Adaptive high-rigidity npr foldable impact-resistant anchor rod and construction method thereof

Abstract

The application discloses a self-adaptive high-rigidity NPR fold paper type impact-proof anchor rod and a construction method thereof, and relates to the technical field of geotechnical engineering and mine roadway supporting. The NPR fold paper outer pipe has the physical characteristic that the more the anchor rod is pulled out, the tighter the outer pipe is clamped in the deformation process of the surrounding rock, the problem that the traditional anchor rod outer pipe does not have the transverse deformation compensation capability is effectively solved, and the pull-out resistance of the anchoring body under the condition of large deformation of the surrounding rock is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering and mine tunnel support technology, and specifically relates to an adaptive high-stiffness NPR origami-type impact-resistant anchor and its construction method. Background Technology

[0002] In deep, high-stress mining, deep-buried tunnel engineering, and various underground space rock reinforcement projects, the ground pressure becomes increasingly intense with increasing mining or tunneling depth, easily inducing severe dynamic disasters such as rockbursts and rock bursts. Traditional anchor bolts are mostly rigid or simply extended structures. When encountering a sudden, intense rockburst shock wave, due to the lack of a dynamic energy absorption and buffering mechanism, the high-pressure impact kinetic energy often acts directly on the main locking nut at the tail, easily causing instantaneous shearing and peeling failure of the end threads (i.e., stripping or breakage). Simultaneously, the outer tube of traditional anchor bolts lacks good lateral deformation compensation capacity and cannot adapt to the large lateral expansion deformation of the surrounding rock, ultimately causing the entire support system to instantly lose its load-bearing capacity.

[0003] In recent years, energy-absorbing anchors with negative Poisson's ratio (NPR) have gradually become a research hotspot in geotechnical engineering. However, most existing NPR anchors rely on complex internal sliding sleeves or electronic sensors for monitoring. When faced with complex alternating high-stress environments, their internal mechanical locking mechanisms are prone to dynamic fatigue failure. Furthermore, in actual engineering drilling, due to the rough borehole walls and varying borehole diameters, traditional solid, straight circular grout-stopping rings are difficult to perfectly seal the borehole opening. During high-pressure grouting, grout leakage and runoff are prone to occur, severely affecting grout saturation and the overall stiffness of the anchor body.

[0004] To address the problems in related technologies, this invention provides an adaptive high-stiffness NPR origami-style impact-resistant anchor bolt and its construction method. Summary of the Invention

[0005] To address the problems in related technologies, this invention proposes an adaptive high-stiffness NPR origami-style impact-resistant anchor and its construction method, thereby overcoming the aforementioned technical problems existing in the existing related technologies.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: An adaptive high-stiffness NPR origami-style impact-resistant anchor bolt includes: The NPR origami outer tube is integrally molded and consists of a smooth section, an origami unit section, and a conical section from top to bottom. The outer surface of the smooth section is threaded. The bamboo-shaped multi-stage locking mandrel is coaxially inserted into the internal cavity of the NPR origami outer tube. The outer periphery of the bamboo-shaped multi-stage locking mandrel is integrally formed with several sets of bamboo-shaped bosses, and the upper part of the bamboo-shaped multi-stage locking mandrel is threaded. A conical stopper is fitted onto the outer periphery of the connection between the folding unit segment and the conical segment. An arched pad, a spherical washer, a cascaded disc-shaped shock-absorbing washer, and a main locking nut are sequentially fitted onto the outer periphery of the smooth section from bottom to top. The main locking nut is threadedly connected to the external thread of the smooth section. The secondary locking nut is threadedly connected to the upper part of the bamboo-shaped multi-stage locking mandrel, and the lower surface of the secondary locking nut is in contact with the upper surface of the NPR origami outer tube.

[0007] Preferably, the NPR origami outer tube has a hollow structure.

[0008] Preferably, the outer tube of the NPR origami tube has a compensating exhaust groove on its wall. One end of the compensating exhaust groove is located in the conical region, and the other end passes through the smooth section and the origami unit section. The compensating exhaust groove has a streamlined drag-reducing edge.

[0009] Preferably, the edge of the compensating exhaust groove follows the distribution of the folding valley line of the folding unit segment.

