Anti-pulling prefabricated anchor rod and construction method thereof

Abstract

The application discloses an anti-pulling prefabricated anchor rod and a construction method thereof, and relates to the technical field of anchor rods, which comprises multiple anchor rod segments, connecting pieces used for connecting adjacent anchor rod segments, and a bearing plate arranged at an orifice; further comprises end heads detachably connected to the end portions of the anchor rod segments at two ends; the anchor rod segments and the connecting pieces are detachably connected through thread cooperation, and the connecting positions are sealed through sealing rings; the outer periphery of the connecting pieces is provided with a sealing capsule which can be radially expanded; and a compression trigger assembly is arranged on the connecting piece. Through the combination of multiple anchor rod segments, the application realizes flexible adjustment of the length of the anchor rod according to the actual drilling depth, facilitates unified prefabrication in a factory and rapid installation on site, and significantly improves the flexibility of use; the segments are reliably connected through thread connecting pieces, the pipe joint is a plug-in pipe joint, and the sealing performance of the connecting positions is ensured through cooperation with the sealing rings, so that the flexibility and adaptability of construction are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anchor rods, in particular to an anti-pulling prefabricated anchor rod and a construction method thereof. BACKGROUND

[0002] In the field of geotechnical engineering, an anchor rod is a very common reinforcing structure, which is essentially a tension rod anchored in the stratum and the overall system formed thereby, and mainly functions to effectively transfer the load borne by the external structure to the stratum, thereby ensuring the stability of the external structure.

[0003] Currently, when cooperating with the anchoring of the rock-soil layer, the traditional anchoring scheme is often adopted. Since the prefabricated anchoring body often has a problem of not being tightly connected with the poured concrete, which leads to instability of the anchoring device and low anchoring force, and other related problems. A Chinese patent (Patent No. CN118273321B) of a prefabricated anchor rod with strong anti-pulling capacity and anchoring structure is proposed in the prior art to solve the above technical problems. The technical scheme disclosed in the patent document is as follows: a prefabricated anti-pulling anchor rod is composed of an anchor rod segment and a free segment, the anchor rod segment is arranged inside the anchoring body, the outer periphery of the free segment is provided with a thread, one side of the outer periphery of the free segment is threadedly connected with a fixed nut, the side of the fixed nut away from the anchoring body is threadedly connected with a fastening sleeve, one side of the outer periphery of the fastening sleeve is fixedly connected with a hand wheel, and one side of the outer periphery of the anchor rod segment away from the free segment is provided with an external thread. The sealing sleeve can press the sealing plate, so that the connecting pipe on the sealing plate and the protective sleeve can completely wrap the top of the anchoring body, thereby protecting the top of the anchoring body, and damage to the weak part of the end of the anchoring body can be effectively avoided.

[0004] This scheme and most similar improvements are mainly dedicated to solving the gripping force between the anchor rod body and the internal grouting mortar and the corrosion protection problem of the end of the anchor rod. However, in the prior art, the gripping ability of the anchor rod through its external spiral design and the mortar is already very strong, and the adhesion strength of the mortar and the hole wall actually affects the final anti-pulling capacity of the anchor rod. Figure 12 As shown in the figure, in the upward or inclined upward drilling, due to gravity and poor exhaust, the grouted mortar is prone to form a continuous cavity at the top of the drilling, which leads to insufficient adhesion of the mortar to the drilling hole wall, which makes the anti-pulling capacity of the anchor rod system not depend on the enhanced rod-mortar strength, but is limited by the defective mortar-hole wall joint. This weak link thus becomes the final bottleneck restricting the performance improvement of the entire anchoring system. SUMMARY

[0005] The present application aims to provide an anti-pulling prefabricated anchor rod and a construction method thereof to solve the problem of cavity in grouting during the installation of the anchor rod in the upward hole, which leads to the failure to fill the hole.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is:

[0007] The anti-pulling prefabricated anchor rod comprises a plurality of anchor rod segments, a connecting piece for connecting adjacent anchor rod segments, and a bearing plate arranged at an orifice; further comprising an end head detachably connected to the end portions of the anchor rod segments at both ends; the anchor rod segments and the connecting piece are detachably connected through threaded cooperation, and the connecting part is sealed by a sealing ring, the outer periphery of the connecting piece is sleeved with a sealing capsule capable of radial expansion; a compression trigger assembly is arranged on the connecting piece, the compression trigger assembly is used to provide axial pressure of the sealing capsule, and the sealing capsule is forced to expand radially outward; the inside of the anchor rod segment is fixedly connected with a communication pipe through a mounting bracket, and pipe joints are arranged at both ends of the communication pipe; the inside of the connecting piece is fixedly connected with a transfer pipe through a mounting bracket, the transfer pipe is provided with an output pipe and an input pipe at different positions along the axial direction, and a partition portion for separating the transfer pipe is arranged inside the transfer pipe and between the input pipe and the output pipe; the input pipe and the output pipe both extend to the outside of the connecting piece; the inside of the end head is fixedly connected with a connecting pipe through a mounting bracket, and the connecting pipe, the transfer pipe and the communication pipe are connected through the pipe joints; the end of the connecting pipe away from the communication pipe extends from the side of the end head to the outside of the end head.

[0008] By adopting the above technical scheme, the length of the anchor rod can be flexibly adjusted according to the actual drilling depth through the combination of the plurality of anchor rod segments, the factory unified prefabrication and the on-site rapid installation are facilitated, and the use flexibility is significantly improved; the segments are reliably connected through the threaded connecting piece, the pipe joint is a plug-in pipe joint, and the sealing ring is used to ensure the sealing property of the connecting part, thereby improving the flexibility and adaptability of construction.

