Telescopic anchor withdrawing base and device for prestressed steel strand double-top anchor withdrawing

Abstract

The utility model provides a telescopic anchor withdrawing base and a device for prestressed steel strand double-top anchor withdrawing. The telescopic anchor withdrawing base and the device are used for solving the problem that in the prior art, an anchor withdrawing base cannot adapt to the length, stretching out of concrete, of a prestressed steel strand. The base comprises a first base body, a second base body and a driving assembly; the driving assembly drives the first base body to be close to or away from the second base body, then the length of the anchor withdrawing base is changed to adapt to different working scenes, the anchor withdrawing base can be repeatedly used after being machined and formed, the construction cost is reduced, meanwhile, the working hole is formed in the connecting position of the first base body and the second base body, and the working efficiency is improved while the length of the anchor withdrawing base is changed. And the working hole is enlarged, so that an operator can operate the working anchor conveniently.

Description

Technical Field

[0001] The utility model belongs to the technical field of prestressed steel strand anchor withdrawal, and particularly relates to a telescopic anchor withdrawal base and a device for double-top anchor withdrawal of prestressed steel strands. Background Art

[0002] A prestressed steel strand is a stranded steel cable composed of 2, 3, 7 or 19 high-strength steel wires. After stress relief treatment (stabilization treatment), it is applicable to prestressed concrete and similar uses. There is also a double-top anchor withdrawal device for prestressed steel strands in the prior art, which includes an anchor withdrawal base, a hole-through jack, a working anchor and a front clamping jack. A working hole is usually arranged on the side of the anchor withdrawal base. Through the cooperation of the four, an operator passes through the working hole to replace the working clamping pieces of the working anchor to achieve anchor withdrawal.

[0003] In this way, since the hole-through jack, the working anchor and the front clamping jack are all standard parts, the length of them passing through the prestressed steel strand is fixed. However, the length of the prestressed steel strand extending out of the concrete is different, and the position of the working anchor in the concrete is different. For example, there is a groove on the concrete, the tool anchor is in the groove, and the size of the groove can only accommodate the tool anchor. In view of such a situation, in the prior art, the anchor withdrawal base with different heights is selected according to the construction scenario to be applied to the construction scenario. However, on the one hand, this method requires pre-producing multiple anchor withdrawal bases with different heights, and the construction cost is relatively high; on the other hand, since in each construction, not only one group of prestressed steel strands is subjected to the anchor withdrawal operation. When there are multiple groups of prestressed steel strands that need to be subjected to the anchor withdrawal operation, and the lengths of the prestressed steel strands extending out of the concrete in different groups are different, it is necessary to bring multiple anchor withdrawal bases to the construction site for use, and the transportation cost and the selection by the operator are also relatively cumbersome, and the work efficiency is not high. Summary of the Utility Model

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present utility model is to provide a telescopic anchor withdrawal base and a device for double-top anchor withdrawal of prestressed steel strands, which are used to solve the problem that the anchor withdrawal base in the prior art cannot adapt to the length of the prestressed steel strand extending out of the concrete.

[0005] To achieve the above purpose and other related purposes, the present utility model provides a telescopic anchor withdrawal base, which includes: a first seat body, a second seat body, and a driving component; a working hole is arranged at the connection of the first seat body and the second seat body; one end of the first seat body is used for connecting with the hole-through jack, and the other end is arranged in the second seat body and is slidably connected with the second seat body; the end of the second seat body far from the first seat body is connected with a preset support surface; the driving component is arranged on the second seat body and is used to drive the first seat body to approach or move away from the second seat body.

[0006] Optionally, the second housing includes a flange and a support member; the support member is disposed on the flange, and one end of the support member away from the flange is connected to the first housing; the drive assembly is disposed on the flange.

[0007] Optionally, the drive assembly includes a cylinder, a liquid storage chamber, and a sliding chamber; the liquid storage chamber is disposed within the flange, the sliding chamber is disposed within the support member, and the first housing is slidably disposed within the sliding chamber; the cylinder is disposed on the flange; the cylinder is configured to drive the liquid within the liquid storage chamber to be transferred into the sliding chamber, and to drive the first housing to slide within the sliding chamber, so that the first housing moves away from the flange.

