Closed grouting anchor cable structure

Abstract

The utility model relates to a deep foundation pit support pile traction anchor cable, in particular to a closed grouting anchor cable structure which comprises an anchor rod body and an isolation sleeve, the isolation sleeve is of a flexible structure and is waterproof, the periphery of the anchor rod body is sleeved with the isolation sleeve in the length direction, and the length of the isolation sleeve is larger than the grouting length. The anchor rod further comprises a guide cap arranged at the front end, the front end of the anchor rod body is fixedly connected with the guide cap, and the front end of the isolation sleeve is fixed to the guide cap and enables the front end of the isolation sleeve to be sealed. The anchor rod body is isolated by sleeving the waterproof isolation sleeve outside the anchor rod body, the guide cap ensures that the anchor cable smoothly enters the anchor cable hole, and meanwhile, the isolation sleeve is sealed and fixed, so that the situation that the isolation sleeve and the anchor rod body cannot synchronously enter due to friction of the wall of the anchor cable hole can be avoided, and meanwhile, the effect of sealing the front end of the isolation sleeve is achieved. The anchor cable structure can completely prevent underground water from washing away grouting liquid or diluting the grouting liquid, ensures that the grouting pressure intensity reaches the standard, and guarantees the anchoring strength of grouting liquid solidification.

Description

Technical Field

[0001] This utility model relates to a traction anchor cable for deep foundation pit support piles, specifically a closed grouting anchor cable structure. Background Technology

[0002] During foundation pit excavation, a support structure consisting of slope protection, retaining piles, a water-cutting curtain, and anchor cables is often used to prevent pit collapse. Anchor cable construction includes anchor hole drilling, anchor cable fabrication, and grouting. Due to varying groundwater levels in different regions, the groundwater volume increases significantly with pit depth in some areas. When anchor cables are installed at such depths, the grouting fluid can be washed away by the flowing groundwater during grouting. This not only dilutes the grouting fluid but also severely reduces the anchoring strength of the anchored section, causing its tensile strength to fall below the design value. Therefore, if traditional anchor cables are used in all anchoring layers of the foundation pit, the upper anchor cables may meet design requirements, while the lower anchor cables may not. Summary of the Invention

[0003] The purpose of this invention is to provide an anchor cable structure that can effectively prevent the grout from being washed away by groundwater. By using a flexible isolation sleeve to enclose the anchor rod body, the grout does not directly contact the inner wall of the anchor cable hole during grouting, thus preventing it from being washed away by groundwater. At the same time, the grout will squeeze the isolation sleeve to fit tightly against the inner wall of the anchor cable hole, achieving the requirement of full and dense grouting, thereby solving the problems mentioned in the background.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a closed-loop grouting anchor cable structure, which includes an inner anchor rod body and an outer isolation sleeve. Specifically, the isolation sleeve is a long, flexible tube structure made of flexible material and is waterproof. It is fitted around the outer periphery of the anchor rod body along its length, and the length of the isolation sleeve is greater than the grouting length. The anchor cable structure also includes a guide cap disposed at the front end of the anchor rod body. The front end of the anchor rod body is fixedly connected to the guide cap, and the front end of the aforementioned isolation sleeve is also fixed to the guide cap, thus sealing the front end of the isolation sleeve and achieving the purpose of isolating the anchor rod body within the anchor cable hole.

[0005] In the above technical solution, the anchor bolt body is isolated by fitting a waterproof isolation sleeve over it. A guide cap at the front end serves a guiding function, ensuring smooth advancement of the anchor cable during insertion into the hole. Simultaneously, it seals and fixes the isolation sleeve, preventing friction between the isolation sleeve and the anchor bolt body from causing them to not enter synchronously. It also seals the front end of the isolation sleeve, preventing grout leakage. This anchor structure completely prevents groundwater from washing away or diluting the grout, ensuring the grouting pressure meets standards and guaranteeing the anchoring strength after solidification.