[0009] Further improvement of the technical scheme of the present application is that the compression trigger assembly comprises a compression ring slidably connected to the outside of the connecting piece, the compression ring is in contact with the sealing capsule, the outside of the connecting piece is fixedly connected with an air disc, the outside of the connecting piece is sleeved with a first spring, and the two sides of the first spring are in contact with the compression ring and the air disc respectively; a plurality of piston cylinders are arranged in the inside of the air disc, a first piston plate is slidably connected between the inner walls of the piston cylinders, a locking rod is fixedly connected to one side of the first piston plate, and the end of the locking rod away from the first piston plate is fixedly connected with the compression ring; the piston cylinders are communicated with the inside of the air disc, an air nozzle is arranged on the air disc, and a sealing cover is detachably connected to the air nozzle; the air nozzle can slowly pass through air.

[0010] By adopting the above technical solution, the compression triggering assembly composed of an air plate, piston cylinder, first spring and pressure ring is used to achieve slow and uniform expansion of the sealing bladder, avoiding damage to the bladder due to excessive expansion. In terms of triggering method, delayed triggering is used to replace on-site operation, thereby overcoming the problem of the outer layer node obstructing the inner layer node. By utilizing the slow air intake characteristics of the air nozzle, the expansion speed and timing can be precisely controlled to ensure that the sealing bladder is in close contact with the hole wall and reliably separates each chamber.

[0011] A further improvement of the technical solution of the present invention is that: the interior of the sealing bladder is divided into two independent chambers by a diaphragm, and the two chambers of the sealing bladder are respectively filled with an adhesive and an initiator. After the adhesive and the initiator are mixed, the adhesive solidifies and releases heat. The sealing bladder is made of thermoplastic plastic, which is configured to melt when the adhesive and the initiator react and release heat. A delayed puncture component is provided inside the sealing bladder. The delayed puncture component is used to delay triggering until the diaphragm is punctured when the pressure inside the sealing bladder changes.

[0012] By adopting the above technical solution, the adhesive and initiator stored separately in the sealed bladder can trigger a mixing reaction after the mortar has initially solidified. This can both use the exothermic reaction to soften or rupture the bladder and use the adhesive to solidify and fill the gaps around the bladder, forming a secondary anchoring structure. This effectively solves the problem of node loosening caused by aging failure of the bladder and improves the long-term stability of the anchor rod.

[0013] A further improvement of the technical solution of the present invention is that: the delayed puncture component includes a delayed cylinder fixedly connected to the inside of the sealed bladder, a second piston plate slidably connected inside the delayed cylinder, a wide opening at one end of the delayed cylinder, and a delayed hole on the side of the delayed cylinder away from the wide opening; a second spring is fixedly connected to both sides of the second piston plate, the end of the second spring away from the second piston plate is fixedly connected to the delayed cylinder, a push rod is slidably connected to the side of the delayed cylinder near the delayed hole, one end of the push rod extends into the inside of the delayed cylinder and is fixedly connected to the second piston plate, and the other end is fixedly connected to a row plate, on which a plurality of puncture needles are fixedly connected.

[0014] The above technical solution utilizes a time-delayed puncture assembly consisting of a time-delay cylinder, a second piston plate, a push rod, and a piercing needle. This assembly leverages the difference in pressure transmission speed between the large and small holes to achieve precise time delay, ensuring that the diaphragm is punctured only after the mortar has initially solidified. This guarantees the strength of the grout body while triggering secondary anchoring, thus improving the accuracy and reliability of the reaction timing. The solution employs a purely mechanical structure, achieving precise time delay through the principle of fluid damping. The design requires no external power source and relies entirely on the system's own pressure changes for drive.

[0015] A further improvement of the technical solution of the present invention is that: the needle includes a rod body and a spike provided at one end of the rod body; the spike has multiple ridges distributed circumferentially and extending axially, and a concave region is formed between two adjacent ridges so that the edges of each ridge are sharp; the lower part of the spike has several downward protruding corners, and each corner forms a barb.

[0016] In this embodiment, the multiple edges of the thorn form sharp edges that can quickly pierce the diaphragm. As the diaphragm is also stretched due to the compression of the sealing capsule, it will be further torn under tension after being punctured. The barbs at the bottom will cut open the diaphragm that is not completely separated again when the thorn is reset, expanding the puncture area and allowing the adhesive and initiator in the sealing capsule to mix and react more fully.

[0017] By adopting the above technical solution, the intense exothermic reaction between diethylenetriamine and epoxy resin can ensure that the low-density polyethylene capsule is reliably softened or even melted. At the same time, the cured epoxy resin material provides bonding strength and durability far exceeding that of ordinary cement mortar, thereby forming a high-performance chemical anchor at the joint.

[0018] A further improvement of the technical solution of the present invention is that: a pipe joint is fixedly installed at the end of the connecting pipe away from the connecting pipe, and an extension pipe is detachably connected to the end inserted into the borehole through the pipe joint; the end of the extension pipe is closed and an opening is provided on the side wall near the end.

[0019] By adopting the above technical solution, by connecting an extension pipe of selectable length to the connecting pipe at the end, the grouting channel can be extended to the deepest part of the borehole, ensuring that the grout can fill from the bottom of the hole regardless of the hole depth, avoiding bottom cavities, and improving the integrity of grouting and the reliability of anchoring.

[0020] A further improvement to the technical solution of the present invention is that the input tube and the output tube form a 180° angle with respect to the end face of the intermediate tube.

[0021] With the above technical solution, both the input pipe and the output pipe are installed on the transfer pipe. Although the two are separated by a partition, the relative angle between the input pipe and the output pipe is not clear. If the angle is too small, the mortar may enter from the input pipe and be discharged directly from the output pipe, causing the cavity to flow into the next section before it is filled, forming a cavity and affecting the grouting quality.

[0022] This invention also provides a construction method for precast anti-pull-out anchor bolts, comprising the following steps:

[0023] S1: According to the drilling design depth, connect the required number of anchor bolt segments and connectors in sequence by thread to form a complete anchor bolt assembly. Ensure that the connecting pipes of each segment and the transfer pipes of the connectors are reliably connected through pipe joints, and install end caps at both ends. According to the hole depth, install the extension pipe of the required length on the end cap on the side that needs to be inserted into the hole.