[0010] Preferably, the outer surface of the origami unit segment is covered with a three-dimensional pleated structure of a three-dimensional concave-convex geometric grid, and its tube body is made of multiple layers of origami units of constant height stacked coaxially, with the circumference and axial phases of positive and negative amplitudes intersecting.

[0011] Preferably, the conical section is located at the end of the origami unit section away from the smooth section, and the whole is a smooth and inwardly tapered truncated cone-shaped tube structure. The end of the conical section is a solid-headed forward high-pressure jet nozzle; radial fluid discharge holes are provided on the outer surface of the NPR origami outer tube.

[0012] Preferably, the cascaded disc damping washer is composed of multiple individual disc washers, which are arranged and stacked in order of stiffness from hard to soft to form a stiffness gradient transition layer from hard to soft.

[0013] Preferably, the outer diameter of the main locking nut is larger than the center hole diameter of the spherical washer, the arched washer, and the cascaded disc damping washer. The end face of the main locking nut can press the cascaded disc damping washer towards the surrounding rock and form a rigid axial limiting block on the spherical washer.

[0014] Preferably, when the bamboo-shaped multi-stage locking mandrel is displaced axially upward relative to the NPR origami outer tube, the bamboo-shaped protrusions squeeze the solidified slurry between the bamboo-shaped multi-stage locking mandrel and the inner wall of the NPR origami outer tube, while squeezing the concave part of the origami unit segment to cause the NPR origami outer tube to expand radially.

[0015] This invention also discloses a construction method for an adaptive high-stiffness NPR origami-style impact-resistant anchor bolt, comprising: S1. Push the NPR origami outer tube, which is pre-threaded with a bamboo-shaped multi-level locking mandrel and fitted with a conical stop plug, into the drill hole until the conical stop plug seals the drill hole opening area. S2. Inject the slurry into the NPR origami outer tube. The slurry is discharged through the compensating venting groove and the radial fluid slurry discharge hole, filling the annular gap between the outer wall of the NPR origami outer tube and the drilled wall. S3. After the slurry has solidified, the arched pad, spherical washer and cascaded disc-shaped shock-absorbing washer are sequentially put into the outer circumference of the smooth section. The main locking nut is screwed onto the external thread of the smooth section. The bamboo-shaped multi-stage locking mandrel is tensioned so that the bamboo-shaped protrusions squeeze the folding unit segment to produce an expansion and interlocking effect. Then the main locking nut is tightened to complete the first stage of locking. S4. Screw the secondary locking nut into the outermost end of the bamboo-shaped multi-stage locking mandrel, so that the lower end face of the secondary locking nut is pressed tightly against the top opening of the smooth section of the NPR origami outer tube, thus completing the second stage of locking.

[0016] The present invention has the following beneficial effects: This invention utilizes the folded unit segment structure of the NPR folded outer tube, taking advantage of its negative Poisson's ratio effect, to generate radial expansion when the anchor is under axial tension. This gives the outer tube the physical characteristic of "the more it is pulled out, the tighter it becomes" during the deformation of the surrounding rock, effectively solving the problem that traditional anchor outer tubes do not have the ability to compensate for lateral deformation, and significantly improving the pullout resistance of the anchor body under large deformation conditions of the surrounding rock.

[0017] This invention transforms traditional linear sliding friction into multi-stage step-like compression and interlocking by integrally forming multiple axial locking bosses on the outer wall of a bamboo-shaped multi-stage locking mandrel. When the mandrel is pulled outward, it forces the concave part of the folding unit segment to be squeezed step by step, thus forming a deep multi-stage micro-misalignment interlocking locking force. This effectively avoids the overall instantaneous pull-out failure of traditional straight rods under rockburst impact.

