Multi-anchor-point self-balancing pre-tightening anchorage device system and steel strand pre-tightening method thereof

Abstract

The invention discloses a multi-anchor-point self-balancing pre-tightening anchorage device system and a steel strand pre-tightening method thereof.The multi-anchor-point self-balancing pre-tightening anchorage device system comprises an upper clamping device, a main jacking oil cylinder, a lower clamping device and a pre-tightening device; the upper clamping device and the lower clamping device are fixedly arranged at the piston end and the bottom of the main jacking oil cylinder respectively, and the upper clamping device and the lower clamping device are used for locking or loosening a steel strand; the pre-tightening device comprises a pre-tightening anchor plate and a plurality of pre-tightening clamping pieces, and the pre-tightening anchor plate is fixedly arranged on the upper clamping device; the pre-tightening anchor plate is provided with a plurality of through holes allowing steel strands to penetrate out, and the through holes are conical holes and used for containing the pre-tightening clamping pieces. The pre-tightening clamping piece is made of plastic or engineering plastic, and the compressive strength of the pre-tightening clamping piece is obtained by calculating the pre-tightening force of the steel strand. According to the steel strand pre-tightening device, a plurality of steel strands can be uniformly pre-tightened at the same time, the steel strand pre-tightening efficiency is improved, and the steel strand pre-tightening quality and operation safety are guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of pre-tightening steel strands for lifting heavy objects, and more specifically, to a multi-anchor point self-balancing pre-tightening anchor system and a method for pre-tightening steel strands. Background Art

[0002] The continuous jack is a construction equipment that provides stable power during the lifting, pushing, horizontal rotation and vertical rotation of large structures. It mainly fixes the installation base of the continuous jack on the reaction platform, and uses high-strength, low-relaxation steel strands as traction rigging. The steel strands move with the heavy components. Generally speaking, heavy components are heavier and require more steel strands. If the pre-tightening is not sufficient, there will be uneven force during the traction process. Some steel strands are under-stressed or unstressed, and some steel strands are over-stressed. Long-term use will cause serious wear of the clips, greatly reducing their service life and affecting construction safety. Therefore, it is necessary to pre-tighten each steel strand before use. There are two commonly used methods for pre-tightening steel strands. The first method is to use a pre-tightened single-hole anchor. Due to the limitation of the working space, this method can only pre-tighten a single anchor point, and cannot pre-tighten multiple strands at the same time. The specific operation process is: the single-hole anchor is placed on the upper clamp plate, and a conventional clamp is arranged in the single-hole anchor hole to clamp the steel strand. The lower clamping cylinder is retracted by 3-4mm, and the steel strand of the lower clamping cylinder is slightly relaxed. The single steel strand is pre-tightened by a 2-ton hand chain hoist or crane, and a force of 10 to 20kN is applied. Then the lower clamping anchor is locked, and this process is repeated to pre-tighten the next steel strand. The second method is to fix a pre-tightening anchor plate on the upper clamp plate, arrange a conical hole on the pre-tightening anchor plate, arrange a conventional clamp on the conical hole to clamp the loose steel strand, and retract the lower clamping cylinder by 3-4mm, and the steel strand of the lower clamping cylinder is slightly relaxed. The extension of the main top oil cylinder drives the pre-tightening anchor plate to move, so that the steel strand is gradually stressed. The pre-tightening force is controlled by the pressure gauge of the hydraulic pump station to achieve pre-tightening, and then the lower clamping anchor is locked. In this method, the degree of relaxation of the steel strands varies, and the pre-tightening force cannot be controlled when multiple steel strands are pre-tightened at the same time. Therefore, this method can only achieve pre-tightening of a single anchor point, and the above process needs to be repeated to pre-tighten the next steel strand. Both of the above methods require repeated operations in turn, which are cumbersome and inefficient. Therefore, in order to solve the above problems, it is urgently necessary to provide a multi-anchor point self-balancing pre-tightening clamping anchor system and method. Summary of the invention

