A body expansion anchor system

Abstract

The utility model discloses a kind of body expanding anchor rod systems, including central force pole body, multistage bearing assembly being arranged on the central force pole body and the body expanding structure being arranged in the lower part of the central force pole body, the multistage bearing assembly includes at least two conical tray of conical cylinder shape being arranged along axial interval, the conical tray of conical cylinder shape is fixedly connected with the central force pole body, the body expanding structure includes composite flexible expansion sac and the grouting assembly being connected with the composite flexible expansion sac, the composite flexible expansion sac is wrapped in the outer periphery of the central force pole body, and the composite flexible expansion sac top is located in the inner cavity of the lowermost conical tray of conical cylinder shape;The wall surface of the composite flexible expansion sac includes anti-permeation layer, anti-puncture stretchable grid layer and wear layer in turn from inside to outside. The body expanding anchor rod system of the utility model solves the problem that bag is easily damaged, anchor rod eccentric phenomenon, stress concentration damage and hole bottom sediment influence end resistance.

Description

Technical Field

[0001] This utility model belongs to the field of geotechnical engineering technology, and in particular relates to an anchor rod. Background Technology

[0002] In the field of geotechnical engineering, anchor bolt support technology is one of the core means to ensure slope stability, deep foundation pit safety, and the stability of underground engineering structures. Currently, expanded-body anchor bolts are widely used in complex geological conditions such as soft soil, water-rich sand layers, and gravel layers, but the following problems exist: First, geotextile bags are prone to damage. When placing anchor bolts in gravel layers containing sharp stones, traditional geotextile or polymer bags are easily punctured, leading to grout leakage during high-pressure grouting and failure of expansion molding.

[0003] Secondly, during actual construction and installation, anchor bolts are prone to eccentricity, meaning the bolt body is not centered in the borehole. This eccentricity leads to uneven grout thickness, reducing the overall durability and load-bearing capacity of the anchor bolt.

[0004] Secondly, there is a sudden change in cross-sectional area at the junction of the expanded section and the straight section of the anchor rod. When subjected to huge pull-out force, the grout at the junction is prone to stress concentration, resulting in shear failure or voiding.

[0005] Finally, sediment at the bottom of the borehole affects end resistance. Sediment is easily left at the bottom of the borehole after drilling. In traditional anchor bolts, grouting is done directly after the bolts are lowered. This sediment can cause a weak interlayer between the bottom of the enlarged section and the soil, which severely weakens the end bearing capacity of the enlarged section.

[0006] Therefore, there is an urgent need for a new type of expanded anchor system to solve the problems of easy breakage of the anchor bag, anchor eccentricity, stress concentration damage, and end resistance caused by sediment at the bottom of the hole. Utility Model Content

[0007] The technical problem to be solved by this utility model is to overcome the deficiencies and defects mentioned in the background art above, and to provide an expanded anchor system that is structurally stable, can automatically center, alleviates stress concentration caused by abrupt changes in cross section, and can ensure that the bottom of the expanded section is in direct contact with the original hard soil layer.

[0008] To solve the above-mentioned technical problems, the technical solution proposed by this utility model is as follows: An expanded anchor system includes a central load-bearing rod, a multi-stage load-bearing assembly disposed on the central load-bearing rod, and an expanded structure disposed at the lower part of the central load-bearing rod. The multi-stage load-bearing assembly includes at least two conical trays arranged axially spaced apart. The conical trays are fixedly connected to the central load-bearing rod. The expanded structure includes a composite flexible expansion bladder and a grouting assembly connected to the composite flexible expansion bladder. The composite flexible expansion bladder is wrapped around the outer periphery of the central load-bearing rod, and the top of the composite flexible expansion bladder is located in the inner cavity of the lowermost conical tray. The wall surface of the composite flexible expansion bladder includes, from the inside to the outside, an impermeable layer, a puncture-resistant expansion mesh layer, and a wear-resistant layer.

