Variable-diameter prestressed tendon conversion anchoring construction method

Abstract

The application discloses a variable-diameter prestressed tendon conversion anchoring construction method, and belongs to the technical field of prestressed tendon anchoring, and solves the problem that it is difficult to integrally pass a cable through a small-diameter reserved channel at present. The method is that first, a traction structure is used to make a cable, and a whole cable body with a diameter smaller than that of the reserved channel is obtained; then the whole cable body is hoisted and passed through the reserved channel, and the whole cable body is temporarily supported; then the whole cable body is lowered, and prestressed tendons are unfolded to correspond to the anchor holes of the anchor plates one by one; the anchor plates are installed, and the whole cable body is continuously hoisted; finally, the anchor plates are lowered to the reserved channel mouth, a working clamp is installed, and the anchoring conversion of the prestressed tendons is completed. The conversion anchoring construction method can guarantee that the cable body units correspond to the anchor holes one by one during the anchoring conversion, can meet the requirement of quickly hanging a cable in a small-diameter reserved channel, and effectively improves the construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of prestressed tendon anchorage technology, and more specifically, to a method for converting and anchoring variable-diameter prestressed tendons. Background Technology

[0002] For some precast concrete structures requiring long prestressed tendons for vertical splicing, such as wind turbine concrete towers and reinforced concrete support columns, prestressing is needed to connect segmental members into a rigid and reliable whole. For such splicing structures, there are two prestressing construction methods in the industry: (A) Precast anchor head integral cable-passing method, where the prestressed tendon 4 is first passed through the anchor plate 16, then positioned by the anchor plate for overall hoisting, and then passed through the reserved duct 9 as a whole. This method is efficient, but requires the anchor plate diameter to be smaller than the reserved duct diameter (e.g., ...). Figure 1 (B) The method of pulling the prestressing tendons one by one from the bottom through the reserved duct 9 to the upper anchoring end, and then through the anchor hole of the upper anchor plate 16. This method is less efficient for anchor cables with a large number of prestressing tendons, but the reserved duct diameter can be smaller than that of the anchor plate (e.g., Figure 2 ).

[0003] According to the requirements of concrete structure design and construction units, the smaller the reserved ducts, the less damage to the structure. However, precast splicing structures also place high demands on construction efficiency. Existing construction methods are either cumbersome, reducing efficiency, or require large ducts, affecting structural stiffness, making it impossible to simultaneously achieve the requirements of construction efficiency and small duct size. Therefore, a variable diameter prestressed tendon conversion and anchorage construction method is proposed. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned shortcomings of the prior art. The purpose of the present invention is to provide a construction method for converting and anchoring variable diameter prestressed tendons. During the anchoring conversion, it can ensure that the cable unit corresponds one-to-one with the anchor hole, which can meet the requirements of rapid cable hanging in small diameter reserved ducts and effectively improve construction efficiency.

[0005] To achieve the above objectives, this invention provides a method for converting and anchoring variable-diameter prestressed tendons. The method involves first using a traction structure to create a bundle of cables with a diameter smaller than the diameter of the pre-reserved duct; then, lifting the bundle of cables through the pre-reserved duct, temporarily supporting the bundle, lowering it so that the prestressed tendons align with the anchor holes of the anchor plate, installing the anchor plate, and continuing to lift the bundle of cables; finally, lowering the anchor plate to the opening of the pre-reserved duct, installing the working clamps, and completing the anchoring conversion of the prestressed tendons.

