Self-drilling and self-anchoring combined type pre-stressed anchor rod and construction type selection and use method thereof

Abstract

The invention provides a self-drilling and self-anchoring combined type pre-stressed anchor rod and a construction type selection using method thereof, and mainly relates to the technical field of fracture zone area construction. The self-drilling and self-anchoring combined type pre-stressed anchor rod mainly comprises a threaded rod body, a drilling structure, a locking disc and a locking piece, the drilling structure is fixedly connected to one end of the threaded rod body, the locking disc is embedded in the end, away from the drilling structure, of the threaded rod body, and the locking piece is in threaded connection with the end, away from the drilling structure, of the threaded rod body; in the anchoring construction process, the drilling structure can be driven by the threaded rod body to directly open and drill in the working wall face, in this way, the situation that under the soil condition similar to a broken zone, a drill hole collapses, and an anchor rod cannot stretch into the drill hole can be avoided, under the arrangement of a fluid channel and a fluid outlet, an anchoring agent can be directly injected, and the anchoring effect is improved. And the anchoring agent is diffused from the position of the drilling structure, and the anchoring agent can be rotated and stirred through the threaded rod body after being injected, so that anchoring is accelerated, and anchoring construction is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of construction in a broken zone area, and in particular to a self-drilling and self-anchoring combined prestressed anchor rod and a method for its construction, selection and use. Background Art

[0002] With the continuous development of underground space and the rapid growth of underground engineering in my country, construction challenges are constantly being uncovered, and adverse geological phenomena are becoming more frequent. One of the most common adverse geological phenomena encountered during underground construction is the fractured zone, a key hazard stratum for underground projects such as rail transit tunnel excavation and coal mine tunneling. The fractured zone is severely affected by tectonic and weathering factors, squeezing and twisting the rock mass, resulting in core fragmentation, crack development, and abundant groundwater with high permeability. Consequently, the surrounding rock is unstable and weak in strength, making it prone to severe problems such as large deformation and landslides, impacting the safety and efficiency of underground construction.

[0003] In the existing technology, there are many types of anchor rods with complex structural forms, mainly to cope with diverse environmental structures. The construction methods also vary with the type of anchor rod, which undoubtedly increases the design and manufacturing costs and construction requirements of the anchor rods, and invisibly reduces construction efficiency. On this basis, the existing anchor rods are unable to cope with the fractured zone strata with uneven soil morphology. The design of anchor rods and construction methods for a specific fractured zone strata cannot be directly replicated, which will greatly increase the application cost of the anchor rods. Therefore, it is urgent to propose an anchor rod and construction method for fractured zone strata that reduces design redundancy, has a universal construction method, has good anchoring effect, and can cope with different situations.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to ordinary technicians in this field. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the above-mentioned prior art and provide a new self-drilling and self-anchoring combined prestressed anchor rod and its construction selection and use method, so as to achieve a simple and universal structure of the anchor rod, and its construction method can be applied to most soil conditions, thereby reducing the design and manufacturing costs of the anchoring operation and improving construction efficiency.

[0006] According to one aspect of the present application, a self-drilling and self-anchoring combined prestressed anchor rod is provided, which mainly includes: a threaded rod body, a drilling structure, a locking disk and a locking piece, the threaded rod body includes a fluid channel, and the fluid channel is arranged along the axis of the threaded rod body; the drilling structure is provided with a fluid outlet, the drilling structure is fixedly connected to one end of the threaded rod body, and the fluid outlet is connected to the fluid channel; the locking disk is nested in the end of the threaded rod body away from the drilling structure, and the threaded rod body can slide relative to the locking disk; the locking piece is threadedly connected to the end of the threaded rod body away from the drilling structure, and the locking piece is abutted against the side of the locking disk away from the drilling structure.

[0007] According to some embodiments of the present application, the threaded rod is a streamlined threaded rod, and further includes a plurality of fluid openings respectively arranged on the surface of the threaded rod;

[0008] The drilling structure includes a drill bit, which is a diamond ball drill. The spiral direction of the drill bit is the same as the thread direction of the threaded rod; the locking member includes a nut segment, which is a low-damping spherical internal thread.

[0009] According to one aspect of the present application, a method for selecting and using a self-drilling, self-anchoring, combined prestressed anchor bolt is provided. The method uses the self-drilling, self-anchoring, combined prestressed anchor bolt described above, and further includes the following steps:

[0010] S100, drilling the self-drilling and self-anchoring combined prestressed anchor into a preset soil layer using an anchor drilling rig;

[0011] S200, injecting an anchoring agent from the fluid channel by a grouting machine;

[0012] S300, maintaining the grouting state and rotating the self-drilling and self-anchoring combined prestressed anchor rod to stir the anchoring agent;

[0013] S400: Rotate the locking member to press the locking disk against the working wall.

[0014] According to some embodiments of the present application, before drilling the self-drilling and self-anchoring combined prestressed anchor into a preset soil layer using an anchor drilling rig, the following steps are further included:

[0015] S01, collect soil quality information of each soil layer in the operation area, and obtain the core compression constitutive model based on the soil quality information;

[0016] S02, selecting the self-drilling and self-anchoring combined prestressed anchor rod according to the rock core compression constitutive model, and testing the mechanical properties of the self-drilling and self-anchoring combined prestressed anchor rod;

[0017] S03, producing the self-drilling and self-anchoring combined prestressed anchor rod with mechanical performance meeting the requirements.

[0018] According to some embodiments of the present application, the selecting of the self-drilling and self-anchoring combined prestressed anchor bolt according to the core compression constitutive model further includes the following steps:

[0019] S021, determining a prestress design value for the anchoring construction area based on the core compression constitutive model;

[0020] S022, determining the depth of the stable rock layer according to the actual anchoring construction area;

[0021] S023: Determine basic parameters of the self-drilling and self-anchoring combined prestressed anchor rod according to the prestress design value of the anchoring construction area and the determined depth of the stable rock layer.

