Tunnel anchor bolt structure and construction method

Abstract

The present invention discloses a tunnel anchor bolt structure and construction method, wherein a plurality of joint units are connected in sequence through a ball joint structure to form an anchor bolt; a first through hole, a second through hole and a third through hole are arranged on the joint unit; the second through hole connecting the plurality of joint units forms a return air duct, and the third through hole connecting the plurality of joint units forms an air inlet duct; the present invention also includes a plurality of traction steel cables, the top of the traction steel cables is connected to the joint unit at the top of the anchor bolt, and the steel cables pass through the first through holes of the plurality of joint units and extend to the end of the traction steel cables at the bottom of the anchor bolt to form a traction control end; the angle bending of the anchor bolt is controlled by pulling the plurality of traction control ends. The controllable bending anchor bolt provided by the present invention can selectively bypass the weak layer during the construction process to anchor the anchor bolt in a relatively hard stratum, obtain an ideal friction force between the anchor bolt and the stratum structure, provide greater tensile strength and anchoring force, and ultimately ensure the safety and stability of the tunnel.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel anchoring bolt construction, and in particular to a tunnel anchoring bolt structure and a construction method. Background Art

[0002] In tunnel engineering, anchor rods play a very important role. The main functions include:

[0003] (1) Support structure: In deep tunnel projects, anchor rods can be used as part of the support structure to support the strata and surface loads around the tunnel, preventing strata collapse and excessive stress on the tunnel structure.

[0004] (2) Strengthening the stratum: The fixing effect of the anchor rods can effectively strengthen the surrounding stratum, improve the bearing capacity and stability of the stratum, and reduce the impact of the tunnel structure on the stratum;

[0005] (3) Reduce surface deformation: The use of anchors can reduce the settlement and deformation of the ground during tunnel excavation, protecting surface buildings and underground pipelines from being affected;

[0006] (4) Increase the stability of the tunnel structure: Anchor rods can increase the overall stability and bearing capacity of the tunnel structure, and improve the safety and life of the tunnel. Therefore, anchor rods are very important in tunnel engineering. They can not only ensure the construction safety and quality of the project, but also improve the performance and reliability of the tunnel.

[0007] However, with the construction of deep buried tunnels represented by the Sichuan-Tibet Railway Tunnel, increasingly complex geological conditions have brought difficulties to the selection and design of anchor rods. Different geological conditions (such as rock, soil, soft rock, etc.) will affect the type, length and arrangement of anchor rods.

[0008] Currently, the most common anchor rods are straight anchor rods and spiral anchor rods, which are usually made of high-strength steel bars or steel pipes. The straight anchor rod is in a straight line shape and is usually used to support and reinforce tunnel walls or underground structures, while the spiral anchor rod has a spiral shape and is often used in soft soil or when the soil stability needs to be increased.

[0009] Spiral anchors can provide greater tensile strength and increase friction with the soil. However, in complex geological conditions, such as faults and karst caves, various fixing methods such as prestressed anchors, post-grouting anchors, and sleeve anchors cannot form a good anchoring force in the weak layer. Special anchors suitable for geological conditions with weak layers are urgently needed.

[0010] In addition, high ground temperature and water inrush are important factors to be considered in the construction of the Sichuan-Tibet Railway tunnel. High temperature causes the performance of electronic components to decline, such as increased resistance and reduced capacitance, thus affecting the normal operation of the equipment; high temperature also causes thermal expansion of electronic components and circuit boards, which may cause solder joints to loosen or break, and even cause equipment damage.

[0011] Water is conductive. If water enters electronic equipment, it may cause a short circuit or corrosion to electronic components and circuit boards, reducing the reliability and life of the equipment. Water can also reduce the insulating properties of insulating materials and increase the risk of equipment failure.

[0012] Therefore, the existing anchor rods cannot adapt to a variety of complex stratum structures during the construction process, and the electric control equipment used causes the electric control equipment of the anchor rods to be easily affected and the anchoring force to fail. Summary of the invention

[0013] The purpose of the present invention is to provide a tunnel anchoring bolt structure and construction method to solve the technical problems in the prior art, that is, the existing bolts cannot adapt to a variety of complex stratum structures during construction, and the electrical control equipment used causes the bolt electrical control equipment to be easily affected and the anchoring force to fail.