[0009] In the aforementioned expanded anchor system, preferably, a buffer layer is further provided between the impermeable layer and the puncture-resistant expansion mesh layer. The impermeable layer, buffer layer, puncture-resistant expansion mesh layer, and wear-resistant layer are fixedly connected as a whole by an adhesive layer. By adding a buffer layer, the point-concentrated stress transmitted by external sharp objects through the puncture-resistant expansion mesh layer is effectively dispersed, preventing the impermeable layer from being punctured. The adhesive layer consolidates each layer into a whole, eliminating relative slippage between layers during grouting expansion and ensuring coordinated deformation.

[0010] In the aforementioned expanded anchor system, preferably, the grouting assembly includes a grout delivery channel located within the cavity of the central load-bearing rod. This grout delivery channel passes through the side wall of the central load-bearing rod and communicates with the cavity of the composite flexible expansion bladder. Thus, the grout is directly injected into the bladder via the delivery channel within the rod, resulting in a simple and reliable delivery path.

[0011] In the aforementioned expanded-body anchor system, preferably, a rubber pad is fitted onto the central load-bearing rod between adjacent conical trays. The upper end of the rubber pad abuts against the inner wall of the upper conical tray, and the lower end abuts against the outer wall of the lower conical tray. The rubber pad fills the annular space between adjacent trays, eliminating the geometrical sharp angles at the abrupt change in cross-section of the grout, allowing for a smooth transition of stress flow lines, and further reducing the peak stress concentration factor in the transition region.

[0012] In the aforementioned expanded anchor system, preferably, among the multiple conical trays arranged from top to bottom, the bottom outer diameter of the lower conical tray is larger than that of the upper conical tray. Thus, each tray forms a progressively transitioning load-bearing system from the expanded section to the straight section, achieving graded transmission of pull-out force.

[0013] In the aforementioned expanded anchor system, preferably, the top of the composite flexible expansion bladder is provided with a first vent, which is located within the inner cavity of the lowest conical tray. A one-way valve is provided at the first vent. The first vent allows gas to be discharged from the bladder during grouting, preventing the formation of air pockets that could affect the quality of the expanded anchor. The one-way valve allows gas to flow only in one direction, i.e., only from the inside of the composite flexible expansion bladder to the outside.

[0014] In the aforementioned expanded-body anchor system, preferably, the conical tray has multiple second vents on its side. These second vents serve two purposes: firstly, they allow gas to escape between the composite flexible expansion bladder and the conical tray, ensuring a tight fit between the expanded bladder and the bottom surface of the conical tray. Secondly, during secondary grouting from the borehole after the composite flexible expansion bladder grouting is completed and before the grout initially sets, the grout can also enter the conical tray through the second vents. After solidification, the grout within the second vents forms "pins," connecting and encasing multiple conical trays in series, ultimately forming a continuous grouted anchor body with a bamboo-like surface. This enhances the anchor body's ability to withstand stress concentration damage, thereby improving the anchor's pull-out bearing capacity and achieving stable anchoring in complex strata.

[0015] This invention features a first vent at the top of a composite flexible expansion bladder (located within the inner cavity of the lowest conical tray), with a one-way valve at the first vent. Simultaneously, multiple second vents are located on the side of the conical tray. The two venting systems have distinct functions and work synergistically: the first vent releases gas from the bladder during grouting, ensuring the grout fills every corner of the bladder and preventing localized voids or insufficient forming in the expanded section due to the presence of air pockets; the second vent releases gas between the outer wall of the bladder and the inner cavity of the conical tray during the outward expansion and compression of the pore walls, ensuring a tight fit between the outer wall of the bladder and the bottom surface of the conical tray, preventing the air cushion effect from hindering effective force transmission between the conical tray and the bladder. Once grouting is complete and the grout has initially set, the one-way valve at the first vent automatically closes to prevent grout leakage; the second vents are filled with grout during secondary grouting, and after solidification, they form pins that further enhance the connection strength between the conical tray and the grouting body. The two work together to ensure the fullness of the expanded section's shape, geometric consistency, and structural integrity.

[0016] In the aforementioned expanded anchor system, preferably, a positioning component is fitted onto the upper middle part of the central load-bearing rod to achieve centering of the central load-bearing rod within the borehole. This positioning component holds the central load-bearing rod at the center of the borehole, preventing eccentric installation.