[0006] As a preferred embodiment, the isolation sleeve has a multi-layer structure, including an inner lining layer and an outer woven layer. The inner lining layer is waterproof, ensuring that the isolation sleeve has a good water-blocking function, while the outer woven layer is used to ensure the compressive strength of the isolation sleeve and protect the inner lining layer from being worn through during construction.

[0007] As a preferred option, a marking line is set along the entire length of the outer surface of the isolation sleeve. The color of the marking line is different from the color of the rest of the outer surface. During the process of anchor cable insertion, by controlling the isolation sleeve to prevent the marking line from twisting significantly, the isolation sleeve can be prevented from twisting inside the anchor cable hole, thereby ensuring the smooth flow of grouting fluid and full filling of the isolation sleeve.

[0008] As a preferred embodiment, the diameter of the isolation sleeve is 30-50mm larger than the diameter of the anchor cable hole. After grouting, the grouting fluid squeezes the isolation sleeve. Since the isolation sleeve itself is a flexible structure, the allowance ensures that the isolation sleeve fully contacts the inner wall of the anchor cable hole, while the remaining part will also be squeezed by the grouting fluid and tightly adhere to the inner wall of the anchor cable hole in a folded form. This satisfies the construction requirement that the isolation sleeve tightly adheres to the wall of the anchor cable hole and ensures the anchoring strength.

[0009] As a preferred option, a sealing end cap is provided at the end of the isolation sleeve, and the anchor rod body passes through an avoidance hole provided on the end face of the sealing end cap. During the grouting process, the sealing end cap seals the isolation sleeve, meeting the construction requirements of sealing grouting and preventing a large amount of grout from leaking out.

[0010] As a preferred embodiment, the guide cap includes an outer cap and an inner cap. The inner cap includes an inner cap body with an annular cross-section and external threads on its outer circumference. The outer cap includes an outer cap body that mates with the inner cap body via internal threads. The front end of the outer cap body is closed, forming a fixing position between the front end of the inner cap body and the inner cap. The front end of the anchor rod is fixed to this fixing position. The outer and inner caps are connected by threads, allowing for simultaneous and quick fixation of the anchor rod after assembly.

[0011] For guide caps employing an outer and inner cap, preferably, the rear end of the inner cap body extends rearward to form a conical inner cap brim; the rear end of the outer cap body extends rearward to form a conical outer cap brim, and a compression cavity is formed between the outer and inner cap bodies; the front end of the isolation sleeve wraps around the inner cap brim and is fixed in the compression cavity. In use, the inner cap is placed inside the front end of the isolation sleeve, and the front end of the isolation sleeve is folded to wrap around the inner cap brim. As the outer cap is gradually screwed onto the inner cap, the outer cap brim gradually compresses the isolation sleeve around the outer periphery of the inner cap brim until it is completely compressed. This allows for quick and non-destructive fixing of the isolation sleeve, preventing slippage and ensuring the front end of the isolation sleeve remains sealed.

[0012] As a preferred embodiment, several receiving holes are made on the inner cap edge. The pleats formed after the isolation sleeve wraps around the inner cap edge are inserted into the corresponding receiving holes. After the pleats are embedded in the receiving holes, the bonding strength between the isolation sleeve and the guide cap can be effectively increased. At the same time, the isolation sleeve can be avoided by cutting it. In addition, after the pleats are embedded in the receiving holes, the inner cap edge can fully fit the isolation sleeve, which ensures that the force is evenly distributed in all parts of the isolation sleeve in the extrusion chamber and ensures the airtightness of the end of the isolation sleeve.

[0013] As a preferred embodiment, the width of the receiving hole gradually decreases from one end near the inner cap body to the rear, and is equipped with a matching extrusion block. The extrusion block is embedded in the pleats and, in the assembled state, the outer cap edge extrudes the extrusion block inward. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0015] Figure 1 A schematic diagram of the planar structure of the closed-loop grouting anchor cable structure provided in this utility model;

[0016] Figure 2 for Figure 1 A schematic diagram of the planar structure of the anchor rod in the anchor cable structure shown;

[0017] Figure 3 for Figure 1 A partial structural diagram of the middle isolation sleeve;

[0018] Figure 4 for Figure 1 A schematic diagram of the longitudinal cross-sectional structure of the guide cap;

[0019] Figure 5 This is a partial cross-sectional view of the guide cap in its installed state.

