Dangerous rock mass reinforcing hollow anchor rod with cutting disc and using method

Abstract

The invention relates to the technical field of geological disaster prevention and control, and discloses a dangerous rock mass reinforcing hollow anchor rod with a cutting disc and a using method of the dangerous rock mass reinforcing hollow anchor rod. The anchoring section of the rod body is provided with a cutting disc; the cutting disc comprises a main base, and a plurality of blade bases are evenly distributed in the circumferential direction of the main base. A sawtooth blade is rotatably mounted on the blade base through an anchor bolt; a buckle is mounted on the blade base; sawteeth are arranged in the circumferential direction of the main base when all the sawtooth blades are in the contraction positions; a torsion piece is mounted at the anchor bolt; the rod body is hollow, a plurality of grouting holes are formed in the anchoring section, and a hollow connecting assembly is arranged at the end, away from the anchoring section, of the rod body. According to the scheme, the anchor rod keeps the original friction effect between slurry and a hole wall, meanwhile, the mechanical meshing effect between the cutting disc and a rock-soil body is increased, meanwhile, based on the optimized anchor rod structure, the two effects are mutually promoted and improved, the pulling resistance of the anchor rod is remarkably improved, the long-term performance of the anchor rod in a complex environment is effectively enhanced, and the service life of the anchor rod is prolonged. The method is especially suitable for engineering reinforcement of dangerous rocks, side slopes, foundation pits and the like.

Description

Technical Field

[0001] The invention relates to the technical field of geological disaster prevention and control, and in particular to a dangerous rock mass reinforcement hollow anchor rod with a cutting disc and a use method thereof. Background Art

[0002] The collapse of dangerous rocks in the Three Gorges Reservoir area affects the safety of waterways and tourism. Therefore, anchor rods are often used to reinforce rock and soil in dangerous rock and slope projects to ensure the stability of the rock and soil. Usually, the anchor rod is introduced into the hole after the anchor hole is formed, and then slurry such as concrete or mortar is poured. The slurry fills the space around the anchor hole and naturally diffuses according to the porosity and pressure of the surrounding medium, penetrating into the tiny cracks and pores of the rock and soil. Over time, once the slurry is completely solidified and tightly combined with the hole wall to form a solid grouting body, significant friction will be generated between the grouting body and the hole wall. This friction makes it so that when external force is applied to the anchor rod, it is not directly borne by the anchor rod alone, but the load is dispersed to a larger range of rock and soil through the friction between the grouting body and the hole wall. The advantage of this is that the stress can be distributed more evenly and the risk of local overload can be reduced. The force is transmitted through the friction between the grouting body and the hole wall, providing strong support and stability, and achieving the reinforcement of the rock and soil.

[0003] In order to improve the pull-out resistance of anchor rods, a widely used method is to increase the friction between the anchor rod or grouting body and the hole wall. Some of them are achieved by changing the performance of the grouting body, and more are achieved by improving the anchor rod to increase the friction. For example, the anchor rods disclosed in Chinese patents 201710164860.2, 201410014781.X, and 201680069725.3 all have expansion structures added to the anchor rod body; for example, the anchor rod disclosed in Chinese patent 201721808323.9 adds some barbs along the anchor rod body to improve the pull-out resistance of the anchor rod.

[0004] Analysis shows that the above-mentioned existing technologies are essentially to improve the working performance of anchor rods by increasing the friction between the anchor rod and the hole wall. However, the improvement of the friction between the anchor rod and the hole wall is limited. First, when the friction coefficient of the hole wall is constant, the pull-out resistance can only be improved by increasing the squeezing force of the anchor rod on the hole wall. However, the improvement of squeezing force in actual engineering is also limited. Therefore, the effect of enhancing the anchoring performance of anchor rods by increasing friction is not ideal. Secondly, when subjected to dynamic disturbances such as earthquakes, the rock and soil and the hole wall may be damaged, resulting in friction failure between the anchor rod and the hole wall. In addition, due to the influence of the anchor rod material, the expansion device may experience stress relaxation, which also causes friction failure.