[0014] In order to solve the above technical problems, the present invention specifically provides the following technical solutions:

[0015] A tunnel anchoring bolt structure comprises a joint unit, a spherical groove is arranged in the middle of the top of the joint unit, and a spherical body is arranged in the middle of the bottom of the joint unit;

[0016] The spherical grooves and the spherical bodies of two adjacent bone joint units are matched and connected to form a ball joint structure, and a plurality of bone joint units are sequentially connected through the ball joint structure to form an anchor rod;

[0017] The condyle unit is provided with a plurality of first through holes connecting the upper and lower surfaces of the condyle unit, and the plurality of first through holes are evenly distributed on the surface of the condyle unit close to the circumferential edge; the condyle unit is provided with a second through hole and a third through hole connecting the upper and lower surfaces of the condyle unit;

[0018] The second through holes connecting the plurality of bone segment units form a return air duct, and the third through holes connecting the plurality of bone segment units form an inlet air duct;

[0019] It also includes a plurality of steel cables, the plurality of steel cables corresponding one by one to the plurality of first through holes on the condyle unit;

[0020] The top of the steel cable is connected to the joint unit at the uppermost part of the anchor rod, and the end of the steel cable sequentially passes through the first through holes at the same position of the plurality of joint units and extends to the bottom of the anchor rod to form a traction control end;

[0021] Wherein, different magnitudes of forces are applied to the steel cable through the plurality of traction control ends, and the bending angle of the anchor rod is controlled with the cooperation of the ball joint structure.

[0022] As a preferred solution of the present invention, a return air duct is formed by connecting the second through holes of a plurality of the segment units through a first telescopic tube;

[0023] The third through holes of a plurality of the joint units are connected by a second telescopic tube to form an air inlet pipeline.

[0024] As a preferred solution of the present invention, an elastic outer layer is sleeved on the outside of the anchor rod, and the top of the elastic outer layer is sleeved on the bottom of the joint unit at the top of the anchor rod.

[0025] As a preferred solution of the present invention, the second through hole of the condyle unit located at the top of the anchor rod forms an upper blasting opening on the upper surface of the condyle unit;

[0026] A side blasting opening is provided on the circumferential side wall of the condyle unit located at the top of the anchor rod, wherein the side blasting opening is connected to the second through hole;

[0027] Wherein, the directional blasting explosive is transported to the upper blasting opening or the side blasting opening through the return air pipeline.

[0028] As a preferred solution of the present invention, a steering pipeline is provided in the segment unit located at the top of the anchor rod, and the steering pipeline is connected to the return air pipeline and the inlet air pipeline.

[0029] As a preferred solution of the present invention, the cross section of the first through hole is rectangular, and an R chamfer is formed at the corner of the first through hole.

[0030] As a preferred solution of the present invention, the upper bursting hole and the side bursting hole are connected at the top edge of the condyle unit.

[0031] The present invention provides a construction method based on the tunnel anchor bolt structure, comprising the following steps:

[0032] Step 100, applying an axial upward force to the joint unit at the bottom of the anchor rod, and applying an axial downward force to the joint unit to multiple steel cables, so that the anchor rod as a whole remains stable;

[0033] Step 200, drilling an initial hole at an anchor point set in the tunnel surrounding rock, and placing the upper surface of the joint unit at the top of the anchor rod against the bottom wall of the initial hole, and determining a blasting direction based on the initial hole, and orienting the upper blasting port or the side blasting port toward the blasting direction;

[0034] Step 300: transport blasting explosives to the upper blasting opening or the side blasting opening through the return air duct to perform blasting operations, and discharge rock debris generated by the blasting through the return air duct;

[0035] Step 400, by changing the magnitude of the downward force of the multiple steel cables controlled by the multiple traction control ends along the axial direction of the joint units, the anchor rod is bent toward the direction of the surrounding rock cave created by the blasting, and the upward force applied to the joint unit at the bottom of the anchor rod is increased, so that the top of the anchor rod enters the surrounding rock cave;

[0036] Step 500, repeating the blasting direction of the current surrounding rock cavern, directing the upper blasting opening or the side blasting opening of the joint unit of the anchor rod toward the blasting direction, conveying the blasting explosive through the return air duct, and steps 300 and 400, until a target hole of a set length and position is formed, and the anchor rod is fixed;

[0037] Step 600: inject slurry into the return air duct and the inlet air duct to fill the target hole with the slurry, while keeping the steel cable taut, so that the slurry is fully solidified and the anchor rod is firmly connected to the rock mass of the target hole.