[0020] Figure 6 This is a schematic diagram of the sealed end cap structure;

[0021] Figure 7 This is a detailed drawing of the support section of the foundation pit.

[0022] In the diagram, the components are: 1. Isolation sleeve; 2. Guide cap; 3. Sealing end cap; 4. Anchor bolt body; 5. Marking line; 21. Outer cap; 22. Inner cap; 31. Cover body; 32. End panel; 33. Cable tie; 41. Steel strand; 42. Isolation frame; 43. Primary grouting pipe; 44. Secondary grouting pipe; 101. Inner lining layer; 102. Braided layer; 103. Pleated part; 212. Cap end; 211. Outer cap body; 213. Outer cap edge; 214. Fixing position; 215. Extrusion chamber; 221. Inner cap body; 222. Inner cap edge; 223. Accommodation hole; 224. Extrusion block; 601. Support pile; 602. Anchor lock hole; 603. Anchor cable I; 604. Anchor cable II; 605. Anchor head assembly. Detailed Implementation

[0023] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0024] Figure 1 As one embodiment of this utility model, a closed-type grouting anchor cable structure includes an inner anchor body 4 and an outer isolation sleeve 1, as well as a front guide cap 2 and a rear sealing end cap 3, such as... Figure 2 As shown, the anchor body 4 mainly consists of three steel strands 41 and multiple isolation frames 42 evenly spaced on the three steel strands 41. It also includes a primary grouting pipe 43 and a secondary grouting pipe 44. The guide cap 2 is fixed to the front end of the anchor body 4, guiding the anchor structure during the anchor insertion process. It also serves to fix and seal the isolation sleeve 1, ensuring that the isolation sleeve 1 moves synchronously with the anchor body 4 during anchor insertion and preventing grout from overflowing from the front end of the isolation sleeve 1 during grouting. This closed-loop grouting anchor structure isolates the anchor body 4 from the anchor hole by using the aforementioned impermeable isolation sleeve 1 and guide cap 2, effectively preventing the grout from being washed away by groundwater and ensuring that the tensile strength of the anchor structure meets the design requirements of the test values.

[0025] Specifically, the isolation sleeve 1 used should have good water-proofing function, which can effectively prevent grout from flowing out or groundwater from seeping in. It should also possess flexibility and wear resistance. The flexibility allows it to fit tightly against the inner wall of the anchor cable hole under the expansion of the grout, while the wear resistance ensures that the isolation sleeve 1 is not damaged during the fabrication of the anchor cable structure and the insertion of the anchor cable into the hole. To meet these requirements, the inner wall of the isolation sleeve 1 used in this embodiment is a rubber lining layer 101, and the outer layer is a woven layer 102, with the structure as follows: Figure 3As shown, in actual construction, a fire hose that meets the above-mentioned characteristics can be used as the isolation sleeve 1. In addition, the anchoring of the support pile often requires an anchor cable (including the anchoring section and the free section) that is more than ten meters long. In this embodiment, the anchor cable structure has an isolation sleeve 1 fitted outside the anchor body 4. Since the isolation sleeve 1 is a flexible structure, it may twist during the process of the anchor cable entering the hole. Excessive twisting will hinder the flow and filling of the grouting fluid, resulting in defects such as local hollowing of the anchor cable after grouting. This will seriously reduce the anchoring strength. In order to avoid this phenomenon, this embodiment sets a marking line 5 along the entire length of the braided layer 102 of the isolation sleeve 1. The color of the marking line is obviously different from the color of the braided layer 102. The marking line 5 can be woven by braiding material or made by spraying. During the process of the anchor cable entering the hole, it is only necessary to ensure that the marking line 5 does not twist significantly to avoid the above-mentioned situation.

