CN116877159A - Expansion shell type combined anchor rod system and construction method - Google Patents

Abstract

The application relates to an expansion shell type combined hollow anchor rod system and a construction method, wherein one end of the anchor rod body is connected with an anchor head assembly through a connecting sleeve, the other end of the anchor rod body is used for extending out of surrounding rock and connecting the anchor head assembly, the connecting sleeve is provided with a grout outlet communicated with an internal space of the anchor rod body, the anchor head assembly comprises a rod body, one end of the rod body is connected with the connecting sleeve, the other end of the rod body is in threaded connection with an expansion anchor crown, the expansion anchor crown comprises a fixing part and a plurality of expansion parts arranged at the end part of the fixing part, the fixing part is in threaded connection with the rod body through a threaded through hole, and the rod body extends into the space among the expansion parts to enable the expansion parts to be opened.

Description

Expansion shell type combined anchor rod system and construction method

Technical Field

The application relates to the technical field of anchor rod support, in particular to a shell-expanding type combined anchor rod system and a construction method.

Background

The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art.

Current tunnel engineering can be classified into mountain tunnels passing under mountains or hills, underwater tunnels passing under rivers or seafloors, and so-called urban tunnels passing under cities. The tunnel is a linear structure built in surrounding rock with a certain stress history and a certain stress field, whether the tunnel is a mountain tunnel, an underwater tunnel or an urban tunnel, primary support of the tunnel is required to be implemented for ensuring the safety of a construction site, and at present, a spray anchor type support structure is mainly adopted for primary support construction in China, and the spray anchor type support structure is widely applied and comprises a spray anchor type concrete support, a spray anchor type concrete type steel arch support and a spray anchor type concrete type steel reinforcement net support, wherein the construction of the anchor is an important link of the spray anchor type support structure.

Traditional shell-expanding type anchor rod system concentrates on the junction of the expansion shell and the rod body, the expansion shell is easy to break, and after the expansion shell is tensioned, the rod body is displaced outwards of the anchor hole, the front end of the rod body and the rock wall form a section of cavity area, and the filling is compact by later grouting. The problem that grouting is not full easily occurs in grouting is solved, whether the bottom of an anchor hole is compact or not cannot be visually observed by human eyes, therefore, the traditional tension expansion shell type anchor rod system is not suitable for IV-level or V-level surrounding rocks with poor surrounding rock grades and large plastic deformation, besides the surrounding rocks are large in plastic deformation, factors such as large surrounding rock vibration and poor responsibility of anchor rod construction operators in drilling and blasting method construction enable the phenomenon of loose anchor device installation in anchor rod construction to be very common, the stress at the tail end of the anchor rod is small even zero due to loose anchor device installation, the anchoring effect of the anchor rod is reduced, and the whole reinforcing effect of the surrounding rocks and the anchor rod is also reduced. The above problems can increase the safety hazards of construction.

Disclosure of Invention

Aiming at the defects existing in the prior art, the application aims to provide a shell-expanding type combined hollow anchor rod system and a construction method, which overcome the problems existing in a tension shell-expanding type anchoring system and are suitable for anchoring surrounding rock under the working condition of poor surrounding rock grade.

In order to achieve the above object, the present application is realized by the following technical scheme:

in a first aspect, an embodiment of the present application provides an expansion shell type combined hollow anchor rod system, including an anchor rod body, one end of the anchor rod body is connected with an anchor head assembly through a connecting sleeve, the other end of the anchor rod body is used for extending to the outside of surrounding rock and connecting the anchor head assembly, the connecting sleeve is provided with a grout outlet hole communicated with an internal space of the anchor rod body, the anchor head assembly includes a rod body, one end of the rod body is connected with the connecting sleeve, the other end of the rod body is in threaded connection with an expansion anchor crown, the expansion anchor crown includes a fixing portion and a plurality of expansion portions arranged at the end of the fixing portion, the fixing portion is in threaded connection with the rod body through a threaded through hole, and the rod body extends into a space between the expansion portions so as to enable the expansion portions to expand.

Optionally, the inner side of the expansion part is provided with a plurality of grooves, correspondingly, the end part of the rod body is provided with flukes, and the flukes are embedded into the corresponding grooves so as to enable the expansion parts to be opened.

Optionally, the outer side surface of the expansion anchor crown is provided with patterns to increase friction force with surrounding rock.

Optionally, the space between the rod body and the expansion part is filled with an early strength anchoring agent.

Optionally, the anchor assembly includes a nut, a washer, a backing plate, and a grout stop sequentially disposed on the anchor body in a direction toward the surrounding rock.

Optionally, the surface that the backing plate is used for laminating the country rock is equipped with the interior section of thick bamboo that stretches rather than coaxial, and is corresponding, the end that the grout stop plug is used for contacting with the backing plate is equipped with and stretches a section of thick bamboo assorted annular draw-in groove in stretching.

