Anti-floating anchor rod and supporting structure thereof

Abstract

The invention relates to the technical field of anti-floating anchor rods, in particular to an anti-floating anchor rod and a supporting structure thereof, and aims at solving the problems that an existing anti-floating anchor rod and a supporting structure thereof are insufficient in reliability, low in construction efficiency and high in whole life cycle cost. The anti-floating anchor rod and the supporting structure thereof comprise an anti-floating anchor group, a radial expansion anchoring unit and a connecting unit, and the supporting structure is matched for use. The radial expansion anchoring unit is arranged on the anchoring section of the anti-floating anchor set, and anchoring keys are formed through radial expansion by means of the water absorption expansion or thermal expansion characteristic of materials. The supporting structure comprises a base, a vertical positioning unit, a horizontal stabilizing unit and a rapid locking unit and is used for accurately positioning the anchor rod. By the adoption of the technical scheme, the anti-floating bearing capacity can be remarkably improved, the construction reliability is improved, the construction technology is simplified, the construction efficiency is improved, and the whole life cycle cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of anti-buoyancy anchor technology, and more specifically, relates to an anti-buoyancy anchor and its support structure. Background Technology

[0002] With the increasing scale of modern construction projects and the deepening utilization of underground space, the demand for foundation structures to resist buoyancy has significantly increased. This makes anti-buoyancy anchors and their supporting structures play an indispensable and crucial role in ensuring the stability of building foundations and preventing buoyancy damage caused by groundwater level fluctuations or geological disasters. The core objective of this technology is to effectively anchor the building foundation structure firmly into deep, stable soil or rock strata to resist and transfer uplift forces, ensuring structural safety and long-term service performance. To address increasingly diverse and complex engineering challenges, the design concepts and construction techniques of anti-buoyancy anchors have continuously evolved, resulting in various technical solutions that strive for the optimal balance between uplift bearing capacity, construction efficiency, and economy.

[0003] Currently, several representative solutions have been applied in the field of anti-buoyancy anchor technology. For example, invention patent CN111287181B discloses an anti-buoyancy anchor, the core design of which involves setting four retractable and expandable anti-buoyancy plates at the bottom of the anchor. Through I-shaped fasteners formed by concrete reinforcement during construction, the anti-buoyancy plates can be embedded between the soil layers after unfolding, effectively resisting high-intensity buoyancy and gravity. This design aims to significantly increase the pull-out area between the anchor and the soil by using a variable cross-section expansion anchoring method, driving the anti-buoyancy plates to unfold mechanically or hydraulically after the anchor reaches the design depth, thereby improving the overall bearing capacity. The technical idea is to utilize the unfolding of the anchor plates to achieve effective interlocking with the surrounding soil, aiming to achieve excellent anti-buoyancy effects. Meanwhile, another invention patent CN11487579B discloses an anti-buoyancy anchor pull-out support, aiming to improve the safety and ease of operation during anti-buoyancy anchor pull-out tests. This support structure, through the ingenious design and coordinated operation of components such as the base, clamping parts, drive cylinder, support frame, protective cover, and elastic plate, enables precise clamping and stable force application of the anchor bolt during pull-out tests. This effectively controls potential risks during the test, ensuring the accuracy of test data and the safety of personnel. This solution focuses on optimizing on-site testing conditions to obtain actual pull-out performance data of the anchor bolt in a safer and more efficient manner, providing a reliable basis for engineering design and construction.

[0004] However, as modern construction engineering places increasingly stringent demands on the safety of foundation structures, construction efficiency, and economic viability throughout the entire life cycle, the aforementioned existing technical solutions have gradually revealed their inherent limitations in practical applications. While pursuing functional improvements, they often introduce new technical contradictions. Specifically, for anchor bolts relying on deployable anti-buoyancy plates, their effectiveness highly depends on the precise, complete, and trouble-free deployment and stable fixation of the anti-buoyancy plates in complex underground environments. However, underground soil conditions vary greatly, potentially including sand, clay, silt, or uneven compaction. These uncertainties can easily interfere with the normal deployment process of the anti-buoyancy plates. Any slight deviation in construction operations, or encountering localized hard obstacles underground, may prevent the anti-buoyancy plates from fully deploying, resulting in an anchorage area far lower than designed, severely weakening their anti-buoyancy capacity. Furthermore, deployable mechanical components, operating in humid and corrosive underground environments for extended periods, face severe challenges to the strength, stiffness, and durability of their materials and connectors, making them susceptible to corrosion, fatigue, and even failure. The resulting maintenance costs and potential safety hazards cannot be ignored. This design philosophy, which trades mechanical complexity for an increase in instantaneous load-bearing capacity, has revealed inherent reliability risks and long-term stability issues in practical engineering applications.

[0005] In contrast, while the design of the anti-buoyancy anchor bolt pull-out support aims to improve the safety and accuracy of the test, its precision mechanical components and drive system, such as clamping parts and drive cylinders, place extremely high demands on machining accuracy, installation, commissioning, and daily maintenance. In typical construction site environments, dust and drastic temperature and humidity fluctuations can easily lead to wear, lubrication failure, or performance degradation of precision components, thus affecting the uniformity of clamping force and the response accuracy of the drive cylinder, ultimately directly impacting the reliability of the test results. The reason for this is that, in pursuit of ultimate test control and safety, this scheme introduces multi-level mechanical coordination; even a small deviation in each component can be amplified through a chain reaction, causing performance fluctuations throughout the entire test system. Furthermore, the installation, commissioning, and dismantling of this complex structure undoubtedly consumes significant time and human resources. Especially in projects with tight schedules, the ease of operation and overall construction efficiency will be significantly constrained, increasing the overall cost of the project.