[0017] In the aforementioned expanded anchor system, preferably, the upper middle part of the central support rod is provided with a threaded section, and the positioning component is a hollow ring with threads in its inner cavity. The hollow ring is connected to the central support rod through the threaded section. Thus, the hollow ring can be flexibly adjusted and locked on the central support rod to adapt to different drilling depths and formation conditions.

[0018] This invention achieves precise centering of the anchor rod within the borehole by installing a positioning component—a hollow ring connected to the rod via a threaded section—at the upper middle part of the central load-bearing rod. The outer diameter of the hollow ring matches the borehole diameter, and during the rod's lowering process, the outer edge of the hollow ring contacts the borehole wall, ensuring the rod remains centered within the borehole. At least two hollow rings are spaced apart along the rod's axial direction, further guaranteeing the rod's straightness and centering accuracy. The threaded section allows the hollow rings to flexibly adjust their axial position and reliably lock according to different borehole depths and geological conditions, offering strong versatility. This structure effectively avoids uneven grout thickness caused by rod eccentricity, ensuring uniform grout coverage and protective layer thickness, thereby improving the overall durability and long-term load-bearing performance of the anchor rod.

[0019] In the aforementioned expanded anchor system, preferably, the lower end of the central load-bearing rod is provided with a conical tip, and the side of the conical tip is provided with multiple high-pressure water holes, which are connected to a high-pressure water channel located inside the central load-bearing rod. This invention features a conical tip at the lower end of the central load-bearing rod, with multiple high-pressure water holes on the side of the conical tip, connected to a high-pressure water channel inside the rod. Before grouting, high-pressure clean water is pumped to the bottom of the hole through the high-pressure water channel. The water flows out at high speed from the high-pressure water holes, cutting, breaking up, and flushing the stone debris and mud sediment deposited at the bottom of the hole, suspending them. The mud-water mixture returns out of the hole along the gap between the hole wall and the rod, until clean water returns from the hole opening. This slag-clearing structure allows the bottom of the expanded section to directly contact the bearing layer (original hard soil layer or rock layer), eliminating the presence of weak sediment interlayers. When the expanded anchor bolt is subjected to pull-out load, the end bearing capacity of the expanded section can be directly transferred to the bearing layer, fully utilizing the end bearing resistance of the expanded section and significantly improving the pull-out bearing capacity of the anchor bolt. The tapered angle design also facilitates the lowering and guiding of the anchor bolt in the borehole, serving as an auxiliary function for lowering the bolt.

[0020] Compared with the prior art, the advantages of this utility model are: This invention's expanded anchor system significantly improves the puncture resistance of the composite flexible expansion bladder, ensuring reliable expansion molding. The composite flexible expansion bladder employs a three-layer composite structure: an impermeable layer, a puncture-resistant expansion mesh layer, and a wear-resistant layer. More preferably, a buffer layer is added between the impermeable layer and the puncture-resistant expansion mesh layer, and each layer is bonded together using an adhesive layer. When the bladder is subjected to concentrated point pressure from sharp gravel, the wear-resistant layer first withstands friction and wear, the puncture-resistant expansion mesh layer provides circumferential tensile strength and resists puncture, the buffer layer disperses point stress into surface stress through its own compression deformation, and the impermeable layer, being the innermost layer, ensures no grout leakage. The four layers work together to form a progressively buffered, layer-by-layer protective puncture-resistant system, fundamentally solving the industry problem of bladder rupture in gravelly strata. Meanwhile, the introduction of the binder layer eliminates the relative slippage between layers caused by differences in elongation during grouting expansion, allowing the impermeable layer, buffer layer, and puncture-resistant expansion mesh layer to deform synergistically as a single sheet. This not only prevents the impermeable layer from thinning and tearing due to excessive local stretching, but also ensures that the geometry of the expanded bladder is uniform and full, significantly improving the quality consistency of the expansion forming.