[0018] This invention places cascaded disc-shaped shock-absorbing washers between a spherical washer and the main locking nut, with each unit arranged and stacked in descending order of stiffness to form a stiffness gradient conversion layer. When the shock wave is transmitted to the tail locking mechanism, dynamic stiffness gradient conversion and elastic compression deformation occur preferentially, effectively absorbing and delaying the impact energy, protecting the end threads from instantaneous shear damage, and solving the problem of slippage or breakage failure of traditional anchor bolt end threads.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a three-dimensional front view of the overall assembly state of the adaptive high-rigidity NPR origami-style impact-resistant anchor bolt of the present invention; Figure 2 This is a patent specification three-dimensional exploded view of the various components of this invention unfolded along the central axis; Figure 3 This is a partial structural schematic diagram of the NPR origami outer tube and the longitudinal exhaust groove of the present invention; Figure 4 This is a schematic diagram of the single-unit side structure of the bamboo-shaped multi-level locking mandrel of the present invention; Figure 5 This is a cross-sectional view of the adaptive conical slurry stop plug of the present invention; Figure 6 This is an isometric structural diagram of the cascaded disc-shaped shock-absorbing washer of the present invention.

[0022] The attached diagram lists the components represented by each number as follows: 1. NPR origami outer tube; 101. Compensating venting groove; 102. Radial fluid discharge hole; 2. Arched pad; 3. Spherical washer; 4. Cascaded disc-shaped shock-absorbing washer; 5. Conical stop plug; 6. Bamboo-shaped multi-stage locking mandrel; 7. Main locking nut; 8. Secondary locking nut. Detailed Implementation

[0023] The technical solutions of the embodiments of the invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the invention, and not all embodiments. Based on the embodiments of the invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the invention.

[0024] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "top", "middle", "inner", etc., which indicate orientation or positional relationship, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention. Example 1

[0025] Please see Figures 1-6 As shown, the present invention is an adaptive high-stiffness NPR origami-type impact-resistant anchor bolt, comprising: NPR origami outer tube 1, used for deep drilling, is made of steel and is integrally formed. NPR origami outer tube 1 has a hollow structure, which consists of a smooth section, an origami unit section and a conical section from top to bottom. The outer surface of the smooth section is threaded. The conical section of the NPR origami outer tube 1 is located at the end of the origami unit section away from the smooth section. The whole tube has a smooth, inwardly tapering truncated cone shape. The end of the conical section is a solid head with a forward high-pressure jet nozzle.

[0026] The conical grout stopper 5 is fitted around the outer periphery of the connection between the folding unit segment and the conical segment to prevent grout from overflowing between the outer wall of the NPR folding outer tube 1 and the borehole wall. At the same time, the conical grout stopper 5 is specially processed into a conical inclined surface structure with a specific guide slope. It uses the reverse grout pressure during grouting to squeeze and crack outward, achieving an adaptive sealing effect where the greater the grout pressure, the tighter the seal.

[0027] The bamboo-shaped multi-stage locking mandrel 6 is coaxially inserted into the internal cavity of the NPR origami outer tube 1, with an annular gap between them for the flow of slurry. The outer periphery of the bamboo-shaped multi-stage locking mandrel 6 has several sets of bamboo-shaped protrusions integrally formed at equal intervals from top to bottom, and the upper part is threaded. The bamboo-shaped multi-stage locking mandrel 6 is inserted into the internal cavity of the NPR origami outer tube 1. When the bamboo-shaped multi-stage locking mandrel 6 is displaced axially upward (outward from the hole) relative to the NPR origami outer tube 1, the axial locking boss step 601 squeezes the solidified slurry between the bamboo-shaped multi-stage locking mandrel 6 and the inner wall of the outer tube 1, and at the same time squeezes the concave part of the origami unit segment of the outer tube 1, causing the outer tube to expand radially. Together, these two factors form a resistance that prevents the bamboo-shaped multi-stage locking mandrel from continuing to move upward, thereby preventing the bamboo-shaped multi-stage locking mandrel from being pulled out upward under impact load. The arched pad 2 is coaxially arranged with the NPR origami outer tube 1; The spherical washer 3 is coaxially arranged with the NPR origami outer tube 1 and is sleeved on the upper outer surface of the NPR origami outer tube 1, and is located on the arched pad 2. The main locking nut 7 is coaxially set with the NPR origami outer tube 1 and is threadedly connected to the outer surface thread of the smooth section. The outer diameter of the main locking nut 7 is larger than the center hole diameter of the spherical washer 3, the arched pad 2 and the cascaded disc damping washer 4, so that the front end face of the main locking nut 7 can press the cascaded disc damping washer 4 towards the surrounding rock and form a rigid axial limiting hard block on the spherical washer 3.