[0022] According to some embodiments of the present application, determining the basic parameters of the self-drilling and self-anchoring combined prestressed anchor rod according to the prestress design value of the anchoring construction area and the determined stable rock layer depth further includes the following steps:

[0023] S0231, calculate the actual preload force of the anchor bolt using the following formula:

[0024] F 实际 =k1F k

[0025] in,

[0026] F k is the design value of anchor bolt preload;

[0027] k1 is the safety factor.

[0028] According to some embodiments of the present application, after determining the actual preload force of the anchor rod, the following steps are further included:

[0029] S0232, selecting the structure of the self-drilling and self-anchoring combined prestressed anchor bolt:

[0030] The following formula is used to calculate the area selection of the self-drilling and self-anchoring combined prestressed anchor rod:

[0031]

[0032] in,

[0033] σ s is the yield strength of the material.

[0034] According to some embodiments of the present application, the structure selection further includes the following steps:

[0035] The length of the self-drilling and self-anchoring combined prestressed anchor rod is calculated using the following formula:

[0036]

[0037] in,

[0038] l1 is the depth of the fracture zone;

[0039] l is the anchor rod length.

[0040] According to some embodiments of the present application, after the structure is selected, the following steps are further included:

[0041] S0233, determine the application of preload force:

[0042] The following formula is used to calculate the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor bolt:

[0043]

[0044] in,

[0045] Determine the elongation length l according to the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor rod. t :

[0046]

[0047] According to the retraction length l0 and the extension length l t Determine the preload force applied:

[0048]

[0049] in,

[0050] E is the deformation modulus of the anchor;

[0051] s is the compressive deformation of the locking disc;

[0052] R0 is the radius of the locking disk;

[0053] Z is the depth of the compressive deformation zone of the rock and soil mass.

[0054] According to some embodiments of the present application, after determining that the preload force is applied, the following steps are included:

[0055] S0234, select the structure of the locking member:

[0056] The number of rotations N of the locking member is determined according to the following formula:

[0057]

[0058] in,

[0059] l t is the elongation length;

[0060] d is the thread pitch of the threaded rod;

[0061] According to the following formula, the torque T of the locking member is determined: t :

[0062]

[0063] in,

[0064] F t is the preload force;

[0065] is the torque conversion rate;

[0066] According to max={N,T t}Determine the selection of the locking member.

[0067] Beneficial effects of this application:

[0068] The present application provides a self-drilling and self-anchoring combined prestressed anchor rod and its construction selection and use method, which mainly include: a threaded rod body, a drilling structure, a locking disk and a locking piece. The threaded rod body includes a fluid channel, and the fluid channel is arranged along the axis of the threaded rod body; the drilling structure is provided with a fluid outlet, the drilling structure is fixedly connected to one end of the threaded rod body, and the fluid outlet is connected to the fluid channel; the locking disk is nested in the end of the threaded rod body away from the drilling structure, and the threaded rod body can slide relative to the locking disk; the locking piece is threadedly connected to the end of the threaded rod body away from the drilling structure, and the locking piece and the side of the locking disk away from the drilling structure are abutted.

[0069] By applying the above-mentioned setting, during the anchoring construction process, the threaded rod can be used to drive the drilling structure to directly open and drill on the working wall surface. This can avoid the situation where the borehole collapses in soil conditions similar to the broken zone, which makes it impossible to insert the anchor rod. Under the setting of the fluid channel and the fluid outlet, the anchoring agent can be directly injected and diffused from the position of the drilling structure. After the anchoring agent is injected, it can also be rotated and stirred by the threaded rod to accelerate the anchoring and realize the anchoring construction.

[0070] At the same time, the present application has a simple structure and reliable functions. The parameters of each component can be adaptively adjusted to cope with different soil conditions to meet different construction needs. The construction plan can remain consistent and has wide adaptability, avoiding overly complicated anchor rod design and construction plan design, saving design costs, and improving construction efficiency.

[0071] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0073] Figure 1 A schematic diagram of the three-dimensional structure of a self-drilling and self-anchoring combined prestressed anchor rod provided in an embodiment of the present application is shown;

[0074] Figure 2 Shown Figure 1 Explosion diagram of the self-drilling and self-anchoring combined prestressed anchor bolt;

[0075] Figure 3 Shown Figure 1 A cross-sectional schematic diagram of a self-drilling and self-anchoring combined prestressed anchor rod;

[0076] Figure 4 Shown Figure 3 An enlarged schematic diagram of the self-drilling and self-anchoring combined prestressed anchor bolt at point A;

[0077] Figure 5 A schematic diagram of the three-dimensional structure of a drilling structure of a self-drilling and self-anchoring combined prestressed anchor bolt provided in an embodiment of the present application is shown;

[0078] Figure 6 A schematic diagram of the construction of a self-drilling and self-anchoring combined prestressed anchor rod provided in an embodiment of the present application is shown;

[0079] Figure 7 A partial flow chart of a method for selecting and using a self-drilling and self-anchoring combined prestressed anchor rod is shown in an embodiment of the present application;

[0080] Figure 8 A partial flow chart of a method for selecting and using a self-drilling and self-anchoring combined prestressed anchor rod is shown in an embodiment of the present application;

[0081] Figure 9 Shown Figure 7 A partial flow chart of the selection process of the self-drilling and self-anchoring combined prestressed anchor rod in the selection and use method;

[0082] Figure 10 Shown Figure 9Schematic diagram of part of the process of selecting and using self-drilling and self-anchoring combined prestressed anchor rods.