[0006] As a further improvement, the traction structure includes a conversion shaft core, a conversion shaft piece, a connecting base, and a connecting pressure plate. The outer wall of the conversion shaft core is provided with a sliding inclined surface, and the conversion shaft piece has a multi-piece structure. The diameter of the conversion shaft piece after it is closed and the size of the connecting pressure plate are both smaller than the diameter of the reserved channel. The method includes the following steps:

[0007] S1: Cut the prestressed tendons into wires, attach the abutment, and install the conversion core, conversion abutment plate, connecting base and connecting pressure plate respectively to obtain the entire cable bundle;

[0008] S2: Lift the entire cable bundle through the reserved channel, so that the traction structure is positioned above the reserved channel;

[0009] S3: Provide temporary support for the traction structure and disconnect the connection between the conversion shaft and the connecting pressure plate;

[0010] S4: Lower the entire cable bundle, the conversion shaft core moves down and squeezes the conversion shaft plate to move radially, the conversion shaft plate drives the prestressed tendons to unfold to correspond one-to-one with the anchor holes of the anchor plate, and release the lifting tools and connecting pressure plates;

[0011] S5: Install the unit traction connector on each connecting base, and then pass the unit traction connector through the anchor hole of the anchor plate one by one to complete the installation of the anchor plate;

[0012] S6: Reinstall the lifting gear, lift the entire cable bundle, and remove the conversion shaft, conversion axle, and temporary support;

[0013] S7: Lower the anchor plate to the reserved duct opening, install the working clamp, release the unit traction connector and connecting base, and complete the anchorage conversion of the prestressed tendon.

[0014] Furthermore, step S1 includes the following specific steps:

[0015] S1.1: Cut each prestressed tendon into wires and then pierce its head;

[0016] S1.2: Install the prestressing tendons through the corresponding holes of the conversion shaft plate and conversion shaft core, so that the center thread anchor is placed above the conversion shaft plate and conversion shaft core;

[0017] S1.3: Install the connecting base one by one on the center thread anchor above the conversion shaft plate and conversion shaft core;

[0018] S1.4: Place the connecting pressure plate on top of the connecting base, and connect it with the conversion shaft piece and conversion shaft core through the connector to form a whole, thus obtaining the entire cable bundle.

[0019] Furthermore, each of the conversion shaft piece and the conversion shaft core is provided with an open slot on one side. In step S1.2, the center wire of the prestressing tendon is embedded into the open slot from one side of the conversion shaft piece and the conversion shaft core. The connecting base is provided with a pier head groove, and one side of the connecting base is provided with an open slot communicating with the pier head groove. In step S1.3, the center wire of the prestressing tendon is embedded into the pier head groove from one side of the connecting base through the open slot.

[0020] Furthermore, the top of both the conversion shaft piece and the conversion shaft core is provided with a base limiting groove. In step S1.3, after the connecting base is installed, the connecting base is then inserted into the base limiting groove.

[0021] Furthermore, step S5 includes the following specific steps:

[0022] S5.1: Install a unit traction connector on each connecting base;

[0023] S5.2: Install connecting components on each unit traction connector;

[0024] S5.3: Pass the connecting components and unit traction connectors through the anchor holes of the anchor plate one by one;

[0025] S5.4: Install the integral traction plate on the connecting member above the anchor plate, connect all the connecting members, and complete the installation of the anchor plate.

[0026] Furthermore, in step S6, after the overall traction plate is lifted until the prestressed tendons are exposed sufficiently at the top for anchoring, the overall traction plate is temporarily fixed with a support frame, and then the conversion shaft core, conversion shaft piece, and temporary support are released.

[0027] Furthermore, step S3 includes the following specific steps:

[0028] S3.1: Install a multi-lobed insert plate below the traction structure, lower the entire cable bundle, and transfer the weight of the entire cable bundle to the multi-lobed insert plate;

[0029] S3.2: Disconnect the connection between the conversion shaft and the connecting pressure plate.

[0030] Furthermore, the multi-lobed insert plate is provided with a sliding groove. In step S3.1, the sliding groove of the multi-lobed insert plate is fitted onto the central wire of the prestressing tendon. In step S4, the conversion shaft plate moves radially along the sliding groove.

[0031] Furthermore, the traction structure also includes a universal hook, and step S1.4 further includes the step of installing the universal hook on the connecting pressure plate.