[0026] Regarding the guide cap 2 used in this embodiment, as follows: Figure 4 As shown, the guide cap 2 includes an outer cap 21 and an inner cap 22. The inner cap 22 includes an inner cap body 221 with a circular cross-section. The outer periphery of the inner cap body 221 is provided with external threads. Its rear end face expands and extends rearward to form a conical inner cap edge 222. The maximum diameter of the inner cap edge 222 is 70-100 mm smaller than the diameter of the isolation sleeve 1. The outer cap body 21 includes an outer cap body 211 that is installed by mating with the inner cap body 221 through internal threads. The front end of the outer cap body 211 is a forward-protruding arc-shaped cap end 212. The rear end face of the outer cap body 211 expands and extends rearward to form a conical outer cap edge 213. In the assembled state, the outer cap 21 and the inner cap 22 of the above structure form a fixed position 214 between the front end of the inner cap body 221 and the outer cap body 211 (cap end 212). At the same time, a uniformly thick extrusion cavity 215 is formed between the outer cap edge 213 and the inner cap edge 222.

[0027] When making the anchor cable structure, the front end of the steel strand 41 in the anchor body 4 is passed through the inner cap 22. Then, the front end of the steel strand 41 is squeezed and fixed using a perforated fixing block 6 (with a diameter larger than the inner diameter of the inner cap 221). At this time, the fixing block 6 is located in front of the inner cap 221. Then, the front end of the isolation sleeve 1 is attached to the outer surface of the inner cap 222. At this time, the outer cap 211 is assembled. As the outer cap 211 and the inner cap 221 are gradually tightened, the fixing block 6 is restricted to the fixing position 214, and the front end of the isolation sleeve 1 is pressed tightly in the compression cavity 215, thereby fixing the anchor body 4 and the isolation sleeve 1, and sealing the front end of the isolation sleeve 1.

[0028] Furthermore, since the diameter of the isolation sleeve 1 is larger than the maximum diameter of the inner cap 222 (the rear part of the inner cap 222), and the inner cap 222 is conical, the isolation sleeve 1 fitted to the inner cap 222 will have wrinkles. In actual construction, the excess portion can be trimmed off. To achieve rapid installation and further improve the fixing strength of the isolation sleeve 1, this embodiment adopts an embedded method for the wrinkled portion: three receiving holes 223 are provided on the inner cap 222. The receiving holes are roughly triangular in shape, and their width gradually decreases from the end near the inner cap 221 to the rear, and are equipped with matching compression blocks 224; Figure 5 As shown, for the pleats 103 formed by the inner cap 222 of the isolation sleeve 1, they are evenly inserted into the corresponding receiving holes 223, and then the compression block 224 is embedded in the pleats 103. In the assembled state, the outer cap 213 presses the compression block 224 inward. This not only further ensures that the isolation sleeve 1 fits tightly against the inner cap 222, ensuring the airtightness of each part and the balanced force of the isolation sleeve in the compression cavity 215, but also effectively improves the tensile strength of the fixed part by combining the pleats 103 and the compression block 224.

[0029] Regarding the sealing end cap 3 at the rear end, its main function is to seal the isolation sleeve 1 during grouting, thereby achieving sealed grouting. Figure 6 As shown, it includes a tubular cover body 31 and an end panel 32 at the rear end of the cover body 31. The outer periphery of the cover body 31 is provided with annular anti-slip protrusions. The rear end of the isolation sleeve 1 is fitted onto the cover body 31 and then fixed by a cable tie 33. The anchor rod body 4 (including steel strand 41, primary grouting pipe 43 and secondary grouting pipe 44) passes through the pre-fabricated hole provided on the end panel 32.

[0030] It should be noted that the anchor cable is divided into an anchoring section and a free section. According to the existing usage process, during the manufacturing process of the anchor rod body, the steel strand of the free section needs to be wrapped to prevent the grouting fluid from wrapping the free section. This process is also applicable to the closed grouting anchor cable mechanism in this embodiment. Specifically, during the manufacturing process of the closed grouting anchor cable structure of this structure, a PVC pipe of appropriate size is used to cover the free section.