[0038] As a preferred embodiment of the present invention, when rock fragments generated by blasting enter the return air duct, high-pressure gas is pumped into the air inlet duct, and the high-pressure gas reaches the blasting port through the turning duct, carrying the rock fragments and being cleaned out by the return air duct.

[0039] As a preferred solution of the present invention, the probe lens and the temperature and humidity sensor are transported to the upper blasting opening or the side blasting opening through the air inlet pipeline and the steering pipeline.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The controllable bending anchor rod provided by the present invention can selectively bypass the weak layer during construction and anchor the anchor rod in a relatively hard stratum, thereby obtaining an ideal friction force between the anchor rod and the stratum structure, providing greater tensile resistance and anchoring force, and ultimately ensuring tunnel safety and stability.

[0042] The anchor rod in the present invention is connected by a plurality of joints, and the steering and bending of the anchor rod body are controlled purely mechanically by pulling the steel cable, thereby avoiding the influence of high ground temperature and water gushing of the stratum caused by the use of electric control equipment.

[0043] The present invention uses explosives to carry out small-scale directional blasting during the anchor construction process, avoids the use of large equipment such as drilling rigs, and has high flexibility in a narrow space. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0045] Figure 1 A schematic diagram of the structure of the joint units connected to form an anchor rod according to an embodiment of the present invention;

[0046] Figure 2 A schematic diagram of the structure of a condyle unit according to an embodiment of the present invention;

[0047] Figure 3 For the embodiment of the present invention Figure 2 Schematic diagram of the connection structure of the upper blasting port and the side blasting port;

[0048] Figure 4 A schematic diagram of the anchor rod structure according to an embodiment of the present invention;

[0049] Figure 5 For the embodiment of the present invention Figure 4 Schematic diagram of the cross-section structure of the middle active steering section;

[0050] Figure 6 The figure is a schematic diagram of the anchor tunnel construction structure according to an embodiment of the present invention.

[0051] The numbers in the figure represent the following:

[0052] 1-joint unit; 2-spherical groove; 3-spherical body; 4-first through hole; 5-second through hole; 6-third through hole; 7-steel cable; 8-elastic outer layer; 9-upper blasting hole; 10-side blasting hole; 11-steering pipeline; 12-return air pipeline; 13-inlet air pipeline; 14-explosive; 15-first telescopic tube; 16-second telescopic tube. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] like Figures 1 to 6 As shown, the present invention provides a tunnel anchoring anchor rod structure, including a joint unit 1, a spherical groove 2 is arranged in the middle of the top of the joint unit 1, a spherical body 3 is arranged in the middle of the bottom of the joint unit 1, and the spherical groove 2 and spherical body 3 of two adjacent joint units 1 are matched and connected to form a ball joint structure.

[0055] A plurality of first through holes 4 connecting the upper surface and the lower surface of the joint unit 1 are arranged on the joint unit 1 , and the plurality of first through holes 4 are evenly distributed on the surface of the joint unit 1 close to the circumferential edge.

[0056] The condyle unit 1 is provided with a second through hole 5 and a third through hole 6 .

[0057] A plurality of condyle units 1 are connected in sequence through a ball joint structure to form an anchor rod.

[0058] The second through holes 5 connecting the multiple bone joint units 1 form a return air duct 12, and the third through holes 6 connecting the multiple bone joint units 1 form an inlet air duct 13;

[0059] It also includes a plurality of steel cables 7 , which correspond one by one to the plurality of first through holes 4 on the condyle unit 1 .

[0060] The top of the steel cable 7 is connected to the joint unit 1 at the uppermost part of the anchor rod, and the end of the steel cable 7 which passes through the first through holes 4 at the same position of the plurality of joint units 1 in sequence and extends to the bottom of the anchor rod forms a traction control end;

[0061] Among them, different pulling forces are applied to the steel cable 7 along the length direction of the line through multiple traction control ends, and the angle bending of the anchor rod is controlled with the cooperation of the ball joint structure.

