Expansion type universal hollow grouting anchor rod and construction method

Abstract

The invention discloses an expansion type universal hollow grouting anchor rod and a construction method, and relates to the technical field of geotechnical engineering supporting, the expansion type universal hollow grouting anchor rod comprises an anchor rod body, a telescopic device and a trigger device; the anchor rod body comprises a hollow anchor rod body, multiple sets of full-surface threads are arranged on the outer wall of the anchor rod body, and a threaded section is arranged on the inner wall of the tail end of the anchor rod body. Micro optical fiber sensors which are uniformly distributed are embedded in the rod body; the front end of the anchor rod body is in threaded connection with an anchor rod head, and the tail of the anchor rod body is in threaded connection with a stop-grouting plug, a base plate and a fastening nut in sequence. The telescopic device comprises a second sleeve. The three-stage expansion joint and the trigger device are cooperatively designed, the sawtooth-shaped push rod, the spring and other components are driven through grouting liquid air pressure, ordered ejection of the expansion joint is achieved, the length can be freely adjusted according to the size of a rock-soil body anchoring area, and the problems that a traditional anchor rod is fixed in length and cannot adapt to different reinforcing ranges are solved; and meanwhile, inconvenience in transportation, storage and construction of the long anchor rod is avoided, and the universality of equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering support technology, specifically to a universally applicable hollow grouting anchor bolt with scalability and its construction method. Background Technology

[0002] As a support structure, anchor bolts are widely used in engineering technology for the main reinforcement of slopes, tunnels, and dams. Compared with other support methods, anchor bolt support technology has significant advantages such as simple process, convenient construction, low material consumption, low cost, and good support effect. Therefore, it is widely used in urban construction and road construction as one of the main support methods.

[0003] There are various types of grouting anchors available. Among them, hollow anchors, due to their hollow design, use the central hole as a high-pressure ventilation and water channel for drilling and a grouting channel. Compared to solid anchors, the hollow design provides better rigidity and shear strength. The anchor's outer surface features a full-length standard large-pitch thread structure. This thread structure facilitates cutting and extending the anchor, and compared to a smooth anchor, it increases the bonding area between the anchor and the grouting material, thereby improving the anchoring force.

[0004] The most commonly used type is the mechanically expanded shell prestressed anchor rod. However, there are not many structures in which the expanded shell anchor head is embedded in the rock and soil, resulting in insufficient anchoring force. Moreover, like other types of anchor rods, it has the disadvantage of not being able to freely expand and contract according to the required anchoring area of ​​the rock and soil. When the required anchoring area of ​​the rock and soil is large, the anchor rod is too long, which will bring many inconveniences to its transportation, storage and construction.

[0005] A search revealed that publication number CN112814714A discloses a prestressed full-length hollow grouting anchor rod with a tensile effect. The rod body has an axially penetrating central grouting hole inside. The rod body consists of a threaded section at the end and a main body section outside the threaded section. The threaded section has external threads. Multiple protruding ribs are uniformly fixedly connected along the length of the main body section, forming a connecting portion between adjacent protruding ribs. The outer diameter of the protruding ribs is smaller than the diameter of the borehole to be drilled. Each connecting portion has multiple axially flat holes and multiple circumferential flat holes connected to the central grouting hole. A sliding support is fitted onto the outside of the threaded section, and a nut is threadedly connected to the outside of the threaded section, closer to the end of the rod body than the support. A centering ring is fitted onto the outside of the main body section, and its outer diameter matches the diameter of the borehole to be drilled. However, this anchor rod only has contact support between the anchor rod itself and the rock mass, resulting in a small contact area and poor anchoring performance. Summary of the Invention

[0006] The purpose of this invention is to provide a universally applicable hollow grouting anchor bolt with scalability and a construction method, thereby solving the problems existing in the background art.

[0007] The objective of this invention can be achieved through the following technical solutions: A universally applicable hollow grouting anchor bolt with expandability includes an anchor bolt body, a telescopic device, and a triggering device; The anchor bolt body includes a hollow anchor bolt body, the outer wall of which is provided with multiple sets of threads covering the entire surface, and the inner wall of the tail end is provided with a threaded section; the rod body is embedded with uniformly distributed miniature fiber optic sensors; The anchor rod body has an anchor head threadedly connected to the front end, and a grout stop plug, a washer plate and a fastening nut threadedly connected to the rear end in sequence. The telescopic device includes a second sleeve, the outer wall of which is fixed to the inner wall of the anchor rod by hexagonal bolts, and a grouting hole, a groove and a telescopic rod are opened in the center of the four sides of the second sleeve; The telescopic rod includes a first telescopic section, with a limiting boss fixed inside, and a grouting hole and a track groove on the outer wall. At the same time, a small buckle protrusion is provided at the tail end to lock with the buckle groove. The second expansion joint has a fixed limiting boss and a limiting track inside, and a grouting hole three on the outer wall. At the same time, a tail wing one is provided at the tail end to match the inner diameter of the limiting boss one. The third expansion joint has a threaded section on the inner wall of the front end, and four grouting holes, two tail wings and a tail end protrusion on the outer wall. At the same time, the inner wall has three long strip protrusions and three short protrusions. The telescopic head has its tail end threadedly connected to the third telescopic section. The triggering device includes a spring preloaded at the tail of the telescopic head, a serrated push rod sleeved on the spring, a rotating core one, and a rotating core two; During grouting, the expansion joint limit is gradually unlocked by the engagement of the first and second core rotors, enabling segmented ejection.