[0006] In summary, while pursuing specific functional improvements, existing anti-buoyancy anchors and their support structures often rely excessively on complex mechanical transmissions, precise dynamic operations, or multi-component collaborative work, neglecting deeper technical contradictions such as decreased reliability, reduced construction efficiency, and increased life-cycle costs that may arise in real-world, variable, and harsh construction environments. Especially given the complexity of underground environments, the non-ideal nature of construction sites, and the need to balance long-term structural safety and economic efficiency, designing a new type of anti-buoyancy anchor and its support structure that is simpler in structure, easier to install, more reliable in operation, more stable in performance, and effectively reduces overall material and construction costs—fundamentally avoiding the potential risks and high overall costs caused by the mechanical complexity of existing technologies—has become a critical technical challenge urgently needing to be addressed in the current construction engineering field. Summary of the Invention

[0007] To address the technical problems of insufficient reliability, low construction efficiency, and high life-cycle costs of existing anti-buoyancy anchors and their support structures, this invention provides an anti-buoyancy anchor and its support structure that is simpler in structure, easier to install, more reliable in operation, more stable in performance, and can effectively reduce the overall material and construction costs.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] The present invention provides a first solution: an anti-buoyancy anchor bolt, comprising an anti-buoyancy anchor group, a radial expansion anchoring unit disposed at the lower anchoring section of the anti-buoyancy anchor group, and a connecting unit disposed at the upper part of the anti-buoyancy anchor group;

[0010] The anti-buoyancy anchor group is an anchoring structure formed by connecting several main anchor rods, and a bent part is provided at the upper end of the main anchor rod to connect with the steel mesh of the upper structure.

[0011] The radial expansion anchoring unit is integrally set and tightly wrapped around the outer surface of the anchoring section of the anti-buoyancy anchor group. When in contact with the concrete slurry, it expands radially through water absorption expansion or thermal expansion mechanism, forming an anchoring key structure that is tightly embedded with the borehole wall around the anti-buoyancy anchor group.

[0012] The connecting unit is located on the upper part of the anti-buoyancy anchor group where it is not anchored.

[0013] In a preferred embodiment of the present invention, the main anchor rod has a cylindrical structure and continuous or discontinuous helical ribs or transverse threads are provided on the outer surface of the main anchor rod. After pouring, the helical ribs or transverse threads generate mechanical interlocking force and adhesive friction with the subsequently poured concrete slurry.

[0014] In a preferred embodiment of the present invention, the radial expansion anchoring unit includes an elastic composite material sleeve that tightly wraps around the outer surface of the anchoring section of the anti-buoyancy anchor group. A continuous thread is provided on the inner surface of the elastic composite material sleeve, which is used in conjunction with a continuous helical rib or transverse thread on the outer surface of the main anchor rod. At least one radial positioning rib is provided on the outer side of the elastic composite material sleeve.

[0015] In a preferred embodiment of the present invention, the matrix material of the elastic composite sleeve is a polymer material with specific water absorption and expansion or thermal expansion characteristics. The polymer material is based on at least one of modified polyacrylate, polyisobutylene or hydrophilic polyurethane elastomer material with cross-linked structure, and is compounded with reinforcing fibers. The reinforcing fibers are at least one of polyester fiber short segments or basalt fiber short segments.

[0016] In a preferred embodiment of the present invention, the radial positioning rib is an arc-shaped steel plate extending radially outward along the elastic composite material sleeve and fixedly connected to the elastic composite material sleeve. Both ends of the radial positioning rib are provided with inwardly bent fitting portions. When the elastic composite material sleeve is in a pre-tightened state, the fitting portions are fitted into the gaps between adjacent main anchor rods. When the elastic composite material sleeve expands due to water absorption or thermal expansion, the middle connecting portion of the radial positioning rib expands radially outward under the compression of the elastic composite material sleeve, and the fitting portions at both ends of the radial positioning rib form an inward bending tendency, forming a plurality of discrete or continuous outwardly protruding anchor key structures around the anti-buoyancy anchor group. The anchor key structures actively compress and occupy the space of the concrete slurry poured in the borehole and fit into the borehole wall.

[0017] In a preferred embodiment of the present invention, the connecting unit is a threaded collar threadedly connected to the upper part of the anti-buoyancy anchor group.

[0018] The present invention provides a second solution, a support structure for installation and positioning in conjunction with an anti-buoyancy anchor rod, comprising a base unit, a vertical positioning unit disposed above the base unit, a horizontal stabilizing unit disposed on top of the vertical positioning unit, and a quick-locking unit disposed on the horizontal stabilizing unit.

[0019] In a preferred embodiment of the present invention, the base unit is a flat plate structure, which is connected to the construction site base, formwork or poured concrete structure by anchor bolts or expansion bolts.