[0005] Therefore, the existing method of increasing the resistance of anchor rods by friction cannot guarantee its long-term stability at all. Summary of the invention

[0006] The present invention aims to provide a hollow anchor rod with a cutting disc for reinforcing dangerous rock masses and a method of use. While maintaining the original friction between the slurry and the hole wall, the anchor rod increases the mechanical bite effect between the cutting disc and the rock and soil mass. At the same time, based on the optimized anchor rod structure, these two effects promote and enhance each other, significantly improving the pull-out resistance of the anchor rod, and effectively enhancing the long-term performance of the anchor rod in complex environments. It is particularly suitable for the reinforcement of dangerous rocks, slopes, foundation pits and other projects.

[0007] The basic scheme provided by the present invention is: a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass, comprising a rod body; along the length direction of the rod body, at least one cutting disc is sleeved on the anchoring section of the rod body, and the cutting disc is in the same axial direction as the rod body;

[0008] The cutting disc comprises a main base, and a plurality of blade bases are evenly distributed along the circumference of the main base; a serrated blade is rotatably mounted on the blade base through an anchor bolt; a buckle is mounted on the blade base, so that when the buckle is engaged with the tip of the adjacent serrated blade behind it, the serrated blade is subjected to a force tending to keep the serrated blade in its retracted position; when all the serrated blades are in the retracted position, the teeth are arranged along the circumference of the main base; a torsion piece is mounted at the anchor bolt, so that the serrated blade is subjected to an elastic biasing force tending to keep the serrated blade in its open position;

[0009] The rod body is a hollow structure, and a plurality of grouting holes are opened in the anchoring section of the rod body. A hollow connecting component is arranged at the end of the rod body away from the anchoring section.

[0010] The present invention is based on a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass, and also provides a method for using the hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass, the method comprising:

[0011] S100, anchor rod preparation, connecting the anchor rod to the equipment through the connecting assembly; all buckles are clamped on the tips of the corresponding sawtooth blades to make all the sawtooth blades in a retracted state;

[0012] S200, placing one end of the anchor rod with the cutting disc into a corresponding preset anchor hole, wherein all the cutting discs are in the anchor hole;

[0013] S300, the anchor rod starts to rotate under the control of the equipment, the buckle rubs against the hole wall and disengages without interfering with the sawtooth blade, the sawtooth blade opens under the elastic bias force of the torsion member, and cuts the surrounding rock and soil during the rotation and opening process, after the sawtooth blade is fully opened, the cutting is completed, and the rotation stops, so that the anchor rod is mechanically engaged with the rock and soil at a preset depth in the anchor hole through the corresponding sawtooth blade of the cutting disk;

[0014] S400, grouting completed.

[0015] The working principle and advantages of the present invention are:

[0016] Although traditional anchor structures can improve pullout resistance to a certain extent by increasing friction, the improvement effect of this method is very limited. More importantly, relying solely on friction is not only difficult to achieve a balance between pullout resistance and anchoring force, but also leads to poor long-term performance.

[0017] This solution takes into account the significant differences between dangerous rock masses and ordinary rock and soil masses, mainly in terms of stability and potential risks. Specifically, dangerous rock masses refer to those rock masses located on steep slopes or cliff edges that are at risk of instability, sliding or collapse due to natural or human factors. Such rock masses are highly unstable and have the potential for destruction, which may pose a serious threat to the human activity areas below. Therefore, the traditional anchor structure that relies solely on friction to increase the pull-out resistance is not suitable for dangerous rock mass scenarios. The unique geological characteristics of these dangerous rock masses require more comprehensive and effective reinforcement measures to ensure their long-term stability and safety. In contrast, ordinary rock and soil masses usually have better internal uniformity and lower risk levels, and do not require the same complex reinforcement technology as dangerous rock masses. Therefore, when facing dangerous rock masses, more advanced and targeted solutions must be adopted to effectively deal with their special geological conditions and high-risk characteristics.