[0028] The cascaded disc-shaped shock-absorbing washer 4 is coaxially arranged with the NPR origami outer tube 1 and sleeved on the outer surface of the NPR origami outer tube 1, located between the spherical washer 3 and the main locking nut 7. The upper and lower surfaces of the cascaded disc-shaped shock-absorbing washer 4 are respectively attached to the lower surface of the main locking nut 7 and the upper surface of the spherical washer 3 to delay and absorb the shock wave, and further prevent stress concentration from destroying the main locking nut 7.

[0029] The cascaded disc damping washer 4 is composed of multiple individual disc washers, which are arranged and stacked in order of stiffness from hard to soft to form a stiffness gradient conversion layer from hard to soft.

[0030] The secondary locking nut 8 is coaxially arranged with the bamboo-shaped multi-stage locking mandrel 6 and is threadedly connected to the upper thread of the bamboo-shaped multi-stage locking mandrel 6. The lower surface of the secondary locking nut 8 is attached to the upper surface of the NPR origami outer tube 1.

[0031] When the outer tube 1 moves axially upward (outward from the hole) relative to the mandrel 6, the top end face of the outer tube 1 is rigidly blocked by the lower end face of the secondary locking nut 8, preventing it from continuing to move upward. This constitutes a rigid end-limiting structure when the outer tube moves upward. The main locking nut 7 and the secondary locking nut 8 are located behind the tail support assembly and at the top of the mandrel, respectively. They are arranged opposite each other to form a locking fit, which together prevents the outer tube from axially separating from the mandrel under impact load.

[0032] Furthermore, on the wall of the NPR origami outer tube 1, a compensating exhaust groove 101 is provided. One end of the compensating exhaust groove 101 is located in the conical region, and the other end passes through the smooth section and the origami unit section. The compensating exhaust groove 101 has a streamlined drag-reducing edge.

[0033] Furthermore, the smooth section presents itself as a cylindrical tubular structure with a flat surface and threads; the outer surface of the origami unit section is covered with a three-dimensional pleated structure of a three-dimensional concave-convex geometric grid. Specifically, its tube body is composed of multiple layers of origami units of constant height stacked coaxially, and the circumferential and axial phases of positive and negative amplitudes are interlaced, giving the tube a unique negative Poisson's ratio effect. The conical section is integrated with the origami unit section, presenting itself as a smooth, inwardly tapering frustum-shaped irregular tube structure.

[0034] Furthermore, the edge of the compensating exhaust groove 101 conforms to the folding valley line distribution of the folding unit segment to eliminate sharp protrusions and avoid stress concentration tearing during impact shearing.

[0035] Furthermore, a radial fluid discharge hole 102 is provided on the outer surface of the NPR origami outer tube 1. Example 2

[0036] An adaptive high-stiffness NPR origami-style impact-resistant anchor bolt construction method includes the following steps: S1. Drilling and anchor bolt assembly insertion; According to the design requirements, drilling operations are carried out on the tunneling face according to the design parameters, keeping the borehole diameter slightly larger than the maximum outer diameter of the anchor bolt. The NPR origami outer tube 1, which has a bamboo-shaped multi-stage locking mandrel 6 pre-coaxially inserted inside and an adaptive conical grout stop plug 5 fitted at the external interface, is smoothly pushed into the borehole along the borehole axis until the adaptive conical grout stop plug 5 is deeply wedged in and seals the borehole opening area. At this time, the smooth section of the NPR origami outer tube 1 and the tail end of the bamboo-shaped multi-stage locking mandrel 6 are completely exposed on the outer side of the surrounding rock surface. The pad and nut are not installed yet, leaving a fully open grouting operation space.

[0037] S2, Adaptive convection high-pressure grouting; Connect the grouting gun head to the exposed smooth section of the hollow outer tube 1 and start the grouting pump. The grout flows forward along the gap between the inner wall of the outer tube and the bamboo-shaped multi-stage locking mandrel. During this fluid propulsion process, the adaptive conical grout stop plug 5, under the continuous pressure of the internal reverse high-pressure grout, opens in a reverse umbrella shape, tightly locking the rough hole wall and preventing grout leakage. The grout is then ejected in multiple stages through the full-length flexible compensation venting groove 101 and the radial fluid grout discharge holes 102 of the outer tube, filling the annular gap between the outer wall of the NPR origami outer tube 1 and the borehole wall from bottom to top, expelling air from the hole and filling the entire surrounding rock borehole, forming a high-strength grout-anchor solid combination.