[0003] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0004] In order to achieve these purposes and other advantages according to the present invention, a multi-anchor point self-balancing pre-tightening anchor system is provided, which is characterized in that it includes: an upper clamping device, a main top oil cylinder, a lower clamping device, and a pre-tightening device; the upper clamping device and the lower clamping device are respectively fixedly arranged on the piston end and the bottom of the main top oil cylinder, and the upper clamping device and the lower clamping device are used to lock or loosen the steel strand; the pre-tightening device includes a pre-tightening anchor plate and a plurality of pre-tightening clips, and the pre-tightening anchor plate is fixedly arranged on the upper clamping device; the pre-tightening anchor plate is provided with a plurality of through holes for the steel strand to pass through, and the through holes are conical holes for placing the pre-tightening clips; the pre-tightening clips are made of plastic or engineering plastics, and the required compressive strength value thereof is calculated by the pre-tightening force of the steel strand.

[0005] Preferably, the pre-tightening clip is made of polylactic acid or polycarbonate.

[0006] Preferably, the inner wall of the pre-tightening clip is provided with saw teeth, and the tooth angle is 5° to 7°.

[0007] Preferably, the required compressive strength of the pre-tightening clip is calculated as follows: p=F*0.013835+2.076195 In the above formula, p is the required compressive strength value of the pre-tightening clip, and F is the pre-tightening force of the steel strand.

[0008] Preferably, the upper clamping device and the lower clamping device have the same structure, both comprising a support foot, a clamping cylinder and a clamping plate, the clamping cylinder being fixedly arranged in the support foot, the support foot being fixedly connected to the piston end or the bottom of the main top cylinder, the piston end of the clamping cylinder being provided with a plurality of first through holes for the steel strands to pass through, a lifting clamp being placed in each of the first through holes; the clamping plate being fixedly connected to the top of the cylinder body of the clamping cylinder, the cylinder body and the piston end of the clamping cylinder being relatively movable under the action of hydraulic oil to drive the clamping plate to approach or move away from the lifting clamp.

[0009] Preferably, the lifting clip is made of 20crMnTi alloy steel, and a sawtooth is provided on the inner wall thereof, and the tooth angle is 5° to 7°.

[0010] Another object of the present invention is to provide a steel strand pre-tightening method, which uses the multi-anchor point self-balanced pre-tightening anchor system, comprising the following steps: S1, passing a plurality of steel strands from top to bottom through the pre-tightening anchor plate, the upper clamping device, the main top oil cylinder, the lower clamping device and connecting with the weight component in sequence; and locking the lower end of each steel strand by the lower clamping device; S2, pushing each of the pre-tightening clips into the corresponding through holes on the pre-tightening anchor plate, locking the upper ends of each steel strand, and placing the lower clamping device in a pre-loose state; S3, extend the piston end of the main top oil cylinder, pull up each of the steel strands, during which the pre-tightening anchor plate rises together with the steel strands; when a certain steel strand reaches the pre-tightening force, the corresponding pre-tightening clip is gradually destroyed, and the force of the steel strand is gradually transferred to the lower clamping device, and is locked again by the lower clamping device; when all the pre-tightening clips are destroyed, the piston end of the main top oil cylinder stops extending; S4. Retract the piston end of the main top oil cylinder, and the pre-tightening anchor plate will drop accordingly, and the damaged pre-tightening clips will be taken out to complete the pre-tightening of all the steel strands.

[0011] Preferably, in step S2, the cylinder body of the lower clamping oil cylinder drives the clamping plate of the lower clamping device to rise by 3-4 mm, and at this time, the lower clamping device is in a pre-loose state.