[0062] Furthermore, in this embodiment, an elastic outer covering layer 8 may be provided on the outside of the anchor rod formed by sequentially connecting a plurality of bone segments.

[0063] The elastic outer layer 8 makes the anchor rod have multiple sections after construction, including an upright section, a passive bending section and an active steering section.

[0064] The active steering section is the part at the front end of the anchor rod that enters the drill hole, and it relies on some joints to steer; while the passive steering section just follows the joints of the active steering section in front, and does not take on the task of steering, but follows passively.

[0065] However, the active steering section is at the front, and as the pioneer, it will encounter a lot of gravel when turning, which will crush and rub the top and side walls of the anchor rod, and will also be damaged by blasting. Therefore, the material of this part of the joint must be strong and hard.

[0066] In the passive steering section, the gravel it contacts has been smoothed out and the force of the explosion is rarely transmitted here, so the material does not need to be too good and more economical metal materials can be used.

[0067] The upright section is designed to support the entire anchor rod from the back and push the anchor rod forward.

[0068] This part is the least useful, so the most economical material can be used. At the same time, if the anchoring direction and length of the anchor rod can be determined through geological exploration, and the length of the vertical section can be determined, then the last section can even be directly replaced by a straight anchor rod.

[0069] Furthermore, in this embodiment, the outer layer 8 is also used to prevent gravel from entering between two adjacent condyle units 1, thereby affecting the relative angular rotation between the two adjacent condyle units 1.

[0070] However, in subsequent construction, the anchor rod and the formed anchor rod opening need to be grouted and fixed, so the outer layer 8 can also be designed to be detachable, that is, when blasting to the target length or position, the connection between the outer layer 8 and the anchor rod's bone unit 1 is released, and then the grouting and fixing operation is performed.

[0071] At this time, since there is a gap between two adjacent bone joint units 1 of the anchor rod, the grouting solidified structure formed in the gap between the two adjacent bone joint units 1 after grouting will be able to generate sufficient anchoring force to strengthen the force between the anchor rod and the tunnel wall.

[0072] The second through hole 5 of the joint unit 1 at the top of the anchor rod forms an upper bursting hole 9 on the upper surface of the joint unit 1 ; a side bursting hole 10 is provided on the circumferential side wall of the joint unit 1 , and the side bursting hole 10 is connected to the second through hole 5 .

[0073] The directional blasting explosive is transported to the upper blasting opening 9 or the side blasting opening 10 through the return air pipeline 12 .

[0074] Furthermore, since the upper blasting hole 9 and the side blasting hole 10 are connected at the top edge of the joint unit 1, this is mainly because the impact generated by the directional blasting will directly act on the side of the joint unit 1 facing the blasting (i.e., the location of the blasting hole), which will in turn have a greater impact on the main body of the anchor rod.

[0075] Therefore, in this embodiment, the upper blasting hole 9 and the side blasting hole 10 can also be connected at the top edge of the joint unit 1, so that the impact force generated by the blasting is guided and released at the other blasting hole, thereby avoiding a complete impact on the anchor structure.

[0076] Furthermore, in this embodiment, a turning pipeline 11 may be provided in the elastic outer covering layer 8 , and the turning pipeline 11 is connected to the return air pipeline 12 and the inlet air pipeline 13 .

[0077] The return air duct 12 is formed by connecting the second through holes 5 of the plurality of joint units 1 through the first telescopic tube 15 ; and the inlet air duct 13 is formed by connecting the third through holes 6 of the plurality of joint units 1 through the second telescopic tube 16 .

[0078] The first telescopic tube 15 and the second telescopic tube 16 can both be metal hoses or braided tubes and can be bent.

[0079] Of course, in this embodiment, a steering pipe 11 is mainly provided in the bone segment unit 1 located at the top of the anchor rod, and the steering pipe 11 connects the return air pipe 12 and the air inlet pipe 13. This is mainly because the top of the anchor rod needs to resist the impact caused by the explosion, so there are certain requirements for its overall hardness and structural strength.

[0080] To this end, the top of the elastic outer layer 8 is sleeved onto the bottom of the topmost condyle unit 1 of the anchor.

[0081] In this embodiment, in order to avoid mechanical wear between the steel cable 7 and the first through hole 4, the cross section of the first through hole 4 is rectangular, and the corners of the first through hole 4 are chamfered.