[0020] In a preferred embodiment of the present invention, the vertical positioning unit includes at least two telescopic support rods, the support rods being a two-stage telescopic tube structure, and the bottom of the support rods being connected to the base unit and the top being connected to the horizontal stabilizing unit.

[0021] In a preferred embodiment of the present invention, the horizontal stabilizing unit includes one or more transverse support beams, which are fixedly connected to the upper end of the vertical positioning unit; the quick-locking unit matches the connecting unit and includes two semi-circular clamps, one end of the two semi-circular clamps is hinged, and the other free end is connected by a connecting bolt.

[0022] Compared with the prior art, the present invention provides an anti-buoyancy anchor and its supporting structure, which has the following characteristics:

[0023] Beneficial effects:

[0024] 1. By setting radial expansion anchoring units in the anchoring section of the anti-buoyancy anchor group, these units can passively and spontaneously expand radially outward during concrete pouring and hydration, utilizing the material's own water absorption and expansion or thermal expansion characteristics. This forms larger-diameter concrete anchoring keys with complex geometries around the anchor rod. These anchoring keys create a wider frictional resistance interface and stronger mechanical interlocking force with the surrounding soil or rock strata, greatly increasing the effective pull-out area and anchoring strength of the anchor rod. This significantly improves the overall anti-buoyancy bearing capacity, and the reliability of its anchoring effect is far higher than that of anchor plates that rely on mechanical moving parts for deployment, thus significantly enhancing its anti-buoyancy bearing capacity.

[0025] 2. The radial expansion anchoring unit of this anti-buoyancy anchor does not require complex mechanical transmission mechanisms, hydraulic systems, or external power sources for driving. Its expansion process is based on the direct physicochemical response of the polymer material with the concrete mixing water or heat of hydration, which is a passive and adaptive expansion mechanism. This fundamentally avoids the problems of jamming, incomplete deployment, or component failure that easily occur in mechanically deployable anchor plates in complex underground environments in existing technologies. It eliminates reliability risks caused by construction deviations or underground obstacles, ensures accurate, complete, and fault-free anchoring, and greatly improves construction reliability.

[0026] 3. This anti-buoyancy anchor eliminates the assembly, debugging, and deployment steps of traditional complex mechanical anchors, and also avoids the stringent precision requirements of precision pull-out supports for on-site operation. On-site, the anchor with pre-installed expansion units only needs to be inserted into the hole and positioned and fixed using a simple and easy-to-operate support structure before concrete pouring can proceed. The entire installation process requires less equipment, simplifies procedures, and reduces the difficulty of personnel operation, thereby significantly shortening the construction cycle, reducing on-site management costs and manpower input, and significantly simplifying the construction process and improving construction efficiency.

[0027] 4. This anti-buoyancy anchor has a simpler structure, primarily using high-strength steel and high-performance polymer composite materials, avoiding the precision machining and assembly costs associated with complex mechanical components. Due to its high reliability and durability, maintenance requirements are significantly reduced during long-term service, minimizing repair costs and safety hazards caused by component corrosion, fatigue, or failure. Furthermore, improved construction efficiency further reduces the overall project cost, achieving higher comprehensive economic benefits and effectively lowering the total life-cycle cost.

[0028] 5. After the radial expansion anchoring unit of this anti-buoyancy anchor is integrally cured with the concrete, it forms a seamless, non-moving, monolithic anchor body, greatly improving the long-term stability of the anchor in humid and corrosive underground environments. The polymer composite elastic composite sleeve itself has excellent corrosion resistance, and after being completely encapsulated by the concrete slurry, it isolates itself from external environmental erosion, significantly extending the service life of the anchor system. Simultaneously, its expansion mechanism has a certain degree of self-adaptability to minor irregularities in the borehole wall, enabling better filling of the cavity, enhancing the anchoring effect, and exhibiting stronger environmental adaptability and durability. This solves the technical problems of insufficient reliability, low construction efficiency, and high total life-cycle cost of existing anti-buoyancy anchors and their support structures. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the anti-buoyancy anchor bolt of the present invention;

[0030] Figure 2 For the present invention Figure 1 A partially enlarged schematic diagram of the radial expansion anchoring unit (in pre-tightened state);

[0031] Figure 3 This is a schematic diagram of the radial expansion of the radial expansion anchoring unit of the present invention;

[0032] Figure 4 This is a schematic diagram of the supporting structure of the present invention;

[0033] Figure 5 This is a schematic diagram of the elastic composite material sleeve and radial positioning ribs of the present invention;

[0034] Figure 6 This is an exploded view of the support structure of the present invention;

[0035] Figure 7 This is a schematic diagram showing the installation and connection between the anti-buoyancy anchor and the support structure of the present invention;

[0036] Figure 8 This is a schematic diagram illustrating the principle of the radial expansion anchoring unit of the present invention expanding in concrete to form an anchoring key;

[0037] Figure 9 This is a flowchart illustrating the installation method of the anti-buoyancy anchor rod and its support structure according to the present invention.

