Pressure type prestressed anti-floating anchor rod and construction method thereof

Abstract

The application discloses a pressure type prestressed anti-floating anchor rod and a construction method thereof, and relates to the technical field of anchor rods. The pressure type prestressed anti-floating anchor rod comprises an anchor rod body, a prestress device and a waterproof device. The anchor rod body comprises a protection pipe and a rod body. The prestress device comprises a prestress transmission assembly, and the prestress transmission assembly comprises a seat body. The waterproof device is arranged around the rod body at the opening of the drill hole and comprises a waterproof coiled material, a waterproof rubber sleeve ring, a waterproof protective layer and a waterproof assembly. The waterproof assembly comprises a base, a top cover and a sealing element with a water absorption expansion effect. The construction method comprises the following steps: S1, drilling; S2, hole cleaning; S3, anchor rod installation; S4, grouting; S5, prestress application; and S6, waterproof construction. The application can effectively improve the waterproof effect after anchor rod construction and effectively improve the structural stability after anchor rod construction, thereby effectively improving the safety of subsequent building construction.

Description

Technical Field

[0001] This application relates to the technical field of anchor bolts, and in particular to a pressure-type prestressed anti-buoyancy anchor bolt and its construction method. Background Technology

[0002] Prestressed pressure anchors are a type of anchoring system that resists the buoyancy of groundwater on structures by applying prestress. Unlike traditional tension anchors, an isolation sleeve is installed between the anchor body (steel strand or reinforcing bar) and the grouting body. The load is transferred to the grouting body through the bearing body at the bottom of the anchor, so that the anchor body mainly bears tensile force rather than compressive force, while the grouting body bears compressive force. This structure avoids direct tensile corrosion of the anchor body, results in a more uniform stress distribution, and ensures reliable anchoring performance. It is particularly suitable for anti-buoyancy projects such as deep foundation pits and basements in high water table areas.

[0003] In existing technologies, construction involves first drilling to the designed depth, installing a bearing plate at the bottom of the hole, and inserting prestressed tendons with isolation sleeves. Then, grout is injected upwards from the bottom of the hole under pressure, forming an enlarged bottom head or a full-length bonded anchoring section. After the grout reaches sufficient strength, the anchor rods are tensioned and locked to the structural base plate or capping beam, allowing the anchor rods to actively withstand pull-out forces. This method effectively controls structural uplift displacement, and due to the compression of the grout and the tension of the steel, durability is significantly improved. It is currently widely used in underground space anti-buoyancy, slope reinforcement, and tower crane foundations.

[0004] However, after the construction of the existing pressure-type prestressed anti-buoyancy anchor rods, one end of the anchor rod will penetrate the substrate and the waterproof layer, making it difficult for the waterproof layer to close effectively due to the penetration of the anchor rod. At this time, groundwater can easily seep upward along the anchor rod, affecting the stability of the anchor rod installation and seriously affecting the structural safety of the building project. Summary of the Invention

[0005] This application provides a pressure-type prestressed anti-buoyancy anchor and its construction method, which can effectively improve the waterproof effect after anchor construction and the structural stability after anchor construction, thereby effectively improving the safety of subsequent building construction.

[0006] On the one hand, this application provides a pressure-type prestressed anti-buoyancy anchor bolt, which adopts the following technical solution: A pressure-type prestressed anti-buoyancy anchor bolt includes an anchor bolt body, a prestressing device, and a waterproofing device; The anchor bolt body includes a protective tube and a rod body inserted into the borehole; the protective tube is disposed at the opening of the borehole, one end of the rod body passes through the protective tube, and its end is located above the protective tube; The prestressing device includes a prestressing transmission component, and the prestressing transmission component includes a base; the base is disposed above the protective pipe, the top of the rod passes through the base, and its end serves as the force-applying end of the prestressing device; The waterproofing device is arranged around the rod body at the opening of the drilled hole, and includes a waterproof membrane, a waterproof rubber collar, a waterproof protective layer, and a waterproof component; the waterproof membrane, the waterproof rubber collar, and the waterproof protective layer are all arranged between the protective tube and the base body, and the waterproof rubber collar is located between the waterproof protective layer and the waterproof membrane; the waterproof component is arranged above the waterproof protective layer and surrounds the base body; The waterproof component includes a base, a top cover, and a seal with a water-absorbing and swelling effect; The base is positioned above the waterproof protective layer, and its bottom dimensions are adapted to the dimensions of the waterproof rubber collar. After installation, its axis coincides with the axis of the rod. The sealing element is located on the inner side of the base and contacts and abuts against the bottom of the waterproof protective layer and the base. The top cover is detachably connected to the top of the base and, after installation, presses down on the sealing element.

[0007] By adopting the above technical solution, after the anchor bolt construction is completed, the waterproof device can effectively reduce the probability of groundwater seeping upwards at the anchor bolt penetration point. When groundwater seeps upwards, the sealant absorbs water and expands, which can further improve its sealing effect, thereby further improving the waterproof effect after the anchor bolt construction. At the same time, it can effectively improve the structural stability after the anchor bolt construction, thereby effectively improving the safety of subsequent building construction.