[0082] The present invention provides a construction method based on the tunnel anchor bolt structure, comprising the following steps:

[0083] Step 100, applying an axial upward force to the joint unit at the bottom of the anchor rod, and applying an axial downward force to the joint unit to multiple steel cables, so that the anchor rod as a whole remains stable;

[0084] Step 200, drilling an initial hole at an anchor point set in the tunnel surrounding rock, and placing the upper surface of the joint unit at the top of the anchor rod against the bottom wall of the initial hole, and determining a blasting direction based on the initial hole, and orienting the upper blasting port or the side blasting port toward the blasting direction;

[0085] Step 300: transport blasting explosives to the upper blasting opening or the side blasting opening through the return air duct to perform blasting operations, and discharge rock debris generated by the blasting through the return air duct;

[0086] Step 400, by changing the magnitude of the downward force of the multiple steel cables controlled by the multiple traction control ends along the axial direction of the joint units, the anchor rod is bent toward the direction of the surrounding rock cave created by the blasting, and the upward force applied to the joint unit at the bottom of the anchor rod is increased, so that the top of the anchor rod enters the surrounding rock cave;

[0087] Step 500, repeating the blasting direction of the current surrounding rock cavern, directing the upper blasting opening or the side blasting opening of the joint unit of the anchor rod toward the blasting direction, conveying the blasting explosive through the return air duct, and steps 300 and 400, until a target hole of a set length and position is formed, and the anchor rod is fixed;

[0088] Step 600: inject slurry into the return air duct and the inlet air duct to fill the target hole with the slurry, while keeping the steel cable taut, so that the slurry is fully solidified and the anchor rod is firmly connected to the rock mass of the target hole.

[0089] When rock fragments generated by blasting enter the return air duct, high-pressure gas is pumped into the air inlet duct, and the high-pressure gas reaches the blasting port through the turning duct, carrying the rock fragments and being cleaned out through the return air duct.

[0090] The probe lens and the temperature and humidity sensor are transported to the upper bursting port or the side bursting port through the air inlet pipe and the steering pipe.

[0091] The operating principle of the directional bending anchor for road use is as follows:

[0092] First, the basic method of anchoring in the presence of soft geological layers. In the presence of soft geological layers, tunnel anchoring is one of the important measures to ensure the stability and safety of the tunnel structure. After the traditional straight anchor rod is drilled into the soft layer from the lining, most of the ends of the anchor rod cannot obtain effective friction, and as the area of ​​the soft layer expands, the construction difficulty of connecting the soft layer with the rock and soil layer increases greatly, and the overall stability of the tunnel cannot be guaranteed. Therefore, by using a new type of curved anchor rod to bypass the soft layer and fix the tunnel in the hard layer, sufficient anchoring force can be obtained to ensure the safety of tunnel operation.

[0093] Second, directional bending anchor pipeline layout.

[0094] Directional bending anchor can be divided into upright section, passive bending section and active steering section according to bending state and position. Two cross-sectional positions are drawn in the attached figure.

[0095] The II section pipeline diagram shows the pipeline location and the contents in the pipeline. There are two pipelines in the new curved anchor rod, the return air pipeline / blasting box pipeline and the inlet air pipeline / data transmission pipeline.

[0096] The return air duct / blasting box duct is responsible for transporting the directional blasting box to the end of the anchor rod for blasting operations. After the blasting, the return air blows out the blasting box and rock debris through this duct. The air inlet duct / data transmission duct should be equipped with probe lens data cables or temperature and humidity sensor data cables and other wires to monitor the environment as needed. After the blasting, the airflow enters through this duct and is redirected by the airflow steering duct.

[0097] The outermost elastic sheath of the anchor rod is to prevent the surrounding rock debris from entering the anchor rod structure and affecting the anchor rod function.

[0098] At the same time, the return air duct / blasting box duct and the air inlet duct / data transmission duct also have elastic outer layers for secondary protection.

[0099] The elastic outer layer can be made of soft and wear-resistant materials, such as nylon, aramid, polyethylene high molecular weight fiber, etc. Nylon is a synthetic fiber with high strength and good wear resistance. It has good wear resistance, moderate softness, strong tensile strength and durability.