[0012] The present invention has at least the following beneficial effects: The multi-anchor point self-balancing pre-tightening anchor system and the method for pre-tightening steel strands provided by the present invention adopt plastic or engineering plastic to make pre-tightening clips, and control the compressive strength thereof so that when the steel strand reaches a predetermined pre-tightening force, the pre-tightening clips just reach their critical damage value; when the pre-tightening clips corresponding to multiple steel strands pre-tightened at the same time are all damaged, it means that all steel strands have reached the predetermined pre-tightening force, and the application of pre-tightening force to the steel strands can be stopped, so as to achieve simultaneous and uniform pre-tightening of multiple steel strands, reduce the tedious installation and disassembly work in the pre-tightening process of a single steel strand, greatly improve the pre-tightening efficiency of the steel strands, ensure the pre-tightening quality of the steel strands, and ensure the safety of subsequent operations.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the multi-anchor point self-balancing pre-tightening anchor system of the present invention; Figure 2 It is a structural schematic diagram of the pre-tightening device of the present invention; Figure 3 It is a structural schematic diagram of the lower clamping device of the present invention; DETAILED DESCRIPTION

[0015] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0016] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0017] like Figure 1 and Figure 2 As shown, the present invention provides a multi-anchor point self-balancing pre-tightening anchor system, comprising: an upper clamping device 3, a main top oil cylinder 4, a lower clamping device 5, and a pre-tightening device 2; the upper clamping device 3 and the lower clamping device 5 are respectively fixedly arranged on the piston end and the bottom of the main top oil cylinder 4, and the upper clamping device 3 and the lower clamping device 5 are used to lock or loosen the steel strand; the pre-tightening device 2 comprises a pre-tightening anchor plate 22 and a plurality of pre-tightening clips 21, and the pre-tightening anchor plate 22 is fixedly arranged on the upper clamping device 3; the pre-tightening anchor plate 22 is provided with a plurality of through holes for the steel strand to pass through, and the through holes are conical holes for placing the pre-tightening clips 21; the pre-tightening clips 21 are made of plastic or engineering plastic, and their compressive strength is calculated by the pre-tightening force of the steel strand.

[0018] In this technical solution, the pre-tightening clip 21 is made of plastic or engineering plastic, and its compressive strength is controlled so that when the steel strand reaches the pre-tightening force, the pre-tightening clip 21 just reaches its critical value of destruction. Therefore, whether the corresponding steel strand has reached the pre-tightening force can be directly judged by whether the pre-tightening clip 21 is destroyed. When the pre-tightening clips corresponding to the multiple steel strands pre-tightened at the same time are all destroyed, the pre-tightening force can be stopped from being applied to the steel strand, so that multiple steel strands can be pre-tightened uniformly at one time, reducing the tedious installation and disassembly work in the pre-tightening process of a single steel strand, greatly improving the pre-tightening efficiency of the steel strand, ensuring the pre-tightening quality of the steel strand, and ensuring the safety of subsequent operations.

[0019] Furthermore, the pre-tightening clip is made of polylactic acid or polycarbonate, which can meet the strength requirements of the pre-tightening clip, are easy to process and shape, have low cost, and are naturally degradable.

[0020] In another technical solution, in order to ensure the locking force of the pre-tightening clip 21, saw teeth are provided on the inner wall of the pre-tightening clip 21, and the tooth angle is 5° to 7°.

[0021] In another technical solution, the preload force applied to the steel strand is equal to the maximum friction force that the preload clip 21 can apply to the steel strand, and the compressive strength of the preload clip 21 is calculated by the following formula: p=F*0.013835+2.076195 (1) In the above formula (1), p is the required compressive strength value of the pre-tightening clip (MPa), and F is the pre-tightening force of the steel strand (N); the multi-anchor self-balanced pre-tightening anchor system is used to carry out multiple steel strand pre-tightening tests, and formula (1) is obtained by data fitting of the required compressive strength value of the pre-tightening clip and the pre-tightening force value of the steel strand obtained in each test.