[0008] Optionally, the waterproof component further includes a limiting structure and a compression structure; The limiting structure includes a first limiting plate; the first limiting plate is disposed on the inner side of the base and located above the sealing element; The extrusion structure includes multiple extrusion members; the extrusion members are movably connected to the first limiting plate, and their direction of movement is parallel to the axial direction of the base; When the top cover is not installed, the top of the extruder is located above the first limiting plate; after the top cover is installed, the bottom of the top cover drives the extruder to move downward.

[0009] By adopting the above technical solution, the positional stability of the seal after installation can be improved to ensure that the seal will strengthen the sealing effect after it absorbs water and expands. At the same time, the sealing effect after the seal is installed can be improved.

[0010] Optionally, the limiting structure further includes four second limiting plates; The second limiting plate is disposed below the first limiting plate, and the four second limiting plates are perpendicular to each other and disposed on the outside of the sealing member; The base has four clearance openings at its bottom, each of which corresponds to one of the four second limiting plates. The side of the second limiting plate closest to the adjacent clearance opening forms a clearance space for the arrangement of reinforcing bars.

[0011] By adopting the above technical solution, the positional stability of the sealing components after installation can be further improved. At the same time, it can facilitate the subsequent arrangement of steel bars by construction personnel and the casting of the base plate, and can effectively improve the construction efficiency and effect of the base plate.

[0012] Optionally, the limiting structure is rotatably connected to the base, and its rotation axis coincides with the axis of the base.

[0013] By adopting the above technical solution, construction workers can easily adjust the rotation position of the limiting structure according to the arrangement requirements of the reinforcing bars, making it easier for them to arrange the reinforcing bars using the clearance space.

[0014] Optionally, the limiting structure further includes multiple positioning frames for positioning the reinforcing bars during installation. The multiple positioning frames are respectively disposed on multiple second limiting plates and located in multiple clearance spaces, and after the reinforcing bars are installed and positioned, their length direction is parallel to the length direction of the adjacent second limiting plates.

[0015] By adopting the above technical solutions, the positional accuracy and stability of the reinforcing bars can be further improved, and the reinforcing bars can be easily tied together, thereby further improving the construction efficiency and effect of the base plate. At the same time, it can make the structural strength distribution around the anchor rod more uniform after the base plate is constructed, reducing the probability of local damage to the anchor rod due to uneven structural strength of the base plate after it is stressed.

[0016] Optionally, two mounting slots are provided on both sides of the top of the base for the installation of the lifting rod. After the lifting rod is installed, its two ends are respectively inserted into the two mounting slots, and its bottom is close to the reinforcing bar below.

[0017] By adopting the above technical solution, it is possible to facilitate the installation and positioning of the suspension rods, improve the accuracy and stability of the installation position, and facilitate the binding and fixing of the suspension rods with the steel bars above and below them, thereby further improving the construction efficiency and effect of the base plate.

[0018] Optionally, the bottom of the top cover has a limiting portion adapted to the four mounting slots; After the top cover is installed on the base, the four limiting parts respectively contact and abut against the two lifting rods.

[0019] By adopting the above technical solutions, the positional accuracy of the suspension rod installation and the positional stability after installation can be further improved.

[0020] Optionally, the base includes a fixed part and a rotating part, the rotating part is located above the fixed part, and the mounting groove is formed on the rotating part; the rotation axis of the rotating part relative to the fixed part coincides with the axis of the base, and the rotating part is fixedly connected to the limiting structure.

[0021] By adopting the above technical solution, construction personnel can easily adjust the rotation of the limiting structure. At the same time, after one adjustment, construction personnel can easily arrange and install the reinforcing bars and lifting rods, effectively improving the relative positional stability of the reinforcing bars and lifting rods after installation.

[0022] Optionally, the prestress transfer assembly further includes a movable plate and several elastic elements; The movable plate is sleeved and installed on the outside of the seat body, and is movably connected to the seat body with its direction of movement coinciding with the axis of the seat body; after the waterproof component is installed, a space adapted to the movable plate is formed between the first limiting plate and the seat body. The elastic element is disposed between the movable plate and the base, and has the tendency to drive the movable plate to move upward to its limit position, and the bottom of the top cover has an abutment portion for contacting the movable plate.

[0023] By adopting the above technical solution, the sealing performance of the sealing components after the waterproof components are installed can be improved, the probability of them coming into contact with concrete during the subsequent base slab pouring process can be reduced, and the sealing effect of water absorption and expansion can be stably exerted when groundwater seeps upward.

[0024] On the other hand, this application also provides a construction method for a pressure-type prestressed anti-buoyancy anchor bolt, which adopts the following technical solution: A construction method for a pressure-type prestressed anti-buoyancy anchor bolt, used for constructing the aforementioned pressure-type prestressed anti-buoyancy anchor bolt, includes the following steps: S1, Drilling; S2, Clean the hole; S3. Anchor bolt installation; S4, Grouting; S5. Prestressing application; S6. Waterproofing construction.