[0021] This invention's expanded-body anchor system significantly alleviates stress concentration by progressively transferring loads through multi-stage load-bearing components. The multi-stage load-bearing components comprise at least two axially spaced conical trays, with the bottom outer diameter of each tray gradually increasing from top to bottom. When the expanded structure is subjected to pull-out force, the lowest tray first absorbs the force from the expanded structure and transmits a portion of this force to the surrounding grouting material through its conical surface. The remaining force is then transmitted upwards along the rod to the second-stage tray, where it is further dispersed and transmitted; this process continues, with the pull-out force gradually decreasing upwards along the rod. This graded load-bearing and progressively transferred mechanical mechanism disperses the enormous pull-out force concentrated on a single interface in traditional anchors into a shared load across multiple interfaces, avoiding stress concentration and shear failure caused by abrupt changes in cross-section. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the expanded anchor system in an embodiment.

[0024] Figure 2 This is a schematic diagram of the structure during grouting of the composite flexible expansion bladder in the embodiment (only some components are shown).

[0025] Figure 3 This is a schematic diagram of the structure of the multi-level load-bearing component in an embodiment.

[0026] Figure 4 This is a schematic diagram of the wall structure of the composite flexible expansion bladder in an embodiment.

[0027] Legend 1. Slurry conveying channel; 2. Composite flexible expansion bladder; 201. Impermeable layer; 202. Puncture-resistant telescopic mesh layer; 203. Wear-resistant layer; 204. Buffer layer; 205. Adhesive layer; 3. Central load-bearing rod; 4. Threaded section; 5. Second vent; 6. Hollow ring; 7. Conical sharp corner; 8. High-pressure water hole; 9. Conical tray; 10. Rubber pad. Detailed Implementation

[0028] To facilitate understanding of this utility model, it will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments. However, the scope of protection of this utility model is not limited to the following specific embodiments.

[0029] It should be noted that when a component is described as being "fixed to, attached to, connected to or connected to" another component, it can be directly fixed to, attached to, connected to or connected to the other component, or it can be indirectly fixed to, attached to, connected to or connected to the other component through other intermediate connectors.

[0030] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of protection of this invention.

[0031] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0032] Example: like Figures 1-3 As shown, the expanded anchor system of this embodiment includes a central load-bearing rod 3, a multi-stage load-bearing assembly disposed on the central load-bearing rod 3, and an expanded structure disposed at the lower part of the central load-bearing rod 3.

[0033] The central load-bearing rod 3 is the core load-bearing skeleton of the expanded anchor system, preferably made of high-strength threaded steel bars or precision-rolled threaded steel bars, and its axial length is determined according to the anchoring depth designed in the engineering project. The central load-bearing rod 3 has an axially spaced high-pressure water channel and a grout delivery channel 1 inside. The high-pressure water channel and the grout delivery channel 1 are two independent axial channels inside the central load-bearing rod 3, arranged in separate sections within the rod's cross-section and not interconnected, ensuring that high-pressure cleaning operations and grouting operations do not interfere with each other.

[0034] The lower end of the central support rod 3 is provided with a conical tip 7, which facilitates the lowering and guidance of the anchor rod in the borehole and also assists in soil breaking. Multiple high-pressure water holes 8 are provided on the side of the conical tip 7, and these holes 8 are connected to the high-pressure water channel inside the central support rod 3. The high-pressure water holes 8 are preferably arranged at a downward 45° angle. This angle allows the high-pressure water flow to impact the sediment at the bottom of the borehole at the optimal scouring angle, effectively breaking up the rock and smoothly carrying the mud mixture out of the borehole. Preferably, there are no fewer than three high-pressure water holes 8, evenly distributed around the circumference of the conical tip 7 to ensure full coverage and scouring of the bottom of the borehole.

[0035] like Figure 3 As shown, a multi-stage load-bearing assembly is mounted on the central load-bearing rod 3, comprising at least two axially spaced conical trays 9 (two are shown in this embodiment; in other embodiments, the number can be optimized and adjusted). The conical trays 9 are made of stainless steel or high-quality carbon structural steel and are fixedly connected to the central load-bearing rod 3 by welding.