Optionally, the side surface of the washer, which is used for contacting with the nut, is provided with a plurality of first linear teeth which are distributed in turn along the circumferential direction, the axes of the first linear teeth are arranged along the radial direction of the washer, the tooth surfaces of the first linear teeth and the plane perpendicular to the axis of the washer form a set first acute angle, the side surface of the other side of the washer is provided with a plurality of first arc teeth which are distributed in turn along the annular direction, the tooth surfaces of the first arc teeth and the plane perpendicular to the axis of the washer form a set second acute angle along the circumferential direction of the washer, the first acute angle is larger than the second acute angle, and the second acute angle is larger than the thread angle of the anchor rod body;

further, the width of the first curved-line tooth is 2 times of that of the first straight-line tooth, and the maximum thickness of the first curved-line tooth is the same as that of the first straight-line tooth;

further, the first acute angle is 25-35 degrees, and the second acute angle is 10-20 degrees.

Further, the side surface of the nut, which is used for being in contact with the gasket, is provided with second linear teeth matched with the first linear teeth, and the side surface of the base plate, which is used for being in contact with the gasket, is provided with second arc teeth matched with the first arc teeth.

Optionally, the gasket is provided with a plurality of vibration damping holes.

Optionally, the expansion anchor further comprises a sleeve, one end of the sleeve is provided with a plurality of limiting blocks, and correspondingly, the end part of the expansion anchor crown is provided with limiting grooves matched with the limiting blocks.

In a second aspect, an embodiment of the present application provides a construction method of the expansion shell type combined hollow anchor rod system according to the first aspect, including the following steps:

assembling an anchor rod body, a connecting sleeve and the rod body, connecting the fixed part of the expansion anchor crown with the rod body in a threaded manner, and putting an early strength anchoring agent into the space among a plurality of expansion parts of the expansion anchor pipe in advance;

placing the assembled anchor rod body, the connecting sleeve and the assembled anchor rod body into a pre-drilled anchor rod pore canal so that the expansion anchor crown reaches the bottommost part of the anchor rod pore canal;

the rod body is rotated, the rod body stretches into the space among the expansion parts and drives the expansion parts to open to be tightly pressed with the surfaces of the anchor rod pore canals, meanwhile, the early-strength anchoring agent is broken and extruded by the rod body, and the space among the expansion parts, the rod body and the surrounding rock is tightly filled;

one end of the anchor rod body is connected with the connecting sleeve, and an anchor assembly is arranged at the other end of the anchor rod body.

The beneficial effects of the application are as follows:

1. according to the anchor rod system and the construction method, the rod body is in threaded connection with the expansion anchor crown, after the rod body stretches into the space among the expansion parts of the expansion anchor crown, the expansion parts can be opened by pushing the rod body, and compared with the traditional method of opening the expansion shell by pulling the rod body, the phenomenon that the expansion shell is pulled out is avoided, and smooth construction of the anchor rod system is ensured.

2. According to the anchor rod system and the construction method, the space between the expansion part and the rod body is provided with the early-strength anchoring agent, after the rod body stretches into the space between the expansion parts, the early-strength anchoring agent can be burst and extruded, the space among the rod body, the expansion part and the surrounding rock is filled and compacted, a cavity area formed by the front end of the rod body and a rock wall is avoided, the later grouting filling process of the cavity area is omitted, the problem of insufficient grouting is avoided, the anchor head of the anchor rod system adopts a method of combining expansion part expansion with the early-strength anchoring agent to bond and anchor, the point anchoring effect is exerted, the pre-stress is exerted in time, the defect that the existing mechanical expansion anchor head requires good rock stratum conditions is overcome, the anchor rod system can be used for soft and weak rock stratum with good grade, large-section tunnel, high-ground stress rock burst, large deformation and other conditions, the application range is expanded, and the problem that the traditional mechanical extrusion expansion anchor head or the early-strength anchoring agent is only used in the early-stage is low, and initial tensile force cannot be effectively exerted is avoided.

3. According to the anchor rod system and the construction method, hole sealing is carried out through the base plate and the grout stop plug, the base plate is provided with the inner extending cylinder, the inner extending cylinder is used for being attached to the hole wall and clamped into surrounding rock, the base plate can play a primary fixing role, the installation construction operation of the whole anchor assembly is achieved, the anchor rod body can be centered in the anchor rod hole channel through the inner extending cylinder, the anchor rod body is prevented from leaning towards and clinging to the hole wall of one side of the anchor rod hole channel, and the thickness of the mortar protection layer is guaranteed.

4. According to the anchor rod system and the construction method, the side face of one side of the gasket is provided with the plurality of linear teeth, the side face of the other side of the gasket is provided with the plurality of arc teeth, the tooth face angle of the linear teeth is larger than the tooth face angle of the arc teeth and larger than the thread angle of the anchor rod body, the whole anchor device has good anti-loosening effect after being screwed, and the problem that a common backing plate and a nut are directly anchored and loose to lose efficacy is solved. In particular, in the blasting construction of large-section tunnels, weak surrounding rocks, high-ground stress rock burst and large deformation, sufficient anchoring force can effectively improve the stress state of the surrounding rocks, restrict the initial deformation rate of the surrounding rocks and control the development of the loose rings of the surrounding rocks.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application.