[0100] Aramid is a high-performance synthetic fiber with extremely high abrasion resistance, strength and heat resistance. It also has good softness and is widely used in the production of bulletproof materials, protective equipment in high temperature environments, aerospace and other fields.

[0101] Polyethylene high molecular weight fiber is an ultra-high molecular weight polyethylene fiber with extremely strong abrasion resistance and chemical resistance, and at the same time exhibits good softness. It is often used to make high-performance ropes, cut protection products, etc., and is particularly suitable for occasions with high requirements for lightweight and high strength.

[0102] Appropriate materials should be selected for the elastic outer layer based on the ambient temperature, construction conditions and cost of the tunnel project.

[0103] In such Figure 5 The cross-sectional pipeline diagram of the outer layer 8 shown shows the pipeline arrangement of the end of the new curved anchor rod, that is, in this embodiment, the first telescopic tube 15 and the second telescopic tube 16 can also be arranged in the outer layer 8, that is, the second through hole 5 and the third through hole 6 are not opened on the bone joint unit 1, then the anchor rod is mainly used for steering, and the outer layer 8 plays the role of explosives transportation and end blasting.

[0104] After the directional blasting box is transported to the blasting hole, it blasts forward at the upper blasting hole 9 or turns sideways at the side blasting hole 10 according to the loading direction of the blasting box.

[0105] After the blasting is completed, the wind flows in through the air inlet duct / data transmission duct, and is diverted through the wind flow diversion duct, and finally led out through the return air duct / blasting box duct. The probe lens data cable or the temperature and humidity sensor data cable is connected to the probe lens and the temperature and humidity sensor to obtain more engineering data.

[0106] Third, the principle of mechanical bending of anchor rods.

[0107] like Figures 1 to 3 The anchor rod of this embodiment is composed of individual bone joint units 1, which can achieve mechanical bending.

[0108] There is an anchor rod joint steering ball seat at the top of the joint unit 1 of the anchor rod, and there is an anchor rod joint steering ball at the bottom, which can be nested with each other.

[0109] The bone joint unit 1 of the anchor rod should be composed of different metal materials, such as carbon steel, stainless steel, alloy steel, aluminum alloy, titanium alloy and the like.

[0110] Carbon steel is a common and affordable metal material with good strength and rigidity. It performs well in general environments and is easy to machine and weld.

[0111] Stainless steel has good corrosion resistance and oxidation resistance, and can be used for a long time in wet, high humidity or corrosive environments without rusting. It also has high strength and durability, so it is considered for use in tunnels with severe water inrush.

[0112] Alloy steel is steel that has its properties improved by adding other elements. It has excellent strength, hardness and corrosion resistance, and is suitable for engineering projects that require higher performance and need to withstand larger loads and complex environments.

[0113] Aluminum alloys are lightweight, have good thermal conductivity and machinability, and are suitable for applications that require light weight and good corrosion resistance. However, aluminum alloys are usually not as strong as steel, so it is not easy to use this material in deep tunnels. Instead, it is lighter to use in shallow tunnels.

[0114] Titanium alloy has excellent corrosion resistance, strength and light weight, and is a high-end choice among engineering materials. However, titanium alloy has a high cost and is used in tunnels and areas with high requirements for strength and corrosion resistance.

[0115] The bone joint unit 1 of the anchor has a through hole for anchor steering, namely the first through hole 4, through which the steering steel cable passes. The number of the first through holes 4 is determined by the construction accuracy. The higher the construction accuracy requirement, the more the number of the first through holes 4, and vice versa.

[0116] The bone segment unit of the anchor rod should also have reserved holes for the air inlet pipeline / data transmission pipeline and the return air pipeline / blasting box pipeline, that is, the second through hole 5 and the third through hole 6 are set.

[0117] like Figure 1 As shown, multiple anchor joint units X1, X2, X3, X4, X5, X6, ..., Xn are superimposed, and the anchor joint steering ball seat and the anchor joint steering ball are matched (i.e., the above-mentioned ball-joint structure is formed).

[0118] In order to ensure that the bone unit X1, X2, X3, X4, X5, X6, ..., Xn of the anchor rod are superimposed and not dispersed, on the one hand, upward pressure is applied to the bottom of the anchor rod bone steering ball, that is, an upward force is applied along the axial direction of the anchor rod, and on the other hand, the steering steel cable and the steel cable anchor (used to fix the top of the steel cable and the bone unit 1 at the top of the anchor rod) are used to apply downward pulling force to the bone unit 1 of the anchor rod on both sides at the same time, downward along the length direction of the steel cable, forming an antagonistic effect to maintain overall stability.