[0025] In summary, this application includes at least one of the following beneficial effects: 1. It can effectively improve the waterproofing effect after anchor bolt construction, thereby effectively improving the structural stability after anchor bolt construction, reducing the probability of groundwater seeping upward, and thus effectively improving the safety of subsequent building construction; 2. When groundwater seeps upward, it can absorb water while enhancing the waterproof sealing effect, thus effectively maintaining the stability of the anchor bolt after groundwater seeps upward; 3. It allows construction workers to complete the subsequent base slab construction after the anchor bolt construction is completed, improving the efficiency and effectiveness of the base slab construction. At the same time, it can reduce the probability that the waterproofing of the anchor bolts will be affected due to the quality of the base slab construction when groundwater seeps upward. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of a pressure-type prestressed anti-buoyancy anchor bolt before grouting, as per this application; Figure 2 This is a cross-sectional view of a pressure-type prestressed anti-buoyancy anchor bolt after grouting and installation of the base, as described in this application. Figure 3 This is a schematic diagram of the structure of a pressure-type prestressed anti-buoyancy anchor bolt after the installation of a waterproof component; Figure 4 This is a sectional view of a pressure-type prestressed anti-buoyancy anchor rod after the installation of waterproof components and the laying of reinforcing bars and suspension rods.

[0027] Explanation of reference numerals in the attached drawings: 1. Foundation; 11. Drill hole; 12. Concrete cushion layer; 2. Anchor bolt body; 21. Protective pipe; 22. Rod body; 3. Prestressing device; 31. Prestressing transfer assembly; 311. Base; 312. Movable plate; 313. Elastic element; 4. Waterproofing device; 41. Waterproof membrane; 42. Waterproof rubber collar; 43. Waterproof protective layer; 44. Waterproofing component; 441. Base; 4411. Fixing part ; 4412, Rotating part; 4413, Leaving opening; 4414, Mounting groove; 4415, Leaving space; 442, Top cover; 4421, Limiting part; 4422, Abutting part; 443, Sealing element; 444, Limiting structure; 4441, First limiting plate; 4442, Second limiting plate; 445, Extrusion structure; 4451, Extruded part; 446, Positioning frame; 5, Base plate; 51, Reinforcing bar; 52, Hanging bar. Detailed Implementation

[0028] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail. Example 1

[0029] Reference Figure 1 and Figure 2 This application discloses a pressure-type prestressed anti-buoyancy anchor bolt, which includes an anchor bolt body 2, a prestressing device 3 for applying prestress to the anchor bolt body 2, and a waterproofing device 4 for reducing the probability of groundwater seeping upward along the anchor bolt body 2.

[0030] The anchor body 2 includes a protective tube 21 and a rod 22 that provides anchoring.

[0031] The protective pipe 21 has a cylindrical structure and is fixedly installed on the foundation 1, positioned at the opening of the borehole 11. The axis of the protective pipe 21 coincides with the axis of the borehole 11, with one end extending out of the borehole 11 and the other end protecting the borehole 11 near the opening, reducing the probability of the borehole 11 collapsing during the installation of the anchor body 2. After the rod body 22 is installed, its axis coincides with the axis of the borehole 11, with one end extending out of the borehole 11 and positioned above the protective pipe 21, allowing the subsequent prestressing device 3 to apply prestress to the anchor body 2. In this embodiment, since the anchor body 2 of the pressure-type prestressed anti-buoyancy anchor is prior art, it will not be described in detail here, and is only briefly shown in the accompanying drawings.

[0032] The prestressing device 3 is installed based on the anchor body 2, and includes a prestressing transfer component 31 for assisting the prestressing device 3 in applying prestress to the anchor body 2.

[0033] The prestress transfer assembly 31 includes a base 311, a movable plate 312, and multiple elastic elements 313.

[0034] The base 311 is cylindrical in shape and is fixedly installed above the protective tube 21, allowing the top of the rod 22 to pass through. The axis of the base 311 coincides with the axis of the protective tube 21, and the rod 22 is centered inside the base 311.

[0035] The movable plate 312 has an overall annular plate structure and is movably mounted on the top of the base 311. Its direction of movement is parallel to its own axis and also parallel to the axis of the base 311. During the movement of the movable plate 312 relative to the base 311, its axis remains coincident with the axis of the base 311. In this embodiment, it is preferable that the inner side of the movable plate 312 is sleeved and fitted with the outer side of the base 311.

[0036] The elastic element 313 is installed between the movable plate 312 and the seat 311, with its two ends fixedly connected to the movable plate 312 and the seat 311 respectively, and it has the tendency to drive the movable plate 312 to move upward to its limit position and hold it there. In this embodiment, the elastic element 313 is preferably a compression spring.

[0037] The movable plate 312 is restricted in its movement relative to the base 311. When the movable plate 312 moves upward to its limit position, the top end face of the movable plate 312 is flush with the top end face of the base 311. At this time, the movable plate 312 and the top of the base 311 are used together for the installation of prestressing application equipment (such as jacks). When the movable plate 312 moves downward to its limit position, there is a certain gap between the movable plate 312 and the bottom of the base 311.

[0038] Reference Figure 2 and Figure 3 The waterproofing device 4 is installed around the anchor bolt body extending out of the drill hole 11. It includes a waterproof membrane 41, a waterproof rubber collar 42, a waterproof protective layer 43, and a waterproof component 44, and the waterproof membrane 41, waterproof rubber collar 42, waterproof protective layer 43, and waterproof component 44 are distributed from bottom to top.