FIG. 1 is a schematic overall view of embodiment 1 of the present application;

FIG. 2 is a front view of an expanded anchor crown according to embodiment 1 of the present application;

FIG. 3 is a cross-sectional view of an expanded anchor crown according to example 1 of the present application;

FIG. 4 is a top view of an expanded anchor crown according to example 1 of the present application;

FIG. 5 is a bottom view of the expansion anchor crown of embodiment 1 of the present application;

FIG. 6 is a schematic view of the structure of an anchor arm of a rod body according to embodiment 1 of the present application;

FIG. 7 is a front view of a gasket according to embodiment 1 of the present application;

FIG. 8 is a top view of a gasket according to example 1 of the present application;

FIG. 9 is a bottom view of the gasket of embodiment 1 of the present application;

FIG. 10 is a front view of a nut according to embodiment 1 of the present application;

FIG. 11 is a bottom view of the nut of embodiment 1 of the present application;

FIG. 12 is a top view of a pallet according to embodiment 1 of the application;

FIG. 13 is a bottom view of the pallet of embodiment 1 of the present application;

FIG. 14 is a front view of a pallet according to embodiment 1 of the present application;

the novel concrete anchor comprises a nut 1, a gasket 2, a backing plate 3, a second exhaust hole 4, a slurry stop 5, an exhaust pipe 6, an anchor rod 7, a second slurry outlet 8, a connecting sleeve 9, a sleeve 10, a sleeve 11, a rod body 12, an expansion anchor crown 13, a second linear tooth 14, a first linear tooth 15, a first arc-shaped tooth 16, a vibration damping hole 17, a second arc-shaped tooth 18, a first exhaust hole 19, an inner extension cylinder 20, an inner threaded through hole 21, a barb-shaped groove 22, a limiting groove 23, an annular bulge 24 and an anchor arm.

Detailed Description

Example 1

The embodiment provides an expansion shell type combined hollow anchor rod system, which is used for grouting and reinforcing tunnel surrounding rock, especially, an anchor head part realizes an expansion anchoring effect through three layers of barb grooves of a supporting combination of an anchor claw and an expansion anchor crown, and an anchor rod body end anchor assembly is fixed through a supporting tooth surface of a nut, a gasket and a backing plate, the combined hollow anchor rod system is formed through the two aspects, so that the reinforcement of the tunnel surrounding rock is completed, the anchor claw of the rod body stretches into a plurality of expansion parts of the expansion anchor crown and is matched with the barb grooves on the inner side surfaces of the expansion parts, the expansion parts can be expanded, and meanwhile, an early strength anchoring agent is pre-placed in the expansion parts to serve as an anchoring material, and the anchor head part, the early strength anchoring agent and the hole wall of an anchor rod hole are tightly attached after expansion to serve as a preliminary anchor rod anchoring body, so that the anchor of an anchor rod body inlet end is anchored, and a supporting force is provided for the prestress of a subsequent construction time. The anchor rod system of this embodiment is sectionally combined to form a whole, and the lengths of the hollow anchor rod body and the solid anchor rod body are determined by the anchor rod design. The hollow grouting anchor rod has the advantages of convenient installation, timely application of prestress and good comprehensive mechanical property of the anchor rod body.

Specifically, as shown in fig. 1, the shell-expanding type combined hollow anchor rod system comprises an anchor rod body 7, wherein the anchor rod body 7 adopts a hollow structure, a cavity is formed in the anchor rod body 7, and an external thread structure is arranged on the whole length of the outer rod surface of the anchor rod body 7 so as to increase the bonding area with grouting materials and improve the anchoring force.

The inlet end of the anchor rod body 7 is in threaded connection with one end of the connecting sleeve 9, the inlet end of the anchor rod body 7 is provided with two rows of first grout outlet holes, preferably, each row is provided with four first grout outlet holes which are arranged at equal intervals along the circumferential direction, correspondingly, the end part of the connecting sleeve 9 connected with the anchor rod body is provided with two rows of second grout outlet holes 8 which correspond to the first grout outlet holes, the connecting sleeve 9 and the anchor rod body 7 relatively rotate to be communicated with the first grout outlet holes and the second grout outlet holes 8, and therefore grout injected into the inner space of the anchor rod body 7 can flow out through the first grout outlet holes and the second grout outlet holes 8.

One end of the connecting sleeve 9 is in threaded connection with the hole inlet end of the anchor rod body 7, the other end of the connecting sleeve is connected with the anchor head assembly, the anchor head assembly comprises a rod body 11 and an expansion anchor crown 12, the connecting sleeve 9 is in threaded connection with one end of the rod body 11, the rod body 11 is made of steel, the whole length of the outer surface of the rod body is provided with an external thread structure, in the embodiment, two ends of the connecting sleeve 9 are respectively provided with an internal thread structure, the thread shapes and the sizes of the internal thread structures at the two ends are different, one end of the connecting sleeve is matched with the external thread structure of the anchor rod body 7, and the other end of the connecting sleeve is matched with the external thread structure of the rod body 11.