[0008] As a further aspect of the present invention: the grouting hole is connected to the internal cavity of the anchor rod; The slot is located at one edge of the grouting hole; The limiting boss is engaged with the tail wing, and the track groove is slidably connected to the tail end protrusion. The second limiting boss is engaged with the third telescopic section, and the limiting track is slidably connected to the tail end protrusion. The front end of the spring presses against the tail of the telescopic head, and the rear end is fitted with a serrated push rod. The serrated push rod has three track grooves on its side wall, and the top is serrated. The serrated push rod passes through the central opening of both rotating core one and rotating core two.

[0009] As a further aspect of the present invention: the width of the tail end protrusion of the third telescopic section matches the width of the limiting track of the second telescopic section, and the side wall of the limiting track is provided with a blocking groove whose size is consistent with the tail end protrusion.

[0010] As a further aspect of the present invention: the width of the elongated protrusion on the inner wall of the third telescopic joint is matched with the clearance of the track groove of the sawtooth push rod.

[0011] As a further aspect of the present invention: an optical fiber sensing network is embedded inside the anchor bolt body, and the miniature optical fiber sensor is uniformly embedded inside the anchor bolt body to realize the transmission and control of wireless signals from the miniature optical fiber sensor.

[0012] As a further aspect of the present invention: the second sleeve and the first telescopic joint form a snap-locking structure through small snap-fit ​​protrusions and slots.

[0013] As a further aspect of the present invention: the anchor rod body is a cylindrical straight tube structure, the outer wall of the anchor rod body is provided with multiple sets of grouting holes that communicate with the inner diameter, the outer surface is provided with threads, and the inner wall of the tail end is provided with a threaded section; The anchor head connection section is threaded and is threaded to the threaded end of the inner wall of the tail end of the anchor rod body. The fastening nut, washer, and grout stopper are all connected to the anchor rod body by internal thread engagement with the external thread of the anchor rod body.

[0014] As a further aspect of the present invention: the limiting boss at the top of the inner cavity of the first telescopic section is aligned and in contact with the tail fin at the outer end of the second telescopic section and is connected in a limiting manner. The limiting boss at the top of the inner cavity of the second telescopic section is aligned and in contact with the tail fin at the outer end of the third telescopic section, thus achieving a hierarchical nested limiting connection.

[0015] As a further aspect of the present invention: the outer side of the sleeve two is provided with a plurality of grouting holes that communicate with the inner cavity of the anchor rod. The inner wall of the sleeve two is provided with threads and the outer side is connected to the anchor rod body by hexagonal bolts. The hexagonal bolts are threadedly connected to the threaded holes on the outer wall of the sleeve two and contact the outer wall of the anchor rod to form a limiting connection.

[0016] The anchor bolt construction method includes the following steps: a. Measure and locate the grouting soil to determine the location of the anchor bolt drilling hole; b. Assemble anchor sections according to the design length and embed fiber optic sensors; fix the sleeve to the rod body with hexagonal bolts, and lock the buckle groove with the expansion joint; install the expansion joints nested in stages, aligning the tail wing with the limiting boss; install the telescopic head and pre-tighten the spring, and complete the debugging of the triggering device. c. Start the drilling rig and drill holes at the predetermined positions. Then, switch to a high-pressure water gun and enlarge the holes at the corresponding enlargement positions according to actual needs to form different enlargement areas; clean the mud and debris inside the anchor bolt drill holes. d. Install the anchor body according to the actual anchoring length requirement, and install the grout stop plug, steel pad and nut in sequence. Connect the grouting anchor to the grouting pump truck through the grouting pipe. e. Using a grouting pump truck, grout is injected into the anchor bolt. Under air pressure, the grout pushes the triggering device of the anchor bolt expansion joint, causing each level of expansion joint to pop out in sequence. Then, the grout flows out from the grouting holes of the expansion joints and diffuses in the soil to form a grouting consolidation section. f. Activate the fiber optic sensor network to monitor stress distribution in real time and upload the data to the cloud platform.