[0039] The waterproof membrane 41 is applied to the top of the protective pipe 21, and it is applied around the portion of the rod 22 that extends out of the protective pipe 21. In this embodiment, it is preferable that the waterproof membrane 41 is annular around the portion of the rod 22 that extends out of the protective pipe 21, and its axis coincides with the axis of the protective pipe 21; and preferably, a concrete pad 12 is pre-cast on the base 1, the top surface of the concrete pad 12 is flush with the top surface of the protective pipe, and a waterproof coating (such as cement-based penetrating crystalline waterproof coating) is applied to the concrete pad 12 near the protective pipe 21, and then the waterproof membrane 41 is applied on top of the waterproof coating; since the above-mentioned waterproof membrane 41 is a common prior art, it will not be described in detail here, and it is only briefly shown in the accompanying drawings.

[0040] The waterproof rubber collar 42 is installed above the waterproof membrane 41. It has an overall ring-shaped sheet structure and an upward-extending pipe structure at its center. The bottom surface of the waterproof rubber collar 42 is firmly and tightly bonded to the waterproof membrane 41 with waterproof adhesive. At this time, the axis of the waterproof rubber collar 42 coincides with the axis of the borehole 11. After the seat 311 is fixedly installed, the upward-extending pipe structure of the waterproof rubber collar 42 will be located inside the seat 311, reducing the probability of groundwater seeping upward and flowing out from the gap at the bottom of the seat 311.

[0041] The waterproof protective layer 43 is constructed on the top surface of the concrete pad 12. The portion near the opening of the borehole 11 is constructed around the part of the rod body 22 extending out of the protective pipe 21, located above the waterproof rubber collar 42. The seat 311 is fixedly installed above the waterproof protective layer 43, further reducing the probability of groundwater seeping upwards along the anchor rod body. In this embodiment, since the waterproof protective layer 43 with the above-mentioned functions is prior art in the field, it will not be described in detail here, and only a brief representation is given in the accompanying drawings.

[0042] Reference Figure 2 and Figure 4 The waterproof component 44 is installed above the waterproof protective layer 43, and includes a base 441, a top cover 442, and a seal 443 with a water-absorbing and swelling effect. In this embodiment, the seal 443 is preferably made of water-absorbing and swelling rubber.

[0043] The base 441 has an overall cylindrical structure. After being installed above the waterproof protective layer 43, it surrounds the seat body 311 and its axis coincides with the axis of the seat body 311. The base 441 includes a fixing part 4411 fixed relative to the waterproof protective layer 43 and a rotating part 4412 rotatably adjustable relative to the fixing part 4411, and the rotation axis of the rotating part 4412 coincides with the axis of the base 441. In this embodiment, preferably, the bottom of the fixing part 4411 has a groove for adapting to the stepped structure formed by the overlapping of the waterproof protective layer 43 and the waterproof roll 41, which facilitates the positioning and installation of the base 441 on the waterproof protective layer 43 through the fixing part 4411.

[0044] The seal 443 has an overall ring structure and is installed on the bottom of the inner side of the base 441. After the waterproof component 44 is installed, it can be wrapped around the outside of the seat 311, and its bottom contacts and abuts against the waterproof protective layer 43 and the bottom of the seat 311.

[0045] The top cover 442 has an overall ring structure and is installed on the top of the base 441. It is detachably connected to the base 441, and after installation, it can compress the seal 443 located below it, thereby increasing the contact between the seal 443 and the waterproof protective layer 43 and the bottom of the seat 311, thus further improving its waterproof sealing effect.

[0046] After the waterproofing device 4 is installed, a construction base slab 5 will be poured on top of the concrete cushion layer 12, so that the prestressing transfer component 31 and the waterproofing component 44 are both embedded in the base slab 5. In order to improve the structural strength of the base slab 5 and reduce the probability that its structural strength will be affected when groundwater seeps upward along the anchor body, it is preferable that multiple steel bars 51 and multiple hanging bars 52 are arranged in a certain pattern inside the base slab 5 to improve the overall structural strength of the base slab 5. In this embodiment, it is preferable that two layers of steel bars 51 are laid inside the base slab 5. The steel bars 51 at the bottom are laid near the concrete cushion layer 12, and the steel bars 51 at the top are laid above the seat body 311. Each layer of steel bars 51 consists of multiple steel bars 51 that are stacked and tied together perpendicularly to each other, forming a grid-like distribution. The two layers of steel bars 51 are connected by multiple hanging bars 52, and the hanging bars 52 are also fixed to the adjacent steel bars 51 by binding. It is preferable that two hanging bars 52 are laid and installed around each seat body 311.

[0047] Furthermore, to facilitate the installation of the reinforcing bars 51 and the hanging bars 52 by construction personnel based on the waterproof component 44, it is preferable that the base 441 is provided with a clearance opening 4413 for easy installation of the reinforcing bars 51 and an installation groove 4414 for easy installation of the hanging bars 52, and the top cover 442 has a limiting part 4421 for positioning the hanging bars 52 after installation.