[0038] S3, Tail stiffness gradient fastening installation and first-stage locking; After the grout reaches the designed strength and is fully solidified, the arched pad 2, the spherical washer 3 and the cascaded disc-shaped shock-absorbing washer 4 are sequentially fitted onto the outer periphery of the exposed smooth section and pushed inward to the rock wall, so that the base of the arched pad 2 is tightly attached to the outer rock surface.

[0039] Then screw the main locking nut 7 onto the external thread of the smooth section.

[0040] A special hollow tensioning jack is used at the outermost end, with its front end pressed against the main locking nut 7 and clamping the tail of the bamboo-shaped multi-stage locking mandrel 6 exposed at the outermost end; the jack is started to pull the bamboo-shaped multi-stage locking mandrel 6 upward, causing the bamboo-shaped multi-stage locking mandrel 6 to slide slightly outward axially inside the tube, and the axial locking boss step 601 on its outer periphery forcibly squeezes the concave part of the outer tube folding unit segment to generate an expansion and interlocking effect, thus establishing a high-rigidity initial active prestress in the system; While the jack maintains the upward load, use a torque wrench to turn the main locking nut 7 downward, so that the front end of the main locking nut 7 presses against the cascaded disc-shaped shock-absorbing washer 4, putting it in a specific pre-contraction standby state, and pressing the arched pad 2 firmly against the surrounding rock surface through the spherical washer 3, completing the first stage of active prestress locking, and then removing the jack.

[0041] S4, End-of-line anti-disengagement lock-up and dynamic anti-rockburst defense; After removing the jack, screw the secondary locking nut 8 into the outermost end as a secondary anti-loosening block. Tighten the secondary locking nut 8 downwards so that its lower end face is firmly pressed against the top opening of the smooth section of the NPR folded outer tube 1, completing the full life cycle assembly of the entire anchor bolt system.

[0042] During long-term service, if the surrounding rock experiences severe stress release and impact, the cascaded disc-shaped shock-absorbing washers 4 will preferentially undergo dynamic stiffness gradient conversion and elastic compression deformation when the shock wave is transmitted to the tail locking mechanism. This effectively absorbs and delays the impact energy, protecting the end threads from instantaneous shear damage. Simultaneously, if the surrounding rock undergoes large deformation of the outer tube, the internal bamboo-shaped multi-stage locking mandrel 6 will generate relative displacement with the outer tube. The axial locking boss step 601 will forcefully compress the folding unit step by step, causing the outer tube to generate a negative Poisson's ratio radial expansion, firmly locking the hardened mortar wall. During this process, the main locking nut 7, which is locked on the surface of the pad, provides resistance to the bottom base, and the secondary locking nut 8 at the top locks the end face of the pipe to form a rigid limit. The two sets of nuts lock in opposite directions, ensuring that the anchor rod as a whole will never physically come off when subjected to strong impact loads, achieving adaptive impact-resistant support throughout its entire life cycle.

[0043] Specifically, the mutual locking mechanism manifests as follows: when the mandrel 6 moves upward relative to the outer tube 1, the axial locking boss step 601 on the mandrel compresses the solidified slurry between the inner wall of the outer tube and the mandrel, as well as the concave part of the outer tube's folded surface, causing the outer tube to expand radially to clamp the external mortar, forming resistance that prevents the mandrel from moving upward further; when the outer tube 1 moves upward relative to the mandrel 6, the lower end face of the secondary locking nut 8 rigidly blocks the top opening of the outer tube, preventing the outer tube from moving upward. In both cases, the main locking nut 7 provides resistance to the bottom base, and the secondary locking nut 8 provides rigid limitation at the top, both working together to ensure the mutual locking effect.