One end of the rod body 11 is in threaded connection with the connecting sleeve 9, and the other end of the rod body is in threaded connection with the expansion anchor crown 12.

The outer side surface of the connecting sleeve 9 is also provided with a thread structure, so that the effect of increasing the bonding friction force is achieved.

In this embodiment, as shown in fig. 2-5, the expansion anchor crown 12 is made of steel material, the cross section is circular, and includes a fixing portion, the end face of the hole inlet end of the fixing portion is provided with a plurality of expansion portions that are disposed at equal intervals along the circumferential direction, preferably, the expansion portions are four, the expansion portions are made of elastic material, the center of the fixing portion is provided with an internal thread through hole 20, the rod 11 is in threaded connection with the fixing portion through the internal thread through hole 20, as shown in fig. 6, the end portion of the rod 11, which is used for being matched with the expansion anchor crown 2, is provided with an anchor arm 24, and the outer circumferential surface of the anchor arm 24 is provided with a plurality of barb grooves along the axial direction to form a plurality of flukes.

The barb type groove is characterized in that the groove is provided with a plane groove surface perpendicular to the axis of the anchor wall, the inner edge of the plane groove surface is connected with the bottom end of the conical groove surface, the conical groove surface gradually inclines outwards along the direction from the inlet end of the anchor arm to the other end, the sizes of the barb type grooves on the anchor arm are the same to form a plurality of flukes with the same size, and preferably, three flukes are arranged in the embodiment.

The inner side surface of the expansion part is provided with a plurality of barb type grooves 21 matched with the shape of the flukes along the axis direction of the expansion anchor crown, and three flukes are arranged, so that three barb type grooves 21 are arranged.

The volume of the space formed by the barb-shaped grooves 21 of the expansion parts gradually increases along the direction from the inlet end to the other end, wherein the volume of the smallest space formed by the barb-shaped grooves of the expansion parts is smaller than the volume of the flukes, so that the anchor arm 24 completely enters the space between the expansion parts, and after the three flukes are respectively matched with the barb-shaped grooves 21 of the corresponding expansion parts, the expansion parts can be opened to be tightly adhered to the hole wall of the anchor rod hole.

Further, the outer side surface of the expansion anchor crown 12 is provided with a plurality of annular protrusions 23 distributed along the axial direction of the expansion anchor crown to form patterns, and friction between the expansion part and the hole wall of the anchor hole channel can be increased through the patterns after the expansion part is attached to the hole wall of the anchor hole channel so as to improve the anchoring effect.

The barb type groove 21 is adopted to improve the pulling resistance of the rod body 11, match the patterns and match the internal thread through hole 20 of the fixing part, strengthen the anchoring effect and restrict the anchor rod body from being pulled out.

The inlet end of the fixing portion is provided with a plurality of expansion portions, and the end face of the other end of the fixing portion is provided with limiting grooves 22, in this embodiment, the limiting grooves 22 are arc-shaped grooves, four limiting grooves 22 are arranged at equal intervals along the circumferential direction, and the four limiting grooves 22 are located on the same circumference.

Correspondingly, the hollow anchor rod system further comprises a sleeve 10, an arc-shaped limiting block matched with the arc-shaped groove 22 is arranged on the end face of the inlet end of the sleeve 10, the thickness of the limiting block is slightly smaller than the width of the limiting groove 22, when the hollow anchor rod system is used, the limiting block at the end of the sleeve 10 is inserted into the corresponding limiting groove 22, the sleeve 10 is fixed when the rod body 11 is rotated, and then the expansion anchor crown 12 is fixed through the limiting block and the limiting groove 22, so that torsion force is provided when the rod body 11 is rotated to push the expansion anchor crown 12, and the rod body 11 cannot be pushed due to slipping between the expansion anchor crown 12 and surrounding rock. Meanwhile, in soft surrounding rock with poor properties, the sleeve 10 plays a role in preventing holes from collapsing when the rod body 11 is pushed in and in the anchoring process of the anchor head assembly, and can be pulled out after the anchor head assembly forms an initial point anchor effect.

After the expansion anchor crown 12 is placed into the bottom of the anchor rod pore canal, the expansion part can be opened by rotating the pushing rod body 11, supporting force is generated immediately after the expansion part is opened and locked, the rock mass is clamped immediately by a local point anchor mode, a pressure arch is formed, and the development of a surrounding rock loose ring is restrained.

The expansion part is opened by pushing the rod body 11, so that compared with the traditional method of opening the expansion shell by pulling the rod body, the phenomenon that the expansion shell is broken by pulling is avoided, and the smooth construction of the anchor rod system is ensured.

In this embodiment, the space between the expansion part and the rod body 11 is filled with an early strength anchoring agent, preferably, a quick-gelling early strength resin cartridge is used as the early strength anchoring agent.

After the rod body 11 is rotationally pushed in, the early-strength anchoring agent can be extruded and burst, so that the space among the expansion part, the rod body 11 and the surrounding rock is filled tightly with the early-strength anchoring agent.