[0031] The closed-loop grouting anchor cable structure described above can effectively prevent the grouting fluid from being washed away by groundwater, and can also meet the construction requirements of full and dense grouting. Furthermore, the tension test values ​​can meet the design requirements. Figure 7The diagram shows a detailed cross-section of a foundation pit support, where the anchor hole 602 has a diameter of 150mm and an inclination angle of 15° relative to the horizontal plane. The diagram only shows four anchor cables at different depths securing the support pile 601. The upper two anchor cables are I603. Since the influence of groundwater within the anchor hole 602 at this depth is small or even negligible, anchor cables I603 are ordinary anchor cables, secured with anchor head assemblies 605. However, in the third and fourth underground layers, groundwater flow is significant within the anchor hole 602. The anchor cables II604 used there are the closed-type grouting anchor cable structure provided in this embodiment, thus preventing the grout from being washed away by groundwater. Specifically, in this project, the third-layer anchor cable II604 is 16.0m long, with a 10.0m anchored section (the part far from the support pile) and a 6.0m free section (the part close to the support pile). The isolation sleeve 1 used has a diameter of 200mm. During the fabrication of the anchor body, a Φ25 PVC pipe is used to cover the free section. At this time, the PVC pipe acts as an isolation device, effectively preventing the grout from encapsulating the free section and thus not affecting the tensioning of the free section. It should be noted that the sealing end cap 3 is only used to achieve sealing during grouting. The sealing end cap 3 needs to be removed before tensioning, and after tensioning, the anchor head assembly 605 is used to fix the steel strand 41.

[0032] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0033] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0034] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A closed-loop grouting anchor cable structure, characterized in that: The anchor cable structure includes an anchor body and an isolation sleeve, wherein the isolation sleeve is a flexible and waterproof structure that is fitted around the periphery of the anchor body along its length and the length of the isolation sleeve is greater than the grouting length. The anchor cable structure also includes a guide cap at the front end, the front end of the anchor body is fixedly connected to the guide cap, and the front end of the isolation sleeve is fixed to the guide cap to seal the front end of the isolation sleeve.

2. The closed-loop grouting anchor cable structure as described in claim 1, characterized in that: The isolation sleeve has a multi-layer structure, including an inner lining layer and an outer woven layer, wherein the inner lining layer is waterproof.

3. The closed-loop grouting anchor cable structure as described in claim 1, characterized in that: A marking line is set along the entire length of the outer surface of the isolation sleeve, and the color of the marking line is different from the color of the rest of the outer surface.

4. The closed-loop grouting anchor cable structure as described in claim 1, characterized in that: The diameter of the isolation sleeve is 30-50 mm larger than the diameter of the anchor cable hole.

5. The closed-loop grouting anchor cable structure as described in claim 1, characterized in that: A sealing end cap is provided at the end of the isolation sleeve, and the anchor rod body passes through an avoidance hole provided on the end face of the sealing end cap.

6. The closed-loop grouting anchor cable structure as described in any one of claims 1 to 5, characterized in that: The guide cap includes an outer cap and an inner cap, wherein the inner cap includes an inner cap body with an annular cross-section and an external thread on the outer periphery of the inner cap body; the outer cap includes an outer cap body that is installed by engaging with the inner cap body through an internal thread, the front end of the outer cap body is closed, and a fixed position is formed between the front end of the inner cap body and the inner cap body; the front end of the anchor rod body is fixed at the fixed position.

7. The closed-loop grouting anchor cable structure as described in claim 6, characterized in that: The rear end of the inner cap body extends backward to form a conical inner cap brim; the rear end of the outer cap body extends backward to form a conical outer cap brim, and a uniformly thick compression cavity is formed between the outer cap body and the inner cap body; the front end of the isolation sleeve wraps around the inner cap brim and is fixed in the compression cavity.

8. The closed-loop grouting anchor cable structure as described in claim 7, characterized in that: Several receiving holes are made on the inner brim, and the folds formed after the isolation sleeve wraps around the inner brim are inserted into the corresponding receiving holes.

9. The closed-loop grouting anchor cable structure as described in claim 8, characterized in that: The receiving hole is equipped with a matching extrusion block, which is embedded in the pleated part and, in the assembled state, the outer cap edge presses the extrusion block inward.

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