[0024] The modular assembly process enables flexible configuration of anchor bolt length, establishes a complete grouting channel through a quick-connect pipe system, and ensures that the grouting pipeline can reach the deepest part of the borehole, laying a solid foundation for subsequent full grouting of the entire borehole.

[0025] S2: Sequentially remove the sealing caps of the air plates on each connector, hoist the assembled anchor bolt assembly and place it steadily into the borehole, ensuring that the end of the extension pipe contacts the end of the hole, install the bearing plate at the borehole opening so that it is close to the rock surface, and then install the hemispherical washer and anchor nut in sequence. Use a torque wrench to tighten the nut to the designed pre-tightening force to complete the initial fixing of the anchor bolt.

[0026] Pre-removal of the sealing cap prepares for subsequent bladder expansion; contact between the extension tube and the bottom of the hole ensures the accuracy of the grouting start point; and the mechanical fixing of the borehole bearing plate and nut provides a stable initial anchoring for the entire anchor system, ensuring the accuracy and stability of the anchor position during construction.

[0027] S3: External air slowly enters the air plate and piston cylinder through the air nozzle, driving the compression trigger component to move, causing the sealing bladder of each node to slowly expand radially until it is tightly fitted with the borehole wall, forming multiple independent sealing grouting chambers;

[0028] By utilizing pneumatic delay, the sealed bladder can be controlled to expand. Through slow radial expansion, a series of independent sealed chambers are formed in the borehole. This segmented sealing structure effectively prevents grout short-circuiting and loss during the grouting process, creating the necessary conditions for sequential grouting.

[0029] S4: Start the grouting equipment and inject mortar into the hole through the deepest grouting pipe. During the grouting process, follow the order from deep to shallow. After the previous chamber is filled and mortar overflows from its output pipe, continue to grout the next higher chamber until all chambers and the hole opening are filled with mortar. Plug the end used for grouting and its connecting pipe, and let it stand and wait for the mortar to solidify.

[0030] By employing a sequential grouting process from deep to shallow, and utilizing the principle of natural liquid level rise, each chamber is ensured to be fully filled. This grouting method effectively eliminates air and moisture in the borehole, completely eliminating the cavity defects that are easily formed in inclined upward drilling using traditional grouting methods.

[0031] S5: Once the mortar has initially solidified and reached the predetermined strength, the delayed puncture components in each node's capsule are automatically triggered, puncturing the diaphragm to allow the chemical components to mix and react. The chemical slurry that overflows after heating and softening the capsule solidifies to form a high-strength reinforced node, completing the construction of the entire anchoring system.

[0032] After the mortar has initially set, the chemical reinforcement mechanism is automatically triggered, and the temporary sealing capsule is transformed into a permanent chemical anchor body through thermo-chemical coupling. This forms a high-strength chemical bond node on the basis of the original mechanical anchor, which significantly improves the long-term durability and overall pull-out resistance of the anchor system.

[0033] By adopting the above technical solution, the technical effects achieved by this invention compared to the prior art are as follows:

[0034] 1. This invention, through the combination of multiple anchor bolt segments, enables flexible adjustment of the anchor bolt length according to the actual drilling depth, facilitating unified prefabrication in the factory and rapid on-site installation, significantly improving the flexibility of use; the segments are reliably connected by threaded connectors, and the pipe joints are plug-in pipe joints, which, together with sealing rings, ensure the sealing of the connection parts, improving the flexibility and adaptability of construction.

[0035] 2. This invention achieves slow and uniform expansion of the sealed bladder by setting a compression trigger component, avoiding damage to the bladder due to excessive expansion. In terms of triggering method, delayed triggering is used to replace on-site operation, thereby overcoming the problem of the outer layer node obstructing the inner layer node. By utilizing the slow air intake characteristic of the air nozzle, the expansion speed and timing can be precisely controlled to ensure that the sealed bladder is in close contact with the hole wall and reliably separates each chamber.

[0036] 3. This invention uses a sealed capsule to store an adhesive and an initiator separately. After the mortar has initially solidified, a delayed mixing reaction is triggered. This reaction can both soften or rupture the capsule by releasing heat and fill the gaps around the capsule by solidifying the adhesive, forming a secondary anchoring structure. This effectively solves the problem of node loosening caused by capsule aging and failure, and improves the long-term stability of the anchor rod.

[0037] 4. This invention utilizes a time-delayed puncture assembly consisting of a time-delay cylinder, a second piston plate, a push rod, and a piercing needle to achieve precise time delay by taking advantage of the pressure transmission speed difference between the large and small holes. This ensures that the diaphragm is punctured only after the mortar has initially solidified, thus triggering secondary anchoring while maintaining the strength of the grout body. This improves the accuracy and reliability of the reaction timing. The design employs a purely mechanical structure and achieves precise time delay through the principle of fluid damping. The design requires no external power source and relies entirely on the system's own pressure changes for drive.

[0038] 5. This invention connects an extension pipe of selectable length to the connecting pipe at the end, allowing the grouting channel to extend to the deepest part of the borehole. This ensures that the grout can fill from the bottom of the hole regardless of the hole depth, avoiding bottom cavities and improving grouting integrity and anchoring reliability. Attached Figure Description

[0039] The invention will now be further described with reference to the accompanying drawings.

