is fixedly installed on the lower layer of steel mesh on the bottom plate of the box girder steel skeleton (6). It is provided with a socket (420) corresponding to each bottom protruding steel bar (31). The bottom of the bottom protruding steel bar (31) is provided with a locking component (8) that can pass through the socket (420) and form a locking structure with the bottom anchor (42).

7. The prefabricated prestressed anchor block according to claim 6, characterized in that: The locking assembly (8) includes a locking sleeve (80) provided at the bottom end of the bottom protruding steel bar (31). The top of the locking sleeve (80) is provided with a limiting top plate (82) and the bottom is provided with an elastic locking part (81). The size of the limiting top plate (82) is larger than the size of the insertion hole (420). The elastic locking part (81) can retract when it is inserted through the insertion hole (420) and reset after passing through to form a locking structure. The gap between the elastic locking part (81) and the limiting top plate (82) is adapted to the width of the side anchor (41). The side anchor (41) can be embedded in the gap.

8. The prefabricated prestressed anchor block according to claim 7, characterized in that: The elastic locking part (81) specifically includes an installation cavity (810) that runs through the lower part of the locking sleeve (80). The upper and lower ends of the installation cavity (810) are provided with limit grooves (811). Two symmetrically arranged locking blocks (812) are movably installed in the installation cavity (810). The outer end of the locking block (812) extends to the outside of the installation cavity (810). Its top is used to form a locking fit with the edge of the insertion hole (420) of the bottom anchor (42). The bottom is provided with a retraction guide slope so that it can slide and retract inward when inserted into the insertion hole (420). The inner end of the locking block (812) is provided with a limit slider (814) that slides with the limit groove (811). A telescopic spring (813) is provided between the two locking blocks (812), which pushes the two locking blocks (812) to open outward under normal conditions.

9. A prefabricated prestressed anchor block according to claim 8, characterized in that: The locking sleeve (80) is provided with a telescopic locking part (83), which includes a sliding cavity (830). The locking sleeve (80) is slidably fitted onto the bottom of the bottom protruding steel bar (31) through the sliding cavity (830). Two limiting grooves (831) are symmetrically arranged on the inner wall of the sliding cavity (830). A limiting block (832) that slides with the limiting groove (831) is provided at the bottom of the bottom protruding steel bar (31). An opening (832) is provided between the sliding cavity (830) and the mounting cavity (810) to communicate with each other. 5) A locking plug (834) is provided at the bottom end of the bottom protruding steel bar (31) that can pass through the opening (835) into and out of the mounting cavity (810). The locking plug (834) is used to lock the two locking blocks (812) in the open state. A tension spring (833) is provided in the sliding cavity (830) and is fitted on the outside of the locking plug (834). The tension spring (833) is located between the bottom wall of the sliding cavity (830) and the bottom end of the bottom protruding steel bar (31), so that the locking plug (834) is normally kept in the retracted state. The insertion hole (420) is an elongated hole, and the bottom end of the locking sleeve (80) is provided with a conical head (84).

10. The assembly method of a prefabricated prestressed anchor block according to any one of claims 1-9, characterized in that: The method includes: S1, Anchor block main body (1) prefabricated; S2, Assembly of the box girder steel reinforcement cage (6); S3, prefabricated connection, the anchor block body (1) is hoisted to the installation area of ​​the box girder steel reinforcement skeleton (6), and the protruding steel bars (3) of the anchor block body (1) are connected to the box girder steel reinforcement skeleton (6); S4. Install the box girder formwork system and pour the box girder concrete.

Images