[0038] The attached figures are labeled as follows:

[0039] 1. Anti-buoyancy anchor assembly; 2. Radial expansion anchoring unit; 3. Connecting unit; 4. Elastic composite sleeve; 5. Radial positioning rib; 10. Support structure; 11. Base unit; 12. Vertical positioning unit; 13. Horizontal stabilizing unit; 14. Quick locking unit; 15. Support rod; 16. Adjusting nut; 17. Transverse support beam; 18. Semi-circular clamp; 19. Connecting bolt; 20. Anchor hole; 21. Concrete grout; 22. Drill hole wall; 23. Main anchor; 24. Bending part; 25. Grouting pipe; 26. Fitting part; 27. Continuous thread. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] Please see Figures 1-9 As shown, this invention provides an anti-buoyancy anchor and its supporting structure, aiming to overcome the limitations of traditional anti-buoyancy anchors in terms of load-bearing capacity, construction efficiency, construction reliability, and total life-cycle cost. The anti-buoyancy anchor and its supporting structure disclosed in this invention achieve excellent anchoring performance and an efficient and convenient construction process through its integrated radial expansion anchoring unit and simplified support system.

[0042] Example 1:

[0043] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 7 As shown, this embodiment provides an anti-buoyancy anchor bolt, the main body of which includes an anti-buoyancy anchor assembly 1, a radial expansion anchoring unit 2 disposed at the lower anchoring section of the anti-buoyancy anchor assembly 1, and a connecting unit 3 disposed at the upper part of the anti-buoyancy anchor assembly 1. Wherein,

[0044] The anti-buoyancy anchor group 1 is an anchoring structure formed by welding three main anchor rods 23 together. The upper end of the main anchor rod 23 is provided with a bent part 24 to connect with the steel mesh of the upper structure to ensure the integrity of the structure after construction. The main anchor rod 23 is a cylindrical structure. The anti-buoyancy anchor group 1 formed by the three main anchor rods 23 mainly bears the pull-out load. The outer surface of the anti-buoyancy anchor group 1 is integrally formed with continuous spiral ribs or transverse threads. The thread depth is usually 1.5 mm to 3 mm and the pitch ranges from 5 mm to 10 mm. This is intended to increase the mechanical interlocking force and adhesive friction between the main anchor rods 23 and the anti-buoyancy anchor group 1 and the subsequently poured concrete grout 21, thereby improving the overall bearing capacity of the anchor body.

[0045] Several radial expansion anchoring units 2 are integrally arranged and tightly wrapped around the outer surface of the anchoring section of the anti-buoyancy anchor group 1, including an elastic composite material sleeve 4. The elastic composite material sleeve 4 is wrapped around the outer surface of the anchoring section of the anti-buoyancy anchor group 1. When the elastic composite material sleeve 4 is not in contact with the concrete mixing water or is not subjected to the heat of hydration, its outer diameter is slightly larger than or equal to the nominal diameter of the anti-buoyancy anchor group 1 to ensure that it can be smoothly inserted into the anchor hole 20. Several radial positioning ribs 5 are fixedly arranged on the outer surface of the elastic composite material sleeve 4. The radial positioning ribs 5 are bow-shaped structures.

[0046] The connecting unit 3 is located on the unanchored upper part of the anti-buoyancy anchor group 1 and is connected to the anti-buoyancy anchor group 1. Its main function is to connect the three main anchor rods 23 to form an integrated structure. At the same time, it provides a standard, high-strength interface to reliably connect the anti-buoyancy anchor rods to the subsequent bearing plate 23, connecting nut 24 and the foundation of the upper building structure.

[0047] In a preferred embodiment, such as Figure 1 , Figure 3 , Figure 4 and Figure 8 As shown, the three main anchor rods 23 are preferably arranged in an equilateral triangle and welded together to form a triangular anti-buoyancy anchor group 1, which can effectively increase the contact area between the anti-buoyancy anchor group 1 and the concrete grout 21, so as to ensure the stability of the anti-buoyancy anchor group 1 after the concrete grout 21 is poured.

[0048] Specifically, the main anchor bolt 23 is constructed using high-strength low-alloy structural steel, such as Q345E or Q420D steel. Q345E steel has a yield strength of not less than 345 MPa and a tensile strength of not less than 490 MPa; Q420D steel has a yield strength of not less than 420 MPa and a tensile strength of not less than 520 MPa. Both materials possess good low-temperature impact toughness, with a V-notch impact energy of not less than 27 J at -20℃. To ensure its long-term service performance in complex underground environments, the surface of the main anchor bolt 23 can be hot-dip galvanized, with a zinc coating thickness of not less than 85 micrometers to provide excellent corrosion resistance. Alternatively, a heavy-duty anti-corrosion coating system combining epoxy zinc-rich primer and polyurethane topcoat can be used, with a total coating thickness of not less than 300 micrometers.

[0049] Specifically, the nominal diameter of the main anchor rod 23 is usually selected between 20 mm and 50 mm. For example, standard diameters such as 25 mm, 32 mm, and 40 mm can be selected. Its length is customized according to the specific engineering geological conditions and design pull-out resistance requirements, usually within the range of 5 meters to 30 meters. Different length sections of the main anchor rod 23 can be spliced ​​through standard threaded connection.