[0040] Figure 1 This is a three-dimensional structural diagram of the two anchor segments combined in this invention;

[0041] Figure 2 This is a schematic diagram of the overall disassembled structure of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of the anchor bolt segment of the present invention;

[0043] Figure 4 This is a schematic diagram of the structure of the end of the present invention;

[0044] Figure 5 This is a schematic diagram of the external three-dimensional structure of the connector of the present invention;

[0045] Figure 6 This is one of the three-dimensional cross-sectional structural schematic diagrams of the connector of the present invention;

[0046] Figure 7 This is a second three-dimensional cross-sectional view of the connector of the present invention;

[0047] Figure 8 This is a schematic diagram of the front sectional view of the combined state of the two anchor segments of the present invention;

[0048] Figure 9 This is a cross-sectional view of the delayed puncture component of the present invention;

[0049] Figure 10 For the present invention Figure 8 Enlarged view of point A in the middle;

[0050] Figure 11 For the present invention Figure 8 Enlarged view at point B in the middle;

[0051] Figure 12 This is a schematic diagram of the structure of existing technology for grouting upward cavities.

[0052] In the diagram: 1. Anchor bolt segment; 101. Connecting pipe; 2. Connector; 201. Transfer pipe; 202. Output pipe; 203. Input pipe; 204. Separator; 3. End; 301. Connecting pipe; 401. Sealing bladder; 402. Diaphragm; 5. Compression trigger assembly; 501. Air plate; 502. Piston cylinder; 503. First piston plate; 504. Locking rod; 505. Pressure ring; 506. First spring; 507. Air nozzle; 508. Sealing cap; 601. Delay cylinder; 602. Wide opening; 603. Delay hole; 604. Second piston plate; 605. Second spring; 606. Top rod; 607. Arrangement plate; 7. Spike; 701. Rod body; 702. Spike head; 703. Barb; 801. Extension pipe; 802. Opening. Detailed Implementation

[0053] The present invention will be further described in detail below with reference to the embodiments.

[0054] Example 1

[0055] like Figures 1-12 As shown, the present invention provides a pull-out resistant precast anchor bolt, including multiple anchor bolt segments 1, a connector 2 for connecting adjacent anchor bolt segments 1, and a bearing plate disposed at the orifice; it also includes end heads 3 detachably connected to the ends of the anchor bolt segments 1 located at both ends; the anchor bolt segments 1 and the connector 2 are detachably connected by threaded engagement, and the connection is sealed by a sealing ring; the outer periphery of the connector 2 is fitted with a radially expandable sealing bladder 401; the connector 2 is provided with a compression trigger assembly 5, which is used to provide axial pressure to the sealing bladder 401, forcing the sealing bladder 401 to expand radially outward; a connecting pipe 101 is fixedly connected inside the anchor bolt segment 1 by a mounting bracket, the mounting bracket being cross-shaped, ensuring that the connecting pipe 101 is fixed while the anchor bolt segment 1... The space between the connecting pipe 101 and the connecting pipe 101 can be filled with mortar. Both ends of the connecting pipe 101 are equipped with pipe joints. The interior of the connector 2 is fixedly connected to the transfer pipe 201 by a mounting bracket. The transfer pipe 201 is provided with an output pipe 202 and an input pipe 203 at different positions along the axial direction. The interior of the transfer pipe 201 and between the input pipe 203 and the output pipe 202 is provided with a partition 204 for separating the transfer pipe 201. The input pipe 203 and the output pipe 202 both extend to the outside of the connector 2. The interior of the end 3 is fixedly connected to the connecting pipe 301 by a mounting bracket. The connecting pipe 301 and the transfer pipe 201 are connected to the connecting pipe 101 by pipe joints. The end of the connecting pipe 301 away from the connecting pipe 101 extends from the side of the end 3 to the outside of the end 3.

[0056] In this embodiment, by combining multiple anchor bolt segments 1, the anchor bolt length can be flexibly adjusted according to the actual drilling depth, which facilitates unified prefabrication in the factory and rapid on-site installation, significantly improving the flexibility of use; the segments are reliably connected by threaded connectors 2, and the pipe joints are plug-in pipe joints, which, together with sealing rings, ensure the sealing of the connection parts, improving the flexibility and adaptability of construction.

[0057] Furthermore, the solution includes sealing bladders 401 on each connector 2, which divide the hole into independent chambers. Combined with the step-by-step grouting method, this ensures that the grout is filled from the deepest chamber outwards, avoiding the cavity problem caused by gravity in the upward or oblique upward hole, enhancing the bonding strength between the mortar and the hole wall and anchor rod, and improving the overall pull-out resistance.

[0058] The multi-section anchor bolt segments 1 are detachably connected via threaded connectors 2 with sealing rings to form an integral anchor bolt structure; the sealing bladder 401 on the outer periphery of the connector 2 is initially flat along the axial direction, and axial pressure is provided by the compression trigger assembly 5 to cause the sealing bladder 401 to expand radially, dividing the hole into multiple independent chambers; the connecting pipe 101, transfer pipe 201, and connecting pipe 301 inside the anchor bolt are connected by plug-in pipe joints to form a grouting channel; (Refer to...) Figure 8 During grouting, mortar is injected from the outer end through each anchor segment 1 and finally directly into the deepest chamber through the extension pipe 801. The deepest chamber is filled first. The mortar is then output from each anchor segment 3 to the innermost chamber. During the grouting process, air is discharged from the connecting pipe 301 through each connecting pipe 101, the chamber, and the transfer pipe 201. After the innermost chamber is filled with mortar, the mortar level is higher than the connecting pipe 301 on the inner end 3 of the hole, and flows from the connecting pipe 301 through the connecting pipe 101, the transfer pipe 201, and the output pipe 202 into the second chamber, and so on, until all chambers are filled.

[0059] like Figure 6 , Figure 7 and Figure 11 As shown, preferably, the compression trigger assembly 5 includes a pressure ring 505 slidably connected to the outside of the connector 2, the pressure ring 505 contacting the sealing bladder 401, an air plate 501 fixedly connected to the outside of the connector 2, and a first spring 506 sleeved on the outside of the connector 2, with both sides of the first spring 506 contacting the pressure ring 505 and the air plate 501 respectively; a plurality of piston cylinders 502 are provided inside the air plate 501, a first piston plate 503 is slidably connected between the inner walls of the piston cylinders 502, a locking rod 504 is fixedly connected to one side of the first piston plate 503, and the end of the locking rod 504 away from the first piston plate 503 is fixedly connected to the pressure ring 505; the piston cylinders 502 communicate with the inside of the air plate 501, an air nozzle 507 is provided on the air plate 501, and a sealing cap 508 is detachably connected to the air nozzle 507; air can slowly pass through the air nozzle 507.