[0032] Beneficial effects

[0033] Compared with the prior art, the advantages of this invention are as follows:

[0034] 1. The variable diameter prestressed tendon conversion and anchorage construction method of the present invention adopts a conversion shaft core to install the inner layer of prestressed tendons and a multi-piece conversion shaft plate to install the outer layer of prestressed tendons. The expansion structure drives the conversion shaft plate to move radially, thereby driving the outer layer of prestressed tendons to expand radially. This can realize the automatic expansion of the prestressed tendons, which facilitates the subsequent installation of anchor plates and clamps. It eliminates the need for manual sorting of the prestressed tendons after cable threading, reduces labor intensity, and effectively improves construction efficiency.

[0035] 2. In the variable diameter prestressed tendon conversion and anchorage construction method of the present invention, the diameter of the conversion shaft after closure and the diameter of the hoisting assembly are both smaller than the diameter of the reserved duct. The small diameter and compact shape is used to pass through the small reserved duct, which can meet the requirements of rapid cable threading in the small diameter reserved duct and effectively improve the construction efficiency.

[0036] 3. The variable diameter prestressed tendon conversion anchorage construction method of the present invention has a detachable structure of conversion shaft core, conversion shaft plate, connecting pressure plate, connecting base and prestressed tendon. After the cable is threaded, the traction structure can be directly disassembled from the top of the reserved duct, which can realize rapid disassembly and assembly and further improve construction efficiency.

[0037] 4. The variable diameter prestressed tendon conversion anchorage construction method of the present invention only operates on the end of the prestressed tendon during the installation of the traction structure, without damaging the outer sheath of other parts of the prestressed tendon, thus ensuring the durability of the prestressed tendon and good construction quality. Attached Figure Description

[0038] Figure 1 A schematic diagram of a large-hole anchorage structure with reserved channels in the prior art;

[0039] Figure 2 A schematic diagram of a small-hole anchorage structure with reserved channels in existing technology;

[0040] Figure 3 This is a cross-sectional structural diagram of the present invention;

[0041] Figure 4 This is an exploded view of the structure of the present invention;

[0042] Figure 5 This is a schematic diagram of the traction structure in this invention;

[0043] Figure 6 This is an enlarged schematic diagram of the structure of the conversion shaft core and conversion shaft piece in this invention;

[0044] Figure 7 This is a schematic diagram illustrating the principle of the change in the arrangement of prestressing tendons in this invention;

[0045] Figure 8 This is an enlarged schematic diagram of the structure of the prestressed tendon and the unit traction connection head in this invention;

[0046] Figure 9 This is a schematic diagram of the temporary support structure for the entire cable bundle in this invention;

[0047] Figure 10 This is a schematic diagram of the structure for lifting the entire cable bundle in this invention;

[0048] Figure 11 This is a schematic diagram of the structure for temporary fixing of the overall traction plate in this invention.

[0049] Among them: 1-conversion shaft core, 2-conversion shaft piece, 3-connecting pressure plate, 4-prestressed tendon, 5-connecting base, 6-multi-lobed insert plate, 7-concrete, 8-sliding inclined surface, 9-reserved hole, 10-opening slot, 11-connector, 12-pier head slot, 13-support frame, 14-base limiting slot, 15-universal hook, 16-anchor plate, 17-slide groove, 18-unit traction connector, 19-integral traction plate, 20-connecting component. Detailed Implementation

[0050] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0051] See Figure 3-11 A variable-diameter prestressed tendon anchorage conversion device includes a temporary pad and a traction structure that can deploy the prestressed tendon 4.

[0052] The traction structure is used for cable making. The overall size of the traction structure is smaller than the diameter of the reserved channel 9, so that the entire cable bundle obtained after cable making can pass through the reserved channel 9.