[0008] Optionally, the drive assembly further includes a pressure relief member, and the pressure relief member is configured to transfer the liquid within the sliding chamber into the liquid storage chamber, so as to drive the first housing to slide within the sliding chamber, and to make the first housing approach the flange.

[0009] Optionally, there are two support members, and sliding chambers are respectively disposed on the two support members; the two support members are spaced apart and symmetrically disposed on the flange; two working holes are formed between the two support members; the cylinder is disposed corresponding to one of the working holes; there are two liquid storage chambers, which are respectively disposed corresponding to one of the support members; the cylinder is configured to simultaneously drive the liquid stored in the two liquid storage chambers to be transferred into the sliding chambers of the corresponding support members; the pressure relief member is connected to the two liquid storage chambers and the two sliding chambers, and is configured to simultaneously drive the liquid within the two sliding chambers to be transferred into the corresponding liquid storage chambers.

[0010] Optionally, the cylinder includes two pressure supply boxes and a plunger assembly; the two pressure supply boxes are respectively disposed in connection with the sliding chamber and the liquid storage box of one of the support members; the plunger assembly includes a first plunger, a second plunger, and a third plunger; one end of the first plunger is disposed within one of the pressure supply boxes, and the other end extends out of the pressure supply box and is connected to the third plunger; one end of the second plunger is disposed within the other pressure supply box, and the other end extends out of the pressure supply box and is connected to the third plunger; the third plunger is configured to simultaneously drive the first plunger and the second plunger to move within the pressure supply box.

[0011] Optionally, a first limiting portion is disposed at one end of the sliding chamber away from and close to the first housing; a second limiting portion is disposed at the connection end of the first housing and the sliding chamber; the first limiting portion and the second limiting portion are configured to limit the sliding of the first housing within the sliding chamber, so as to prevent the first housing from sliding out of the sliding chamber.

[0012] Optionally, a sealing member connected to the inner side surface of the sliding chamber is disposed on the outer side surface of the second limiting portion.

[0013] Optionally, a fixing member is further disposed on the flange, and the fixing member is configured to fix the second housing on a preset support surface.

[0014] The present utility model further provides an anchor withdrawing device for double-top anchor withdrawal of prestressed steel strands, which includes the above-mentioned retractable anchor withdrawing base, and further includes a hole-through jack, a tool anchor and a front clamping jack; the hole-through jack is sleeved on the prestressed steel strand, one end of which is connected to the retractable anchor withdrawing base, and the other end is connected to the tool anchor; the tool anchor is arranged on the prestressed steel strand; the front clamping jack is arranged on the prestressed steel strand, and one end of which is connected to the end of the tool anchor away from the hole-through jack.

[0015] As described above, the retractable anchor withdrawing base and the device for double-top anchor withdrawal of prestressed steel strands of the present utility model have at least the following beneficial effects: by setting the anchor withdrawing base as a retractable structure, specifically, the anchor withdrawing base includes a first seat body, a second seat body and a driving component, and the driving component drives the first seat body to approach or move away from the second seat body, so as to change the length of the anchor withdrawing base to adapt to different working scenarios. Moreover, after the anchor withdrawing base is processed and formed, it can be reused, reducing the construction cost. At the same time, a working hole is arranged at the connection of the first seat body and the second seat body. While changing the length of the anchor withdrawing base, the working hole is enlarged, facilitating the operation of the working anchor by the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It shows a three-dimensional schematic diagram of the retractable anchor withdrawing base of the present utility model.

[0017] Figure 2 It shows a top view schematic diagram of the retractable anchor withdrawing base of the present utility model.

[0018] Figure 3 It shows a sectional view taken along the Figure 2 section line A-A in

[0019] Figure 4 It shows a sectional view taken along the Figure 2 section line B-B in

[0020] Figure 5 It shows an enlarged schematic diagram of the C part in Figure 4

[0021] Figure 6 It shows a sectional view of the flange of the present utility model.

[0022] Figure 7 It shows a structural schematic diagram of the anchor withdrawing device of the present utility model.