[0048] The clearance opening 4413 is located on the rotating part 4412 near the fixed part 4411, and a total of four clearance openings 4413 are provided on the rotating part 4412. The four clearance openings 4413 are arranged in a circular array on the fixed part 4411 with the axis of the base 441 as the axis, which facilitates the laying of two steel bars 51 that are inserted into adjacent clearance openings 4413 in a horizontal and mutually perpendicular position.

[0049] The mounting slots 4414 are formed on the rotating part 4412 and located above the clearance opening 4413. A total of four mounting slots 4414 are formed on the rotating part 4412. The four mounting slots 4414 are distributed in pairs at both ends of the rotating part 4412 in the horizontal direction. Each mounting slot 4414 forms an opening through the inner and outer sides of the rotating part 4412 and also forms an opening through the top of the rotating part 4412. The mounting slots 4414 at both ends of the rotating part 4412 are paired and aligned, facilitating the simultaneous insertion of the lifting rod 52 into the corresponding two mounting slots 4414, thus providing a certain degree of positional stability. In this embodiment, preferably, after the lifting rod 52 is installed on the rotating part 4412 through two mounting slots 4414, it is positioned above the lower reinforcing bar 51, facilitating the binding and fixing of the lifting rod 52 to the lower reinforcing bar 51.

[0050] After the waterproof component 44 is installed, the top of the top cover 442 provides support for the laying of the reinforcing bars 51, facilitating the laying of the reinforcing bars 51 in the top layer and making it easier for the upper reinforcing bars 51 to be tied and fixed with the hanging bars 52. In this embodiment, it is preferable that the top cover 442 and the base 441 are stably and detachably connected by multiple screws and nuts threaded together; and preferably, the top of the top cover 442 has a groove to facilitate the laying of the reinforcing bars 51, and drives the upper reinforcing bars 51 and the lower reinforcing bars 51 to be aligned in the vertical direction.

[0051] The top cover 442 has four limiting parts 4421 below it that are adapted to and correspond one-to-one with the mounting slots 4414. During the installation of the top cover 442, after aligning the four limiting parts 4421 with the four mounting slots 4414, it can be moved downward in the vertical direction, so that the limiting parts 4421 are engaged in the corresponding mounting slots 4414. When the top cover 442 is installed, the four limiting parts 4421 will contact and abut against the inclined part of the corresponding suspension rod 52. Therefore, during the installation process, the top cover 442 can drive the two suspension rods 52 initially installed through the mounting slots 4414 to be centered (to achieve the correction effect), and finally can also limit the suspension rods 52, thereby improving the positional accuracy and reliability of the suspension rods 52 after installation.

[0052] Furthermore, in order to further improve the sealing effect of the seal 443 when groundwater seeps in, and to further facilitate the laying and installation of the reinforcing steel 51 by construction personnel, the preferred waterproof component 44 also includes a limiting structure 444 for improving the positional stability of the seal 443 and a compression structure 445 for assisting the top cover 442 in compressing the seal 443.

[0053] The limiting structure 444 is installed inside the rotating part 4412 and located near the fixed part 4411. It includes a first limiting plate 4441 for fixing the sealing member 443 and four second limiting plates 4442.

[0054] The first limiting plate 4441 is an overall annular plate structure, located above the seal 443, and is used to limit the upward deformation of the seal 443. After the base 441 is installed, a space is formed between the first limiting plate 4441 and the seat 311 that is compatible with the movable plate 312. At this time, when the movable plate 312 moves downward to its limit position, it will form an integral part with the first limiting plate 4441, preventing concrete from entering the interior of the base 441 and contacting the seal 443 during the subsequent pouring and molding of the base plate 5. In this embodiment, preferably, the bottom of the top cover 442 extends outward along the axial direction with an abutment portion 4422 that fits with the seat 311 and can contact and abut against the movable plate 312. During the installation of the top cover 442, a downward force will be applied to the movable plate 312 through the abutment portion 4422 to drive the movable plate 312 to move downward to its limit position.

[0055] During the installation of the top cover 442, when it moves downward to its limit position relative to the base 441, the abutment portion 4422 will contact the bottom structure of the suspension rod 52, which is initially installed using the mounting groove 4414, and simultaneously contact the four movable parts, driving the movable parts to move downward to their limit position to compress the seal 443. In this embodiment, preferably, the bottom of the abutment portion 4422 has two grooves that are adapted to the bottom structure of the suspension rod 52, so that the abutment portion 4422 can make way for the bottom structure of the two suspension rods 52 when it contacts the movable parts.

[0056] The second limiting plate 4442 is a rectangular plate structure. One end of its width direction is fixedly connected to the inner wall of the rotating part 4412, and its width direction is parallel to the axis of the base 441. The four second limiting plates 4442 correspond one-to-one with the four clearance openings 4413. The length directions of adjacent second limiting plates 4442 are perpendicular to each other, and the thickness direction of the second limiting plates 4442 is parallel to the opening direction of the corresponding clearance opening 4413. The rotating part 4412 forms a clearance space 4415 on the side of the second limiting plate 4442 near the adjacent clearance opening 4413 to facilitate the laying of the reinforcing bar 51. The second limiting plate 4442 can also help the reinforcing bar 51 to be laid neatly. After the base 441 is installed, the four second limiting plates 4442 will surround the sealing member 443, restricting the outward deformation of the sealing member 443. At the same time, it can effectively prevent the concrete used for casting the base plate 5 from entering through the clearance opening 4413 and contacting the sealing member 443.