[0017] The beneficial effects of this invention are: (1) The present invention adopts a three-stage expansion joint and triggering device in a coordinated design. The serrated push rod, spring and other components are driven by the grouting liquid air pressure to realize the orderly pop-out of the expansion joint. The length can be freely adjusted according to the size of the rock and soil anchoring area, which solves the problem of the fixed length of traditional anchor rods and the inability to adapt to different reinforcement ranges. At the same time, it avoids the inconvenience of long anchor rod transportation, storage and construction, and improves the versatility of the equipment. (2) In this invention, the anchor rod body, sleeve one, and each level of expansion joint are all provided with through grouting holes. After the expansion joint pops out, the grouting holes are fully opened, and the grouting liquid can diffuse into the soil through multiple layers of channels to form a large-scale grouting consolidation section. Compared with the traditional anchor rod method of grouting only on the surface of the rod body, this method greatly increases the contact area and bonding strength between the anchor rod and the soil, and solves the problem of insufficient anchoring force of existing anchor rods. (3) The components in this invention are connected by thread and snap-fit, which enables quick assembly and disassembly. No complicated tools are required to complete the splicing, which shortens the construction preparation time and improves the efficiency of on-site operation. It is especially suitable for engineering scenarios with tight schedules. The inner wall of the anchor rod is embedded with a micro fiber optic sensor to form a distributed sensor network, which can monitor the stress distribution of the anchor rod in real time. The data is uploaded to the cloud platform through a wireless transmission module. Compared with the traditional anchor rod that relies on manual inspection, it can detect stress abnormalities in time and give early warning, avoid engineering accidents caused by anchor failure, and improve the safety and reliability of the support structure. (4) The construction method of the present invention adopts a standardized process of measurement and positioning, assembly and debugging, drilling and cleaning, installation and grouting, and monitoring and feedback. Each step is closely connected. During the grouting process, the grouting liquid and air pressure synchronously drive the trigger device to pop out the expansion joint, realizing the integration of grouting, expansion and diffusion. With the on-demand hole expansion design during drilling, the grouting liquid can fully diffuse in the hole expansion area to form a targeted consolidation section, which solves the problems of limited grouting range and uneven reinforcement of traditional anchor bolts. It is especially suitable for support needs under complex soil conditions. (5) This invention expands the grouting range by using multi-level expansion joints and combined with the design of multiple grouting holes, which significantly increases the bonding area between the anchor rod and the soil and greatly improves the anchoring force. Compared with fixed-length hollow anchor rods, the telescopic structure can adapt to different anchoring areas, solving the transportation and construction problems of long anchor rods. Compared with traditional support technology, the combination of fiber optic sensing and cloud monitoring realizes active early warning, overcomes the lag of passive inspection, and provides an intelligent solution for geotechnical engineering support. Attached Figure Description

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the overall structure of the anchor bolt in this invention; Figure 2 This is a full sectional view of the anchor bolt in this invention; Figure 3 yes Figure 2 Enlarged view of point A in the middle; Figure 4 yes Figure 2 Enlarged view of point B in the middle; Figure 5 This is the sleeve cross-sectional structure in this invention; Figure 6 This is a planar structural diagram of the multi-stage expansion joint in this invention; Figure 7 This is a top view of the first telescopic joint in this invention; Figure 8 This is a cross-sectional view of the first expansion joint in this invention; Figure 9 This is a structural diagram of the second expansion joint in this invention; Figure 10 This is a top view of the third telescopic joint in this invention; Figure 11 This is a cross-sectional view of the third expansion joint in this invention; Figure 12 This is a structural diagram of the ejection device in this invention.