[0083] The above drawings contain the following reference numerals:

[0084] 10. Threaded rod; 11. Fluid channel; 12. Fluid opening; 20. Drilling structure; 21. Fluid outlet; 22. Drill bit; 30. Locking disc; 40. Locking piece; 41. Nut segment; 50. Crushing zone; 51. Channel; 52. Crushing gap. DETAILED DESCRIPTION

[0085] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0086] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0087] For ease of description, spatially relative terms may be used herein to describe the relative position or movement of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," "above," "front," "rear," and the like. Such spatially relative terms are intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures undergoes a positional flip, a change in posture, or a change in motion, the directional indications will also change accordingly. For example, an element described as "below" or "below" another element or feature would subsequently be oriented "above" or "above" the other element or feature. Thus, the example term "below" can encompass both above and below orientations. The device may be alternatively oriented rotated 90 degrees or in other orientations and the spatially relative descriptors used herein should be interpreted accordingly.

[0088] This application mainly provides a self-drilling and self-anchoring combined prestressed anchor rod and its construction selection and use method, which are used to cope with the complex and changeable conditions of the stratum properties in different regions. On the basis of designing to meet the engineering requirements, the anchor rod should reduce the design redundancy as much as possible to achieve the purpose of reducing costs and increasing efficiency.

[0089] like Figures 1 to 3 As shown, on the first aspect, in some exemplary embodiments of the present application, a self-drilling and self-anchoring combined prestressed anchor rod is provided, which mainly includes: a threaded rod body 10, a drilling structure 20, a locking disk 30 and a locking member 40; the threaded rod body 10 includes a fluid channel 11, and the fluid channel 11 is arranged along the axis of the threaded rod body 10; the drilling structure 20 is provided with a fluid outlet 21, the drilling structure 20 is fixedly connected to one end of the threaded rod body 10, and the fluid outlet 21 is connected to the fluid channel 11; the locking disk 30 is nested in the end of the threaded rod body 10 away from the drilling structure 20, and the threaded rod body 10 can slide relative to the locking disk 30; the locking member 40 is threadedly connected to the end of the threaded rod body 10 away from the drilling structure 20, and the locking member 40 is abutted against the side of the locking disk 30 away from the drilling structure 20.

[0090] Based on the above structural design, during anchoring construction, the threaded rod body 10 can directly drive the drilling structure 20 to drill holes in the working wall. This integrated design can effectively avoid the problem of borehole collapse and the inability to extend the anchor rod under soft soil conditions such as broken zones. With the help of the fluid channel 11 running through the inside of the threaded rod body and the fluid outlet 21 at the front end of the drilling structure, the anchoring agent can be directly injected through the channel without pulling out the anchor rod, so that the anchoring agent is evenly diffused from the fluid outlet 21 at the front end of the drilling structure. After the injection is completed, the anchoring agent can be stirred by rotating the threaded rod body to accelerate the curing reaction, thereby efficiently realizing the entire anchoring construction process.

[0091] At the same time, the device described in this application has a simple structure and reliable performance. The specifications of each component can be flexibly adjusted to adapt to different soil conditions, ensuring that the construction process can be maintained consistent without major adjustments, significantly improving the universality of the construction plan. This design avoids the need for complex anchor rod structures and construction plan design, reducing initial design costs and effectively improving on-site operation efficiency through standardized construction processes.

[0092] In comparison, the construction process for existing self-drilling anchor bolts is complex. During drilling, attention must be paid to protecting the bolt body and securing the joints. After drilling, a curing agent must be injected into the hole for grouting reinforcement. During the grouting process, the pressure and volume must be controlled to ensure uniform grouting. Otherwise, problems such as cavities within the anchor section may occur, requiring a high level of professional expertise.

[0093] Traditional self-drilling anchor rods are usually anchored by cement grouting. Whether to perform secondary grouting is determined based on the actual project conditions. After the grouting is completed, it is necessary to wait for the slurry to solidify, resulting in a long construction time and poor support timeliness.

[0094] In the above-mentioned structural design, the threaded rod 10, locking member 40, and drilling structure 20 all utilize a threaded connection. This standardized interface design facilitates easy assembly, disassembly, and replacement of the drilling structure 20. During construction, the drilling structure 20 can be quickly replaced with a suitable material or model based on the soil properties. This effectively addresses complex working conditions such as sudden changes in rock hardness that may be encountered during drilling, avoids construction delays caused by tool compatibility issues, and ensures the continuity of drilling operations from a hardware perspective, effectively improving construction efficiency.

[0095] In some embodiments, the locking disk 30 forms a seal with the working wall, and a coaxial through-hole in the center allows the threaded rod 10 to rotate freely without interference. This design allows the anchoring agent to be uniformly stirred within the hole by rotating the threaded rod 10 after injection, effectively improving the mixing quality and curing efficiency of the anchoring agent while ensuring a good seal.

[0096] In some embodiments, the anchoring agent is an injectable thixotropic anchoring agent. Once pressure is applied, this type of material rapidly forms a bond with the surrounding soil layer due to its thixotropic properties. Its fluidity ensures effective penetration and filling of minute gaps in the fractured zone. Through the dual effects of physical interlocking and chemical bonding, it strengthens the integrity of the fractured layer, significantly improving the overall anchoring performance after the anchor bolt is fixed.

[0097] It is understandable that for areas with more severe fractures within the rock mass, traditional grouting methods are difficult to effectively penetrate into the fracture zone, and are unable to fully play the role of anchor support and achieve optimal support.