[0050] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 8 As shown, the elastic composite material sleeve 4 and the anti-buoyancy anchor group 1 are connected by a reliable mechanical fixing method. For example, the inner surface of the elastic composite material sleeve 4 is provided with a continuous thread 27, which is used to cooperate with the continuous helical ribs or transverse threads on the outer surface of the main anchor rod 23. This facilitates the screw connection of the elastic composite material sleeve 4 during use. After installation, the position of the elastic composite material sleeve 4 on the outer surface of the anti-buoyancy anchor group 1 is axially locked by the interlocking relationship between the threads. At the same time, the compression force (interference fit) of the elastic composite material sleeve 4 after deformation enables the elastic composite material sleeve 4 to be effectively and stably fixed on the outer surface of the anti-buoyancy anchor group 1, thereby ensuring that the elastic composite material sleeve 4 will not slide axially or radially relative to the anti-buoyancy anchor group 1 during the expansion process, so as to ensure the effective transmission of the expansion force.

[0051] Specifically, the matrix material of the elastic composite sleeve 4 is a polymer material with specific water absorption and swelling or thermal expansion properties. For example, it can be based on modified polyacrylate (such as sodium polyacrylate crosslinked copolymer), polyisobutylene (such as butyl rubber-isoprene copolymer), or a hydrophilic polyurethane elastomer material with a crosslinked structure. To further improve the overall mechanical strength, tear resistance, and dimensional stability of the elastic composite sleeve 4, composite reinforcing fibers are uniformly mixed into the matrix material of the elastic composite sleeve 4. For example, short segments of polyester fiber (1 mm to 3 mm in length, 10 μm to 20 μm in diameter) or short segments of basalt fiber (1 mm to 3 mm in length, 12 μm to 18 μm in diameter) with a volume content of 8% to 12% can be added. These fibers are tightly bonded to the polymer matrix material through physical or chemical bonding to form a high-toughness composite material. The Shore A hardness of the elastic composite sleeve 4 is typically controlled between 45 and 75. When exposed to saturated water-absorbing conditions, such as contact with concrete mixing water, its linear expansion rate can reach 10% to 25%. This expansion originates from the three-dimensional network swelling generated after the hydrophilic polymer chains absorb water. Alternatively or supplementarily, when the elastic composite sleeve 4 is exposed to the temperature range (approximately 40°C to 70°C) generated by the exothermic reaction of concrete hydration, its radial expansion rate can reach 10% to 25%. This thermal expansion is due to the large linear expansion coefficient of the polymer material, resulting in a significant increase in size during heating. Furthermore, if the material contains microcapsules containing low-boiling-point liquid, the evaporation upon heating will further promote expansion. The wall thickness of the elastic composite sleeve 4 is designed to range from 2 mm to 8 mm, for example, a uniform wall thickness of 4 mm can be used to balance expansion efficiency, structural strength, and manufacturing cost.

[0052] In a preferred embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 8As shown, the radial positioning rib 5 is an arc-shaped steel plate extending radially outward along the elastic composite sleeve 4, fixedly connected to the elastic composite sleeve 4. Both ends of the radial positioning rib 5 have inwardly bent fitting portions 26. When the elastic composite sleeve 4 is in a pre-tightened state, the fitting portions 26, together with the radial positioning rib 5 structure, tightly close and fit into the gap between adjacent main anchor rods 23, thus providing a clearance function without expansion. When the matrix material of the elastic composite sleeve 4 is triggered by water absorption or thermal expansion, the central connecting portions of these radial positioning ribs 5 will expand radially outward under the compression of the elastic composite sleeve 4. Correspondingly, the fitting portions 26 at both ends of the radial positioning rib 5 tend to bend inward under the action of concrete grout and the pressure of the opening sidewall. The maximum radial expansion of the positioning rib 5 under the compression of the elastic composite sleeve 4 can reach 0.5 to 1.5 times the diameter of the anti-buoyancy anchor assembly 1, thereby forming several discrete or continuous outwardly protruding "anchoring key" structures around the anchor rod through the positioning rib 5. Before the concrete grout 21 solidifies, these "anchoring keys" can actively and effectively compress and occupy the space of the concrete grout poured in the borehole. More importantly, during the expansion process, these expanding structures can push part of the concrete grout 21 into the fine cracks, irregular holes, or uneven surfaces of the borehole wall 22. After the concrete solidifies and reaches the design strength, this mechanism forms an integral concrete anchor body that is tightly fitted to the borehole wall 22 and highly matched in shape, greatly increasing the effective contact area and mechanical interlocking force between the anchor rod and the foundation, and avoiding the connection between the anti-buoyancy anchor assembly 1 and the borehole wall 22. At the same time, the continuous thread 27 expands inward and is tightly connected to the corresponding thread groove, ensuring the integrity between the elastic composite sleeve 4 and the anti-buoyancy anchor assembly 1.

[0053] Specifically, when the central connecting part of the radial positioning rib 5 expands outward radially under the compression of the elastic composite material sleeve 4, and the fitting parts 26 at both ends of the radial positioning rib 5 tend to bend inward, multiple radial positioning ribs 5 and elastic composite material sleeves 4 on the same plane can form a positioning structure to ensure the connection between the anti-buoyancy anchor group 1 and the borehole wall 22.