[0057] The limiting structure 444 is fixedly connected to the rotating part 4412, and it can rotate with the rotating part 4412 relative to the fixed part 4411. This makes it convenient for construction personnel to rotate and adjust the rotating part 4412 according to the installation requirements of the reinforcing bar 51 and the hanging bar 52. This facilitates the subsequent laying and installation of the reinforcing bar 51 and the hanging bar 52 by the construction personnel using the clearance space 4415 and the installation groove 4414.

[0058] To further facilitate the installation and positioning of the reinforcing bars 51 by inserting them into the clearance space 4415, it is preferable that multiple positioning frames 446 are fixedly installed on the side of each of the four second limiting plates 4442 near the adjacent clearance space 4415, allowing the reinforcing bars 51 to be installed and positioned horizontally and parallel to the length direction of the corresponding second limiting plate 4442. In this embodiment, it is preferable that four positioning frames 446 are installed on each second limiting plate 4442, which facilitates the installation and positioning of the reinforcing bars 51 in a grid pattern around the base 441 by the construction personnel; and preferably, the positioning frames 446 are claws with a certain amount of deformation, which facilitates the direct insertion and positioning of the reinforcing bars 51; since the positioning frames 446 with the above functions are common existing technology, they will not be described in detail here, and are only briefly shown in the accompanying drawings.

[0059] The implementation principle of a pressure-type prestressed anti-buoyancy anchor rod in this application embodiment is as follows: During construction, holes 11 are first drilled in the foundation 1. Then, based on the holes 11, the waterproof membrane 41, waterproof rubber collar 42, and waterproof protective layer 43 of the anchor rod body 2, prestressing device 3, and waterproof device 4 are constructed. Next, the base 441 is installed and positioned around the part of the anchor rod body 2 that extends out of the holes 11, and the suspension rod 52 is initially installed using the four mounting slots 4414. Then, the top cover 442 is installed on the base 441, so that the abutment part 4422 of the top cover 442 can pass through. The extrusion structure 445 extrudes the seal 443 to improve the sealing effect of the seal 443, and at the same time can correct and position the initially installed lifting rod 52. Then, the lower layer of steel bars 51 can be laid with the help of multiple positioning frames 446 in the four clearance spaces 4415, and the upper layer of steel bars 51 can be laid with the help of the groove above the top cover 442. The steel bars 51 are tied and positioned together and the lifting rod 52 is tied to the steel bars 51, which facilitates the subsequent casting and molding of the base plate 5. During application, when groundwater seeps upward along the anchor body 2, the waterproof membrane 41, waterproof rubber collar 42, and waterproof protective layer 43 can effectively reduce the probability of groundwater seeping out from below the base 311. If groundwater still seeps out from below the base 311, the seal 443 will absorb it and expand, further improving its sealing performance, thereby effectively inhibiting the continued seepage of groundwater, and thus effectively improving the reliability of the pressure-type prestressed anti-buoyancy anchor and the safety of building construction. Example 2

[0060] Reference Figure 2 and Figure 4 This application discloses a construction method for a pressure-type prestressed anti-buoyancy anchor rod, wherein a concrete cushion layer 12 is first constructed on the surface of the foundation 1 before construction, including the following steps: S1, Drill hole 11.

[0061] (1) A construction method that causes minimal disturbance to the surrounding strata of borehole 11 should be selected, and the drilling rig should be positioned accurately, horizontally, vertically, and stably; (2) The verticality deviation of borehole 11 should be less than 1%, the diameter deviation should not be greater than 100 mm, and the negative diameter deviation should not be greater than 10 mm; (3) Casing drilling is recommended for construction in unstable soil layers.

[0062] S2, Clean the hole.

[0063] Before grouting, the inside of borehole 11 should be cleaned to remove the mud from the borehole and ensure that the grout is fully bonded to the soil and rock layers.

[0064] S3, Anchor bolt installation.

[0065] Based on borehole 11, the construction of the anchor rod body, prestressed device 3 and waterproof device 4 includes waterproof membrane 41, waterproof rubber collar 42 and waterproof protective layer 43.

[0066] Note: (1) The anchor bolt body should have a central structure. During the assembly, storage and transportation of the reinforcement, rust, damage, dirt or oil stains and excessive deformation should be prevented. (2) The grouting pipe is inserted into the borehole 11 together with the anchor body, and the anchor body extends out of the bottom of the pit for no less than 1.2 times the designed anchorage length; (3) The anchor bolt body should be fixed at the hole opening and should not be shaken, pulled or collided before the grout reaches 70% of the design strength.

[0067] S4, Grouting.