[0036] In the multiple conical trays 9 arranged from top to bottom, the outer diameter of the bottom end of the lower conical tray 9 is larger than that of the upper conical tray 9, meaning the diameter of each conical tray 9 decreases sequentially from bottom to top. This arrangement, with the larger diameter at the bottom and the smaller diameter at the top, matches the force transmission path of the expanded anchor bolt. The expanded structure is located at the bottom of the bolt and bears the greatest pull-out force; therefore, the bottom conical tray 9 has the largest diameter, providing the largest bearing area. As the pull-out force is transmitted upwards along the bolt, the required bearing area decreases sequentially, and the diameter of each conical tray 9 decreases accordingly. Through this optimized geometric configuration, a reasonable force state is achieved where the magnitude of the force matches the bearing area.

[0037] A rubber pad 10 is fitted onto the central support rod 3 between adjacent conical trays 9. The rubber pad 10 is preferably made of natural rubber or polyurethane elastomer, possessing certain elasticity and aging resistance. The upper end of the rubber pad 10 abuts against the inner wall of the upper conical tray 9, and the lower end abuts against the outer wall of the lower conical tray 9, precisely filling the annular space between adjacent conical trays 9. The inner diameter of the rubber pad 10 is slightly larger than the outer diameter of the central support rod 3, ensuring smooth installation without damaging the rod surface.

[0038] Each conical tray 9 has multiple second exhaust ports 5 on its side. The second exhaust ports 5 are evenly distributed around the circumference of the conical tray 9 to ensure effective exhaust at any installation angle.

[0039] The expansion structure is located at the lower part of the central load-bearing rod 3, and includes a composite flexible expansion bladder 2 and a grouting assembly connected to the composite flexible expansion bladder 2.

[0040] The composite flexible expansion bladder 2 is wrapped around the outer periphery of the central load-bearing rod 3, with its top located inside the inner cavity of the lowest conical tray 9. The lower end of the composite flexible expansion bladder 2 is fixed above the conical tip 7 at the lower end of the central load-bearing rod 3 by clamps or binding, and the upper end is fixed to the section of the central load-bearing rod 3 located inside the inner cavity of the lowest conical tray 9 by clamps or binding.

[0041] The top of the composite flexible inflatable bladder 2 is provided with a first exhaust port (not shown in the figure), which is located in the inner cavity of the lowest conical tray 9. A one-way valve is provided at the first exhaust port, which only allows gas to be discharged from the inside of the bladder to the outside in one direction.

[0042] The grouting assembly includes a grout delivery channel 1 located within the cavity of the central load-bearing rod 3. For example... Figure 2 As shown, the slurry delivery channel 1 extends axially within the central support rod 3 and, near the lower end of the rod, passes through the side wall of the central support rod 3 and communicates with the inner cavity of the composite flexible expansion bladder 2. The outlet end of the slurry delivery channel 1 is preferably located at the bottom region of the inner cavity of the composite flexible expansion bladder 2, allowing the injected slurry to gradually fill upwards from the bottom of the bladder. This facilitates the complete discharge of gas from the bladder through the first exhaust port at the top, ensuring the fullness of the bladder formation.

[0043] The upper end of the grout delivery channel 1 is connected to the external grouting conduit via a detachable quick-connect coupling. Preferably, the quick-connect coupling is equipped with a one-way check valve to prevent grout from flowing back and contaminating the pipeline after the grouting pressure is released.

[0044] A positioning component for centering the central support rod 3 within the borehole is fitted onto its upper middle portion. Specifically, the upper middle portion of the central support rod 3 has a threaded section 4, which is a threaded section of a certain length extending along the axial direction of the rod. The positioning component is a hollow ring 6 with threads in its inner cavity, which is threadedly connected to the central support rod 3 via the threaded section 4.

[0045] The outer diameter of the hollow ring 6 is matched with the borehole diameter (preferably slightly smaller than the borehole diameter). During the lowering of the rod, the outer edge of the hollow ring 6 contacts the borehole wall, supporting the rod at the center of the borehole. At least two hollow rings 6 are arranged at intervals along the axial direction of the rod, further ensuring the straightness of the rod.