[0060] Although the above solution proposes to expand the sealing bladder 401 by compressing the trigger component 5, the specific structure and triggering method of the component are not clearly defined. This triggering presents the following technical difficulties: Multiple sealing bladders 401 exist within the cavity and require triggering expansion. Due to limitations in operating space and structural complexity, it is difficult to operate the sealing bladders 401 deep within the cavity; there are also limitations in the timing of operations. If operations are performed simultaneously, the sealing bladders 401 near the orifice will block the operation of the inner sealing bladders 401. If operations are performed sequentially, the operating efficiency will be affected; a stable and controllable driving force is needed, otherwise, uneven or excessive expansion of the bladders will occur, affecting the chamber separation effect and even damaging the bladders.

[0061] In this embodiment, the compression trigger assembly 5, composed of the air plate 501, piston cylinder 502, first spring 506 and pressure ring 505, enables the sealing bladder 401 to expand slowly and evenly, avoiding damage to the bladder due to excessive expansion. At the same time, by utilizing the slow air intake characteristic of the air nozzle 507, the expansion speed and timing can be precisely controlled to ensure that the sealing bladder 401 is in close contact with the hole wall and reliably separates each chamber.

[0062] Specifically, in the compression trigger assembly 5, the pressure ring 505 contacts the sealing bladder 401, the air plate 501 is fixed on the connector 2, and the two ends of the first spring 506 are connected to the pressure ring 505 and the air plate 501 respectively. In the initial state, the piston cylinder 502 in the air plate 501 restricts the movement of the pressure ring 505 through the first piston plate 503 and the locking rod 504, and the first spring 506 is in a compressed state. When the sealing cap 508 on the air nozzle 507 is removed, air slowly enters the air plate 501 and the piston cylinder 502 through the air nozzle 507. The pressure in the piston cylinder 502 gradually increases, pushing the first piston plate 503 to move the locking rod 504 and release the pressure ring 505. Under the action of the elastic force, the first spring 506 pushes the pressure ring 505 to slowly squeeze the sealing bladder 401 axially, forcing the sealing bladder 401 to expand radially outward until it closely contacts the borehole wall, completing the chamber separation.

[0063] Example 2

[0064] like Figure 6 , Figure 7 and Figure 11As shown, based on Embodiment 1, the present invention provides a technical solution: Preferably, the interior of the sealing bladder 401 is divided into two independent chambers by a diaphragm 402. The two chambers of the sealing bladder 401 are respectively filled with an adhesive and an initiator. After the adhesive and the initiator are mixed, the adhesive solidifies and releases heat. The sealing bladder 401 is a thermoplastic material configured to melt when the adhesive and the initiator react exothermically. A delayed puncture component is provided inside the sealing bladder 401. The delayed puncture component is used to delay triggering until the diaphragm 402 is punctured when the pressure inside the sealing bladder 401 changes.

[0065] In the above scheme, the chamber is separated by sealing bladder 401 and grout is injected. However, the sealing bladder 401 itself may become loose at the node due to aging, corrosion or cracking, which will affect the overall stability of the anchor bolt. The existing technology lacks a secondary reinforcement mechanism for the failure of the bladder and cannot guarantee the long-term anchoring effect.

[0066] In this embodiment, the adhesive and initiator stored separately inside the sealed capsule 401, after the mortar has initially solidified, trigger a mixing reaction after a delay. This can both use the exothermic reaction to soften or rupture the capsule and use the adhesive to solidify and fill the gaps around the capsule, forming a secondary anchoring structure. This effectively solves the problem of node loosening caused by capsule aging and failure, and improves the long-term stability of the anchor rod.

[0067] Specifically, the sealing capsule 401 is made of flexible thermoplastic (such as low-density polyethylene), and its interior is divided into two chambers by a diaphragm 402, which respectively store an adhesive (such as epoxy resin) and an initiator (such as diethylenetriamine). After the mortar is injected into the chamber and initially solidifies, a delayed puncture component triggers an action, puncturing the diaphragm 402 to mix the adhesive and initiator. The initiator accelerates the solidification of the adhesive and releases heat, which softens or even melts the thermoplastic sealing capsule 401. Since the capsule itself is under compression, it will rupture after softening. The mixed adhesive and initiator flow into the gap between the capsule and the hole wall and the anchor rod, and after solidification, form a strong joint bond, achieving secondary anchoring. After molding, the anchor rod and the hole are intermittently bonded together by multiple sections of mortar and adhesive, improving tensile strength.

[0068] like Figure 6 , Figure 7 and Figure 9As shown, preferably, the delayed puncture assembly includes a delay cylinder 601 fixedly connected inside the sealing bladder 401. A second piston plate 604 is slidably connected inside the delay cylinder 601. One end of the delay cylinder 601 is provided with a wide opening 602, and a delay hole 603 is opened on the side of the delay cylinder 601 away from the wide opening 602. A second spring 605 is fixedly connected to both sides of the second piston plate 604. The end of the second spring 605 away from the second piston plate 604 is fixedly connected to the delay cylinder 601. A push rod 606 is slidably connected to the side of the delay cylinder 601 near the delay hole 603. One end of the push rod 606 extends into the interior of the delay cylinder 601 and is fixedly connected to the second piston plate 604, and the other end is fixedly connected to a plate 607. A plurality of puncture needles 7 are fixedly connected to the plate 607.