[0068] The following should be noted during grouting: (1) The mortar diameter of the grout should not be greater than 2 mm, the mixing time should not be less than 1 min, and it should be used immediately after mixing; (2) The water-cement ratio for the initial grouting is 0.40 to 0.45, and the grouting pressure is 0.8 to 1.0 MPa. Starting from the bottom of the hole, the front edge of the grouting pipe is pulled out from the two sides of the grouting or in sections until uniform grout overflows from the hole opening. (3) If grouting fails to return or leaks during grouting, measures should be taken and the grouting volume should be controlled to not exceed 100 kg / m³. (4) The anchor rods in this project adopt a secondary grouting process. The secondary grouting should be carried out 4 to 8 hours after the primary grouting. The secondary grouting pipe should be fixed on the rod body 22. Grouting holes should be set within the range of L / 4 to L / 3 (L is the total length of the anchor rod) at the end of the anchor rod. The grout is cement grout with a water-cement ratio of 0.50 to 0.55. The grouting pressure is 2 to 3 MPa. The pressure at which grouting is prohibited should not be less than 1.5 MPa, and the pressure should be stabilized for 5 minutes. During grouting, it should be observed whether the surrounding soil is slurry. If the above phenomenon occurs, grouting should be stopped and measures should be taken before grouting can be resumed.

[0069] (5) The anchor rods in this project adopt the secondary high-pressure splitting grouting process. The secondary grouting should be carried out after the strength of the solidified body after initial setting reaches 5MPa (4h to 8h after the first grouting). The secondary grouting pipe should be fixed on the rod body 22, and grouting holes should be set within the range of L / 4 to L / 3 (L is the total length of the anchor rod) at the end of the anchor rod. The grout is cement grout with a water-cement ratio of 0.70. The grouting should be carried out in layers from the inside to the outside. The grouting pressure should reach 2.5 to 4.5MPa. After the secondary grouting pressure rises to 4.5MPa, it should be stabilized for 5 minutes. During grouting, it should be observed whether the surrounding soil is slurry. If the above phenomenon occurs, grouting should be stopped and measures should be taken before grouting can be resumed.

[0070] S5. Prestressing application.

[0071] Prestress is applied to the top of the anchor bolt body using prestressing device 3. Note the following: (1) Before tensioning the anchor bolts, the tensioning equipment should be inspected and calibrated. The bearing surfaces of each anchor head should be flat, and the strength grade of the grout concrete should reach the design strength before tensioning can begin. The anchor bolts should be tensioned evenly and in an orderly manner to avoid the adverse effects of concentrated tensioning in local areas on adjacent anchor bolts. (2) The locking tension of the prestressed anchor rod in this project is 1.5 times the characteristic value of the anchor rod bearing capacity; (3) An anchor cable anti-slip test shall be carried out before tensioning. The number of anchor cables for the anchor cable anti-slip test shall not be less than 5% of the total number of anchor rods, and shall not be less than 6. (4) Before the anchor bolt is formally tensioned, the anchor bolt should be pre-tensioned 1 to 2 times with 10% to 15% of the anchor cable tension value to make the bolt body 22 completely straight and the displacement of each part stable; (5) Anchor bolt tensioning should be done in stages. It is recommended to tension at 25%, 50%, 75%, 90%, 100% and 110% of the anchor cable tension value. The loading rate should not exceed 0.1 times the characteristic value of the anchor bolt bearing capacity per minute. When tensioning to 110% of the design locking value, hold the load for 20 minutes and then unload and lock. (6) During the locking process of prestressed anchor bolts, it is advisable to monitor the axial force of the anchor bolts. If the prestress loss exceeds 10% of the locking value within 48 hours after locking, supplementary tensioning should be carried out in time. The number of supplementary tensioning times should generally not exceed 2. (7) No less than 10% of the tensioned anchor rods shall be randomly selected for over-tensioning inspection, and the over-tensioning load shall not be less than 1.2 times the design locking value; S6. Waterproofing construction.

[0072] Waterproof components 44 are constructed above the waterproof protective layer 43, and the installation of steel bars 51 and hanging bars 52 inside the base plate 5 can be completed with the help of waterproof components 44 during the construction of waterproof components 44.

[0073] In addition to the construction of waterproof component 44, attention should also be paid to corrosion prevention and waterproofing during the construction of other structures of waterproof device 4 and the main body of anchor bolts: (1) Before processing, the anchor bolt should be free of rust and grease. The steel strand and the sheath should be coated with an anti-corrosion and lubricating coating to ensure that they can slide relative to each other permanently. (2) The top of the anchor bolt should be chiseled to a dense area, and after removing debris, dust or mud, it should be leveled to the design elevation using polymer cement waterproof mortar. (3) After the prestressing tendon tensioning operation is completed, the anchor and bearing plate should be protected against corrosion in a timely manner. Before concrete pouring, the anchor material should be inspected and secondary corrosion protection should be carried out.