[0054] In a preferred embodiment, such as Figure 1 , Figure 3 , Figure 4 and Figure 8As shown, the connecting unit 3 is a threaded collar threadedly connected to the upper part of the anti-buoyancy anchor group 1. Specifically, it is threadedly connected to the anti-buoyancy anchor group 1 through an internal thread, and the internal thread of the connecting unit 3 matches the external thread section of the anti-buoyancy anchor group 1. The thread type of the thread section is a standard metric coarse thread, such as M30, M36, M42, etc., and the thread accuracy class meets the 6g class in ISO 965-2 standard to ensure the strength, interchangeability, and ease of construction of the connection. After the thread is machined, it should be surface hardened, such as by high-frequency quenching or carbonitriding, to improve the wear resistance and shear resistance of the thread and prevent damage to the thread profile during pre-tightening or long-term stress.

[0055] Example 2:

[0056] like Figure 1 , Figure 3 , Figure 7 , Figure 8 and Figure 9 As shown, unlike Embodiment 1, this embodiment provides a support structure 10 for use with the anti-buoyancy anchor rod during concrete pouring to ensure precise vertical positioning and stability of the anti-buoyancy anchor rod described in Embodiment 1. The support structure 10 aims to provide an efficient, convenient, and reliable anchor rod positioning and fixing solution, and its core components include a base unit 11, a vertical positioning unit 12, a horizontal stabilizing unit 13, and a quick-locking unit 14. Wherein:

[0057] The base unit 11 is a flat plate structure and is used in conjunction with the anti-buoyancy anchor group 1 to fix the anti-buoyancy anchor group 1.

[0058] The vertical positioning unit 12 is disposed above the base unit 11 to provide a precisely adjustable vertical support height, so as to ensure that the top of the anti-buoyancy anchor group 1 is aligned with the design elevation at the millimeter level.

[0059] The horizontal stabilizing unit 13 is disposed on top of the vertical positioning unit 12 to provide lateral support, so as to effectively prevent the anti-buoyancy anchor group 1 from being laterally offset or tilted due to concrete lateral pressure, vibration force or construction disturbance during the concrete pouring process.

[0060] The quick-locking unit 14 is disposed on the horizontal stabilizing unit 13 and is used in conjunction with the connecting unit 3 to achieve quick and reliable axial and radial clamping and fixing of the anti-floating anchor group 1.

[0061] In a preferred embodiment, such as Figure 6 , Figure 7 and Figure 8As shown, the base unit 11 serves as the foundation of the entire support system. Its material is a high-strength steel plate with a thickness of not less than 10 mm, such as Q235B or Q345B steel plate, to ensure structural rigidity and stability in complex construction environments. Its dimensions can be adjusted according to actual construction needs, typically a square plate ranging from 500 mm × 500 mm to 1000 mm × 1000 mm. The base unit 11 has multiple pre-drilled mounting holes with diameters of 16 mm to 20 mm. These holes are precision-machined for securely fixing it to the construction site base, formwork, or poured concrete structure using M12 or M16 grade anchor bolts or expansion bolts. To ensure the long-term service life of the base unit 11 in humid and corrosive construction environments, its surface undergoes strict anti-corrosion treatment, preferably using hot-dip galvanizing with a zinc layer thickness of not less than 85 micrometers, or it can be made of weather-resistant steel.

[0062] In a preferred embodiment, such as Figure 6 , Figure 7 and Figure 8 As shown, the vertical positioning unit 12 consists of at least two telescopic support rods 15. Each support rod 15 is made of high-strength steel pipe or square steel (for example, Q345B seamless steel pipe with a wall thickness of not less than 4 mm). The height can be precisely adjusted by a threaded adjustment mechanism or a pin hole locking mechanism.

[0063] Specifically, the support rod 15 is a two-stage telescopic tube structure. The inner diameter of the outer tube and the outer diameter of the inner tube are precisely matched to ensure smooth telescopic movement without significant wobbling. The outer surface of the inner tube has continuous precision-machined threads with a pitch of 2 mm to 4 mm. By rotating the adjusting nut 16 fitted on the top of the outer tube, millimeter-level vertical height adjustments can be achieved. The bottom of the adjusting nut 16 is connected to the outer tube by a stainless steel thrust bearing or a PTFE low-friction washer, ensuring smooth rotation even under load and reducing frictional resistance. The bottom of the support rod 15 is firmly fixed to the base unit 11 by full penetration welding or high-strength bolts, while the top of the support rod 15 is connected to the horizontal stabilizing unit 13.

[0064] In a preferred embodiment, such as Figure 6 , Figure 7 and Figure 8As shown, the horizontal stabilizing unit 13 includes one or more transverse support beams 17. The transverse support beams 17 are made of I-beams or rectangular steel pipes (e.g., 80mm x 40mm x 4mm rectangular steel pipes of Q345B material or equivalent strength I-beams), and are firmly fixed to the upper end of the vertical positioning unit 12 by high-strength bolts or full-penetration welding. The length and number of the transverse support beams 17 are optimized according to the number and spacing of the supported anti-buoyancy anchors 1 to ensure the overall stability of the support system. Appropriate positions on the transverse support beams 17 are provided with bolt hole arrays that match the quick-locking unit 14, allowing for quick and flexible installation and adjustment of the quick-locking unit 14.