[0044] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] The preferred embodiments of the invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An adaptive high-stiffness NPR origami-style impact-resistant anchor bolt, characterized in that, include: The NPR origami outer tube is integrally molded and consists of a smooth section, an origami unit section, and a conical section from top to bottom. The outer surface of the smooth section is threaded. The bamboo-shaped multi-stage locking mandrel is coaxially inserted into the internal cavity of the NPR origami outer tube. The outer periphery of the bamboo-shaped multi-stage locking mandrel is integrally formed with several sets of bamboo-shaped bosses, and the upper part of the bamboo-shaped multi-stage locking mandrel is threaded. A conical stopper is fitted onto the outer periphery of the connection between the folding unit segment and the conical segment. An arched pad, a spherical washer, a cascaded disc-shaped shock-absorbing washer, and a main locking nut are sequentially fitted onto the outer periphery of the smooth section from bottom to top. The main locking nut is threadedly connected to the external thread of the smooth section. The secondary locking nut is threadedly connected to the upper part of the bamboo-shaped multi-stage locking mandrel, and the lower surface of the secondary locking nut is in contact with the upper surface of the NPR origami outer tube.

2. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, The NPR origami tube has a hollow structure.

3. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, The outer tube of the NPR origami tube has a compensating exhaust groove on its wall. One end of the compensating exhaust groove is located in the conical area, and the other end passes through the smooth section and the origami unit section. The compensating exhaust groove has a streamlined drag-reducing edge.

4. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 3, characterized in that, The edge of the exhaust groove follows the distribution of the origami valley line of the origami unit segment.

5. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 4, characterized in that, The outer surface of the origami unit segment is covered with a three-dimensional pleated structure of concave and convex geometric grids. Its tube body is made up of multiple layers of origami units of constant height stacked coaxially, with the circumference and axial phases of positive and negative amplitudes intersecting.

6. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, The conical section is located at the end of the origami unit section away from the smooth section. It has a smooth, inwardly tapering truncated cone-shaped tube structure. The end of the conical section is a solid-headed forward high-pressure jet nozzle. Radial fluid discharge holes are provided on the outer surface of the NPR origami outer tube.

7. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, The cascaded disc damping washer is composed of multiple individual disc washers, which are arranged and stacked in order of stiffness from hard to soft, forming a stiffness gradient transition layer from hard to soft.

8. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, The outer diameter of the main locking nut is larger than the center hole diameter of the spherical washer, the arched washer and the cascaded disc damping washer. The end face of the main locking nut can press the cascaded disc damping washer towards the surrounding rock and form a rigid axial limiting hard block on the spherical washer.

9. The adaptive high-stiffness NPR origami-type impact-resistant anchor bolt according to claim 1, characterized in that, When the bamboo-shaped multi-stage locking mandrel is displaced axially upward relative to the NPR origami outer tube, the bamboo-shaped bosses squeeze the solidified slurry between the bamboo-shaped multi-stage locking mandrel and the inner wall of the NPR origami outer tube, while squeezing the concave part of the origami unit segment to cause the NPR origami outer tube to expand radially.

10. A construction method for an adaptive high-stiffness NPR origami-style impact-resistant anchor bolt, characterized in that, include: S1. Push the NPR origami outer tube, which is pre-threaded with a bamboo-shaped multi-level locking mandrel and fitted with a conical stop plug, into the drill hole until the conical stop plug seals the drill hole opening area. S2. Inject the slurry into the NPR origami outer tube. The slurry is discharged through the compensating venting groove and the radial fluid slurry discharge hole, filling the annular gap between the outer wall of the NPR origami outer tube and the drilled wall. S3. After the slurry has solidified, the arched pad, spherical washer and cascaded disc-shaped shock-absorbing washer are sequentially put into the outer circumference of the smooth section. The main locking nut is screwed onto the external thread of the smooth section. The bamboo-shaped multi-stage locking mandrel is tensioned so that the bamboo-shaped protrusions squeeze the folding unit segment to produce an expansion and interlocking effect. Then the main locking nut is tightened to complete the first stage of locking. S4. Screw the secondary locking nut into the outermost end of the bamboo-shaped multi-stage locking mandrel, so that the lower end face of the secondary locking nut is pressed tightly against the top opening of the smooth section of the NPR origami outer tube, thus completing the second stage of locking.

Images