[0020] In the diagram: 1. Anchor bolt body; 2. Sleeve 1; 3. Telescopic rod; 11. Anchor bolt body; 12. Fastening nut; 13. Washer plate; 14. Grout stop plug; 15. Anchor bolt head; 16. Miniature fiber optic sensor; 21. Sleeve 2; 22. Hex bolt; 31. First telescopic joint; 32. Second telescopic joint; 33. Third telescopic joint; 34. Telescopic head; 41. Spring; 42. Serrated push rod; 43. Rotary core 1; 44. Rotating core 2; 211, Grouting hole 1; 212, Slot; 311, Limiting boss 1; 312, Grouting hole 2; 313, Track groove; 314, Small buckle protrusion; 321, Limiting boss 2; 322, Limiting track; 323, Grouting hole 3; 324, Tail wing 1; 331, Threaded section; 332, Grouting hole 4; 333, Tail wing 2; 334, Tail end protrusion; 335, Long strip protrusion; 336, Short protrusion. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1 Please see Figures 1-12 As shown, the present invention is a universally applicable hollow grouting anchor bolt with an expandable design, comprising an anchor bolt body 1, a telescopic device, and a triggering device; The anchor body 1 includes an anchor rod body 11, a fastening nut 12, a washer 13, a grout stop plug 14, an anchor head 15, and a miniature fiber optic sensor 16. The anchor rod body 11 is a cylindrical straight tube structure with multiple sets of grouting holes that communicate with the inner diameter on the outer wall. The outer surface is threaded, and the inner wall of its tail end is threaded. Miniature fiber optic sensors 16 are evenly embedded in the inner wall of the anchor bolt body 11; the connecting section of the anchor bolt head 15 is threaded. The anchor rod body 11, fastening nut 12, washer 13, grout stop plug 14, and anchor head 15 are all threaded; The outer side of the sleeve 12 is evenly provided with multiple grouting holes 211 that communicate with the inner cavity of the anchor rod body 11. The inner wall is provided with threads, and the outer side is provided with hexagonal bolts 22 that are connected to the anchor rod body 11. A groove 212 is provided around the wall of the grouting hole 211 to cooperate with the small buckle protrusion 314 on the outside of the first expansion joint 31; The telescopic device includes a second sleeve 21, a first telescopic joint 31, a second telescopic joint 32, a third telescopic joint 33, and a telescopic head 34; The first telescopic section 31 has a limiting boss 311 at the top of its inner cavity, and multiple grouting holes 312 are evenly provided on its outer wall along the circumference. Its inner wall has a track groove 313 that is adapted to the tail protrusion 334 of the third telescopic section 33, and a small buckle protrusion 314 is provided on its outer tail end, which can be locked and connected with the inner wall groove 212 of the sleeve 2. The second telescopic section 32 has a limiting boss 321 at the top of its inner cavity, and a limiting track 322 adapted to the tail protrusion 334 of the third telescopic section 33 on its inner wall. The outer wall has multiple grouting holes 323 evenly distributed along the circumference, and the outer tail end has a tail wing 324 with an outer diameter equal to the inner diameter of the limiting boss 311 of the first telescopic section. The inner wall of the third expansion joint 33 has a threaded section 331 at the front, and multiple grouting holes 332 are evenly provided on the outer wall along the circumference. The outer tail end has a tail wing 333 with an outer diameter equal to the inner diameter of the limiting boss 321 of the second expansion joint and a tail end protrusion 334. The inner tail end has three long strip protrusions 335 and three short protrusions 336 evenly provided. The telescopic head 34 is a conical drill bit with a threaded tail connection section. The threaded hole on the outer wall of sleeve 12 is coaxially fitted with the hole on the outer wall of anchor rod body 11; each level of expansion joint and expansion head 34 form a nested fit, and each level of expansion joint contacts the previous expansion joint to form a limit; The hex bolt 22 is connected to the threaded hole on the outer wall of the sleeve 2 and contacts the outer wall of the anchor rod 11 to form a limit; The triggering device includes a spring 41, a serrated push rod 42, a rotating core 43, and a rotating core 44; The front end of the spring 41 contacts the telescopic head 34, and the rear end is fitted onto the serrated push rod 42. The serrated push rod 42 has three evenly spaced track grooves on its side, and the top edge has a serrated shape. The middle sections of rotating core 43 and rotating core 44 are hollow. In this invention, preferably, the grouting hole 211 communicates with the inner cavity of the anchor rod body 11; The slot 212 is provided at the edge of the grouting hole 211; The limiting boss 311 is engaged with the tail wing 324, and the track groove 313 is slidably connected to the tail end protrusion 334. The second limiting boss 321 is engaged in the third telescopic section 33, and the limiting track 322 is slidably connected to the tail end protrusion 334. The front end of spring 41 presses against the tail of telescopic head 34, and the rear end is sleeved with sawtooth push rod 42. The serrated push rod 42 has three track grooves 313 on its side wall, and the top is serrated. The serrated push rod 42 passes through the central opening of rotating core 43 and rotating core 44.

[0023] In this invention, preferably, the width of the tail end protrusion 334 on the outer wall of the third telescopic joint 33 is the same as the width of the limiting track 322 of the second telescopic joint 32, and the limiting track 322 of the second telescopic joint 32 has a blocking groove on its side, the length and width of which are the same as the length and width of the tail end protrusion 334 on the outer wall of the third telescopic joint 33.