[0098] In some embodiments, the thixotropic anchoring agent can be of various types, such as cement-based, resin-based, polyurethane-based, and water glass-based. Cement-based thixotropic anchoring agents use sulfoaluminate cement as a base material, and have both early strength and rapid hardening and penetration capabilities, making them suitable for wet strata. Resin-based anchoring agents, with their high-strength bonding and corrosion resistance, excel in rapid curing scenarios. Polyurethane-based anchoring agents have expansion properties and low-temperature applicability, making them suitable for cold regions and dynamic load environments. Water glass-based anchoring agents, due to their inorganic environmental protection and high-temperature resistance, are often used in ecologically sensitive areas or high-temperature working conditions. These materials are all formulated with thixotropic agents to achieve the characteristics of "shear thinning and static thickening." After injection, they can quickly bond to the stratum and penetrate into cracks in broken zones. When used in conjunction with self-drilling and self-anchoring devices, they can significantly improve the anchoring effect and construction efficiency under complex geological conditions, combining the advantages of convenient construction, strong adaptability to working conditions, and reliable performance.

[0099] like Figure 3 and Figure 4As shown, in some embodiments, the threaded rod body 10 is a streamlined threaded rod body, and also includes a plurality of fluid openings 12 respectively arranged on the surface of the threaded rod body 10; the streamlined threaded rod body design can reduce the resistance when inserted into the working wall, while ensuring the processing accuracy to ensure the assembly accuracy with the drilling structure 20; on the other hand, the fluid openings 12 distributed along the circumference of the rod body are connected to the internal fluid channel 11, which can make the anchor overflow from multiple points on the side of the threaded rod body 10 and penetrate into the surrounding soil layer, forming a three-dimensional bonding structure on the hole wall, significantly enhancing the anchoring effect of the anchor rod and the formation.

[0100] like Figure 5 As shown, in some embodiments, the drilling structure 20 includes a drill bit 22, which is a diamond ball drill. The spiral direction of the drill bit 22 is the same as the thread direction of the threaded rod 10. On the one hand, the diamond ball drill can efficiently crush hard rock layers or high-strength concrete layers with its ultra-high hardness and wear resistance, significantly improving the drilling capacity under complex geological conditions. On the other hand, the spiral structure of the drill bit and the rod thread in the same direction can form a synergistic slag removal effect during rotary drilling - the axial thrust generated by the thread of the threaded rod 10 during rotation, combined with the cutting direction of the drill bit's spiral blade, synchronously discharges the crushed rock chips along the outside of the rod out of the hole, avoiding the risk of drill sticking caused by debris accumulation, while reducing drilling resistance and making torque transmission more efficient. This integrated rotation design ensures the stability and continuity of the drilling process, and is particularly suitable for hard rock formations or rock formation mutation conditions, ensuring construction efficiency and drilling quality from the mechanical structure level.

[0101] Understandably, the excessively large borehole diameter of traditional self-drilling anchor bolts increases the area of ​​structural damage in the rock mass, reducing the stability of the surrounding rock mass. This also reduces the contact area between the bolt and the hole wall, leading to a decrease in anchoring force. This also causes uneven stress on the bolt within the rock mass, impacting the stability of the anchor structure and reducing anchoring quality. Furthermore, anchor bolts are often prestressed using jacks, which are heavy and impractical for single-person installation. Furthermore, prestressing can occur, requiring over-tensioning, making it difficult to accurately apply prestress.

[0102] like Figure 3As shown, in some embodiments, the locking member 40 includes a nut segment 41, which is a low-damping spherical internal thread. The nut segment 41 of the locking member 40 employs a low-damping spherical internal thread structure. This design optimizes the thread profile to a spherical fit and reduces the friction coefficient of the thread pair. On the one hand, the low-damping characteristics significantly reduce the twisting resistance of the nut segment 41 on the threaded rod 10, facilitating rapid adjustment of the axial position of the locking disc 30 during construction, significantly improving operational efficiency, particularly in conditions requiring frequent prestress adjustments. On the other hand, the curved mating structure of the spherical internal thread adapts to subtle angular deviations of the rod. When the anchor rod deflects slightly under load, the spherical contact ensures uniform load distribution, avoiding the stress concentration issues that can occur with traditional flat threads. This enhances the fatigue resistance and long-term anchoring reliability of the locking structure. This design offers significant advantages in complex stress environments or high-precision prestress control scenarios, balancing ease of construction with structural safety.

[0103] Based on the design of the spherical nut component and the application of the matching thixotropic anchor, it is possible for a single person to quickly apply preload force, actively reinforce the surrounding rock, and effectively improve the bearing capacity and stability of the surrounding rock.

[0104] In an optional embodiment, a self-drilling and self-anchoring combined prestressed anchor bolt is provided, wherein the relationship between the components is as follows:

[0105] The streamlined threaded rod 10 and the low-damping ball nut (locking member 40) are connected by interlocking threads. The streamlined threaded rod 10 and the locking plate 30 are nested together. The threaded rod 10 and the drilling structure 20 are also interlocking threads. The threaded rod 10 and the thixotropic anchor are chemically bonded, surrounding the threaded rod with the thixotropic anchor.

[0106] The streamlined threaded rod 10 serves to combine the various components and bear the force to provide meshing and anchoring force. The low-damping spherical nut serves to transmit stable prestress and ensure that the contact surfaces between the connectors are fully fitted. The locking disc 30 serves to transmit and diffuse prestress and to reinforce the surrounding rock and prevent displacement. The drilling structure 20 is specifically a grinding drill bit that realizes the drilling function and assists in grouting and anchoring. The thixotropic anchoring agent serves to grout and anchor and improve the mechanical properties of the rock mass.

[0107] The drilling structure 20 can be a diamond ball drill, which has the ability to break hard rock formations. During the drilling process of fractured formations such as fractured zones and collapsed formations, the fractured fracture surface can be effectively utilized to efficiently break and crush the rock mass. The drilling structure 20 is provided with three fluid outlets 21 for delivering and diffusing the thixotropic anchoring agent.