By arranging the early strength anchoring agent, the cavity area formed by the front end of the rod body and the rock wall is avoided, the process of grouting and filling the cavity area in the later period is also omitted, the problem of unsatisfactory grouting is also avoided, the anchor head of the anchor rod system adopts a method of combining expansion of the expansion part with the bonding and anchoring of the early strength anchoring agent, the point anchoring function is exerted to apply prestress in time, the defect of good rock stratum condition required by the existing mechanical expansion anchor head is overcome, the method can be used for not only the rock stratum with good grade, but also the stratum conditions such as weak broken rock stratum with poor grade, large-section tunnel, high-ground stress rock burst and large deformation, the application range is expanded, and the problem that the expansion anchor head is extruded by traditional mechanical anchoring or the initial tension cannot be effectively applied due to low early strength of the traditional mechanical anchoring agent is avoided.

One end of the anchor rod body 7 is connected with the anchor head assembly through a connecting sleeve 9, and the other end is connected with the anchor assembly.

The anchor assembly comprises a nut 1, a gasket 2, a backing plate 3 and a grout plug 5 which are sequentially arranged on an anchor body.

The nut 1, the washer 2 and the backing plate 3 are used for being arranged on a rod section of the anchor rod body 7 extending out of surrounding rock, and the grout stop plug 5 is used for being arranged inside an anchor rod pore canal and at an orifice position.

As shown in fig. 7 to 14, the washer 2 is provided with a plurality of first linear teeth 14 on the outer side surface contacting with the nut 1 along the circumferential direction, the long axis of the first linear teeth 14 is arranged along the radial direction of the washer 2, and the tooth surface of the first linear teeth 14 is arranged at a set first acute angle with the plane perpendicular to the axis of the washer 2 along the circumferential direction of the washer 2, and the first acute angle is 25 ° -35 °, preferably 30 °.

Correspondingly, the inner side surface of the nut 1, which is used for being contacted with the gasket 2, is provided with a plurality of second linear teeth 13 matched with the first linear teeth 14 along the circumferential direction, and after the nut 1 is contacted with the gasket 2, the first linear teeth 14 and the second linear teeth 13 are meshed with each other. The nut 1 adopts a regular hexagonal prism structure, the contact surface with the gasket 2 is removed, and the rest surfaces of the nut 1 are smooth surfaces.

The side surface of the gasket 2, which is used for being in contact with the backing plate 3, is provided with a plurality of first arc-shaped teeth 15 along the circumferential direction of the gasket, the tooth surfaces of the first arc-shaped teeth 15 are arranged at a set second acute angle with a plane perpendicular to the axis of the gasket 2, and the second acute angle is 10 degrees to 20 degrees, preferably 15 degrees. The degree of the first acute angle is greater than the degree of the second acute angle, and the degree of the second acute angle is greater than the thread angle of the external thread structure of the anchor body 11.

The width of the first curved-line type teeth 15 is 2 times the width of the first curved-line type teeth 14, i.e., the width of the first curved-line type teeth 15 is 2 times the width of the first curved-line type teeth 14 at the same position in the radial direction of the gasket 2. The first linear teeth 14 and the first arcuate teeth 15 form tooth slots of the same depth.

The backing plate 3 comprises a plate body, a second arc-shaped tooth 17 matched with the first arc-shaped tooth 15 is arranged on one side surface of the plate body, and after the gasket 2 is contacted with the backing plate 3, the first arc-shaped tooth 15 and the second arc-shaped tooth 17 are meshed with each other.

By the construction of the straight-line teeth and the curved-line teeth, the anchoring forces aimed at reinforcing the nut 1 and the backing plate 3 can be explained as: if one side of the washer 2 has a reverse loosening trend, the nut 1 or the backing plate 3 overcomes the meshing friction force of the tooth surface of the washer 2 and also overcomes the meshing friction force of the tooth surface of the other side of the washer 2, and the reverse loosening constraint force occurs due to different inclination angles of two sides and different tooth socket shapes, so that a good loosening prevention effect is achieved, and the problem of direct anchoring loosening failure of the common backing plate and the nut is solved. In particular, in the blasting construction of large-section tunnels, weak surrounding rocks, high-ground stress rock burst and large deformation, sufficient anchoring force can effectively improve the stress state of the surrounding rocks, restrict the initial deformation rate of the surrounding rocks and control the development of the loose rings of the surrounding rocks.

A plurality of vibration reduction holes 16 are formed in the gasket 2 at equal intervals along the circumferential direction, and the vibration reduction effect of the nut 1 and the backing plate 3 is achieved, so that the anchor assembly is prevented from being broken and invalid due to the fact that the vibration frequency is too high or the amplitude is too high.

The side surface of the other side of the plate body is used for being in contact with the surface of the surrounding rock and is a concave arc-shaped surface, and the concave arc-shaped surface can be better attached to the rock body. The center of the side surface of the plate body is provided with an inner extending cylinder 19 coaxial with the plate body, the outer diameter of the inner extending cylinder 19 is slightly smaller than the diameter of the anchor rod pore canal, and the inner extending cylinder can be clamped into the anchor rod pore canal.