[0065] In a preferred embodiment, such as Figure 6 , Figure 7 and Figure 8 As shown, the quick-locking unit 14 includes two semi-circular clamps 18 made of high-strength alloy steel. The inner surface of the clamps 18 is precision-machined to form multiple transverse or longitudinal anti-slip textures, or is lined with a high-wear-resistant, high-friction coefficient rubber pad (such as nitrile rubber or polyurethane elastomer) to ensure effective clamping of the anchor bolt surface when used with the connecting unit 3, while avoiding damage to the anchor bolt surface. The two semi-circular clamps 18 are connected by a high-strength stainless steel hinge pin, and the other free end is integrated with a connecting bolt 19. When the connecting bolt 19 is operated, the free ends of the two clamps 18 move towards each other, cooperating with the connecting unit 3 (clamping onto the outside of the connecting unit 3, or located under the connecting unit 3, so as to apply prestress to the connecting unit 3 by adjusting the extension and retraction of the support rod 15).

[0066] like Figure 9 As shown in Embodiments 1 and 2 above, the installation and working principle of the anti-buoyancy anchor and its support structure are as follows:

[0067] Step 1: First, at the precise location specified in the engineering design, use specialized drilling equipment, such as a fully hydraulic crawler drilling rig, to drill anchor bolt holes 20 according to the diameter and depth requirements of the design drawings. After drilling, high-pressure air or high-pressure water must be used to remove residual rock cuttings, mud, loose soil, and other debris from the hole, ensuring that the hole wall 22 of the anchor bolt hole 20 is clean, smooth, and stable, and checking whether the bottom depth of the hole meets the design requirements.

[0068] Step 2: Subsequently, the anti-buoyancy anchor assembly 1, pre-assembled in the factory or on-site and equipped with radial expansion anchoring units 2, is slowly and vertically inserted into the cleaned anchor bolt hole 20 using hoisting equipment. During this process, it should be ensured that the axis of the anchor bolt is aligned with the axis of the hole to avoid severe friction or jamming between the anchor bolt and the hole wall 22, until the bottom of the anti-buoyancy anchor assembly 1 precisely reaches the designed pre-embedded depth, that is, the anchoring section is completely inserted into the preset anchoring stratum.

[0069] Step 3: Next, place the support structure 10 of the present invention on the precise location of the foundation or reserved template near the anchor bolt hole. Securely fix the base unit 11 of the support structure 10 to the base surface, template, or poured concrete structure using anchor bolts or expansion bolts. After ensuring the base unit 11 is stable and without wobbling, operate the adjusting nut 16 of the vertical positioning unit 12 to extend or retract its support rod 15, thereby precisely adjusting the top elevation of the anti-buoyancy anchor group 1 to accurately align it with the design elevation (e.g., the top elevation of the foundation), typically with an accuracy requirement within ±5 mm. Simultaneously, use the horizontal stabilizing unit 13 to perform lateral calibration of the anti-buoyancy anchor group 1, ensuring its axis is strictly perpendicular to the horizontal plane or reaches the designed tilt angle. At this stage, fully close the semi-circular clamp 18 of the quick-locking unit 14 and operate the connecting bolts 19 to reliably clamp and fix the anti-buoyancy anchor group 1 axially and radially. This clamping mechanism ensures that the anchor rod 1 can resist external disturbances during subsequent concrete pouring and vibration, always maintaining its preset precise position and preventing any form of displacement or tilting.

[0070] Step 4: After the anti-buoyancy anchor group 1 is positioned and fixed, pre-mixed concrete is poured into the anchor hole 20 according to strict concrete construction specifications. The concrete is usually self-compacting concrete or high-flowability concrete with a strength grade of C30 to C50. To ensure that the concrete slurry 21 can fully fill the entire space of the anchor hole 20 and make full contact with the radial expansion anchoring unit 2, its slump should be strictly controlled between 180 mm and 220 mm. As the concrete slurry 21 is injected upward from the bottom of the anchor hole through the grouting pipe 25, the hydrostatic pressure generated and the heat released during the subsequent concrete hydration process (usually raising the internal temperature of the concrete to 40°C to 70°C) will trigger the water absorption expansion and / or thermal expansion mechanism of the radial expansion anchoring unit 2, respectively or in combination. The polymer matrix material in the elastic composite sleeve 4 begins to absorb the concrete mixing water or expand due to heat, causing the radial positioning ribs 5 on the outside of the elastic composite sleeve 4 to expand radially outward. This expansion exerts a squeezing effect on the uncured concrete slurry 21, forcing some of the slurry to efficiently fill the tiny irregularities, voids, or cracks on the borehole wall 22, and forming a "anchor key" structure with a significantly increased diameter and complex geometry, which tightly interlocks with the borehole wall 22.

[0071] Step 5: Once the concrete to be poured reaches its initial setting strength (typically 10% to 20% of the design strength), sufficient to support the anchor bolt position on its own, operate the connecting bolt 19 of the quick-locking unit 14 to release the clamping force on the anti-floating anchor group 1. Subsequently, dismantle the support structure 10 to allow for subsequent backfilling of the foundation pit or construction of the superstructure. At this point, the anchor bolt has achieved initial anchoring through the "anchoring key" formed with the concrete.