[0022] In another technical solution, Figure 1 and Figure 3 As shown, the upper clamping device 3 and the lower clamping device 5 have the same structure, both including a support leg, a clamping cylinder and a clamping plate 11, the clamping cylinder is fixedly arranged in the support leg, and the support leg is fixedly connected to the piston end or the bottom of the main top cylinder 4. Specifically, the support leg is an upper support leg 3 and a lower support leg 6 corresponding to the upper clamping device 3 and the lower clamping device 5 respectively; the upper clamping device 3 is fixedly arranged in the upper support leg 1, and the upper support leg 1 is fixedly arranged at the piston end of the main top cylinder 4; the lower clamping device 3 is fixedly arranged in the lower support leg 6, and the lower support leg 6 is fixedly arranged at the bottom of the main top cylinder 4. The lower support leg 6 is usually placed on a load-bearing platform 7. The piston end 13 of the clamping cylinder is provided with a plurality of first through holes for the steel strands to pass through, and a lifting clip 12 is placed in each of the first through holes; the clip pressure plate 11 is fixedly connected to the top of the cylinder body 14 of the clamping cylinder, and the cylinder body 14 and the piston end 13 of the clamping cylinder can move relative to each other under the action of hydraulic oil to drive the clip pressure plate 11 to approach or move away from the lifting clip 12, thereby locking or loosening the steel strands.

[0023] Furthermore, the lifting clip 12 is made of 20crMnTi alloy steel, and a sawtooth is arranged on the inner wall thereof, and the tooth angle is 5° to 7°.

[0024] The present invention also provides a steel strand pre-tightening method, which realizes synchronous and uniform pre-tightening of multiple steel strands through the multi-anchor point self-balanced pre-tightening anchor system, and specifically comprises the following steps: S1, passing a plurality of steel strands from top to bottom through the pre-tightening anchor plate 22, the upper clamping device 3, the main top oil cylinder 4, the lower clamping device 5 and connecting with the weight component 8 in sequence; and locking the lower end of each steel strand by the lower clamping device 5; the weight component 8 is connected to the steel strand through the clamp 9, and each steel strand at the upper clamping device 3 is in a relaxed state; S2, push each of the pre-tightening clips 21 into the corresponding through holes on the pre-tightening anchor plate 22, lock the upper end of each steel strand, and put the lower clamping device 5 in a pre-loose state; Specifically, the pre-loose state of the lower clamping device 5 is achieved by the cylinder body 14 of the lower clamping cylinder driving the clamping plate 11 of the lower clamping device to rise by 3~4mm. At this time, the lifting clamp 12 in the piston end 13 of the lower clamping device still locks the lower part of the steel strand, but when an upward force is applied to the steel strand, the steel strand can rise accordingly and drive the corresponding lifted clamp 12 to slightly disengage from the conical hole section until it is limited by the clamping plate 11 again.

[0025] S3, extend the piston end of the main top oil cylinder 4, pull up each of the steel strands, during which the pre-tightening anchor plate 22 rises together with the steel strands; when a certain steel strand reaches the pre-tightening force, the corresponding pre-tightening clip 21 is gradually destroyed, and the force of the steel strand is gradually transferred to the lower clamping device 5, and is locked again by the lower clamping device 5; when all the pre-tightening clips 21 are destroyed, the piston end of the main top oil cylinder 4 stops extending; When the pre-tightening clips 21 are gradually damaged, it means that the corresponding steel strands have reached the predetermined pre-tightening force. At this time, the pre-tightening clips 21 will no longer be able to lock the steel strands. When the steel strands fall, they will drive the lifting clips 12 of the lower clamping device 5 to fall back into the corresponding conical holes to re-lock the steel strands. When all the pre-tightening clips 21 are damaged, it means that each steel strand has reached the predetermined pre-tightening force, and the piston end of the main top oil cylinder 4 can be stopped from being extended.

[0026] S4, retract the piston end of the main jacking cylinder 4, the pre-tightening anchor plate 22 will drop accordingly, and the damaged pre-tightening clips 21 will be taken out to complete the pre-tightening of all the steel strands.

[0027] In the above process, the extension and retraction of the main top cylinder 4 and the lower clamping cylinder are completed by a hydraulic pump station and a hydraulic control system, which is a hydraulic control device conventionally used in the prior art and will not be described in detail here.