[0023] Description of Component Labels

[0024] ​1. First seat body, 11. Second limiting part, 111. Sealing part, 2. Second seat body, 21. Flange, 211. Fixing part, 22. Supporting part, 3. Driving assembly, 31. Cylinder, 311. Pressure supply box, 312. Plunger assembly, 3121. First plunger, 3122. Second plunger, 3123. Third plunger, 32. Liquid storage chamber, 33. Sliding chamber, 331. First limiting part, 34. Pressure relief part, 4. Working hole, 5. Through-type jack, 6. Tool anchor, 7. Front card jack. DETAILED DESCRIPTION

[0025] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0026] Please refer to all the following drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the utility model without affecting the effects and purposes that can be achieved by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change in the technical content.

[0027] The following embodiments are only for illustration purposes and can be combined with each other, and are not limited to the contents presented in the following single embodiments.

[0028] See also Figure 1-7The utility model provides a retractable anchor removal base, which includes: a first base body 1, a second base body 2, and a driving assembly 3; a working hole 4 is provided at the connection between the first base body 1 and the second base body 2; one end of the first base body 1 is used to connect with a through-type jack 5, and the other end is arranged in the second base body 2 and is slidably connected with the second base body 2; one end of the second base body 2 away from the first base body 1 is connected with a preset support surface; the driving assembly 3 is arranged on the second base body 2, and is used to drive the first base body 1 to approach or move away from the second base body 2. Specifically, after the first body and the second base body 2 are installed together, the working hole 4 is formed at the connection between the first base body 1 and the second base body 2, that is, a part of the structure of the working hole 4 is provided at the corresponding position of the circumference of the first base body 1 and the second base body 2, and the two parts of the structure are combined to form the working hole 4 after the first base body 1 and the second base body 2 are connected. When the driving assembly 3 drives the first seat body 1 to approach or move away from the second seat body 2, on the one hand, the length of the anchor withdrawal base is changed to adapt to different construction scenes, and on the other hand, the working holes 4 on the first seat body 1 and the second seat body 2 are enlarged to facilitate the operator to replace the working clips of the working anchor.

[0029] The second seat body 2 includes a flange 21 and a support member 22; the support member 22 is arranged on the flange 21, and one end of the support member 22 away from the flange 21 is connected to the first seat body 1; the drive assembly 3 is arranged on the flange 21. The flange 21 is a hollow cylindrical structure, the support member 22 is arranged on one side surface of the flange 21, and the drive assembly 3 is also arranged on the side surface; the other side surface of the flange 21 is used to connect with a preset support surface. The support member 22 can be a hollow truncated cone structure with a part of the structure of the working hole 4, or it can be an arc-shaped side plate, and the two side plates are arranged on the flange 21 at intervals, and the interval between the two forms a part of the structure of the working hole 4, which is not limited in this embodiment. It can be understood that the preset support surface can be a support surface on concrete with prestressed steel strands or other components with prestressed steel strands, which is not limited in this embodiment.

[0030] The driving component 3 includes a cylinder 31, a liquid storage chamber 32, and a sliding chamber 33; the liquid storage chamber 32 is arranged within the flange 21, the sliding chamber 33 is arranged within the support member 22, and the first seat body 1 is slidably arranged within the sliding chamber 33; the cylinder 31 is arranged on the flange 21; the cylinder 31 is used to drive the liquid within the liquid storage chamber 32 to transfer into the sliding chamber 33, and is used to drive the first seat body 1 to slide within the sliding chamber 33, so that the first seat body 1 moves away from the flange 21. An inner side of the flange 21 forms a liquid storage tank for containing hydraulic oil, and a sliding chamber 33 for containing hydraulic oil is arranged within the support member 22. Specifically, the liquid storage tank and the sliding chamber 33 are connected to the cylinder 31 through a liquid inlet pipe, and a check valve is arranged on the pipe. During use, the cylinder 31 transfers the hydraulic oil within the liquid storage chamber 32 into the sliding chamber 33, that is, the hydraulic oil within the sliding chamber 33 increases, and then drives the first seat body 1 to slide along the sliding chamber 33 in a direction away from the flange 21, thereby increasing the length of the anchor retraction base.