[0053] The aforementioned traction structure is a variable-diameter prestressed tendon traction structure, which includes a conversion shaft core 1 and a conversion shaft plate 2. Both the conversion shaft core 1 and the conversion shaft plate 2 have holes for threading the tendons, and the prestressing tendons 4 can be threaded through them. The conversion shaft plate 2 is a multi-piece structure, and an expansion structure is provided between the conversion shaft core 1 and the conversion shaft plate 2 to drive the conversion shaft plate 2 to move radially, thereby unfolding the prestressing tendons 4. In this embodiment, taking a twelve-hole prestressed tendon as an example, the conversion shaft core 1 has three holes, and the conversion shaft plate 2 consists of three pieces, each with three holes evenly distributed. The prestressing tendons installed on the conversion shaft core 1 constitute the inner cable unit, and the prestressing tendons installed on the conversion shaft plate 2 constitute the outer cable unit. A hoisting assembly is provided above the conversion shaft plate 2, which is detachably connected to the conversion shaft plate 2, the conversion shaft core 1, and the prestressing tendons 4, facilitating connection with hoisting devices, such as a winch or tower crane.

[0054] The variable-diameter prestressed tendon traction structure of this embodiment uses a conversion core 1 to install inner prestressed tendons to form an inner cable unit, and multiple conversion plates 2 to install outer prestressed tendons to form an outer cable unit. The expansion structure of the conversion core 1 drives the conversion plates 2 to move radially, thereby driving the outer prestressed tendons to expand radially. This can realize automatic expansion of the prestressed tendons, which facilitates the subsequent installation of anchor plates and clamps. It eliminates the need for manual sorting of the prestressed tendons after cable threading, reduces labor intensity, and effectively improves construction efficiency.

[0055] Preferably, the expansion structure includes a sliding inclined surface 8 formed on the outer wall of the conversion shaft core 1, wherein the conversion shaft core 1 is movably inserted into the conversion shaft piece 2, that is, the conversion shaft core 1 is inserted into the hole formed by the three conversion shaft pieces 2. When the conversion shaft core 1 moves downward, its sliding inclined surface 8 presses against the inner surface of the three conversion shaft pieces 2, thereby causing the three conversion shaft pieces 2 to move radially, thus realizing the expansion of the prestressing tendon 4. Further, a sliding inclined surface 8 is provided on the inner wall of the conversion shaft piece 2, which is adapted to the sliding inclined surface 8 of the conversion shaft core 1. When the conversion shaft core 1 is inserted into the conversion shaft piece 2 and relatively fixed, the two sliding inclined surfaces 8 fit together, making the entire traction structure more compact and facilitating the traction structure to pass through the reserved hole 9. In other embodiments, the expansion structure may also include a sliding inclined surface 8 formed on the inner wall of the conversion shaft piece 2. When the conversion shaft core 1 moves downward, its outer wall presses against the sliding inclined surface 8 of the conversion shaft piece 2, which can also make the three conversion shaft pieces 2 move radially, thereby realizing the expansion of the prestressing tendon 4.

[0056] Preferably, the diameter of the conversion shaft 2 after it is closed, as well as the overall size of the hoisting assembly, are both smaller than the diameter of the reserved channel 9. Using a small-diameter, compact design to pass through the smaller reserved channel 9 allows for rapid cable threading through the small-diameter channel 9, effectively improving construction efficiency.

[0057] Preferably, an opening groove 10 communicating with each hole of the conversion shaft core 1 and the conversion shaft piece 2 is provided on one side to facilitate the installation or removal of the prestressing tendon 4.

[0058] Preferably, the hoisting assembly includes a connecting pressure plate 3 and a connecting base 5. A connecting base 5 is placed above each hole of the conversion shaft core 1 and the conversion shaft piece 2. The connecting pressure plate 3 overlaps the top of the connecting base 5. The connecting pressure plate 3 is detachably connected to the conversion shaft core 1 and the conversion shaft piece 2 simultaneously via a connector 11 (bolt). The prestressing tendon 4 is detachably installed inside the connecting base 5. After passing through the conversion shaft core 1 and the conversion shaft piece 2, the prestressing tendon 4 connects to the connecting base 5. Further, a head groove 12 is provided inside the connecting base 5 for installing the center wire head of the prestressing tendon 4. Even further, an open slot 10 communicating with one side of the head groove 12 is provided on one side of the connecting base 5, allowing the center wire of the prestressing tendon 4 to be inserted into the connecting base 5 before or after the head, eliminating the need for the traditional method of first passing through the device and then heading, or all cable units being arranged on the outer ring, thus achieving quick installation.