Further, grooves which are arranged along the ring shape are arranged on the inner ring surface of the gasket, which is used for being contacted with the anchor rod body, so that the friction force of the contact surface is increased.

Along the outside of the anchor rod pore canal to the inside direction, the cross section area of the grout stop plug 5 is gradually reduced, the end part with larger area is provided with an annular clamping groove, and the inner extension cylinder 19 can be clamped into the annular clamping groove.

The inner extension tube 19 and the slurry stop plug 5 are jointly combined and compacted ^{In the following} Anchor rodThe pore wall of the pore canal, the inner extension cylinder 19 enables radial acting force to exist between the backing plate 3 and the pore wall of the pore canal of the anchor rod, preliminary fixation is achieved, the anchor rod body 7 is centered, the anchor rod body 7 is prevented from deflecting to one side of the pore wall to influence the anchor rod strength after grouting, the thickness of a mortar protection layer is guaranteed, and construction and installation are facilitated.

Be provided with first exhaust hole 18 on the plate body of backing plate, correspondingly, be provided with the second exhaust hole 4 that corresponds with first exhaust hole 18 on the grout stop plug 5 for the air in the discharge stock pore when grouting, the convenience is under construction, blast pipe 6 can be put into to first exhaust hole 18 and second exhaust hole 4.

In this embodiment, the anchor rod body 7 is used for injecting slurry, the injected slurry adopts the expansion cement mortar, the early strength of the expansion cement is high, the later strength is increased greatly, the long-term strength is stably increased, the self inside of the reinforced expansion cement is provided with expansion self-stress, stronger bond force is generated after the reinforced expansion cement is combined with the anchor rod body, the expansion cement mortar is used for rapidly realizing the expansion hardening of filling the gaps and filling holes, so as to strengthen the anchoring capability of the anchor rod, and the reinforced expansion cement mortar has good anchoring effect on weak surrounding rock and good waterproofness and durability.

When the anchor rod system is installed upwards, i.e. the anchor rod duct extends upwards, the exhaust pipe 6 is installed in the exhaust holes of the backing plate 3 and the grout stop 5, and the end of the exhaust pipe 6 extends to the expansion anchor crown 12.

Grouting liquid is injected from the anchor rod body 7, is discharged through two rows of second grout outlet holes 8 of the connecting sleeve 9 and gradually overflows an anchor rod pore canal, the grouting liquid flows upwards from the orifice of the anchor rod pore canal until the anchoring position of the bottom of the anchor rod pore canal, and air in the anchor rod pore canal is gradually discharged from the bottom of the anchor rod pore canal through the pre-inserted exhaust pipe 6.

When the anchor rod is installed downwards, namely when the anchor rod pore canal extends downwards, the exhaust pipe 6 is not installed, the slurry gradually flows to the orifice from the anchoring position at the bottom of the hole, the air in the hole is directly discharged from the exhaust holes of the backing plate 3 and the grout stop plug 5, and the specific grouting upwards and grouting downwards functions improve the reliability of the grouting of the anchor rod.

Example 2

The embodiment provides an anchoring method of the expansion shell type combined hollow anchor rod system described in the embodiment 1, comprising the following steps:

after the drilling of the anchor rod pore canal is finished, connecting the anchor rod body 7 and the anchor rod body 11 by using the connecting sleeve 9 in advance, connecting the end part of the anchor rod body 11 with the expansion anchor crown 12 in a threaded manner, filling an early strength anchoring agent into a space between the expansion parts of the expansion anchor crown 12, and inserting the assembled anchor rod body, the assembled anchor rod body and the assembled expansion anchor crown into the anchor rod pore canal.

Then one end of the sleeve 10 is clamped into a limiting groove at the end part of the expansion anchor crown through a limiting block, a grout stop plug 5 and a backing plate 3 are arranged at the end part of the anchor rod body 7, a gasket 2 and a nut 1 are sleeved, and then the sleeve 10, the connected anchor rod body 7, the rod body 11 and the expansion anchor crown 12 are inserted into an anchor rod pore canal until reaching the bottom of the anchor rod pore canal.

The sleeve 10 is propped against, pressure is applied to the anchor rod body 7 and drives the anchor rod body to rotate, the anchor rod body 7 drives the rod body 11 to rotate through the connecting sleeve 9, the anchor arms 24 of the rod body 11 enter spaces among a plurality of expansion parts of the expansion anchor crown 12, the flukes are clamped into barb type grooves 21 of the expansion parts and drive the expansion parts to expand, the expansion parts extrude the hole wall of an anchor rod hole, and meanwhile, the anchor arms 24 burst and extrude the early-strength anchoring agent, so that the space among the expansion parts, the anchor arms 24 and surrounding rocks is closely filled by the early-strength anchoring agent, and the anchoring of the anchor head assembly is realized.

When the anchor head assembly is anchored, the grout stop plug 5 and the inward extending cylinder 19 of the backing plate 3 are inserted into the anchor rod pore canal to be fixed, the centering of the anchor rod body 7 is realized, and after the anchor head assembly is anchored, the nut 1 is screwed.