[0069] To achieve reliable delayed triggering, a delay component with a simple structure and stable operation is needed. Traditional delay devices are often complex in structure and difficult to arrange within the confined space of the anchor bolt connector 2;

[0070] In this embodiment, the time-delayed puncture assembly, consisting of a time-delay cylinder 601, a second piston plate 604, a push rod 606, and a puncture needle 7, utilizes the difference in pressure transmission speed between the large and small holes to achieve precise time delay. This ensures that the diaphragm 402 is punctured only after the mortar has initially solidified, thus triggering secondary anchoring while maintaining the strength of the grout body and improving the accuracy and reliability of the reaction timing. The scheme adopts a purely mechanical structure and achieves precise time delay through the principle of fluid damping. The design requires no external power source and relies entirely on the system's own pressure changes for drive.

[0071] Initially, the second spring 605 is in equilibrium, and the needle 7 is away from the diaphragm 402. When the sealing bladder 401 expands or the internal pressure increases (because the sealing bladder 401 is squeezed and expanded by the pressure ring 505, and its interior receives positive pressure), the fluid quickly enters one side of the delay cylinder 601 through the wide opening 602, while the other side can only slowly exhaust through the delay hole 603, forming a pressure difference. The pressure difference pushes the second piston plate 604 to compress the second spring 605 on one side, driving the push rod 606 and the needle 7 to move towards the diaphragm 402. As the pressure gradually balances, the second piston plate 604 returns to its original position under the action of the spring force, and the needle 7 completes the piercing action of the diaphragm 402, realizing the delayed trigger. By reasonably designing the diameter of the delay hole 603 during production, the triggering time can be controlled after the mortar solidifies.

[0072] like Figure 7 As shown, preferably, the needle 7 includes a rod body 701 and a spike 702 disposed at one end of the rod body 701; the spike 702 has a plurality of ridges distributed circumferentially and extending axially, and a concave region is formed between two adjacent ridges so that the edges of each ridge are sharp; the lower part of the spike 702 has a plurality of downwardly protruding corners, each corner forming a barb 703.

[0073] Ordinary needle 7 may have problems such as low puncture efficiency, only able to puncture once and unable to further damage diaphragm 402 when resetting, resulting in insufficient mixing of binder and initiator;

[0074] In this embodiment, the multiple edges of the barb 702 form sharp edges that can quickly pierce the diaphragm 402. Since the diaphragm 402 is also under tension due to the compression of the sealing capsule 401, it will be further torn under tension after being pierced. The lower barb 703 will cut open the incompletely separated diaphragm 402 again when the barb 7 is reset, expanding the piercing area and allowing the adhesive and initiator in the sealing capsule 401 to mix and react more fully.

[0075] Preferably, the adhesive is epoxy resin; the initiator is diethylenetriamine; and the sealing capsule 401 is made of low-density polyethylene material.

[0076] In this embodiment, by setting up a vigorous exothermic reaction between diethylenetriamine and epoxy resin, it is ensured that the low-density polyethylene capsule is reliably softened or even melted. At the same time, the cured epoxy resin material provides bonding strength and durability far exceeding that of ordinary cement mortar, thereby forming a high-performance chemical anchor solid at the joint.

[0077] During operation, when the delayed-burst component punctures the diaphragm 402, the highly reactive diethylenetriamine molecules rapidly undergo a cross-linking and curing reaction with the epoxy groups in the epoxy resin. This ring-opening polymerization process releases a large amount of heat, causing the local temperature inside the sealing capsule 401 to rise sharply within a short period of time, exceeding the melting point of low-density polyethylene. The molten capsule material ruptures under the pressure of the external mortar, allowing the uniformly mixed epoxy resin slurry to overflow and fill the node cavity, ultimately curing to form a reinforcement with extreme adhesion and mechanical strength.

[0078] Optionally, to ensure the absolute reliability of the thermal triggering mechanism under specific conditions (such as low ambient temperature or high melting point of the capsule material), a small amount of peroxide microcapsules can be premixed into the epoxy resin as an auxiliary heat-generating agent, and fine metal salt powder can be uniformly dispersed in diethylenetriamine as a catalyst. When the peroxide microcapsules rupture during mixing, the released peroxides, upon contact with the metal salt, trigger a violent and rapid catalytic decomposition reaction. This secondary reaction can instantly release a large amount of additional heat, providing thermal supplementation for the main curing reaction, acting together on the capsule material, while its impact on the main curing reaction of the epoxy resin and the final mechanical properties can be controlled within a very small range.

[0079] Optionally, the sealing capsule 401 can be a composite material made by melt blending low-density polyethylene (LDPE) and ethylene-vinyl acetate copolymer (EVA). The introduction of EVA can effectively disrupt the regular arrangement of LDPE molecular chains, thereby reducing the overall crystallinity of the material and lowering its melting temperature. At the same time, the EVA phase can induce crazes and shear bands under stress, significantly improving the material's impact resistance and elongation at break, ultimately obtaining a capsule material with both excellent low-temperature triggering characteristics and good toughness.

[0080] Example 3

[0081] like Figure 1 and Figure 2 As shown, based on Embodiment 2, the present invention provides a technical solution: preferably, a pipe joint is fixedly installed at the end of the connecting pipe 301 away from the connecting pipe 101, and an extension pipe 801 is detachably connected to the end 3 inserted into the borehole through the pipe joint; the end of the extension pipe 801 is closed and an opening 802 is provided on the side wall near the end.

[0082] Since the length of anchor bolt segment 1 is fixed, but the actual drilling depth varies, when the hole depth is greater than the total length of the anchor bolt, a cavity will be formed between the anchor bolt end 3 and the bottom of the hole, which will cause the grouting to not completely fill the bottom of the hole, affecting the overall anchoring effect.

[0083] In this embodiment, by connecting an extension pipe 801 of selectable length to the connecting pipe 301 at the end 3, the grouting channel can be extended to the deepest part of the borehole, ensuring that the grout can be filled from the bottom of the hole regardless of the hole depth, avoiding bottom cavities, and improving grouting integrity and anchoring reliability.