[0018] In view of the defects of the existing technology, this solution completely changes the relationship between the anchor rod and the rock mass for the special structure of dangerous rock mass and similar soil mass. The improved cutting disc cuts the rock mass around the anchor hole, so that the cutting disc is embedded in the rock mass, and at the same time realizes the dual pull-out effect of friction between the slurry and the hole wall, and mechanical bite between the cutting disc and the rock and soil mass. At the same time, the two pull-out effects also promote each other, that is, the mechanical bite increases the grouting space around the anchor hole again, and the cutting disc structure increases the complexity of the space at the same time. Therefore, the mechanical bite method further increases the friction between the slurry and the hole wall. When the slurry fills the grouting space increased by the mechanical bite, the friction between the slurry and the hole wall further increases the mechanical bite. Therefore, under the above-mentioned dual pull-out effect and the mutual promotion and lifting effect, the pull-out ability of the anchor rod of this solution in the application of dangerous rock reinforcement is significantly increased, the long-term performance of the anchor rod in complex environment is effectively enhanced, the long-term stability of the reinforced rock and soil mass is effectively guaranteed, the project safety is guaranteed, and the project investment is reduced. It is especially suitable for the reinforcement of dangerous rocks, slopes, foundation pits and other projects. In addition, the cutting disc has a simple structure and can be mass-produced, which effectively reduces the production cost and is conducive to popularization and use.

[0019] During the specific installation, there is no need to add additional equipment. Instead, the existing drilling rigs and other equipment required for other processes can be used to complete the rotation operation. At the same time, based on the installation characteristics of the anchor rod, the designed clips and torsion parts can realize the convenient contraction and strong opening of the blade, and quickly achieve stable and firm mechanical engagement between the cutting disc and the rock mass during the rotation process. The entire anchor rod installation process is simple to operate and convenient to construct. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass provided by an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a cutting disc provided in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the structure of the cutting disc in a retracted state provided by an embodiment of the present invention;

[0023] Figure 4 A schematic structural diagram of a cutting disc in an open state provided by an embodiment of the present invention;

[0024] Figure 5 A schematic flow chart of a method for using a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass provided by an embodiment of the present invention;

[0025] Figure 6 A comparison diagram of the stress conditions of a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass provided by an embodiment of the present invention and a traditional anchor rod under the same displacement;

[0026] Figure 7 A comparison diagram of the force distribution of a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass provided by an embodiment of the present invention and a traditional anchor rod under the same displacement;

[0027] The symbols in the drawings of the specification include: cutting disc 1, main base 11, blade base 12, serrated blade 13, anchor bolt 14, torsion member 15, buckle 16, rod body 2, grouting hole 3, pad 4, nut 5, and clamp 6. DETAILED DESCRIPTION

[0028] The following is a further detailed description through specific implementation methods:

[0029] Embodiment 1

[0030] Basically as attached Figure 1 As shown: A hollow anchor rod with a cutting disc for reinforcing dangerous rock mass, comprising a rod body 2; along the length direction of the rod body 2, the anchoring section of the rod body 2 is sleeved with at least one cutting disc 1, and the cutting disc 1 is axially the same as the rod body 2; in this embodiment, all components are made of steel to ensure the rigidity of the anchor rod itself. Along the length direction of the rod body 2, the cutting disc 1 is segmented and provided with a plurality of segments, and the spacing between adjacent cutting discs 1 is adapted to the depth of the anchor hole at the installation location and the characteristics of the rock and soil mass. In this embodiment, 4 cutting discs 1 are provided, with an interval of 500-1000mm, and the length of all cutting discs 1 is one quarter to one half of the length of the rod body 2, and the rod body 2 can be of equal diameter, thereby ensuring the stable engagement of the cutting disc 1, and at the same time, the length is appropriate to ensure safe and stable rotation.

[0031] like Figure 2 The cutting disc 1 includes a main base 11, and a plurality of blade bases 12 are evenly distributed along the circumference of the main base 11; a serrated blade 13 is rotatably mounted on the blade base 12 via an anchor bolt 14. In the present embodiment, the main base 11 is in a circular ring structure, which is used to sleeve the cutting disc 1 on the rod body 2 and is welded to the rod body 2, and a groove is provided on the side of the circular ring along the circumference of the main base 11; 6 blade bases 12 are evenly distributed, and each blade base 12 includes two sub-bases, which are symmetrically distributed on both sides of the groove of the main base 11, and the main base 11 and the blade base 12 are welded; the anchor bolt 14 simultaneously penetrates the two sub-bases and the serrated blade 13, and the serrated blade 13 is located between the two sub-bases; the serrated blade 13 has an arc, and the serrations are arranged at the end of the serrated blade 13 away from the blade base 12, that is, the tip, and the end away from the tip is connected to the anchor bolt 14, and the serrated blade 13 The length is sufficient to not interfere with the adjacent blade base 12 in the retracted state, that is, all the serrated blades 13 belonging to the cutting disk 1 have no overlapping parts along the circumference of the main base in the retracted state; the length of the sawtooth accounts for two-fifths to one-half of the length of the blade; all the serrated blades 13 are arranged circumferentially along the main base 11 when they are in the retracted position, and the influence of the curvature of the serrated blade 13 itself on the circumferential arrangement is considered on the basis of the circumferential arrangement, so as to optimize the arrangement of all the sawtooths along the main base 11; the end of the serrated blade 13 where the anchor bolt 14 is installed has a mounting hole, and the aperture of the mounting hole is larger than the diameter of the anchor bolt 14, so that the serrated blade 13 can rotate well. The number of blade bases 12 is appropriate, and the structure of the serrated blade 13 is reasonable, which can achieve smooth rotation cutting and stable circumferential engagement of the anchor hole while ensuring that the structure and cost are reasonable.