Grouting is carried out on the anchor rod pore canal through the anchor rod body 7, and after the set design strength is reached, the anchor rod body 7 is tensioned to apply prestress.

The anchoring method of the present embodiment includes the following detailed steps:

(1) Preparing, namely preparing all parts of components of the expansion shell type combined hollow anchor rod system and matched installation equipment, assembling an initial anchoring device according to the drawing requirements, and preparing quick hardening expansion cement slurry;

(2) Measuring and marking, namely measuring and lofting after the formation of a concrete surface layer is completed by primary spraying of a tunnel, determining the drilling position of an anchor rod and marking;

(3) Drilling. The intelligent anchor rod trolley is used for drilling, the drill bit is a high-precision drill bit suitable for the anchor rod system of the embodiment, and the existing drill bit is adopted, so that the detailed description is omitted.

(4) And (5) cleaning the holes. The broken stone in the anchor rod pore canal is flushed by the compressed air or high-pressure water carried by the intelligent anchor rod trolley.

(5) And inserting an anchor rod. The anchor rod body 7 and the rod body 11 are connected by the connecting sleeve 9 in advance, then the anchor arm hole inlet end of the rod body 11 is clamped into the first layer barb type groove 21 of the expansion anchor crown 12, the early strength anchoring agent is placed in the position of the residual barb type groove 21, and the assembled nut 1, the gasket 2, the backing plate 3, the grout stop plug 5, the anchor rod body 7, the rod body 11, the connecting sleeve 9 and the combined rod body formed by the expansion anchor crown 12 in the anchor rod warehouse are inserted into the drilled anchor rod pore canal by the intelligent anchor rod trolley.

Specific: the rod body 11 is clamped into the first layer barb groove 21 of the expansion anchor crown 12, in this state, the thread of the rod body 11 just starts to be screwed into the internal thread through hole 20 of the expansion anchor crown fixing part, meanwhile, the limiting block of the sleeve 10 is clamped into the limiting groove 22 of the expansion anchor crown 12, and the early strength anchoring agent is placed in the position of the residual barb groove 21 of the expansion anchor crown 12, and adopts an early strength cement cartridge. The intelligent anchor rod trolley synchronously pushes the sleeve 10 and the combined rod body into the anchor rod pore canal, and the expansion part of the expansion anchor crown 12 is not required to be opened during pushing, so that the minimum diameter state of the expansion anchor crown is maintained, and the anchor head assembly is ensured to smoothly reach the bottommost part of the anchor rod pore canal.

(6) And rotating the pushing rod body. The anchoring machine of the intelligent anchoring trolley drives the anchoring body 7 to rotate, three flukes of the anchoring body 11 are smoothly clamped into three layers of barb type grooves 21 of the expansion anchor crown 12 through the anchoring body 7 and the connecting sleeve 9, the expansion part of the expansion anchor crown 12 is fully opened at the bottom of an anchor rod pore canal, meanwhile, the anchoring body breaks and extrudes the early-strength anchoring agent and is filled and compacted at the anchor head part, and at the moment, the anchor head assembly is tightly and firmly attached to the circumferential direction and the front hole wall of the anchoring body 11, so that the early-strength anchoring body is formed.

(7) And (5) installing an anchor. The intelligent anchor rod trolley is provided with a grout stop 5, a backing plate 3, a gasket 2 and a nut 1 on an anchor rod body 7 in sequence before the anchor rod is installed in an anchor rod warehouse. And after the early-strength anchoring body at the anchor head assembly reaches the required strength, the nut 1 is rotated to anchor the backing plate 2, the gasket 2 and the nut 1, and then the nut 1 is rotated by the anchoring machine to perform preliminary prestress application, so that the anchor body 7 is fixed in the anchor rod pore canal after the anchor assembly and the anchor head assembly are anchored.

(8) And (5) applying prestress. The anchor body 7 can be tensioned by an anchor machine, an anchor tensioning instrument, a torque wrench or the like of the intelligent anchor trolley, and the nut 1 is screwed, so that the anchor body 7 is prestressed to a specified value. The on-site quick construction can also be performed by adopting a rated torque pneumatic wrench after a process test.

(9) Grouting. The grouting material uses quick hardening expansion cement slurry, and all slurry in the feeder is pumped back to the feeder before grouting, so that the slurry is fully mixed by the pump and then grouting of the anchor rod is carried out. Thus, the slurry has good workability and good grouting effect. Before grouting, plastic sleeves with required lengths can be arranged on the outer side of the anchor rod body 7 to form the free end of the anchor rod for applying high prestress.

(10) And (5) quality detection. And (5) performing construction quality inspection by adopting an anchor rod nondestructive detector and the like.

According to the hollow anchor rod system, the anchor head assembly is fully contacted with the annular surrounding rock body in front of the rod body due to pressure expansion, the anchoring agent is used for filling joints, the early anchoring body and the rock body at the anchor head assembly have sufficient connectivity, a stable whole is formed, and the reliability of the whole anchor rod support is improved.