[0024] In this invention, preferably, the inner wall of the third telescopic joint 33 has three elongated protrusions 335, the width of which is consistent with the width of the track groove of the sawtooth push rod 42.

[0025] In this invention, preferably, when the third telescopic joint 33 retracts, the elongated protrusion 335 on the inner wall is in clearance fit with the track groove of the sawtooth push rod 42; the tail protrusion 334 on the outer wall is inserted into the blocking groove of the second telescopic joint 32.

[0026] In this invention, preferably, an optical fiber sensor network is embedded inside the anchor bolt body, and the data from the miniature optical fiber sensor 16 is connected to an external monitoring terminal via a wireless transmission module to provide real-time feedback on the stress state of the anchor bolt.

[0027] In this invention, preferably, the sleeve 2 and the first telescopic joint 31 adopt a snap-locking structure.

[0028] Working principle of telescopic device: In the contracted state: the various expansion joints are nested through a multi-layer limiting structure: the tail fin 333 of the third expansion joint 33 is attached to the limiting boss 321 of the second expansion joint 32, and the tail fin 324 of the second expansion joint 32 is attached to the limiting boss 311 of the first expansion joint 31, forming a hierarchical nesting constraint. The tail end protrusion 334 of the third telescopic joint 33 is engaged with the blocking groove on the side of the limiting track 322 of the second telescopic joint 32. At the same time, the long strip protrusion 335 on its inner wall is in clearance fit with the track groove of the sawtooth push rod 42 to further restrict axial movement. The small buckle protrusion 314 of the first expansion joint 31 locks with the slot 212 of the sleeve 2, fixing the entire expansion device to the end of the anchor rod 11. At this time, all the grouting holes 2 312, grouting holes 323 and grouting holes 4 332 are in a closed or semi-closed state. Pop-up state: When the triggering device is activated, the third telescopic section 33 moves along the limiting track 322 of the second telescopic section 32 under the action of thrust, and the tail protrusion 334 disengages from the blocking groove, releasing the axial constraint; at the same time, driven by the third telescopic section 33, the tail wing 324 of the second telescopic section 32 disengages from the limiting boss 311 of the first telescopic section 31 and moves along the track groove 313 of the first telescopic section 31; finally, the small buckle protrusion 314 of the first telescopic section 31 disengages from the slot 212 of the sleeve 2, realizing the overall extension; After ejection, the grouting holes 212, 323, and 332 of each expansion joint are connected to the inner cavity of the anchor rod body 11 and the grouting hole 211 of the sleeve 2. The grouting fluid can diffuse into the soil through these channels to form a consolidation section.

[0029] Working principle of the triggering device: Initial state: Spring 41 is in a pre-tightened state, with its front end in contact with telescopic head 34 and its rear end fitted onto serrated push rod 42; the three track grooves of serrated push rod 42 are in clearance fit with the long strip protrusion 335 on the inner wall of the third telescopic joint 33, and the serrated structure at the top end fits against the hollow inner wall of rotating core one 43 and rotating core two 44 in the middle to form initial positioning; Triggering process: During grouting, the grouting fluid is injected through the inner cavity of the anchor rod body 11, and under the action of air pressure, it pushes the telescopic head 34, thereby compressing the spring 41; the elastic force of the spring 41 is transmitted to the sawtooth push rod 42, causing it to move axially; When the serrated push rod 42 moves, its track groove cooperates with the elongated protrusion 335 of the third telescopic section 33, driving the third telescopic section 33 to move synchronously, forcing the tail protrusion 334 of the third telescopic section 33 to disengage from the blocking groove of the limiting track 322 of the second telescopic section 32, thus releasing the radial constraint. As the push rod continues to move, the interaction between the serrated tip and the rotating core 43 and rotating core 44 generates a guiding force, ensuring that the push rod moves stably along the axial direction. Finally, it sequentially drives the second expansion joint 32 and the first expansion joint 31 to break through the limit, realizing the orderly ejection of each level of expansion joint.

[0030] It should be noted that the action of the triggering device is linked with the limiting structure of the telescopic device: after the push rod drives the third telescopic section 33 to move, the second and first telescopic sections, under the action of the grouting fluid pressure and their own nesting gap, successively disengage from the limiting boss of the upper-level telescopic section, and finally complete the overall extension. At the same time, the grouting hole is fully opened, realizing the diffusion of grout into the soil. The telescopic device ensures shrinkage stability through hierarchical nesting and limiting structure, and the triggering device drives the limiting unlock through pneumatic mechanical force conversion. The two work together to realize the integrated function of shrinkage, pop-out, and grouting, adapting to different anchorage length requirements.