[0032] The blade base 12 is provided with a buckle 16, so that when the buckle 16 is locked at the tip of the adjacent serrated blade 13, the serrated blade 13 is subjected to a force tending to keep the serrated blade 13 in its retracted position. When all the serrated blades 13 are kept in their retracted positions, the entire cutting disc 1 is in a retracted state as shown in FIG. Figure 3 As shown, Figure 3 The direction indicated by the arrow is the rearward direction, and correspondingly, the direction opposite to the rearward direction is the forward direction. In this embodiment, the buckle 16 is installed in the rear direction of the sawtooth blade 13 to which the blade base 12 belongs. Specifically, the buckle 16 has a triangular bracket and the bottom edge penetrates the two sub-bases of the blade base 12, and the penetrating part is located in the rear direction of the sawtooth blade 13 to which the blade base 12 belongs. The length of the buckle 16 meets the requirement that the diameter of the circle formed by the outermost ends of all the buckles of the cutting disk is slightly smaller than the diameter of the anchor hole wall, so that the buckle 16 can be smoothly separated from the sawtooth blade 13 when rubbing against the hole wall, and does not interfere with the opening of the sawtooth blade 13.

[0033] The anchor bolt 14 is provided with a torsion member 15 so that the sawtooth blade 13 is subjected to an elastic biasing force tending to keep the sawtooth blade 13 in its open position. When all the sawtooth blades 13 are kept in their open position, the entire cutting disc 1 is in an open state as shown in FIG. Figure 4 In this embodiment, the torsion member 15 is a strong torsion spring.

[0034] The rod body 2 is a hollow structure, and a plurality of grouting holes 3 are opened in the anchoring section of the rod body 2. A hollow connecting component is arranged at the end of the rod body 2 away from the anchoring section.

[0035] In this embodiment, the connection assembly includes a pad 4 with a center hole, a hollow chuck 6, and a nut 5 installed between the pad 4 and the hollow chuck 6; the chuck 6 is a square chuck with a small hole on each of the four sides, and the square chuck 6 is used to connect with equipment (such as a drilling rig). The chuck 6 is an integral part of the rod body 2, and the square shape and hole design are for better connection with the rotating equipment. The nut 5 and the rod body 2 are a rotating connection like a "screw" structure, and the pad 4 is stuck between the rock mass and the nut. The pad 4 and the nut 5 are common components of conventional anchor rods and are of conventional design.

[0036] Except for a cutting disc 1 near the connecting assembly, the grouting holes 3 are evenly arranged above the connecting assembly of other cutting discs 1. For better grouting, the grouting liquid does not have to be injected through the hollow anchor rod in actual engineering, and can be injected directly from the anchor hole.

[0037] like Figure 5 As shown, the above-mentioned hollow anchor rod for reinforcing a dangerous rock mass with a cutting disc 1 is used, and a method for using the hollow anchor rod for reinforcing a dangerous rock mass with a cutting disc 1 is also provided, the method comprising:

[0038] S100, anchor rod preparation, connecting the anchor rod to the equipment through the connecting assembly; all buckles 16 are clamped on the tips of the corresponding serrated blades 13 to make all serrated blades 13 in a retracted state; the equipment can be a drilling rig, connected to the drilling rig through the clamp 6 to control the rotation of the anchor rod.