[0074] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A pressure-type prestressed anti-buoyancy anchor bolt, characterized in that, It includes the anchor body (2), the prestressing device (3) and the waterproofing device (4); The anchor body (2) includes a protective tube (21) and a rod (22) inserted into the drill hole (11); the protective tube (21) is located at the opening of the drill hole (11), one end of the rod (22) passes through the protective tube (21), and its end is located above the protective tube (21); The prestressing device (3) includes a prestressing transmission component (31), and the prestressing transmission component (31) includes a seat (311); the seat (311) is disposed above the protective tube (21), the top of the rod (22) passes through the seat (311), and its end serves as the force-applying end of the prestressing device (3); The waterproofing device (4) is arranged around the rod body (22) at the opening of the drill hole (11), and includes a waterproof membrane (41), a waterproof rubber collar (42), a waterproof protective layer (43), and a waterproof component (44); the waterproof membrane (41), the waterproof rubber collar (42), and the waterproof protective layer (43) are all arranged between the protective tube (21) and the base body (311), and the waterproof rubber collar (42) is located between the waterproof protective layer (43) and the waterproof membrane (41); the waterproof component (44) is arranged above the waterproof protective layer (43) and is arranged around the base body (311); The waterproof component (44) includes a base (441), a top cover (442), and a seal (443) with a water absorption and expansion effect. The base (441) is positioned above the waterproof protective layer (43), and its bottom dimensions are adapted to the dimensions of the waterproof rubber collar (42). After installation, its axis coincides with the axis of the rod (22). The sealing element (443) is positioned inside the base (441) and contacts and abuts against the bottom of the waterproof protective layer (43) and the seat (311). The top cover (442) is detachably connected to the top of the base (441) and, after installation, presses down on the sealing element (443).

2. The pressure-type prestressed anti-buoyancy anchor bolt according to claim 1, characterized in that, The waterproof component (44) also includes a limiting structure (444) and a compression structure (445). The limiting structure (444) includes a first limiting plate (4441); the first limiting plate (4441) is disposed on the inner side of the base (441) and located above the sealing member (443); The extrusion structure (445) includes a plurality of extrusion members (4451); the extrusion members (4451) are movably connected to the first limiting plate (4441), and their direction of movement is parallel to the axial direction of the base (441); When the top cover (442) is not installed, the top of the extruder (4451) is located above the first limiting plate (4441); after the top cover (442) is installed, the bottom of the top cover (442) drives the extruder (4451) to move downward.

3. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 2, characterized in that, The limiting structure (444) also includes four second limiting plates (4442). The second limiting plate (4442) is disposed below the first limiting plate (4441), and the four second limiting plates (4442) are perpendicular to each other and disposed on the outside of the sealing member (443); The base (441) has four clearance openings (4413) at its bottom. The four clearance openings (4413) correspond one-to-one with the four second limiting plates (4442). The side of the second limiting plate (4442) close to the adjacent clearance opening (4413) forms a clearance space (4415) for the arrangement of the reinforcing bars (51).

4. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 3, characterized in that, The limiting structure (444) is rotatably connected to the base (441), and its rotation axis coincides with the axis of the base (441).

5. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 3, characterized in that, The limiting structure (444) further includes a plurality of positioning frames (446) for the installation and positioning of the reinforcing bars (51). The plurality of positioning frames (446) are respectively disposed on a plurality of second limiting plates (4442) and respectively located in a plurality of clearance spaces (4415). After the reinforcing bars (51) are installed and positioned, their length direction is parallel to the length direction of the adjacent second limiting plates (4442).

6. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 4, characterized in that, The base (441) has two mounting slots (4414) on both sides of the top for the installation of the lifting rod (52). After the lifting rod (52) is installed, its two ends are respectively inserted into the two mounting slots (4414), and its bottom is close to the steel bar (51) below.

7. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 6, characterized in that, The bottom of the top cover (442) has a limiting part (4421) that is adapted to four mounting slots (4414). After the top cover (442) is installed on the base (441), the four limiting parts (4421) respectively contact and abut against the two lifting rods (52).

8. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 6, characterized in that, The base (441) includes a fixed part (4411) and a rotating part (4412). The rotating part (4412) is located above the fixed part (4411), and the mounting groove (4414) is formed on the rotating part (4412). The rotation axis of the rotating part (4412) relative to the fixed part (4411) coincides with the axis of the base (441), and the rotating part (4412) is fixedly connected to the limiting structure (444).

9. A pressure-type prestressed anti-buoyancy anchor bolt according to claim 2, characterized in that, The prestress transfer assembly (31) also includes a movable plate (312) and several elastic elements (313). The movable plate (312) is sleeved and installed on the outside of the seat (311), and is movably connected to the seat (311) with its direction of movement coinciding with the axis of the seat (311); after the waterproof component (44) is installed, a space is formed between the first limiting plate (4441) and the seat (311) that is compatible with the movable plate (312); The elastic element (313) is disposed between the movable plate (312) and the seat (311), and has the tendency to drive the movable plate (312) to move upward to the limit position, and the bottom of the top cover (442) has an abutment portion (4422) for contacting the movable plate (312).

10. A construction method for a pressure-type prestressed anti-buoyancy anchor bolt, used for constructing a pressure-type prestressed anti-buoyancy anchor bolt as described in any one of claims 1-9, characterized in that, Includes the following steps: S1, Drilling (11); S2, Clean the hole; S3. Anchor bolt installation; S4, Grouting; S5. Prestressing application; S6. Waterproofing construction.

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