[0031] Example 2 The anchor bolt installation method includes the following steps: a. Measure and locate the grouting soil, and determine the location of the anchor bolt drilling holes; b. Assemble anchor sections according to the design length and embed fiber optic sensors; fix the sleeve to the rod body with hexagonal bolts 22, and lock the buckle groove with the expansion joint; install the expansion joints nested in stages, aligning the tail wing with the limiting boss; install the telescopic head 34 and pre-tighten the spring 41, and complete the debugging of the triggering device. c. Start the drilling rig and drill holes at the predetermined positions. Then, switch to a high-pressure water gun and enlarge the holes at the corresponding enlargement positions according to actual needs to form different enlargement areas; clean the mud and debris inside the anchor bolt drill holes. d. Install the anchor body 1 according to the actual anchoring length requirement, and install the grout stop plug 14, steel pad 13 and nut in sequence. Connect the grouting anchor to the grouting pump truck through the grouting pipe. e. Using a grouting pump truck, grout is injected into the anchor bolt. Under air pressure, the grout pushes the triggering device of the anchor bolt expansion joint, causing each level of expansion joint to pop out in sequence. Then, the grout flows out from the grouting holes of the expansion joints and diffuses in the soil to form a grouting consolidation section. f. Activate the fiber optic sensor network to monitor stress distribution in real time and upload the data to the cloud platform.

[0032] Specific construction steps: a. Measurement and positioning and drilling location determination: First, conduct detailed measurements of the soil area that needs grouting reinforcement to clarify the design parameters such as the layout range, spacing and depth of the anchor bolts; According to the design requirements, the drilling position of each anchor rod is accurately marked on the soil surface to ensure that the drilling position matches the stress requirements and reinforcement range of the soil, providing a precise benchmark for subsequent drilling construction.

[0033] b. Anchor bolt assembly and adjustment: According to the designed anchoring length, multiple sections of anchor rod 11 are spliced ​​together into a whole by threaded connection to ensure that the splice is sealed and axially aligned; at the same time, miniature fiber optic sensors 16 are embedded evenly at intervals in the inner wall of the anchor rod 11 and connected to the sensor circuit. Sleeve 12 is fixed to the corresponding position of anchor rod 11 with hex bolt 22, ensuring that the threaded hole on the outer wall of sleeve 12 is coaxial with the hole on the outer wall of anchor rod 11; then, the small buckle protrusion 314 of the first expansion joint 31 is aligned with the buckle groove 212 of sleeve 12 and locked to achieve quick buckle fixation. The second telescopic section 32 and the third telescopic section 33 are installed in a nested manner to ensure that the tail fin 324 of the second telescopic section 32 is aligned with the limiting boss 311 of the first telescopic section 31, and the tail fin 333 of the third telescopic section 33 is aligned with the limiting boss 321 of the second telescopic section 32, thus forming a stable nested structure. Connect the telescopic head 34 to the threaded section 331 on the inner wall of the third telescopic section 33 via the tail thread. Install the spring 41 so that its front end abuts against the telescopic head 34 and its rear end is fitted onto the serrated push rod 42. Pre-tighten the spring 41 to the designed elastic force. Check whether the track groove of the serrated push rod 42 and the long strip protrusion 335 of the third telescopic section 33 are in clearance fit to ensure that the triggering device operates smoothly. c. Drilling and cleaning: Start the drilling rig and drill holes at the positions marked in step a. The diameter of the holes should match the maximum outer diameter of the anchor rod 11 and the telescopic device, and the depth should be slightly greater than the designed anchoring length. According to the soil reinforcement requirements, in designated locations of the boreholes where enhanced anchoring force is needed, high-pressure water jets are used to enlarge the boreholes, forming enlarged areas of different diameters, creating conditions for the subsequent diffusion of grouting fluid to form a larger consolidation section. After drilling and reaming are completed, use a high-pressure water gun or compressed air to clean the mud and debris inside the hole to ensure that the inner wall of the hole is clean and unobstructed, and to avoid impurities affecting the installation of anchor bolts and the grouting effect.

[0034] d. Anchor bolt installation and grouting preparation: Anchor bolt placement: Based on the actual anchoring length, place the assembled anchor bolt into the borehole as a whole, adjust the position of the anchor bolt so that its axis coincides with the borehole axis, and ensure that the anchor bolt head 15 faces the bottom of the borehole and the tail protrudes from the borehole opening by an appropriate length; Installation of accessories: Install the grout stop plug 14, the gasket 13, and the fastening nut 12 in sequence from the borehole opening inwards: The grout stop plug 14 is threadedly engaged with the anchor rod body 11 and fits tightly against the soil surface at the borehole opening to prevent grout leakage; the gasket 13 is fitted onto the anchor rod body 11 and placed outside the grout stop plug 14; by tightening the fastening nut 12 with the threaded engagement of the anchor rod body 11, the gasket 13 presses against the grout stop plug 14 to achieve borehole sealing; Connect the grouting pipe of the grouting pump truck to the grouting interface of the anchor rod 11, check the sealing of the connection, and ensure that there is no leakage during the grouting process.