[0039] S200, place one end of the anchor rod with the cutting disc 1 into the corresponding preset anchor hole, wherein all the cutting discs 1 are in the anchor hole; the circular diameter formed by the outermost ends of all the buckles 16 belonging to each cutting disc is slightly smaller than the hole diameter, firstly to facilitate the entire device to be smoothly placed in the anchor hole, and secondly to enable the buckle 16 to collide and rub with the hole wall as soon as possible after the rotation starts to open, so that the blade is in a retracted state when it is put in.

[0040] S300, the anchor rod starts to rotate under the control of the equipment, the buckle 16 rubs against the hole wall and disengages without interfering with the serrated blade 13, the serrated blade 13 gradually opens under the elastic bias force of the torsion piece 15, and cuts the surrounding rock and soil during the rotation and opening process, after the serrated blade 13 is fully opened, the cutting is completed, and the rotation stops, so that the anchor rod mechanically engages with the rock and soil at a preset depth in the anchor hole through the corresponding serrated blade 13 of the cutting disk 1; after the serrated blade 13 is fully opened, the blade will not be able to cut the rock and soil, and the rotation resistance of the anchor rod will be significantly reduced, at which time the cutting is completed and the rotation stops; the difference between the height occupied by all cutting disks 1 after being inserted into the anchor hole and the depth of the anchor hole is 100-200mm, and since the cutting disk is deeper in the hole, the entire rotation operation process is safe, and the rotation can be stopped in the conventional way.

[0041] S400, grouting is completed. The grouting pump pushes the pre-prepared slurry into the hollow rod body 2 by high pressure, and then spreads to the entire anchor hole, as well as the complex grouting space formed by the cutting disc and the rock and soil. For better grouting, in actual engineering, the slurry does not have to be injected through this hollow anchor rod, but can be injected directly from the anchor hole.

[0042] like Figure 6 , 7 As shown, in order to illustrate the beneficial effects of the anchor rod of this scheme, the stress conditions of the traditional anchor rod and the anchor rod with a cutting disk when they are pulled to the same displacement are numerically simulated, where the depth of the color in the figure indicates the magnitude of the force.

[0043] Depend on Figure 6 It can be obtained that when the same displacement occurs, Figure 6 The pull-out force that the anchor with a cutting disc shown in (b) can withstand is Figure 6 The pull-out force borne by the traditional anchor shown in (a) is 1.744 times (1.91 / 1.095≈1.744), and the pull-out resistance of the anchor in this scheme is significantly improved.

[0044] Depend on Figure 7 It can be obtained that when the same displacement occurs, Figure 7 (a) The traditional anchor is fully loaded. Figure 7 The anchor rod with a cutting disc shown in (b) is basically not stressed within more than 50% of the length behind the cutting disc, that is, the length of this part of the anchor rod can be reduced in actual engineering, thereby reducing the amount of anchor rod material and reducing engineering costs. In comprehensive comparison, when the same displacement occurs, the length of the anchor rod with a cutting disc can be more than 30% shorter than that of the traditional anchor rod.

[0045] In summary, under the same displacement, the anchor rod with one cutting disc provides about 1.744 times the pull-out force of the traditional anchor rod through 70% of the length of the traditional anchor rod, which reduces the cost and improves the reliability of the anchor rod. Similarly, it can be predicted that the above effect can exist in the case of multiple cutting discs.

[0046] The hollow anchor needle with cutting disc for dangerous rock reinforcement and the use method provided in this embodiment completely solve the problem of low anchor force and poor long-term performance of the traditional anchor rod, which is caused by the traditional anchor rod relying only on friction to provide the pull-out resistance of the anchor rod. Compared with the prior art, the anchor rod of this scheme increases the mechanical bite between the cutting disc and the rock and soil while maintaining the original friction between the slurry and the hole wall. At the same time, based on the optimized anchor rod structure, these two effects promote each other, significantly increase the pull-out resistance of the anchor rod, effectively enhance the long-term performance of the anchor rod in complex environments, effectively ensure the long-term stability of the reinforced rock and soil, ensure the safety of the project, reduce the project investment, and is particularly suitable for the reinforcement of dangerous rocks, slopes, foundation pits and other projects. The structure is simple, which is conducive to mass production and reduces costs. The installation process is simple and easy to operate, and the construction is convenient.