[0108] The drilling structure 20 is tightly connected to the threaded rod body 10 through threads. The drilling point is set in advance before drilling, and the anchor rod is placed on the anchor drilling rig. The anchor drilling rig is used to drive the threaded rod body 10 to drive the drilling structure 20 to rotate while drilling into the broken zone 50. The rotation direction is consistent with the interlocking thread direction of the drilling structure 20 and the threaded rod body, making the connection between the two tighter to prevent disconnection. Drilling is carried out until the predetermined depth is reached to complete the drilling work.

[0109] Figure 6 The diagram also shows the working principle of thixotropic anchoring. After the anchor hole drilling is completed, a thixotropic anchoring agent is injected into the threaded rod 10 via a grouting device. The streamlined threaded rod is hollow. The thixotropic anchoring agent exhibits significant thixotropy, rapid setting, and variable shear stiffness. It can penetrate deep into the hole 51 and the crushing gap 52 to achieve a bonding effect, while reducing the problem of grouting dripping at high angles. The threaded rod 10 is then rotated to agitate the thixotropic anchoring agent, reducing its viscosity, enhancing its fluidity, and accelerating its contact with the threaded rod 10, the inner wall of the hole 51, and the crushing gap 52.

[0110] Specifically, the dual-control valve can be controlled to achieve sufficient grouting and complete the anchoring of the surrounding rock mass, and finally allowed to stand for one minute to allow the thixotropic anchoring agent to fully react, tightly connecting the threaded rod body 10, the inner wall of the channel 51 and the broken gap 52 to complete the grouting anchoring.

[0111] In some optional embodiments, the dual-control valve includes a manual control valve and a pressure control valve. During grouting, the manual control valve is first opened to ensure that air in the anchor hole is exhausted. The manual control valve is then closed to ensure that the grouting pressure in the anchor hole is separated, allowing the thixotropic anchoring agent to fully penetrate the cracked rock mass. The pressure is then reached, and the agent overflows from the pressure control valve.

[0112] In some optional embodiments, the streamlined threaded rod body 10 can be subjected to electrophoresis treatment on the surface to improve the corrosion resistance of the exposed end while reducing the surface roughness of the rod, thereby improving the conversion efficiency of preload torque and preload force.

[0113] like Figure 6 and Figure 7 As shown, in the second aspect, an embodiment of the present application provides a construction selection and use method for a self-drilling and self-anchoring combined prestressed anchor rod. The construction selection and use method uses a drilling and self-anchoring combined prestressed anchor rod as in any of the above embodiments. The specific structure and advantages of the drilling and self-anchoring combined prestressed anchor rod are detailed in the above embodiments and will not be repeated here.

[0114] The construction selection and use method also includes the following steps:

[0115] S100, drilling a self-drilling and self-anchoring combined prestressed anchor into a preset soil layer using an anchor drilling rig;

[0116] Specifically, the self-drilling, self-anchoring, combined prestressed anchor bolt is drilled into the pre-set soil layer at the designed angle and depth via the anchor drill rig's coaxial drive. During drilling, the streamlined threaded rod 10 and the co-rotating diamond ball drill 22 create a synergistic cutting effect, leveraging the drill bit's ultra-high hardness to break up hard rock formations. Simultaneously, the rod threads and the drill bit's helical blades simultaneously remove debris, preventing the risk of sticking caused by debris accumulation. This ensures efficient, adaptive drilling in fractured zones or with sudden rock changes.

[0117] S200, injecting the anchoring agent from the fluid channel through the grouting machine;

[0118] Specifically, a grouting machine is used to continuously inject a thixotropic anchoring agent through the fluid channel 11 inside the threaded rod 10. Due to the through-hole design of the fluid outlet 21 and the fluid opening 12 on the side of the rod, the anchoring agent can be injected from the front end of the drilling structure and multiple points around the rod. Under the "shear thinning" thixotropic property, it quickly penetrates the cracks in the soil layer, forming a three-dimensional bonding network, especially in the fracture zone, avoiding the leakage and uneven filling problems of traditional extraction grouting.

[0119] S300, maintains the grouting shape and rotates the self-drilling and self-anchoring combined prestressed anchor to stir the anchoring agent;

[0120] Specifically, after maintaining the grouting pressure at the designed threshold, the anchor rod is rotated at a low speed, utilizing the spiral structure of the threaded rod body 10 to three-dimensionally stir the anchoring agent within the channel 51. This operation not only promotes the thorough mixing of the anchoring agent with the soil particles, eliminating bubbles and optimizing the gelling reaction environment, but also ensures that the locking disc 30 and the working wall seal the mixing process without leakage, allowing the anchoring agent to form a uniform and dense bond within the cracks of the fracture zone, significantly improving the interfacial bond strength.

[0121] S400: Rotate the locking member to press the locking disk against the working wall.

[0122] Specifically, counterclockwise rotation of the locking element 40, leveraging the smooth adjustment characteristics of its low-damping spherical internal thread, pushes the locking disc 30 axially along the threaded rod 10 and compresses the working surface. The locking torque is controlled by a torque wrench, accurately transmitting the anchor rod's pretension to the ground. The curved contact structure of the spherical thread adapts to even the slightest deviation of the rod, preventing stress concentration. Ultimately, a composite anchoring system combining mechanical locking and chemical bonding is formed, ensuring prestressed stability during construction.

[0123] For reference Figure 6The construction process of a single anchor rod is shown as follows: first, a self-drilling anchor rod is driven into the broken rock mass using an anchor drilling rig. During the driving process, the anchor rod is rotated in the direction of the thread setting and pushed axially. The anchor rod does not need to be removed during drilling, thus avoiding the problem of collapse caused by pre-drilling.