[0084] Specifically, a pipe joint is installed at the end of the connecting pipe 301 away from the connecting pipe 101. An extension pipe 801 of appropriate length is selected according to the drilling depth and is detachably connected to the connecting pipe 301 through the pipe joint, so that the free end of the extension pipe 801 extends to the deepest part of the borehole. During grouting, mortar enters the extension pipe 801 through the connecting pipe 301 and starts to fill from the bottom of the borehole to ensure that there are no cavities at the bottom of the hole until the mortar fills the entire borehole.

[0085] like Figure 6 , Figure 7 and Figure 11 As shown, preferably, the input tube 203 and the output tube 202 form a 180° angle with respect to the end face of the relay tube 201.

[0086] In this embodiment, both the input pipe 203 and the output pipe 202 are installed on the transfer pipe 201. Although they are separated by the partition 204, the relative angle between the input pipe 203 and the output pipe 202 is not clear. If the angle is too small, the mortar may enter from the input pipe 203 and be discharged directly from the output pipe 202, causing the cavity to flow into the next section before it is filled, forming a cavity and affecting the grouting quality.

[0087] This invention also provides a construction method for precast anti-pull-out anchor bolts, comprising the following steps:

[0088] S1: According to the drilling design depth, the required number of anchor bolt segments 1 and connectors 2 are connected sequentially by threads to form a complete anchor bolt assembly. Ensure that the connecting pipes 101 of each segment and the transfer pipes 201 of connectors 2 are reliably connected through pipe joints, and install end caps 3 at both ends. According to the hole depth, install the extension pipe 801 of the required length on the end cap 3 on the side that needs to be inserted into the hole.

[0089] The modular assembly process enables flexible configuration of anchor bolt length, establishes a complete grouting channel through a quick-connect pipe system, and the addition of extension pipe 801 ensures that the grouting pipeline can reach the deepest part of the borehole, laying a solid foundation for subsequent full grouting of the entire borehole section.

[0090] S2: Sequentially remove the sealing cover 508 of the air plate 501 on each connecting part 2, hoist the assembled anchor bolt assembly and place it steadily into the borehole, ensuring that the end of the extension pipe 801 contacts the end of the hole, install the bearing plate at the borehole opening so that it is close to the rock surface, and then install the hemispherical washer and anchor nut in sequence. Use a torque wrench to tighten the nut according to the design preload to complete the initial fixing of the anchor bolt.

[0091] Pre-removal of the sealing cap 508 prepares for subsequent bladder expansion. The contact between the extension tube 801 and the bottom of the hole ensures the accuracy of the grouting starting point. The mechanical fixation of the borehole bearing plate and the nut provides a stable initial anchoring for the entire anchor system, ensuring the accuracy and stability of the anchor position during construction.

[0092] S3: External air slowly enters the air plate 501 and piston cylinder 502 through the air nozzle 507, driving the compression trigger component 5 to move, causing the sealing bladder 401 of each node to slowly expand radially until it is tightly fitted with the borehole wall, forming multiple independent sealing grouting chambers.

[0093] Controllable expansion of the sealing bladder 401 was achieved by using pneumatic delay. Through slow radial expansion, a series of independent sealing chambers were formed in the borehole. This segmented sealing structure effectively prevented grout short-circuiting and loss during the grouting process, creating the necessary conditions for sequential grouting.

[0094] S4: Start the grouting equipment and inject mortar into the hole through the deepest grouting pipe. During the grouting process, follow the order from deep to shallow. After the previous chamber is filled and mortar overflows from its output pipe 202, continue to grout the next higher chamber until all chambers and the hole opening are filled with mortar. Plug the end 3 used for grouting and its connecting pipe 301, and let it stand and wait for the mortar to solidify.

[0095] By employing a sequential grouting process from deep to shallow, and utilizing the principle of natural liquid level rise, each chamber is ensured to be fully filled. This grouting method effectively eliminates air and moisture in the borehole, completely eliminating the cavity defects that are easily formed in inclined upward drilling using traditional grouting methods.

[0096] S5: Once the mortar has initially solidified and reached the predetermined strength, the delayed puncture components in each node's capsule are automatically triggered, puncturing the diaphragm 402 to cause the chemical components to mix and react. The chemical slurry that overflows after heating and softening the capsule solidifies to form a high-strength reinforced node, completing the construction of the entire anchoring system.

[0097] After the mortar has initially set, the chemical reinforcement mechanism is automatically triggered, and the temporary sealing capsule 401 is transformed into a permanent chemical anchor body through thermo-chemical coupling. This forms a high-strength chemical bonding node on the basis of the original mechanical anchoring, which significantly improves the long-term durability and overall pull-out resistance of the anchor system.

[0098] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A precast pull-out anchor bolt, comprising multiple anchor bolt segments (1), a connector (2) for connecting adjacent anchor bolt segments (1), and a bearing plate disposed at the orifice; characterized in that: It also includes end caps (3) that are detachably connected to the ends of the anchor bolt segments (1) located at both ends; the anchor bolt segments (1) and the connectors (2) are detachably connected by threaded engagement, and the connection is sealed by a sealing ring, and the outer periphery of the connectors (2) is fitted with a radially expandable sealing bladder (401). The connector (2) is provided with a compression trigger assembly (5), which is used to provide axial pressure to the sealing bladder (401) and force the sealing bladder (401) to expand radially outward; The anchor segment (1) is fixedly connected to a connecting pipe (101) by a mounting bracket, and pipe joints are installed at both ends of the connecting pipe (101); the connector (2) is fixedly connected to a transfer pipe (201) by a mounting bracket, and the transfer pipe (201) is provided with an output pipe (202) and an input pipe (203) at different positions along the axial direction. A partition (204) is provided inside the transfer pipe (201) and between the input pipe (203) and the output pipe (202) to separate the transfer pipe (201); the input pipe (203) and the output pipe (202) both extend to the outside of the connector (2); The end (3) is fixedly connected to a connecting pipe (301) by a mounting bracket. The connecting pipe (301) and the transfer pipe (201) are connected to the connecting pipe (101) by pipe joints. The end of the connecting pipe (301) away from the connecting pipe (101) extends from the side of the end (3) to the outside of the end (3).