[0059] The variable diameter prestressed tendon traction structure of this embodiment has a detachable structure of conversion shaft core 1, conversion shaft plate 2, connecting pressure plate 3, connecting base 5, and prestressed tendon 4. After the cable is threaded, the traction structure can be directly disassembled from above the reserved hole 9, which can realize quick disassembly and assembly, and can complete the anchorage conversion without the need for a destructive device, further improving construction efficiency.

[0060] Preferably, a base limiting groove 14 is provided at the top of each hole of the conversion shaft core 1 and the conversion shaft piece 2. The connecting base 5 is movably inserted into the base limiting groove 14, which plays a role in positioning the connecting base 5. After the connecting pressure plate 3 is connected to the conversion shaft core 1 and the conversion shaft piece 2, the connecting base 5 will not fall off due to collision, vibration or other factors during hoisting. At the same time, the connecting base 5 can move radially with the conversion shaft piece 2, thereby driving the prestressed tendon 4 to unfold.

[0061] Preferably, the lifting assembly also includes a universal hook 15, which is detachably connected to the connecting pressure plate 3. Specifically, the universal hook 15 is connected to the connecting pressure plate 3 by threads or bolts, which facilitates the connection between the traction structure and the lifting device for lifting.

[0062] The aforementioned temporary pad is used to temporarily support the entire cable bundle, facilitating the disassembly of part of the traction structure and the installation of the anchor plate 16. The temporary pad is provided with a groove 17 for guiding and limiting the unfolding of the prestressing tendons 4, ensuring that the arrangement of the prestressing tendons 4 aligns with the anchor hole arrangement of the anchor plate 16. This ensures that after removing the connecting pressure plate 3, the sliding direction of the conversion shaft 2 is radial, while simultaneously increasing the bearing area to prevent the conversion shaft 2 from tipping over. In this embodiment, the groove 17 is designed so that the end position of the groove 17 is consistent with the hole arrangement of the conversion shaft core 1 and the anchor holes of the anchor plate 16, ensuring that the radial movement of the conversion shaft 2 causes the final position of the unfolded prestressing tendons 4 to align with the anchor holes of the anchor plate 16. Furthermore, the temporary pad has a multi-lobed structure for easy installation and disassembly. The groove 17 extends radially along the temporary pad, and the prestressing tendons 4 pass through the groove 17, ensuring that the prestressing tendons 4 can unfold radially.

[0063] Preferably, the anchoring conversion device further includes a unit traction connector 18, which is detachably connected to the connecting base 5. Specifically, the connecting base 5 is also provided with a structure that can be detachably connected to the unit traction connector 18. This structure can be a thread or a bolt hole, so that the connecting base 5 can be detachably connected to the unit traction connector 18 by threads or bolts.

[0064] Preferably, the anchoring conversion device also includes an integral traction plate 19, which is detachably connected to the unit traction connector 18 via a connecting member 20. The connecting member 20 can be a screw with a hook or a wire rope, which fixes multiple unit traction connectors 18 onto the integral traction plate 19, thereby achieving simultaneous lifting of the entire cable bundle and improving construction efficiency.

[0065] Preferably, the anchoring conversion device also includes a support frame 13, which is placed on the concrete 7 surrounding the reserved hole 9, and the overall traction plate 19 is attached to the top of the support frame 13 to facilitate the disassembly and assembly of the traction structure and the installation of the working clamp.

[0066] A method for converting and anchoring variable-diameter prestressed tendons is disclosed. The method involves first using a traction structure to create a bundle of cables with a diameter smaller than that of the pre-reserved duct 9; then, lifting the bundle of cables through the pre-reserved duct 9, temporarily supporting the bundle, lowering it so that the prestressed tendons 4 are deployed to correspond one-to-one with the anchor holes of the anchor plate 16, installing the anchor plate 16, and continuing to lift the bundle of cables; finally, lowering the anchor plate 16 to the opening of the pre-reserved duct 9, installing the working clamps, and completing the anchoring conversion of the prestressed tendons.