[0119] Mechanical bending becomes possible due to the presence of the steel cable and the steel cable anchor for steering. After blasting at the upper blasting hole 9 or the side blasting hole 10, the rocks in the front or side space are cleared, and the steering steel cable is pulled on one side, and the pulling force is transmitted to the end of the bending anchor rod through the steel cable anchor to complete the steering.

[0120] It is only necessary to turn the blasting hole at the end. The joint unit 1 of the anchor rod at the rear is movable. Under the external thrust, it will automatically bend along the blasting route. Of course, the anchor rod as a whole can also rotate circumferentially to adjust the position of the blasting hole.

[0121] As shown in the figure, the anchor joint hole opening process should pay attention to making it into a smooth edge, that is, R chamfering. The need for a smooth transition edge when passing through a circular hole to prevent the steering cable from being worn off can be explained from the perspective of materials science and mechanics. When the steering cable passes through the edge of the anchor rod steering hole, it may be subjected to local stress concentration, which may cause the steering cable to break or be damaged.

[0122] The rounded edges can reduce the possibility of stress concentration and make the steering cable receive more uniform force when passing through the steering hole of the anchor rod, thereby reducing the risk of wear and damage.

[0123] In materials science, the strength and toughness of a material are key factors in determining its durability. Sharp or rough edges can cause local stress concentrations, which can increase wear and damage to the material. Rounded edges can reduce this stress concentration and help protect the steering cable from damage.

[0124] From a mechanical point of view, when the steering cable passes through a sharp or rough edge, due to the local high stress, the steering cable may be slightly displaced or twisted, which may accelerate the wear process of the steering cable. In contrast, the edge with smooth transition can provide a smoother surface, reduce the twisting and friction of the steering cable when passing through the steering hole of the anchor rod, thereby extending the service life of the steering cable.

[0125] Fourth, the principle of directional blasting. Figure 2 , Figure 3 as well as Figure 5After the directional blasting box is transported to the blasting port by the return air duct / blasting box duct, there are two opening directions, the upper blasting port 9 and the side blasting port 10, which are connected to form a whole opening, with a sideward opening and a top-oriented opening.

[0126] Specifically, the directional blasting box has an opening, and when the opening is transported to the blasting opening of the joint unit at the top of the anchor rod, the directional blasting opening of the directional blasting box faces the upper blasting opening 9 or the side blasting opening 10 .

[0127] Among them, the interior of the directional blasting box is filled with explosives in the form of Broadsword dynamite. The explosion of Broadsword dynamite will blast towards the direction of the Broadsword dynamite filling port. The direction of blasting is determined when the directional blasting box is installed into the return air duct / blasting box duct. When the Broadsword dynamite is facing upwards, it blasts forward, and when the Broadsword dynamite is facing sideways, it blasts sideways.

[0128] At this point, the new curved anchor rod has achieved bypassing the weak layer through a mechanical steering structure, fixing the anchor rod in the hard layer and generating sufficient anchoring force.

[0129] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A tunnel anchor bolt structure, characterized in that: It comprises a joint unit (1), wherein a spherical groove (2) is arranged in the middle of the top of the joint unit (1), and a spherical body (3) is arranged in the middle of the bottom of the joint unit (1); The spherical grooves (2) and the spherical bodies (3) of two adjacent bone joint units (1) are connected in cooperation to form a ball joint structure, and a plurality of bone joint units (1) are connected in sequence through the ball joint structure to form an anchor rod; The condyle unit (1) is provided with a plurality of first through holes (4) communicating with the upper and lower surfaces of the condyle unit (1), and the plurality of first through holes (4) are evenly distributed on the surface of the condyle unit (1) close to the circumferential edge; the condyle unit (1) is provided with a second through hole (5) and a third through hole (6) communicating with the upper and lower surfaces of the condyle unit (1); Wherein, the second through holes (5) connecting the plurality of bone joint units (1) form an air return duct (12), and the third through holes (6) connecting the plurality of bone joint units (1) form an air inlet duct (13); It also comprises a plurality of steel cables (7), wherein the plurality of steel cables (7) correspond one by one to the plurality of first through holes (4) on the joint unit (1); The top of the steel cable (7) is connected to the joint unit (1) at the uppermost part of the anchor rod, and the end of the steel cable (7) sequentially passes through the first through holes (4) at the same position of the plurality of joint units (1) and extends to the bottom of the anchor rod to form a traction control end; Wherein, different forces are applied to the steel cable (7) through the plurality of traction control ends, and the bending angle of the anchor rod is controlled under the cooperation of the ball joint structure; A steering pipeline (11) is arranged in the joint unit (1) located at the top of the anchor rod, and the steering pipeline (11) is connected to the return air pipeline (12) and the inlet air pipeline (13).