[0031] The driving component 3 further includes a pressure relief member 34. The pressure relief member 34 is used to transfer the liquid within the sliding chamber 33 into the liquid storage chamber 32, so as to drive the first seat body 1 to slide within the sliding chamber 33, so that the first seat body 1 approaches the flange 21. Specifically, the sliding chamber 33 and the liquid storage tank are connected through a liquid outlet pipe, and the pressure relief member 34 is connected to the liquid outlet pipe. When the pressure relief member 34 is opened, the hydraulic oil within the sliding chamber 33 is transferred into the liquid storage tank through the pipe, thereby driving the first seat body 1 to approach the flange 21. The pressure relief member 34 can be a check valve, that is, the hydraulic oil within the sliding chamber 33 can flow into the liquid storage tank through the liquid outlet pipe, but the hydraulic oil within the liquid storage tank cannot flow into the sliding chamber 33 through the liquid outlet pipe.

[0032] There are two support members 22, and sliding chambers 33 are respectively arranged on the two support members 22; the two support members 22 are spaced apart and symmetrically arranged on the flange 21; two working holes 4 are formed between the two support members 22; the cylinder 31 is arranged corresponding to one of the working holes 4; there are two liquid storage chambers 32, which are respectively arranged corresponding to one of the support members 22; the cylinder 31 is used to simultaneously drive the liquid stored in the two liquid storage chambers 32 to transfer into the sliding chamber 33 of the corresponding support member 22; the pressure relief member 34 is connected to the two liquid storage chambers 32 and the two sliding chambers 33, and is used to simultaneously drive the liquid in the two sliding chambers 33 to transfer into the corresponding liquid storage chamber 32. In this embodiment, there are two support members 22, specifically two support plates with an arc-shaped cross-section. The two support members 22 are spaced apart and symmetrically arranged on the flange 21. Since they are spaced apart, a part of the two working holes 4 is formed on the second seat body 2. When the first seat body 1 and the second seat body 2 are connected, the two working holes 4 are formed. Each support member 22 is provided with a sliding chamber 33, and there are two liquid storage tanks on the flange 21, which are respectively arranged corresponding to one of the support members 22. The cylinder 31 is used to simultaneously drive the liquid in the two liquid storage chambers 32 to move into the sliding chamber 33, thereby driving the first seat body 1 arranged in the two support members 22 to rise synchronously, avoiding the first seat body 1 from deviating to one side. As a result, after the through-hole jack 5 is installed on the first seat body 1, the force is uneven, affecting the stability of the operation of the entire device.

[0033] The cylinder 31 includes two pressure supply boxes 311 and a plunger assembly 312; the two pressure supply boxes 311 are respectively arranged corresponding to the sliding chamber 33 and the liquid storage tank of one of the support members 22; the plunger assembly 312 includes a first plunger 3121, a second plunger 3122 and a third plunger 3123; one end of the first plunger 3121 is arranged in one of the pressure supply boxes 311, and the other end extends out of the pressure supply box 311 and is connected to the third plunger 3123; one end of the second plunger 3122 is arranged in the other pressure supply box 311, and the other end extends out of the pressure supply box 311 and is connected to the third plunger 3123; the third plunger 3123 is used to simultaneously drive the first plunger 3121 and the second plunger 3122 to move in the pressure supply box 311. The first plunger and the second plunger 3122 are respectively arranged corresponding to one of the liquid storage chambers 32 and the sliding chamber 33, and the third plunger 3123 connects the two together. Thus, when the operator drives the third plunger 3123 to move, the second plunger 3122 and the first plunger 3121 move synchronously. It can be understood that the two pressure supply boxes 311 can be two sub-pressure supply boxes 311 formed by separating a box body with a partition, or two independent pressure supply boxes 311. This embodiment does not limit this.