[0028] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A multi-anchor self-balancing pre-tightening anchor system, characterized in that: include: An upper clamping device, a main top oil cylinder, a lower clamping device, and a pre-tensioning device; the upper clamping device and the lower clamping device are respectively fixedly arranged on the piston end and the bottom of the main top oil cylinder, and the upper clamping device and the lower clamping device are used to lock or loosen the steel strand; the pre-tensioning device includes a pre-tensioning anchor plate and a plurality of pre-tensioning clips, and the pre-tensioning anchor plate is fixedly arranged on the upper clamping device; the pre-tensioning anchor plate is provided with a plurality of through holes for the steel strand to pass through, and the through holes are conical holes for placing the pre-tensioning clips; the pre-tensioning clips are made of plastic or engineering plastics, and the required compressive strength value thereof is calculated by the pre-tensioning force of the steel strand.

2. The multi-anchor self-balancing pre-tightening anchor system according to claim 1, characterized in that: The pre-tightening clip is made of polylactic acid or polycarbonate.

3. The multi-anchor self-balancing pre-tightening anchor system according to claim 1, characterized in that: The inner wall of the pre-tightening clip is provided with saw teeth, and the tooth angle is 5°~7°.

4. The multi-anchor self-balancing pre-tightening anchor system according to claim 1, characterized in that: The required compressive strength of the preloaded clip is calculated as follows: p=F*0.013835+2.076195 In the above formula, p is the required compressive strength value of the pre-tightening clip, and F is the pre-tightening force of the steel strand.

5. The multi-anchor self-balancing pre-tightening anchor system according to claim 1, characterized in that: The upper clamping device and the lower clamping device have the same structure, and both include a support foot, a clamping cylinder and a clamping plate. The clamping cylinder is fixedly arranged in the support foot, and the support foot is fixedly connected to the piston end or the bottom of the main top cylinder. The piston end of the clamping cylinder is provided with a plurality of first through holes for the steel strands to pass through, and a lifting clamp is placed in each of the first through holes; the clamping plate is fixedly connected to the top of the cylinder body of the clamping cylinder, and the cylinder body and the piston end of the clamping cylinder can move relatively under the action of hydraulic oil to drive the clamping plate to approach or move away from the lifting clamp.

6. The multi-anchor self-balancing pre-tightening anchor system according to claim 5, characterized in that: The lifting clip is made of 20crMnTi alloy steel, and a sawtooth is arranged on the inner wall thereof, and the tooth angle is 5° to 7°.

7. A method for pre-tightening a steel strand, using the multi-anchor self-balancing pre-tightening anchor system according to claim 5, characterized in that: The following steps are involved: S1, passing a plurality of steel strands from top to bottom through the pre-tightening anchor plate, the upper clamping device, the main top oil cylinder, the lower clamping device and connecting with the weight component in sequence; and locking the lower end of each steel strand by the lower clamping device; S2, pushing each of the pre-tightening clips into the corresponding through holes on the pre-tightening anchor plate, locking the upper ends of each steel strand, and placing the lower clamping device in a pre-loose state; S3, extend the piston end of the main top oil cylinder, pull up each of the steel strands, during which the pre-tightening anchor plate rises together with the steel strands; when a certain steel strand reaches the pre-tightening force, the corresponding pre-tightening clip is gradually destroyed, and the force of the steel strand is gradually transferred to the lower clamping device, and is locked again by the lower clamping device; when all the pre-tightening clips are destroyed, the piston end of the main top oil cylinder stops extending; S4. Retract the piston end of the main top oil cylinder, and the pre-tightening anchor plate will drop accordingly, and the damaged pre-tightening clips will be taken out to complete the pre-tightening of all the steel strands.

8. The steel strand pre-tightening method according to claim 7, characterized in that: In step S2, the cylinder body of the lower clamping oil cylinder drives the clamping plate of the lower clamping device to rise by 3-4 mm, and at this time, the lower clamping device is in a pre-loose state.

Images