[0046] Through the threaded section 4, the hollow ring 6 can flexibly adjust its axial position on the rod body according to the drilling depth and formation conditions, and achieve reliable locking through the thread self-locking function. The hollow ring 6 is preferably made of elastic nylon rubber or steel. When elastic nylon rubber is used, it also has a certain shock absorption and buffering effect, reducing rigid collisions with the borehole wall during the lowering of the rod body. The hollow ring 6 has slurry grooves / holes.

[0047] like Figure 4 As shown, the wall of the composite flexible expansion bladder 2 includes, from the inside out, a seepage-proof layer 201, a buffer layer 204, a puncture-resistant expansion mesh layer 202, and a wear-resistant layer 203. The seepage-proof layer 201, the buffer layer 204, the puncture-resistant expansion mesh layer 202, and the wear-resistant layer 203 are fixedly connected as one unit by an adhesive layer 205.

[0048] The impermeable layer 201 is located at the innermost layer of the grout body wall and is in direct contact with the injected grout, serving to prevent seepage and retain water. The impermeable layer 201 uses a high-strength geomembrane, preferably HDPE (high-density polyethylene) or LLDPE (linear low-density polyethylene) geomembrane, with a thickness of 2-4 mm. This material has excellent impermeability and certain tensile strength, ensuring that the grout does not leak outwards during high-pressure grouting.

[0049] A buffer layer 204 is located between the impermeable layer 201 and the puncture-resistant expansion mesh layer 202. It is a thin layer of natural or synthetic rubber, with a thickness 1-2 times (preferably 2-4 mm) that of the impermeable layer 201. The function of the buffer layer 204 is as follows: when the outer surface of the capsule is subjected to concentrated point pressure from sharp gravel, this pressure first acts on the wear-resistant layer 203 and the puncture-resistant expansion mesh layer 202, and then is transmitted to the buffer layer 204 through the grid nodes of the puncture-resistant expansion mesh layer 202. The buffer layer 204 disperses this concentrated force into planar stress through its own compression deformation, and then transmits it to the impermeable layer 201. This point-to-planar stress transfer mechanism fundamentally prevents the impermeable layer 201 from being punctured due to excessive local pressure.

[0050] The puncture-resistant telescopic mesh layer 202 is located between the buffer layer 204 and the wear-resistant layer 203, and adopts a telescopic mesh structure woven from flexible metal wire mesh or high-strength fibers. The metal wire is preferably stainless steel wire or galvanized steel wire with a diameter of 3-4 mm. During grouting, as the pressure inside the bladder increases, the puncture-resistant telescopic mesh layer 202 is stretched and tightened, providing strong circumferential tensile strength to prevent the bladder from bursting under high pressure; simultaneously, this mesh layer acts as a physical barrier to resist puncture of the bladder by sharp stones on the borehole wall.

[0051] The wear-resistant layer 203 is located on the outermost layer of the bladder wall and is made of wear-resistant non-woven fabric with a thickness of 2-3 mm. The wear-resistant layer 203 is in direct contact with the borehole wall and is the first to bear the friction with the borehole wall during the anchor bolt lowering process and the first to bear the pressure of sharp gravel during the grouting expansion process. It plays the role of a sacrificial protective layer and effectively protects the internal layers from wear and direct puncture.

[0052] The adhesive layer 205 securely connects the impermeable layer 201, the buffer layer 204, the puncture-resistant expansion mesh layer 202, and the wear-resistant layer 203 into a single unit. The adhesive layer 205 is preferably a polyurethane or epoxy resin-based flexible adhesive, with a coating thickness of 0.5mm-2mm. After curing, the adhesive layer 205 maintains a certain degree of flexibility, and its shear modulus is lower than that of each layer. This allows the adhesive layer 205 to coordinate the deformation of each layer when the composite sheet is subjected to overall stress, further improving the durability and fatigue resistance of the composite sheet.