[0034] A first limiting portion 331 is provided at one end of the sliding cavity 33 away from the first seat body 1; a second limiting portion 11 is provided at the connecting end of the first seat body 1 and the sliding cavity 33; the first limiting portion 331 and the second limiting portion 11 are used to limit the sliding of the first seat body 1 in the sliding cavity 33 to prevent the first seat body 1 from sliding out of the sliding cavity 33. Specifically, a liquid inlet pipe and a liquid storage pipe are provided at the bottom of the sliding cavity 33 and are connected to the liquid storage tank, and a first limiting portion 331 is provided at the top, that is, a first limiting portion 331 is provided at one end of the sliding cavity 33 close to the first seat body 1. The first limiting portion 331 can be a structure protruding from the inner side surface of the cavity, or can also be a structure covering the top of the sliding cavity 33 and provided with an opening for the first seat body 1 to pass through. This embodiment does not limit this. The second limiting portion 11 can be a protruding structure provided at the connecting end of the first seat body 1 and the sliding cavity 33. Of course, it can also be other structures. This embodiment does not limit this. When the first seat body 1 slides in the sliding cavity 33 and is away from the second seat body 2, the first limiting portion 331 and the second limiting portion 11, as mechanical limiting structures, limit the maximum sliding stroke of the first seat body 1 to prevent the first seat body 1 from sliding out of the sliding cavity 33.

[0035] In one embodiment, a sealing member 111 connected to the inner side surface of the sliding cavity 33 is provided on the outer side surface of the second limiting portion 11. It can be understood that since the hydraulic oil is provided in the sliding cavity 33, the setting of the sealing member 111 prevents the hydraulic oil from leaking through the gap between the first seat body 1 and the sliding cavity 33. The sealing member 111 can be an elastic sealing member 111 made of rubber material, or can also be a sealing structure supported by other materials. This embodiment does not limit this, as long as it can achieve sealing.

[0036] A fixing member 211 is further provided on the flange 21. The fixing member 211 is used to fix the second seat body 2 on a preset support surface; the fixing member 211 can be a ground nail or a bolt provided on the side surface of the flange 21 away from the first seat body 1. In one embodiment, both the ground nail and the bolt are provided on the flange 21. During use, the ground nail and / or the bolt penetrate into the preset support surface to fix the anchor withdrawal base on the preset support surface.

[0037] The present utility model further provides an anchor withdrawal device for double-top of prestressed steel strands, including the above-mentioned telescopic anchor withdrawal base, and further including a hole-through jack 5, a tool anchor 6 and a front clamping jack 7; the hole-through jack is sleeved on the prestressed steel strand, one end of which is connected to the first seat body 1 of the telescopic anchor withdrawal base, and the other end is connected to the tool anchor 6; the tool anchor 6 is arranged on the prestressed steel strand; the front clamping jack 7 is arranged on the prestressed steel strand, and one end of which is connected to the end of the tool anchor 6 away from the hole-through jack 5.

[0038] Specifically in use, first install the retractable anchor-removing base, and then install the hole-through jack 5. The hole-through jack 5 is pre-extended by a certain distance, for example, 18 cm. Then install the tool anchor 6 and the front clamping jack 7 on the prestressed steel strand. Then, tension and retract the prestressed steel strand through the front clamping jack 7. When the working wedges of the working anchor are easy to remove, stop tensioning the prestressed steel strand. The operator takes out the working wedges through the working hole 4, returns the oil and jacks back the hole-through jack, so that the oil cylinder of the hole-through jack retracts by a certain distance (for example, 17 cm), and then reinstall the working wedges, so that the prestressed steel strand is re-anchored on the working anchor. Then retract the oil cylinder of the hole-through jack by a certain distance (for example, 1 cm) until the prestressed steel strand is only anchored to the working anchor by the working wedges. Then remove the tension of the prestressed steel strand by the front clamping jack 7, that is, complete one unloading of the prestressed steel strand. Until all the prestressed steel strands are unloaded, this device can be removed.

[0039] In summary, the present utility model provides a retractable anchor-removing base and a device for double jacking and retracting of prestressed steel strands. By setting the anchor-removing base as a retractable structure, specifically, the anchor-removing base includes a first seat body 1, a second seat body 2 and a driving component 3. The driving component 3 drives the first seat body 1 to approach or move away from the second seat body 2, thereby realizing the change of the length of the anchor-removing base to adapt to different working scenarios. And after the anchor-removing base is processed and formed, it can be reused, reducing the construction cost. At the same time, a working hole 4 is provided at the connection between the first seat body 1 and the second seat body 2. While changing the length of the anchor-removing base, the working hole 4 is enlarged, which is convenient for the operator to operate the working anchor. Therefore, the present utility model effectively overcomes various disadvantages in the prior art and has high industrial utilization value.