[0067] The method includes the following steps:

[0068] S1: Cut the prestressing tendon 4 into wires, and install the conversion core 1, conversion shaft plate 2, connecting base 5 and connecting pressure plate 3 at the pier head to obtain the entire cable bundle;

[0069] S2: Lift the entire cable bundle through the reserved channel 9, so that the traction structure is positioned above the reserved channel 9;

[0070] S3: Provide temporary support for the traction structure and disconnect the connection between the conversion shaft 2 and the connecting pressure plate 3;

[0071] S4: Lower the entire cable bundle, the conversion shaft core 1 moves down and squeezes the conversion shaft piece 2 to move radially, the conversion shaft piece 2 drives the prestressed tendon 4 to unfold until it corresponds one-to-one with the anchor hole of the anchor plate 16, and release the lifting tool and connecting pressure plate 3.

[0072] S5: Install the unit traction connector 18 on each connecting base 5, and then pass the unit traction connector 18 through the anchor hole of the anchor plate 16 one by one to complete the installation of the anchor plate 16.

[0073] S6: Reinstall the lifting gear, lift the entire cable bundle, and release the conversion shaft core 1, conversion shaft plate 2, and temporary support;

[0074] S7: Lower the anchor plate 16 to the reserved hole 9, install the working clamp, release the unit traction connector 18 and the connecting base 5, and complete the anchorage conversion of the prestressed tendon.

[0075] Step S1 above includes the following specific steps:

[0076] S1.1: Cut each prestressed tendon 4 into wires and then pierce the ends;

[0077] S1.2: Install the prestressing tendons 4 through the corresponding holes of the conversion shaft plate 2 and the conversion shaft core 1, so that the center thread anchor is placed above the conversion shaft plate 2 and the conversion shaft core 1;

[0078] S1.3: Install the connecting base 5 one by one on the center threaded head above the conversion shaft 2 and conversion shaft core 1;

[0079] S1.4: Place the connecting pressure plate 3 on top of the connecting base 5, and connect it with the conversion shaft plate 2 and the conversion shaft core 1 through the connecting piece 11 to form a whole, thus obtaining the entire cable bundle; specifically, the connecting piece 11 is a bolt, which moves through the hole of the connecting pressure plate 3 and is threadedly connected to the conversion shaft plate 2 and the conversion shaft core 1. After the connecting piece 11 is connected to the conversion shaft plate 2 and the conversion shaft core 1, there is still a distance between the nut of the connecting piece 11 and the connecting pressure plate 3, so that the conversion shaft core 1 has sufficient downward stroke when the entire cable bundle is lowered.

[0080] In this embodiment, only the ends of the prestressing tendon 4 are operated during the installation of the traction structure, without damaging the outer sheath of other parts of the prestressing tendon 4, thus ensuring the durability of the prestressing tendon and achieving good construction quality.

[0081] In step S1.2 above, the center wire of the prestressing tendon 4 is embedded into the opening groove 10 from one side of the conversion shaft piece 2 and the conversion shaft core 1; in step S1.3 above, the center wire of the prestressing tendon 4 is inserted into the pier head groove 12 from one side of the connecting base 5 through the opening groove 10. This facilitates the assembly and disassembly of the conversion shaft core 1, the conversion shaft piece 2, and the connecting base 5.

[0082] In step S1.3 above, after the connecting base 5 is installed, the connecting base 5 is then inserted into the base limiting groove 14.

[0083] Step S5 above includes the following specific steps:

[0084] S5.1: Install a unit traction connector 18 on each connecting base 5;

[0085] S5.2: Install connecting member 20 on each unit traction connector 18;

[0086] S5.3: Pass the connecting member 20 and the unit traction connector 18 through the anchor holes of the anchor plate 16 one by one;

[0087] S5.4: Install the integral traction plate 19 on the connecting member 20 above the anchor plate 16, connect all the connecting members 20, and complete the installation of the anchor plate 16.