[0053] Through the consolidation effect of the adhesive layer 205, there is no relative slippage between the layers of the impermeable layer 201, buffer layer 204, puncture-resistant expansion mesh layer 202 and wear-resistant layer 203 during grouting expansion. This fundamentally avoids the problem of local excessive stretching and thinning of the impermeable layer 201 due to the difference in elongation of each layer of material, and ensures the uniformity of the expansion of the bladder and the reliability of the seal.

[0054] The expanded anchor system of this embodiment can be constructed according to the following steps: Step 1: Drilling. Anchor holes are constructed using conventional drilling techniques according to design requirements. The hole diameter and depth are determined as per design specifications.

[0055] Step 2: Hole Cleaning. The expanded anchor system of this embodiment is lowered into the drilled anchor hole. High-pressure clean water is pumped into the high-pressure water channel inside the central load-bearing rod 3 using a ground high-pressure water pump. The water flows through the high-pressure water channel and is ejected at high speed from the high-pressure water hole 8, which is inclined at 45° to the side of the conical tip 7, impacting the sediment at the bottom of the hole. The high-pressure water flow cuts and breaks up the stone debris at the bottom of the hole, suspending it in the mud. The mud-water mixture returns out of the hole along the annular gap between the hole wall and the rod body. High-pressure clean water is continuously pumped in until clean water returns from the hole opening, indicating that the sediment at the bottom of the hole has been cleaned. Since the high-pressure water channel and the slurry delivery channel 1 are independent of each other, the cleaning operation will not contaminate the subsequent grouting channel.

[0056] Step 3: Primary grouting (bladder grouting). After the borehole is cleaned, highly fluid cement grout or super-fluid cement grout is injected into the composite flexible expansion bladder 2 through the grout delivery channel 1 inside the central support rod 3. The grout enters from the bottom of the bladder and gradually fills upwards. As the pressure inside the bladder gradually increases: the wear-resistant layer 203 first comes into close contact with the borehole wall, bearing friction and wear; the puncture-resistant stretchable mesh layer 202 is stretched and tightened, providing circumferential tensile strength; the buffer layer 204 disperses stress through its own compression deformation when subjected to external point pressure; the seepage-proof layer 201 ensures that the grout does not leak in the innermost layer; each layer deforms synergistically due to the consolidation effect of the adhesive layer 205, without interlayer slippage; the gas inside the bladder is discharged from the one-way valve of the first exhaust port at the top; the gas between the outer wall of the bladder and the lowest conical tray 9 is discharged through the second exhaust port 5.

[0057] After the grouting pressure reaches the design limit, maintain the pressure for 3-5 minutes to ensure the bladder fully expands and fits tightly against the borehole wall, then stop grouting. The one-way valve at the first vent port automatically closes after the pressure inside the bladder reaches the set value, locking the grout inside. At this time, the upper end of the bladder and the inner cavity of the lowermost conical tray 9 are in close contact.

[0058] Step 4: Secondary grouting (grouting of section 9 of the conical tray). Secondary grouting is performed through drilling before the grout in the main body is completed and before the grout initially sets. After the grout solidifies, the grout in the second vent 5 forms a pin, connecting and wrapping each level of the conical tray 9 with the grouting body, creating a continuous grouting anchor body with a bamboo-like surface in section 9. This bamboo-like structure not only enhances the interlocking ability between the anchor body and the surrounding soil but also further disperses stress concentration at each level of the conical tray 9.

[0059] Step 5: Curing. Curing should be carried out according to standard anchor bolt construction specifications. Once the grout has reached the design strength, a pull-out test can be conducted or the product can be put into use.

[0060] Throughout the construction process, the hollow ring 6 kept the central load-bearing rod 3 at the center of the borehole, ensuring uniform coverage of the rod by the grout. The high-pressure water hole 8 ensured direct contact between the bottom of the expanded structure and the bearing layer, eliminating weak interlayers. The multi-stage conical tray 9 progressively distributed the pull-out force, preventing stress concentration. The composite flexible expansion bladder 2 maintained structural integrity and reliable sealing throughout high-pressure grouting and long-term service.