[0124] Then, a thixotropic anchoring agent is injected to generate chemical bonding between the anchor rod and the hole 51, and a portion of the anchoring agent is pressed into the crushing gap 52 by increasing the amount, and then the thixotropic anchoring agent is left to solidify. The anchoring effect achieved in this way can reinforce the crushed rock mass.

[0125] After the grouting and anchoring are completed, the locking member 40 is rotated to make it fit tightly against the locking plate 30 and drive the locking plate 30 to fit tightly against the outer wall of the drilled hole. The locking member is further rotated to cause the threaded rod 10 to deform axially along the direction of the hole 51, completing the application of prestress. This completes the construction process of a single anchor rod.

[0126] In an alternative embodiment:

[0127] Before drilling, a site survey is required to determine the specific location suitable for anchor drilling. This step is fundamental to ensuring the effectiveness and safety of the subsequent anchoring work. After the drilling point is determined, the anchor is accurately drilled to the predetermined depth using appropriate drilling equipment. This step requires precise control of the depth and angle of the drill hole to ensure that the anchor is firmly fixed in the rock or soil.

[0128] After the anchor is drilled to the desired depth, a thixotropic anchoring agent is injected into the borehole. This agent rapidly solidifies and develops a strong chemical bond, firmly binding the anchor to the surrounding rock or soil. Once solidified in the borehole, the thixotropic anchor forms a strong bond layer, tightly bonding the anchor to the rock or soil. This improves the properties of the rock and soil and enhances the stability of the anchoring system. This setup is particularly suitable for soils in fractured zones.

[0129] After the anchoring agent solidifies, use a torque wrench or other tool to rotate the torque nut on the anchor rod to apply prestress, thereby enhancing the bond between the anchor rod and the rock or soil, and further improving the stability and bearing capacity of the anchoring system.

[0130] After completing the above steps, the anchoring of a single anchor is complete. At this point, the anchor is firmly anchored in the rock or soil and can withstand certain tensile and shear forces. After the anchoring of a single anchor is complete, continue anchoring at other locations on the same working face as needed to complete the support of the entire working face. After completing the support work for the current working face, transfer the construction equipment and personnel to the next working face to be supported. Repeat the above steps until the entire anchor support project is complete.

[0131] See also Figure 8 As shown, in some exemplary embodiments of the present application, before drilling the self-drilling and self-anchoring combined prestressed anchor into the preset soil layer by the anchor drilling machine, the following steps are also included:

[0132] S01, collect soil quality information of each soil layer in the operation area, and obtain the core compression constitutive model based on the soil quality information;

[0133] Specifically, the physical and mechanical parameters (including compressive strength, cohesion, internal friction angle, etc.) of each soil layer in the operating area can be collected through drilling sampling and in-situ testing (such as standard penetration test and static penetration test) to obtain representative core samples. Based on the theory of rock mechanics, a servo press is used to conduct uniaxial / triaxial compression tests on the core, and the stress-strain curve of the entire process is collected simultaneously to construct a compressive constitutive model of the core suitable for the target stratum. This model is numerically verified by finite element software such as ABAQUS, accurately characterizing the elastic-plastic deformation characteristics and failure mode of the soil layer under compression, providing a basic mechanical basis for the selection of anchor rods.

[0134] S02: Select the self-drilling and self-anchoring combined prestressed anchor bolts based on the core compression constitutive model, and test the mechanical properties of the self-drilling and self-anchoring combined prestressed anchor bolts;

[0135] This step is used to ensure that the selected anchor rod is suitable for the corresponding soil layer to meet the operational requirements of anchoring construction.

[0136] S03, self-drilling and self-anchoring combined prestressed anchor rod with production and mechanical performance meeting the requirements.

[0137] See also Figure 9 As shown, in some exemplary embodiments of the present application, according to some embodiments of the present application, the selection of the self-drilling and self-anchoring combined prestressed anchor bolt is performed according to the core compression constitutive model, and further includes the following steps:

[0138] S021: Determine the prestress design value of the anchoring construction area based on the core compression constitutive model;

[0139] The prestress design value calculated based on the core compression constitutive model can make the load transfer in the anchor precise and the multi-working condition fault-tolerant design, ensuring that the anchor support effect of the anchor under complex stress conditions meets the requirements, that is, the synergistic effect of "active support" and "passive bearing" is achieved.

[0140] S022: Determine the depth of the stable rock layer based on the actual anchoring construction area;

[0141] Obtaining the depth of the stable rock layer can determine the relationship between the application position of the prestress and the fracture zone, which can avoid the anchoring section being suspended or embedded in the weak interlayer, and improve the bonding strength between the anchor and the stable rock mass; at the same time, the length of the threaded rod 10 can be optimized, and under the premise of meeting the minimum anchoring length requirement, the consumption of invalid rod materials can be reduced, thereby reducing construction costs.

[0142] S023. Determine the basic parameters of the self-drilling and self-anchoring combined prestressed anchor bolt based on the prestress design value of the anchoring construction area and the depth of the stable rock layer.

[0143] See also Figure 10 As shown, in some exemplary embodiments of the present application, determining the basic parameters of the self-drilling and self-anchoring combined prestressed anchor rod according to the prestress design value of the anchoring construction area and the determined depth of the stable rock layer further includes the following steps:

[0144] S0231, calculate the actual preload force of the anchor bolt using the following formula:

[0145] F 实际 =k1F k

[0146] in,

[0147] F k is the design value of anchor bolt preload;

[0148] k1 is the safety factor.

[0149] At the same time, the stress loss of the anchor rod should be determined during calculation. The stress loss of the anchor rod should include the compressive deformation of the rock mass and the stress loss caused by the deformation of the tray. This can increase the systematic consideration of the stress loss of rock mass deformation and optimize the mechanical structure in response to the stress loss of tray deformation.