[0035] e. Grouting and expansion joint pop-out: Grouting fluid injection: Start the grouting pump truck and inject the prepared grouting fluid, such as cement grout or cement mortar, into the hollow cavity of the anchor rod body 11 through the grouting pipe; Under the pressure of the pump truck, the grouting fluid flows along the inner cavity of the anchor rod body 11 into the depth of the borehole. Triggering device action: As the grouting fluid is continuously injected, the air pressure in the inner cavity gradually increases, pushing the telescopic head 34 to compress the spring 41. The spring force drives the sawtooth push rod 42 to move axially. The push rod cooperates with the elongated protrusion 335 of the third telescopic section 33 through the track groove, driving the third telescopic section 33 to move, so that its tail end protrusion 334 disengages from the blocking groove of the limiting track 322 of the second telescopic section 32. The telescopic joints pop out in sequence: After the third telescopic joint 33 pops out, it pushes the second telescopic joint 32 to move along the track groove 313 of the first telescopic joint 31, and the tail fin 324 disengages from the limiting boss 311; then the small buckle protrusion 314 of the first telescopic joint 31 disengages from the slot 212 of the sleeve 2, realizing the orderly pop-out of the three telescopic joints, and finally achieving the designed telescopic length. Grout diffusion: After the expansion joints are ejected, the grouting holes of each level are connected to the internal cavity of the anchor rod. The grout flows into the gap between the borehole and the anchor rod through these grouting holes and diffuses and penetrates into the surrounding soil, eventually forming a grouting consolidation section to achieve soil reinforcement.

[0036] f. Monitoring startup and data upload; After grouting is completed, the network of miniature fiber optic sensors 16 embedded inside the anchor bolt body is activated. The sensors monitor the stress distribution, deformation and other state parameters of the anchor bolt in the soil in real time, with a monitoring accuracy of ±0.1MPa. The data collected by the sensors is transmitted to an external monitoring terminal via a wireless transmission module and simultaneously uploaded to a cloud platform, enabling real-time display, storage, and analysis of the data. This facilitates construction and management personnel in remotely monitoring the working status of the anchor bolts, promptly identifying abnormalities, and taking appropriate measures.

[0037] The above steps, including measurement, assembly, drilling, installation, grouting, and monitoring, enable efficient construction and precise reinforcement of prefabricated telescopic hollow grouting anchor bolts. Furthermore, the adaptive pop-out of the expansion joints and real-time monitoring ensure the reliability of the reinforcement effect.

[0038] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A universally applicable hollow grouting anchor bolt with expandable design, characterized in that, Includes the anchor bolt body (1), the telescopic device, and the triggering device; The anchor body (1) includes a hollow anchor rod body (11), the outer wall of the anchor rod body (11) is provided with multiple sets of threads covering the entire surface, and the inner wall of the tail end is provided with a threaded section (331); the rod body is embedded with uniformly distributed miniature fiber optic sensors (16). The anchor rod body (11) is threaded to the front end with an anchor head (15), and the tail end is threaded to a grout stop plug (14), a pad (13) and a fastening nut (12). The telescopic device includes a sleeve two (21), the outer wall of the sleeve two (21) is fixed to the inner wall of the anchor rod body (11) by a hexagonal bolt (22), and a grouting hole one (211), a slot (212) and a telescopic rod (3) are opened in the middle of the sleeve two (21). The telescopic rod (3) includes a first telescopic section (31), with a limiting boss (311) fixed inside, and a grouting hole (312) and a track groove (313) on the outer wall. At the same time, a small buckle protrusion (314) and a buckle groove (212) are provided at the tail end for locking. The second expansion joint (32) has a fixed limiting boss (321) and a limiting track (322) inside, and a grouting hole (323) on the outer wall. At the same time, a tail wing (324) is provided at the tail end to match the inner diameter of the limiting boss (311). The third expansion joint (33) has a threaded section (331) on the inner wall of the front end, and four grouting holes (332), two tail wings (333) and a tail end protrusion (334) on the outer wall. At the same time, the inner wall has three long strip protrusions (335) and three short protrusions (336). The telescopic head (34) is threaded to the tail end of the third telescopic joint (33); The triggering device includes a spring (41) preloaded at the tail of the telescopic head (34), a serrated push rod (42) sleeved on the spring (41), a rotating core one (43) and a rotating core two (44). During grouting, the expansion joint limit is gradually unlocked by the engagement of the first rotating core (43) and the second rotating core (44), so as to achieve segmented pop-out.