Claims

1. A retractable anchor undocking base, characterized in that: The retractable anchor-removing base comprises: a first base body, a second base body and a driving assembly; A working hole is provided at the connection between the first seat body and the second seat body; One end of the first seat body is used to connect with the through-type jack, and the other end is disposed in the second seat body and slidably connected with the second seat body; one end of the second seat body away from the first seat body is connected to a preset support surface; The driving assembly is disposed on the second base, and is used to drive the first base to approach or move away from the second base.

2. The retractable anchor undocking base according to claim 1, characterized in that: The second seat body comprises a flange and a support member; the support member is arranged on the flange, and one end of the support member away from the flange is connected to the first seat body; the driving assembly is arranged on the flange.

3. The retractable anchor removal base according to claim 2, characterized in that: The driving assembly includes a cylinder, a liquid storage chamber and a sliding chamber; The liquid storage cavity is arranged in the flange, the sliding cavity is arranged in the support member, and the first seat body is slidably arranged in the sliding cavity; the cylinder is arranged on the flange; The cylinder is used to drive the liquid in the liquid storage cavity to transfer to the sliding cavity, and to drive the first seat body to slide in the sliding cavity, so as to move the first seat body away from the flange.

4. The retractable anchor removal base according to claim 3, characterized in that: The driving assembly further includes a pressure relief member, which is used to transfer the liquid in the sliding cavity to the liquid storage cavity to drive the first seat body to slide in the sliding cavity, so that the first seat body is close to the flange.

5. The retractable anchor removal base according to claim 4, characterized in that: There are two support members, and each of the two support members is provided with a sliding cavity; The two support members are spaced apart and symmetrically arranged on the flange; two working holes are formed between the two support members; The cylinder is arranged corresponding to one of the working holes; There are two liquid storage chambers, each corresponding to one of the supporting members; the cylinder is used to simultaneously drive the liquid stored in the two liquid storage chambers to be transferred to the corresponding sliding chamber of the supporting member; The pressure relief member is connected to the two liquid storage chambers and the two sliding chambers, and is used for simultaneously driving the liquid in the two sliding chambers to be transferred to the corresponding liquid storage chamber.

6. The retractable anchor removal base according to claim 5, characterized in that: The cylinder comprises two pressure supply boxes and a plunger assembly; the two pressure supply boxes are respectively arranged with the sliding cavity of one of the support members and the liquid storage tank; The plunger assembly includes a first plunger, a second plunger and a third plunger; one end of the first plunger is arranged in one of the pressure supply boxes, and the other end extends out of the pressure supply box to be connected to the third plunger; one end of the second plunger is arranged in the other pressure supply box, and the other end extends out of the pressure supply box to be connected to the third plunger; the third plunger is used to simultaneously drive the first plunger and the second plunger to move in the pressure supply box.

7. A retractable anchor removal base according to any one of claims 3 to 6, characterized in that: A first limiting portion is provided at one end of the sliding cavity away from the first seat body; a second limiting portion is provided at the connecting end of the first seat body and the sliding cavity; The first limiting portion and the second limiting portion are used to limit the first seat body from sliding in the sliding cavity to prevent the first seat body from sliding out of the sliding cavity.

8. The retractable anchor-removing base according to claim 7, characterized in that: The outer side surface of the second limiting portion is provided with a sealing member connected to the inner side surface of the sliding cavity.

9. The retractable anchor removal base according to claim 8, characterized in that: The flange is also provided with a fixing member, and the fixing member is used to fix the second seat body on the preset supporting surface.

10. An anchor removal device for double top anchor removal of prestressed steel strand, characterized in that: It comprises the retractable anchor withdrawal base as claimed in any one of claims 1 to 9, and also comprises a through-type jack, a tool anchor and a front-clip jack; The through-type jack is sleeved on the prestressed steel strand, one end of which is connected to the retractable anchor withdrawal base, and the other end is connected to the tool anchor; The tool anchor is arranged on the prestressed steel strand; the front cardan-type jack is arranged on the prestressed steel strand, and one end of the front cardan-type jack is connected to the end of the tool anchor away from the through-type jack.

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