[0072] Step 6: Finally, install the bearing plate and connecting nuts sequentially on the pre-reserved threaded section at the top of the anti-buoyancy anchor group 1, according to the design requirements. By tightening the connecting nuts, the anti-buoyancy anchor rod is reliably connected to the upper building structure foundation or anti-buoyancy bearing component, thereby forming an integrated and efficient anti-buoyancy system that effectively resists the buoyancy of the foundation caused by groundwater level, rising water pressure, etc.

[0073] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An anti-buoyancy anchor bolt, characterized in that: It includes an anti-buoyancy anchor group (1), a radial expansion anchoring unit (2) disposed at the lower end anchoring section of the anti-buoyancy anchor group (1), and a connecting unit (3) disposed at the upper part of the anti-buoyancy anchor group (1); The anti-buoyancy anchor group (1) is an anchoring structure formed by connecting several main anchor rods (23), and a bent part (24) is provided at the upper end of the main anchor rod (23) to connect with the steel mesh of the upper structure; The radial expansion anchoring unit (2) is integrally set and tightly wrapped around the outer surface of the anchoring section of the anti-buoyancy anchor group (1). When in contact with the concrete slurry (21), it expands radially through water absorption expansion or thermal expansion mechanism, forming an anchoring key structure that is tightly fitted with the borehole wall (22) around the anti-buoyancy anchor group (1). The connecting unit (3) is located on the upper part of the anti-buoyancy anchor group (1) when it is not anchored.

2. The anti-buoyancy anchor bolt according to claim 1, characterized in that: The main anchor rod (23) has a cylindrical structure, and continuous or intermittent spiral ribs or transverse threads are provided on the outer surface of the main anchor rod (23). After pouring, the spiral ribs or transverse threads generate mechanical interlocking force and adhesive friction with the subsequently poured concrete slurry (21).

3. The anti-buoyancy anchor bolt according to claim 1, characterized in that: The radial expansion anchoring unit (2) includes an elastic composite material sleeve (4), which tightly wraps around the outer surface of the anchoring section of the anti-buoyancy anchor group (1). A continuous thread (27) is provided on the inner surface of the elastic composite material sleeve (4), and the continuous thread (27) is used in conjunction with the continuous helical rib or transverse thread on the outer surface of the main anchor rod (23). At least one radial positioning rib (5) is provided on the outer side of the elastic composite material sleeve (4).

4. The anti-buoyancy anchor bolt according to claim 3, characterized in that: The matrix material of the elastic composite sleeve (4) is a polymer material with specific water absorption and expansion or thermal expansion characteristics. The polymer material is based on at least one of modified polyacrylate, polyisobutylene or hydrophilic polyurethane elastomer material with cross-linking structure, and is made by compounding reinforcing fibers. The reinforcing fibers are at least one of polyester fiber short segments or basalt fiber short segments.

5. The anti-buoyancy anchor bolt according to claim 4, characterized in that: The radial positioning rib (5) is an arc-shaped steel plate extending radially outward along the elastic composite sleeve (4), which is fixedly connected to the elastic composite sleeve (4). Both ends of the radial positioning rib (5) are provided with inwardly bent fitting parts (26). When the elastic composite sleeve (4) is in a pre-tightened state, the fitting parts (26) are fitted into the gap between adjacent main anchor rods (23). When the elastic composite sleeve (4) expands due to water absorption or thermal expansion, the middle connecting part of the radial positioning rib (5) expands radially outward under the compression of the elastic composite sleeve (4). The fitting parts (26) at both ends of the radial positioning rib (5) form an inward bending tendency, forming several discrete or continuous outwardly protruding anchor key structures around the anti-buoyancy anchor group (1). The anchor key structures actively compress and occupy the space of the concrete slurry (21) poured in the borehole (20) and fit into the borehole wall (22).

6. The anti-buoyancy anchor bolt according to claim 1, characterized in that: The connecting unit (3) is a threaded collar that is threadedly connected to the upper part of the anti-buoyancy anchor group (1).

7. A support structure for installation and positioning in conjunction with the anti-buoyancy anchor bolt according to any one of claims 1-6, characterized in that: It includes a base unit (11), a vertical positioning unit (12) disposed above the base unit (11), a horizontal stabilizing unit (13) disposed on the top of the vertical positioning unit (12), and a quick-locking unit (14) disposed on the horizontal stabilizing unit (13).

8. The support structure according to claim 7, characterized in that: The base unit (11) is a flat plate structure, which is connected to the construction site base, formwork or poured concrete structure by anchor bolts or expansion bolts.

9. The support structure according to claim 7, characterized in that: The vertical positioning unit (12) includes at least two telescopic support rods (15). The support rods (15) are two-stage telescopic tube structures, and the bottom of the support rods (15) is connected to the base unit (11), and the top is connected to the horizontal stabilizing unit (13).

10. The support structure according to claim 7, characterized in that: The horizontal stabilizing unit (13) includes one or more transverse support beams (17), which are fixedly connected to the upper end of the vertical positioning unit (12); the quick locking unit (14) matches the connecting unit (3) and includes two semi-circular clamps (18), one end of the two semi-circular clamps (18) is hinged, and the other free end is connected by a connecting bolt (19).

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