2. The universally applicable hollow grouting anchor bolt with extended functionality according to claim 1, characterized in that, The grouting hole (211) is connected to the inner cavity of the anchor rod body (11); The slot (212) is opened at the edge of the grouting hole (211); The limiting boss (311) is engaged with the tail fin (324), and the track groove (313) is slidably connected to the tail end protrusion (334); The second limiting boss (321) is engaged in the third telescopic section (33), and the limiting track (322) is slidably connected to the tail end protrusion (334); The front end of the spring (41) presses against the tail of the telescopic head (34), and the rear end is sleeved with a sawtooth push rod (42). The sawtooth push rod (42) has three track grooves (313) on its side wall and the top is sawtooth-shaped; The sawtooth push rod (42) passes through the central opening of the rotating core one (43) and the rotating core two (44).

3. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The width of the tail end protrusion (334) of the third telescopic section (33) matches the width of the limiting track (322) of the second telescopic section (32), and the side wall of the limiting track (322) is provided with a blocking groove, the size of which is consistent with the tail end protrusion (334).

4. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The width of the elongated protrusion (335) on the inner wall of the third telescopic joint (33) is matched with the clearance of the track groove (313) of the sawtooth push rod (42).

5. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The anchor body (1) is embedded with an optical fiber sensing network, and the miniature optical fiber sensor (16) is uniformly embedded inside the anchor body (11) to realize the transmission and control of the wireless signal of the miniature optical fiber sensor (16).

6. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The second sleeve (21) and the first telescopic section (31) form a snap-lock structure through a small snap-lock protrusion (314) and a slot (212).

7. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The anchor rod body (11) is a cylindrical straight tube structure. The outer wall of the anchor rod body (11) is provided with multiple sets of grouting holes that communicate with the inner diameter. The outer surface is provided with threads, and the inner wall of the tail end is provided with a threaded section (331). The anchor head (15) connection section is threaded and is threaded to the inner wall of the tail end of the anchor rod body (11); The fastening nut (12), washer (13), and grout stopper (14) are all connected to the outer surface of the anchor rod body (11) by internal thread engagement.

8. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The limiting boss (311) at the top of the inner cavity of the first telescopic section (31) is aligned and in contact with the tail fin (324) at the outer end of the second telescopic section (32) and is limited and connected. The limiting boss 2 (321) at the top of the inner cavity of the second telescopic section (32) is aligned and contacted with the tail fin 2 (333) at the outer tail end of the third telescopic section (33) and is limited to achieve a hierarchical nested limiting connection.

9. A universally applicable hollow grouting anchor bolt with expandable design according to claim 1, characterized in that, The outer side of the sleeve (21) is provided with a plurality of grouting holes (211) that communicate with the inner cavity of the anchor rod body (11) along the axial direction. The inner wall of the sleeve (21) is provided with threads and the outer side is connected to the anchor rod body (11) by a hexagonal bolt (22). The hexagonal bolt (22) is threadedly connected to the threaded hole on the outer wall of the sleeve (21) and contacts the outer wall of the anchor rod body (11) to form a limiting connection.

10. An anchor bolt construction method, characterized in that, A universally applicable hollow grouting anchor bolt with extended functionality, according to any one of claims 1-9, comprises the following steps: a. Measure and locate the grouting soil, and determine the position of the anchor bolt drilling hole; b. Assemble anchor sections according to the design length and embed fiber optic sensors; fix the sleeve to the rod body with hexagonal bolts (22), and lock the buckle groove with the expansion joint; install expansion joints in nested layers, align the tail wing with the limiting boss; install the telescopic head (34) and pre-tighten the spring (41), and complete the debugging of the trigger device; c. Start the drilling rig and drill holes at the predetermined positions. Then, switch to a high-pressure water gun and enlarge the holes at the corresponding enlargement positions according to actual needs to form different enlargement areas; clean the mud and debris inside the anchor bolt drill holes. d. Install the anchor rods according to the actual anchoring length requirements, and install the grout stop plug (14), steel pad (13) and nut in sequence. Connect the grouting anchor rods to the grouting pump truck through the grouting pipe. e. Using a grouting pump truck, grout is injected into the anchor bolt. Under air pressure, the grout pushes the triggering device of the anchor bolt expansion joint, causing each level of expansion joint to pop out in sequence. Then, the grout flows out from the grouting holes of the expansion joints and diffuses in the soil to form a grouting consolidation section. f. Activate the fiber optic sensor network to monitor stress distribution in real time and upload the data to the cloud platform.

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