[0047] Embodiment 2

[0048] Different from the first embodiment, the structure of the serrated blade 13 is further designed. In this embodiment, the serrated blade rotates to cut the rock and soil. In this application scenario, all the saw teeth are involved in cutting in the early stage of cutting. As the cutting progresses, the diameter of the cutting seam gradually increases. The serrated blade 13 gradually opens under the elastic bias force of the torsion member 15, and the number of saw teeth involved in cutting gradually decreases. Finally, only the saw teeth at the tip cut the rock, and the resistance of the cutting disc 1 is also reduced.

[0049] For the above-mentioned application scenarios of this scheme, the serrated blade 13 comprehensively considers the rod structure, anchor hole structure, cutting rock and soil characteristics and equipment parameters during structural design. For example, the blade curvature, sawtooth tooth angle and tooth spacing are designed based on the rod diameter, elastic modulus, cohesion and internal friction angle of the cutting rock and soil, anchor hole diameter and depth, rotation speed provided by the equipment and other factors, so as to develop a serrated blade structure design scheme suitable for different application scenarios.

[0050] The radian design of the serrated blade is to make the serrated blade 13 and the main base 11 as close as possible, so that the entire cutting disc 1 is approximately circular, adapted to the cylindrical structure of the rod body and the anchor hole structure, and easier to place in the anchor hole during construction. At the same time, it is optimized to quickly contact the rock mass after the serrated blade is opened to achieve rapid cutting.

[0051] Design a basic curvature, and then use the following formula to correct the curvature in different application scenarios, taking into account factors such as the rod diameter, elastic modulus of the cut rock and soil, cohesion and internal friction angle, anchor hole diameter and depth, etc.:

[0052]

[0053] Among them, R is the corrected blade arc, R0 is the basic arc, E is the elastic modulus of the rock and soil (unit: GPa); C is the cohesion of the rock and soil (unit: MPa), is the internal friction angle of rock and soil (unit: °), D a is the anchor hole diameter (unit: mm), D r is the rod diameter (unit: mm), k1, k2, k3, k4 are empirical constants.

[0054] In this embodiment, the basic curvature R0 of the sawtooth blade 13 is π / 3, and six blades are conventionally designed with a matching curvature.

[0055] A basic sawtooth profile angle is designed, and then correction is made in different application scenarios in combination with the above characteristics. In this embodiment, the sawtooth is triangular, the basic sawtooth profile angle is 45°, and the following formula is used for angle correction:

[0056] θ=θ0+Δθ

[0057]

[0058] Among them, θ is the corrected sawtooth profile angle, θ0 is the basic sawtooth profile angle, E is the elastic modulus of the rock and soil (unit: GPa); C is the cohesion of the rock and soil (unit: MPa), is the internal friction angle of rock and soil (unit: °), k5, k6, k7 are empirical constants.

[0059] In this embodiment, the basic sawtooth profile angle θ0 is 45°, and the sawtooth is an isosceles triangle.

[0060] The design of the tooth profile spacing needs to be combined with the rock particle size, cutting depth and feed speed provided by the equipment. Reasonable tooth profile spacing can ensure that each saw tooth can work effectively during the cutting process.

[0061] S=k8×E+k9×h+k 10 ×V f

[0062] Where: S is the tooth spacing, E is the elastic modulus of the rock mass (unit: GPa), h is the cutting depth (unit: mm), V f Feed speed provided for the equipment (unit: mm / min), k8, k9, k 10 is an empirical constant.

[0063] For example: This device uses regional rock and soil samples, elastic modulus E = 25GPa, cohesion C = 35MPa, internal friction angle Rod diameter Dr =30mm, anchor hole diameter D a =150mm, empirical constants k1=0.001, k2=0.0025, k3=0.0015, k4=0.12, k5=0.3, k6=0.1, k7=0.15. After calculation, R is 1.136rad and θ is 48.2°.

[0064] In addition, when using the machine, the cutting strategy should be adjusted appropriately according to the rotation speed and feed speed provided by the machine. For example, for harder rock and soil, a lower rotation speed and a higher feed speed can be selected; for more brittle rock and soil, the opposite is true.

[0065]

[0066] Where: N is the cutting disc speed (unit: rpm), E is the elastic modulus of the rock and soil (unit: GPa), V f Feed speed provided by the equipment (unit: mm / min), k 11 is an empirical constant.