[0150] See also Figure 10 As shown, in some exemplary embodiments of the present application, after determining the actual preload force of the anchor rod, the following steps are further included:

[0151] S0232, selecting the structure of the self-drilling and self-anchoring combined prestressed anchor bolt:

[0152] S02321, use the following formula to calculate the area selection of the self-drilling and self-anchoring combined prestressed anchor rod:

[0153]

[0154] in,

[0155] σ s is the yield strength of the material.

[0156] In the above settings, the anchor support density is determined based on the support force requirement per unit area of ​​the anchoring area, and the effective cross-sectional area of ​​the anchor is determined based on the preload design value and the yield strength of the material.

[0157] In some exemplary embodiments of the present application, the structure selection further includes the following steps:

[0158] S02322, use the following formula to calculate the length of the self-drilling and self-anchoring combined prestressed anchor rod:

[0159]

[0160] in,

[0161] l1 is the depth of the fracture zone;

[0162] l is the anchor rod length.

[0163] The principle of the above setting is that the anchoring area needs to exceed the length of the broken zone or be longer than 4m. Such a setting can ensure the anchoring quality.

[0164] In some exemplary embodiments of the present application, after the structure is selected, the following steps are further included:

[0165] S0233, determine the application of preload force:

[0166] S02331, calculate the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor bolt using the following formula:

[0167]

[0168] in,

[0169] S02332, determine the elongation length l according to the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor rod t :

[0170]

[0171] S02333, according to the retraction length l0 and the extension length l of the self-drilling and self-anchoring combined prestressed anchor rod t Determine the preload force applied:

[0172]

[0173] in,

[0174] E is the deformation modulus of the anchor;

[0175] s is the compressive deformation of the locking disk 30;

[0176] R0 is the radius of the locking disk 30;

[0177] Z is the depth of the compressive deformation zone of the rock and soil mass.

[0178] See also Figure 10 As shown, in some exemplary embodiments of the present application, after determining that the preload force is applied, the following steps are included:

[0179] S0234, selecting the structure of the locking member 40:

[0180] S02341. Determine the number of rotations N of the locking member 40 according to the following formula:

[0181]

[0182] in,

[0183] l t is the elongation length;

[0184] d is the thread pitch of the threaded rod 10;

[0185] S02342, determine the torque T of the locking member 40 according to the following formula: t :

[0186]

[0187] in,

[0188] F t is the preload force;

[0189] is the torque conversion rate;

[0190] S02343, according to max={N,T t}Determine the type of the locking member 40.

[0191] Based on the above embodiments, the present application can meet the needs of different usage environments, especially adapt to collapsed formations in broken zones, through the design of a new self-drilling and self-anchoring combined prestressed anchor rod.

[0192] It is understandable that the mechanical performance testing of self-drilling anchor rods, as a widely used type of anchor rod, often focuses on rod strength and deformation testing. However, traditional construction lacks systematic performance testing and evaluation for anchor rod selection. Therefore, anchor rods face a large number of engineering problems in actual application, such as uncoupled strength and stiffness in the anchoring system, deformation and damage of the tray, and large anchor cable force loss. However, this application conducts soil testing and anchor rod selection and design before construction, making full use of the simple structure of the anchor rod and improving the construction method. The efficiency of the anchoring operation is significantly improved, which helps to shorten the construction period and has good support performance.

[0193] It also includes the following advantages:

[0194] The use of an injectable thixotropic anchoring agent, characterized by variable shear stiffness, allows it to penetrate deep into fractured rock mass to provide a bond and reduce grouting issues at high angles. Its rapid setting significantly increases overall construction speed, overcoming the long post-grouting construction time associated with traditional self-drilling anchors and improving the timeliness of support.

[0195] Compared to traditional self-drilling anchors, the drilling structure 20 is designed to be interchangeable for different soil layers. This allows for tailoring the damage model to the rock mass type, leveraging the disadvantages of cracks and fracture surfaces in rock mass damage and failure to effectively crush the rock mass. Furthermore, the borehole diameter can be reduced, overcoming the problems of uneven force and low anchoring force caused by overly large boreholes.

[0196] By injecting anchoring agents, the thixotropic anchoring agent can fully penetrate into the cracked rock mass, enhancing the stability of the rock mass around the anchor hole. After the grouting overflows, the manual closing pressure control valve can be closed. When the pressure reaches a certain level, the slurry is automatically flushed to ensure that the thixotropic anchoring agent can penetrate into the surrounding cracked rock mass.

[0197] The locking member 40 in each embodiment can adopt a low-damping spherical nut, which can enhance the tightness of the connection with the locking disk 30, ensure the transmission of force between components and reduce the friction effect between components, and enhance the conversion efficiency of preload torque and preload force.

[0198] The construction selection method of the present application integrates the drilling and anchoring functions into one, which greatly reduces the construction process, improves the construction efficiency, and overcomes the problem of easy hole collapse during anchor drilling in broken strata.

[0199] At the same time, a more comprehensive anchor performance test and evaluation system was constructed based on indoor tests and numerical simulations, which can effectively select anchors for different soil layers.

[0200] In summary, the present application has many significant advantages, especially in the anchoring construction operations for collapsed strata in broken zones. By injecting thixotropic anchoring agents for anchoring, the anchoring quality is improved, the construction speed is greatly increased, and the timeliness of support is ensured; by setting up the drilling structure 20, the broken rock mass is refined, and the disadvantageous position of the cracked fracture surface in rock damage is utilized to effectively crush the rock mass, accelerate the drilling speed, and enhance the rock breaking ability; the integrated drilling and anchoring design simplifies the construction process, solves the problem of collapsed holes in anchor rod drilling in broken zones, and improves construction efficiency and safety; by quickly applying pre-tightening force through the locking member 40, the convenience of construction operation is improved, and active reinforcement of the surrounding rock is realized, which significantly improves the stability of the surrounding rock and the safety of the overall project.