2. The pull-out resistant precast anchor bolt according to claim 1, characterized in that: The compression trigger assembly (5) includes a pressure ring (505) slidably connected to the outside of the connector (2), the pressure ring (505) being in contact with the sealing bladder (401), an air plate (501) being fixedly connected to the outside of the connector (2), and a first spring (506) being sleeved on the outside of the connector (2), the two sides of the first spring (506) being in contact with the pressure ring (505) and the air plate (501) respectively; a plurality of piston cylinders (502) are provided inside the air plate (501), the piston cylinders (502) being... 2) A first piston plate (503) is slidably connected between the inner walls of the piston cylinder (502) and the first piston plate (503) is fixedly connected to a locking rod (504) on one side. The end of the locking rod (504) away from the first piston plate (503) is fixedly connected to the pressure ring (505). The piston cylinder (502) communicates with the interior of the air plate (501). An air nozzle (507) is provided on the air plate (501). A sealing cover (508) is detachably connected to the air nozzle (507). Air can slowly pass through the air nozzle (507).

3. The pull-out resistant precast anchor bolt according to claim 2, characterized in that: The interior of the sealing bladder (401) is divided into two independent chambers by a diaphragm (402). The two chambers of the sealing bladder (401) are respectively filled with an adhesive and an initiator. The adhesive and the initiator are mixed to accelerate the solidification of the adhesive and release heat. The sealing bladder (401) is a thermoplastic material configured to melt when the adhesive and the initiator react exothermically. The interior of the sealing bladder (401) is provided with a delayed puncture component, which is used to delay triggering until the diaphragm (402) is punctured when the pressure inside the sealing bladder (401) changes.

4. A precast anti-pull-out anchor bolt according to claim 3, characterized in that: The delayed puncture assembly includes a delayed cylinder (601) fixedly connected inside a sealed bladder (401). A second piston plate (604) is slidably connected inside the delayed cylinder (601). One end of the delayed cylinder (601) is provided with a wide opening (602). A delayed hole (603) is opened on the side of the delayed cylinder (601) away from the wide opening (602). A second spring (605) is fixedly connected to both sides of the second piston plate (604). The end of the second spring (605) away from the second piston plate (604) is fixedly connected to the delayed cylinder (601). A push rod (606) is slidably connected to the side of the delayed cylinder (601) near the delayed hole (603). One end of the push rod (606) extends into the interior of the delayed cylinder (601) and is fixedly connected to the second piston plate (604). The other end is fixedly connected to a plate (607). Several needles (7) are fixedly connected to the plate (607).

5. A precast anti-pull-out anchor bolt according to claim 4, characterized in that: The needle (7) includes a rod (701) and a spike (702) disposed at one end of the rod (701); the spike (702) has a plurality of ridges distributed circumferentially and extending axially, and a concave region is formed between two adjacent ridges so that the edges of each ridge are sharp; the lower part of the spike (702) has a plurality of downwardly protruding corners, each corner forming a barb (703).

6. A precast anti-pull-out anchor bolt according to claim 5, characterized in that: The adhesive is epoxy resin; the initiator is diethylenetriamine; and the sealing capsule (401) is made of low-density polyethylene material.

7. A pull-out resistant precast anchor bolt according to claim 6, characterized in that: The end of the connecting pipe (301) away from the connecting pipe (101) is fixedly equipped with a pipe joint, and the end (3) inserted into the borehole is detachably connected to the extension pipe (801) through the pipe joint; the end of the extension pipe (801) is closed and an opening (802) is provided on the side wall near the end.

8. A precast anti-pull-out anchor bolt according to claim 7, characterized in that: The input tube (203) and the output tube (202) are at a 180° angle relative to the end face of the relay tube (201).

9. A construction method for a pull-out resistant precast anchor bolt, characterized in that: The method applicable to the pull-out precast anchor bolt of claim 8 includes the following steps: S1: According to the drilling design depth, the required number of anchor bolt segments (1) and connectors (2) are connected sequentially by threads to form a complete anchor bolt assembly. Ensure that the connecting pipe (101) of each segment and the transfer pipe (201) of the connector (2) are reliably connected by pipe joints, and install end caps (3) at both ends. According to the hole depth, install the required length of extension pipe (801) on the end cap (3) on the side that needs to be inserted into the hole. S2: Separate the sealing cover (508) of each connecting part (2) and the air plate (501) in sequence. Hoist the assembled anchor rod assembly and place it steadily into the borehole. Ensure that the end of the extension tube (801) is in contact with the end of the hole. Install the bearing plate at the borehole opening so that it is close to the rock surface. Then install the hemispherical washer and the anchor nut in sequence. Use a torque wrench to tighten the nut according to the design pre-tightening force to complete the initial fixing of the anchor rod. S3: External air slowly enters the air plate (501) and piston cylinder (502) through the air nozzle (507), driving the compression trigger assembly (5) to move, causing the sealing bladder (401) of each node to slowly expand radially until it is tightly attached to the borehole wall, forming multiple independent sealing grouting chambers. S4: Start the grouting equipment and inject mortar into the hole through the deepest grouting pipe. During the grouting process, follow the order from deep to shallow. After the previous chamber is filled and mortar overflows from its output pipe (202), continue to grout the next higher chamber until all chambers and the hole opening are filled with mortar. Plug the end (3) used for grouting and its connecting pipe (301) and let it stand for the mortar to solidify. S5: Once the mortar has initially solidified and reached the predetermined strength, the delayed puncture components in each node's capsule will be automatically triggered, puncturing the diaphragm (402) to cause the chemical components to mix and react. After the chemical slurry overflows and heats up to soften the capsule, it solidifies to form a high-strength reinforced node, thus completing the construction of the entire anchoring system.

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