[0088] In step S6 above, after the overall traction plate 19 is lifted to a position where the prestressing tendons 4 are sufficiently exposed for anchoring, the overall traction plate 19 is temporarily fixed with the support frame 13, and then the conversion shaft core 1, conversion shaft piece 2, and temporary support are released. This can effectively improve construction efficiency.

[0089] Step S3 above includes the following specific steps:

[0090] S3.1: Install a multi-lobed insert plate 6 below the traction structure, lower the entire cable bundle, and transfer the weight of the entire cable bundle to the multi-lobed insert plate 6. The connecting piece 11 between the connecting pressure plate 3 and the conversion shaft plate 2 is not under stress, making it easy to disassemble.

[0091] S3.2: Disconnect the connection between the conversion shaft 2 and the connecting pressure plate 3, that is, remove the connecting piece 11 between the conversion shaft 2 and the connecting pressure plate 3.

[0092] In step S3.1 above, the groove 17 of the multi-lobed insert plate 6 is fitted onto the center wire of the prestressing tendon 4. In step S4 above, the conversion shaft plate 2 moves radially along the groove 17.

[0093] The above-mentioned step S1.4 also includes the step of installing the universal hook 15 on the connecting pressure plate 3.

[0094] This invention employs a combined variable-diameter structure, using a compact, small-diameter design to pass through a smaller pre-reserved channel 9. After passing through the pre-reserved channel, a multi-lobed insert plate 6 for support is inserted, and the connecting pressure plate 3 is removed. Under the influence of the cable's own weight, the conversion shaft core 1 and conversion shaft piece 2 slide against each other to change diameter, unfolding to a larger diameter design. The spacing between the compact inner and outer cable units is restored to the initial design, ensuring that the arrangement of prestressing tendons and the anchor hole arrangement on the anchor plate are consistent. This facilitates the subsequent installation of anchor plates and clamps, completing the conversion from cable threading to anchoring of the entire bundle of cables. This method achieves the conversion process while reducing the required channel size, and is convenient to operate with high conversion efficiency.

[0095] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention, and these will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method for constructing a variable-diameter prestressed tendon conversion anchorage, characterized in that, The method involves first using a traction structure to create a cable bundle with a diameter smaller than that of the pre-reserved channel (9); then lifting the cable bundle through the pre-reserved channel (9), temporarily supporting the cable bundle, and then lowering the cable bundle so that the prestressed tendons (4) are unfolded to correspond one-to-one with the anchor holes of the anchor plate (16), installing the anchor plate (16), and continuing to lift the cable bundle; finally, lowering the anchor plate (16) to the opening of the pre-reserved channel (9), installing the working clamp, and completing the anchoring conversion of the prestressed tendons. The traction structure includes a conversion shaft core (1), a conversion shaft piece (2), a connecting base (5), and a connecting pressure plate (3). The outer wall of the conversion shaft core (1) is provided with a sliding inclined surface (8), and the conversion shaft piece (2) is a multi-piece structure. The diameter of the conversion shaft piece (2) after closing and the size of the connecting pressure plate (3) are both smaller than the diameter of the pre-reserved channel (9). The method includes the following steps: S1: Cut the prestressed tendon (4) into wires, pierce the head, and install the conversion core (1), conversion shaft piece (2), connecting base (5) and connecting pressure plate (3) respectively to obtain the whole cable bundle; S2: Lift the entire cable bundle through the reserved channel (9) so that the traction structure is positioned above the reserved channel (9); S3: Provide temporary support for the traction structure and disconnect the connection between the conversion shaft (2) and the connecting pressure plate (3); S4: Lower the entire cable bundle, the conversion shaft core (1) moves down and squeezes the conversion shaft piece (2) to move radially, the conversion shaft piece (2) drives the prestressed tendon (4) to unfold to correspond one-to-one with the anchor hole of the anchor plate (16), and release the lifting tool and connecting pressure plate (3). S5: Install unit traction connectors (18) on each connecting base (5), and then pass the unit traction connectors (18) through the anchor holes of the anchor plate (16) one by one to complete the installation of the anchor plate (16); S6: Reinstall the lifting device, lift the entire cable bundle, and release the conversion shaft core (1), conversion shaft piece (2), and temporary support; S7: Lower the anchor plate (16) to the reserved hole (9), install the working clamp, release the unit traction connector (18) and the connecting base (5) to complete the anchorage conversion of the prestressed tendon.