[0201] Furthermore, each solution in this application is designed with a complete support system method to guide construction, which can significantly improve the standardization and efficiency of support. These advantages together constitute the unique technical advantages and broad application prospects of this patent in the field of support in fractured zones.

[0202] It should be understood that the present application is not limited to the detailed structure and arrangement of the components proposed in this application. The present application can have other embodiments and can be implemented and executed in a variety of ways. The aforementioned variations and modifications fall within the scope of this application. It should be understood that the present application disclosed and defined in this application extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or the drawings. All of these different combinations constitute multiple alternative aspects of the present application. The embodiments described in this application illustrate the best known methods for implementing the present application and will enable those skilled in the art to utilize the present application.

Claims

1. A self-drilling and self-anchoring combined prestressed anchor rod, characterized in that: include: A threaded rod (10) includes a fluid channel (11), wherein the fluid channel (11) is provided through the axis of the threaded rod (10); A drilling structure (20) is provided with a fluid outlet (21), the drilling structure (20) is fixedly connected to one end of the threaded rod (10), and the fluid outlet (21) is communicated with the fluid channel (11); A locking disk (30) is nested in the end of the threaded rod (10) facing away from the drilling structure (20), and the threaded rod (10) can slide relative to the locking disk (30); and The locking member (40) is threadedly connected to the end of the threaded rod (10) away from the drilling structure (20), and the locking member (40) abuts against the side of the locking plate (30) away from the drilling structure (20).

2. The self-drilling and self-anchoring combined prestressed anchor rod according to claim 1, characterized in that: The threaded rod (10) is a streamlined threaded rod, and further comprises a plurality of fluid openings (12) respectively arranged on the surface of the threaded rod (10); The drilling structure (20) comprises a drill bit (22), the drill bit (22) is a diamond ball drill, and the spiral direction of the drill bit (22) is the same as the thread direction of the threaded rod (10); The locking member (40) comprises a nut section (41), and the nut section (41) is a low-damping spherical internal thread.

3. A construction selection and use method for a self-drilling and self-anchoring combined prestressed anchor rod, characterized in that: The construction selection and use method uses the self-drilling and self-anchoring combined prestressed anchor rod according to any one of claims 1 or 2, and the construction selection and use method further includes the following steps: Drilling the self-drilling and self-anchoring combined prestressed anchor rod into a preset soil layer by an anchor drilling rig; injecting an anchoring agent from the fluid channel (11) by a grouting machine; Maintaining the grouting shape and rotating the self-drilling and self-anchoring combined prestressed anchor rod to stir the anchoring agent; The locking member (40) is rotated to cause the locking disk (30) to press against the working wall surface.

4. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 3 is characterized in that: Before drilling the self-drilling and self-anchoring combined prestressed anchor into a preset soil layer by an anchor drilling rig, the method further includes the following steps: Collect soil quality information of each soil layer in the operation area and obtain the core compression constitutive model based on the soil quality information; Selecting the self-drilling and self-anchoring combined prestressed anchor rod according to the core compression constitutive model, and testing the mechanical properties of the self-drilling and self-anchoring combined prestressed anchor rod; The self-drilling and self-anchoring combined prestressed anchor rod meets the production and mechanical performance requirements.

5. The construction, selection and use method of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 4 is characterized in that: The method of selecting the self-drilling and self-anchoring combined prestressed anchor bolt according to the rock core compression constitutive model further includes the following steps: Determining the prestress design value of the anchoring construction area according to the core compression constitutive model; Determine the depth of the stable rock layer based on the actual anchoring construction area; The basic parameters of the self-drilling and self-anchoring combined prestressed anchor rod are determined according to the prestressed design value of the anchoring construction area and the determined depth of the stable rock layer.

6. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 5 is characterized in that: The method further comprises the following steps: determining the basic parameters of the self-drilling and self-anchoring combined prestressed anchor rod according to the prestress design value of the anchoring construction area and the determined depth of the stable rock layer; The actual preload force of the anchor rod is calculated using the following formula: F 实际 =k1F k in, F k is the design value of anchor bolt preload; k1 is the safety factor.

7. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 6, characterized in that: After determining the actual preload force of the anchor rod, the following steps are also included: Carry out the structural selection of the self-drilling and self-anchoring combined prestressed anchor rod: The following formula is used to calculate the area selection of the self-drilling and self-anchoring combined prestressed anchor rod: in, σ s is the yield strength of the material.

8. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 7, characterized in that: The structure selection also includes the following steps: The length of the self-drilling and self-anchoring combined prestressed anchor rod is calculated using the following formula: in, l1 is the depth of the fracture zone; l is the anchor rod length.

9. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 8, characterized in that: After the structure is selected, the following steps are also included: Determine the preload force applied: The following formula is used to calculate the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor bolt: Determine the elongation length l according to the retraction length l0 of the self-drilling and self-anchoring combined prestressed anchor rod. t : According to the retraction length l0 and the extension length l t Determine the preload force applied: in, E is the deformation modulus of the anchor; s is the compressive deformation of the locking disc (30); R0 is the radius of the locking disk (30); Z is the depth of the compressive deformation zone of the rock and soil mass.

10. The method for construction, selection and use of the self-drilling and self-anchoring combined prestressed anchor rod according to claim 9, characterized in that: After the determination of the preload force, the following steps are included: The structure of the locking member (40) is selected as follows: The number of rotations N of the locking member (40) is determined according to the following formula: in, l t is the elongation length; d is the thread pitch of the threaded rod (10); The torque T of the locking member (40) is determined according to the following formula: t : in, F t is the preload force; is the torque conversion rate; According to max={N,T t }Determine the type of the locking member (40).

Images