The structural design of the nut, the gasket and the backing plate with tooth grooves ensures that the anchor assembly has sufficient anchoring force and good looseness prevention effect.

Because the anchor rod body is adopted for centering, the full self-waterproof expansion slurry can ensure that the rod body does not lose efficacy for a long time. The exhaust pipe can be disassembled, and the upper and lower dip angles can be applied according to actual conditions.

The combined hollow anchor rod system of the embodiment meets the actual construction requirements in each performance, and is convenient to construct. Can be widely popularized and used in surrounding rock tunnels of various grades.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. The utility model provides a shell-expanding type combined hollow anchor rod system, its characterized in that, including the stock body, stock body one end is connected with anchor head subassembly through the adapter sleeve, and the other end of stock is used for stretching out to the country rock outside and connects the ground tackle subassembly, and the adapter sleeve is equipped with the play thick liquid hole with the inside space intercommunication of stock, the anchor head subassembly includes the body of rod, body of rod one end is connected with the adapter sleeve, and the other end threaded connection has the inflation anchor crown, and the inflation anchor crown includes fixed part and sets up a plurality of inflation portions at the fixed part tip, and the fixed part passes through threaded through hole and body of rod threaded connection, and the body of rod stretches into the space between a plurality of inflation portions so that a plurality of inflation portions open.

2. A shell-and-tube hollow bolt system according to claim 1, wherein the inner side of the expansion portion is provided with a plurality of recesses, and the end of the bolt body is provided with flukes which engage in corresponding recesses to expand the plurality of expansion portions.

3. A expansion shell type combined hollow bolt system according to claim 1, wherein the outer side of the expansion anchor crown is provided with a pattern to increase friction with surrounding rock.

4. A shell-and-tube composite hollow bolt system according to claim 1, wherein the space between the bolt body and the expansion is filled with an early strength anchoring agent.

5. A expansion shell type composite hollow bolt system according to claim 1, wherein the anchor assembly comprises nuts, washers, pads and grout stop plugs for sequential placement on the bolt body in a direction toward the surrounding rock.

6. A shell-and-rise type composite hollow anchor rod system as claimed in claim 5, wherein the surface of the backing plate for being attached to the surrounding rock is provided with an inner extension tube coaxial with the backing plate, and correspondingly, the end of the grout stop plug for being contacted with the backing plate is provided with an annular clamping groove matched with the inner extension tube.

7. The expansion shell type combined hollow anchor rod system as claimed in claim 5, wherein the side surface of the gasket, which is used for being contacted with the nut, is provided with a plurality of first linear teeth which are sequentially distributed along the circumferential direction of the gasket, the axes of the first linear teeth are arranged along the radial direction of the gasket, the tooth surfaces of the first linear teeth are arranged at a set first acute angle with a plane perpendicular to the axis of the gasket along the circumferential direction of the gasket, the side surface of the other side of the gasket is provided with a plurality of first arc-shaped teeth which are sequentially distributed along the circumferential direction of the gasket, the tooth surfaces of the first arc-shaped teeth are arranged at a set second acute angle with the plane perpendicular to the axis of the gasket, and the first acute angle is larger than the second acute angle, and the second acute angle is larger than the thread angle of the anchor rod body;

further, the width of the first curved-line tooth is 2 times of that of the first straight-line tooth, and the maximum thickness of the first curved-line tooth is the same as that of the first straight-line tooth;

further, the first acute angle is 25-35 degrees, and the second acute angle is 10-20 degrees;

further, the side surface of the nut, which is used for being in contact with the gasket, is provided with second linear teeth matched with the first linear teeth, and the side surface of the base plate, which is used for being in contact with the gasket, is provided with second arc teeth matched with the first arc teeth.

8. A shell-and-tube hollow bolt system according to claim 7, wherein the washer is provided with a plurality of vibration dampening holes.

9. The expansion shell type combined hollow anchor rod system as claimed in claim 1, further comprising a sleeve, wherein one end of the sleeve is provided with a plurality of limiting blocks, and correspondingly, the end part of the expansion anchor crown is provided with limiting grooves matched with the limiting blocks.

10. A method of constructing a shell-and-tube composite hollow bolt system according to any one of claims 1 to 9, comprising the steps of:

assembling an anchor rod body, a connecting sleeve and the rod body, connecting the fixed part of the expansion anchor crown with the rod body in a threaded manner, and putting an early strength anchoring agent into the space among a plurality of expansion parts of the expansion anchor pipe in advance;

placing the assembled anchor rod body, the connecting sleeve and the assembled anchor rod body into a pre-drilled anchor rod pore canal so that the expansion anchor crown reaches the bottommost part of the anchor rod pore canal;

the rod body is rotated, the rod body stretches into the space among the expansion parts and drives the expansion parts to open to be tightly pressed with the surfaces of the anchor rod pore canals, meanwhile, the early-strength anchoring agent is broken and extruded by the rod body, and the space among the expansion parts, the rod body and the surrounding rock is tightly filled;

one end of the anchor rod body is connected with the connecting sleeve, and an anchor assembly is arranged at the other end of the anchor rod body.