[0061] This invention highly integrates multiple functions such as puncture resistance of the anchor body, rod alignment, stress dispersion, bottom hole cleaning, and air venting into a single anchor system. The coordination relationships between the components are clear and well-defined, and the construction process is simple and controllable. During on-site construction, only the standard procedure of lowering the rod → cleaning the hole → grouting → secondary grouting needs to be followed. No additional special equipment or complex processes are required, significantly reducing construction difficulty and the impact of human error, and demonstrating good prospects for engineering application.

[0062] The expanded anchor system of this utility model has a reasonable structure, integrated functions, and convenient construction. It is suitable for various geotechnical engineering anchoring scenarios such as slope reinforcement, deep foundation pit support, tunnel surrounding rock stabilization, and mine roadway anchoring. It is especially suitable for expanded anchoring projects under complex geological conditions such as gravel layers and sand layers, and has broad industrial application prospects.

[0063] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A widened anchor bolt system, characterized in that, The system includes a central load-bearing rod (3), a multi-stage load-bearing assembly disposed on the central load-bearing rod (3), and an expansion structure disposed at the lower part of the central load-bearing rod (3). The multi-stage load-bearing assembly includes at least two conical trays (9) arranged axially spaced apart. The conical trays (9) are fixedly connected to the central load-bearing rod (3). The expansion structure includes a composite flexible expansion bladder (2) and a grouting assembly connected to the composite flexible expansion bladder (2). The composite flexible expansion bladder (2) is wrapped around the outer periphery of the central load-bearing rod (3), and the top of the composite flexible expansion bladder (2) is located in the inner cavity of the lowest conical tray (9). The wall surface of the composite flexible expansion bladder (2) includes, from the inside to the outside, an impermeable layer (201), a puncture-resistant expansion mesh layer (202), and a wear-resistant layer (203).

2. The expanded anchor bolt system according to claim 1, characterized in that, A buffer layer (204) is provided between the impermeable layer (201) and the puncture-resistant expansion mesh layer (202). The impermeable layer (201), the buffer layer (204), the puncture-resistant expansion mesh layer (202) and the wear-resistant layer (203) are fixedly connected as a whole by an adhesive layer (205).

3. The expanded anchor bolt system according to claim 1, characterized in that, The grouting assembly includes a grout delivery channel (1) located in the inner cavity of the central support rod (3). The grout delivery channel (1) passes through the side wall of the central support rod (3) and communicates with the inner cavity of the composite flexible expansion bladder (2).

4. The expanded anchor bolt system according to claim 1, characterized in that, A rubber pad (10) is fitted on the central support rod (3) between adjacent conical trays (9). The upper end of the rubber pad (10) abuts against the inner wall of the upper conical tray (9), and the lower end of the rubber pad (10) abuts against the outer wall of the lower conical tray (9).

5. The expanded-body anchor system according to claim 1, characterized in that, Among the multiple conical trays (9) arranged from top to bottom, the bottom outer diameter of the lower conical tray (9) is larger than the bottom outer diameter of the upper conical tray (9).

6. The expanded-body anchor system according to claim 1, characterized in that, The top of the composite flexible expansion bladder (2) is provided with a first exhaust port, which is located in the inner cavity of the lowest conical tray (9), and a one-way valve is provided at the first exhaust port.

7. The expanded anchor bolt system according to claim 1, characterized in that, The conical tray (9) has multiple second exhaust ports (5) on its side.

8. The expanded-body anchor system according to claim 1, characterized in that, The upper middle part of the central load-bearing rod (3) is fitted with a positioning component for centering the central load-bearing rod (3) inside the borehole.

9. The expanded anchor bolt system according to claim 8, characterized in that, The upper part of the central load-bearing rod (3) is provided with a threaded section (4), and the positioning component is a hollow ring (6) with a threaded inner cavity. The hollow ring (6) is connected to the central load-bearing rod (3) through the threaded section (4).

10. The expanded-body anchor system according to claim 1, characterized in that, The lower end of the central load-bearing rod (3) is provided with a conical tip (7), and the side of the conical tip (7) is provided with a plurality of high-pressure water holes (8), which are connected to the high-pressure water channel located inside the central load-bearing rod (3).

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