2. A tunnel anchor bolt structure according to claim 1, characterized in that: A return air duct (12) is formed by connecting the second through holes (5) of a plurality of the joint units (1) via a first telescopic tube (15); The third through holes (6) of a plurality of the joint units (1) are connected via a second telescopic tube (16) to form an air inlet pipeline (13).

3. A tunnel anchoring bolt structure according to claim 1, characterized in that: An elastic outer layer (8) is sleeved on the outside of the anchor rod, and the top of the elastic outer layer (8) is sleeved on the bottom of the joint unit (1) at the top of the anchor rod.

4. A tunnel anchor bolt structure according to claim 2, characterized in that: The second through hole (5) of the joint unit (1) located at the top of the anchor rod forms an upper bursting hole (9) on the upper surface of the joint unit (1); A side blasting hole (10) is provided on the circumferential side wall of the bone joint unit (1) located at the top of the anchor rod, and the side blasting hole (10) is connected to the second through hole (5); The directional blasting explosive is transported to the upper blasting opening (9) or the side blasting opening (10) through the return air pipeline.

5. The tunnel anchor bolt structure according to claim 1, characterized in that: The cross section of the first through hole (4) is rectangular, and an R chamfer is formed at the corner of the first through hole (4).

6. A tunnel anchoring bolt structure according to claim 4, characterized in that: The upper bursting hole (9) and the side bursting hole (10) are connected at the top edge of the condyle unit (1).

7. A construction method for the tunnel anchor bolt structure according to claim 4 or 6, characterized in that: The steps include: Step 100, applying an axial upward force to the joint unit at the bottom of the anchor rod, and applying an axial downward force to the joint unit to multiple traction cables, so that the anchor rod as a whole remains stable; Step 200, drilling an initial hole at an anchor point set in the tunnel surrounding rock, and placing the upper surface of the joint unit at the top of the anchor rod against the bottom wall of the initial hole, and determining a blasting direction based on the initial hole, and orienting the upper blasting port or the side blasting port toward the blasting direction; Step 300: transporting blasting explosives to the upper blasting opening or the side blasting opening through the return air duct to perform blasting operations, and the rock debris generated by the blasting is discharged through the return air duct; Step 400, by changing the magnitude of the downward force of the multiple steel cables controlled by the multiple traction control ends along the axial direction of the joint units, the anchor rod is bent toward the direction of the surrounding rock cave created by the blasting, and the upward force applied to the joint unit at the bottom of the anchor rod is increased, so that the top of the anchor rod enters the surrounding rock cave; Step 500, repeating the blasting direction of the current surrounding rock cavern, directing the upper blasting opening or the side blasting opening of the joint unit of the anchor rod toward the blasting direction, conveying the blasting explosive through the return air duct, and steps 300 and 400, until a target hole of a set length and position is formed, and the anchor rod is fixed; Step 600: inject slurry into the return air duct and the air inlet duct to fill the target hole with the slurry, while keeping the traction cable taut, so that the slurry is fully solidified and the anchor rod is firmly connected to the rock mass of the target hole.

8. The construction method according to claim 7, characterized in that: When rock fragments generated by blasting enter the return air duct, high-pressure gas is pumped into the air inlet duct, and the high-pressure gas reaches the blasting port through the turning duct, carrying the rock fragments and being cleaned out through the return air duct.

9. The construction method according to claim 7, characterized in that: The probe lens and the temperature and humidity sensor are transported to the upper bursting port or the side bursting port through the air inlet pipe and the steering pipe.

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