2. The method for converting and anchoring variable-diameter prestressed tendons according to claim 1, characterized in that, Step S1 includes the following specific steps: S1.1: Cut each prestressed tendon (4) into wires and pierce the ends; S1.2: Install the prestressing tendons (4) through the corresponding holes of the conversion shaft plate (2) and the conversion shaft core (1) respectively, so that the center thread anchor is placed above the conversion shaft plate (2) and the conversion shaft core (1); S1.3: Install the connecting base (5) one by one on the center threaded head above the conversion shaft plate (2) and the conversion shaft core (1); S1.4: Place the connecting pressure plate (3) on top of the connecting base (5) and connect it with the conversion shaft piece (2) and conversion shaft core (1) through the connector (11) to form a whole, thus obtaining the whole cable body.

3. The method for converting and anchoring variable-diameter prestressed tendons according to claim 2, characterized in that, The conversion shaft piece (2) and the conversion shaft core (1) are provided with an opening groove (10) on one side. In step S1.2, the center wire of the prestressing tendon (4) is embedded into the opening groove (10) from one side of the conversion shaft piece (2) and the conversion shaft core (1). The connecting base (5) is provided with a pier head groove (12). The connecting base (5) is provided with an opening groove (10) communicating with the pier head groove (12) on one side. In step S1.3, the center wire of the prestressing tendon (4) is embedded into the pier head groove (12) from one side of the connecting base (5) through the opening groove (10).

4. The method for constructing a variable-diameter prestressed tendon conversion anchorage according to claim 2, characterized in that, The top of the conversion shaft piece (2) and the conversion shaft core (1) are both provided with a base limiting groove (14). In step S1.3, after the connecting base (5) is installed, the connecting base (5) is then inserted into the base limiting groove (14).

5. The method for converting and anchoring variable-diameter prestressed tendons according to claim 1, characterized in that, Step S5 includes the following specific steps: S5.1: Install unit traction connector (18) on each connecting base (5); S5.2: Install connecting components (20) on each unit traction connector (18); S5.3: Pass the connecting member (20) and the unit traction connector (18) through the anchor holes of the anchor plate (16) one by one; S5.4: Install the integral traction plate (19) on the connecting member (20) above the anchor plate (16), connect all the connecting members (20), and complete the installation of the anchor plate (16).

6. The method for converting and anchoring variable-diameter prestressed tendons according to claim 5, characterized in that, In step S6, after the overall traction plate (19) is lifted to a position where the prestressed tendon (4) is exposed enough for anchoring, the overall traction plate (19) is temporarily fixed with a support frame (13), and then the conversion shaft core (1), conversion shaft piece (2), and temporary support are released.

7. The method for constructing a variable-diameter prestressed tendon conversion anchorage according to claim 1, characterized in that, Step S3 includes the following specific steps: S3.1: Install a multi-lobed insert plate (6) below the traction structure, and lower the entire cable bundle so that the weight of the entire cable bundle is transferred to the multi-lobed insert plate (6). S3.2: Disconnect the connection between the conversion shaft (2) and the connecting pressure plate (3).

8. The method for converting and anchoring variable-diameter prestressed tendons according to claim 7, characterized in that, The multi-lobed insert plate (6) is provided with a sliding groove (17). In step S3.1, the sliding groove (17) of the multi-lobed insert plate (6) is fitted onto the center wire of the prestressing tendon (4). In step S4, the conversion shaft piece (2) moves radially along the sliding groove (17).

9. A method for constructing a variable-diameter prestressed tendon conversion anchorage according to claim 2, characterized in that, The traction structure also includes a universal hook (15), and step S1.4 further includes the step of installing the universal hook (15) on the connecting pressure plate (3).

Images