[0067] Therefore, not only is the sawtooth blade structure optimized in combination with the actual application scenario, but the cutting efficiency is also improved by adjusting the cutting strategy and optimizing other cutting parameters (such as cutting disc speed and feed speed), so that the sawtooth can work efficiently in different cutting stages, thereby achieving the goal of efficient cutting of rock and soil.

[0068] This embodiment provides a hollow anchor needle with a cutting disc for reinforcing dangerous rock mass and a method of use. In specific applications, according to the hardness, particle size, brittleness coefficient of the rock mass, and the size of the rod body and the anchor hole, a correction formula is used to adjust the blade curvature and sawtooth profile angle to ensure that the blade can work efficiently under different conditions. This embodiment provides a systematic method to optimize the design of the sawtooth blade so that it can adapt to different geological conditions and construction requirements.

[0069] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field are aware of all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement the scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for the ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A hollow anchor rod for reinforcing dangerous rock mass with a cutting disc, characterized in that: It comprises a rod body; along the length direction of the rod body, the anchoring section of the rod body is sleeved with at least one cutting disc, and the cutting disc is in the same axial direction as the rod body; The cutting disc comprises a main base, and a plurality of blade bases are evenly distributed along the circumference of the main base; a serrated blade is rotatably mounted on the blade base through an anchor bolt; a buckle is mounted on the blade base, so that when the buckle is locked on the tip of the adjacent serrated blade behind it, the serrated blade is subjected to a force tending to keep the serrated blade in its retracted position; when all the serrated blades are in the retracted position, the teeth are arranged along the circumference of the main base; a torsion piece is mounted at the anchor bolt, so that the serrated blade is subjected to an elastic biasing force tending to keep the serrated blade in its open position; The rod body is a hollow structure, and a plurality of grouting holes are opened in the anchoring section of the rod body. A hollow connecting component is arranged at the end of the rod body away from the anchoring section.

2. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: Along the length direction of the rod body, the cutting discs are divided into multiple sections, and the spacing between adjacent cutting discs is adapted to the depth of the anchor hole at the installation location and the rock mass characteristics.

3. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: The sawtooth blade has a curvature, and the effect of the curvature of the sawtooth blade itself on the circumferential arrangement is increased on the basis of the saw teeth being arranged circumferentially along the main base.

4. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: The saw teeth are arranged at one end of the sawtooth blade away from the blade base, and the total length of the saw teeth accounts for two-fifths to one-half of the length of the sawtooth blade.

5. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: All the sawtooth blades belonging to the cutting disc have no overlapping parts along the circumference of the main base body in the retracted state.

6. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: One end of the sawtooth blade for mounting with the anchor bolt is provided with a mounting hole, and the diameter of the mounting hole is larger than the diameter of the anchor bolt.

7. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: The main base is in a circular ring structure, and a groove is arranged on the side surface of the circular ring along the circumference of the main base.

8. The hollow anchor rod with cutting disc for reinforcing dangerous rock mass according to claim 7, characterized in that: The blade base comprises two sub-bases which are symmetrically distributed on both sides of the groove of the main base. The anchor bolt passes through the two sub-bases, and the serrated blade is located between the two sub-bases.

9. The hollow anchor rod for reinforcing dangerous rock mass with a cutting disc according to claim 1, characterized in that: The connection assembly includes a backing plate with a central hole, a hollow chuck, and a nut mounted between the backing plate and the hollow chuck, wherein the hollow chuck is away from the cutting disk.

10. A method for using a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass, characterized in that: Using a hollow anchor rod with a cutting disc for reinforcing a dangerous rock mass according to any one of claims 1 to 9, the method comprises: S100, anchor rod preparation, connecting the anchor rod to the equipment through the connecting assembly; all buckles are clamped on the tips of the corresponding sawtooth blades to make all the sawtooth blades in a retracted state; S200, placing one end of the anchor rod with the cutting disc into a corresponding preset anchor hole, wherein all the cutting discs are in the anchor hole; S300, the anchor rod starts to rotate under the control of the equipment, the buckle rubs against the hole wall and disengages without interfering with the sawtooth blade, the sawtooth blade opens under the elastic bias force of the torsion member, and cuts the surrounding rock and soil during the rotation and opening process, after the sawtooth blade is fully opened, the cutting is completed, and the rotation stops, so that the anchor rod is mechanically engaged with the rock and soil at a preset depth in the anchor hole through the corresponding sawtooth blade of the cutting disk; S400, grouting completed.

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