Expansion shell type anchor rod and construction method thereof

Abstract

The invention discloses an expansion shell type anchor rod which comprises an anchor rod body, a nut, an antifriction gasket, a spherical gasket and a cushion plate with a wedge-shaped groove, the nut, the antifriction gasket, the spherical gasket and the cushion plate with the wedge-shaped groove are sequentially arranged on the anchor rod body, and the expansion shell type anchor rod further comprises an inner conical sleeve and an end conical sleeve; the anchor rod body is a variable-thread-direction rod body and comprises an inner threaded rod body, a middle threaded rod body and an outer threaded rod body, and the thread direction of the middle rod body is opposite to the thread direction of the inner rod body and the thread direction of the outer rod body; the inner conical sleeve is in threaded connection with the middle-section rod body, the end conical sleeve is in threaded connection with the outer-section rod body, and one end of the end conical sleeve is arranged outside the outer-section rod body. When the expansion shell anchoring device is applied, the defects that traditional expansion shell anchoring is only one-way anchoring, and the anchoring performance of the expansion shell piece cannot be fully exerted are overcome, two-way anchoring of the expansion shell is achieved, the structure stress is better, meanwhile, the anchoring performance is more reliable, and the anchoring force is improved.

Description

Technical Field

[0001] The invention relates to the field of tunnel support, in particular to an expansion shell type anchor rod and a construction method thereof. Background Art

[0002] Shell-expanding anchors are widely used in tunnels and underground projects because of their fast anchoring and easy installation. However, there are some shortcomings in their use. The "single-sided" anchoring form leads to poor anchoring reliability, especially in tunnels affected by impact loads. The anchoring force decreases very commonly and significantly. Therefore, how to improve anchoring reliability and enhance anchoring performance has become a problem that needs to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art, such as poor anchoring reliability of the "single-sided" anchoring form of the expanding shell anchor rod and the general and obvious reduction of the anchoring force in the tunnel affected by the impact load, and to provide an expanding shell anchor rod which, when used, utilizes the symmetry of the expanding shell anchoring to improve the anchoring reliability and anchoring performance.

[0004] The purpose of the present invention is mainly achieved through the following technical solutions:

[0005] An expansion shell type anchor rod, comprising an anchor rod body, a nut, a friction-reducing washer, a spherical washer and a pad with a wedge groove, wherein the nut, friction-reducing washer, spherical washer and pad with a wedge groove are sequentially arranged on the anchor rod body, and also comprises an internal tapered sleeve and an end tapered sleeve; the anchor rod body is a variable thread direction rod body, comprising three sections of threaded rod bodies, namely, inner, middle and outer sections, wherein the thread direction of the middle section of the rod body is opposite to the thread directions of the inner section of the rod body and the outer section of the rod body; the internal tapered sleeve is threadedly connected to the middle section of the rod body, the end tapered sleeve is threadedly connected to the outer section of the rod body, and one end of the end tapered sleeve is placed outside the outer section of the rod body; the internal tapered sleeve and the end tapered sleeve are both provided with steel expansion shell sheets, and the barbs of the steel expansion shell sheets arranged on the internal tapered sleeve and the end tapered sleeve are in opposite directions. In the prior art, the inventors found that most of the expansion shell anchor rods are anchored in the form of "single-sided" anchoring, that is, the barbs of the expansion shell pieces are all facing the same side, which makes the anchoring reliability of the expansion shell anchor rod poor, especially in tunnels affected by impact loads, the anchoring force decreases very commonly and obviously. Based on this, the inventors invented an expansion shell anchor rod to solve the shortcomings of the "single-sided" anchoring form of the expansion shell anchor rod, which has poor anchoring capacity and a common and obvious decrease in anchoring force in tunnels affected by impact loads. In this scheme, in addition to the nuts, anti-friction washers, spherical washers and pads with wedge grooves arranged in sequence on the anchor rod body, the anchor rod body is set to three sections, namely the inner rod body, the middle rod body and the outer rod body, and the thread direction on the middle rod body is opposite to the thread direction on the inner rod body and the outer rod body, wherein, during installation, the nuts, anti-friction washers, spherical washers and pads with wedge grooves are installed on the inner rod body, and the outer rod body faces the inside of the anchor hole. In this solution, an internal conical sleeve and an end conical sleeve are respectively provided on the middle rod body and the outer rod body, and steel expansion shell plates are provided on the internal conical sleeve and the end conical sleeve. The barbs of the steel expansion shell plates provided on the internal conical sleeve and the end conical sleeve are in opposite directions, so that bidirectional anchoring is achieved by the steel expansion shell plates provided on the internal conical sleeve and the end conical sleeve during anchoring, thereby improving the anchoring reliability and anchoring performance.Different from the prior art in which the anchor rod body is set as a single-section form, this solution innovatively sets the anchor rod body as a three-section form, wherein the thread direction of the middle section rod body is opposite to the thread direction of the inner section rod body and the outer section rod body, and an inner tapered sleeve and an end tapered sleeve are respectively provided on the middle section rod body and the outer section rod body, and steel expansion shell plates are respectively provided on the inner tapered sleeve and the end tapered sleeve. Therefore, when the anchor rod body is installed, when the anchor rod body is pushed to the bottom of the anchor hole, one end of the end tapered sleeve is placed outside the outer section rod body, so that the end tapered sleeve reaches the bottom of the anchor hole. When the inner tapered sleeve and the end tapered sleeve are installed and the nut is tightened, in the process that the outer section rod body reaches the bottom of the end tapered sleeve, the inner tapered sleeve also approaches the end tapered sleeve. When the outer section rod body reaches the bottom of the end tapered sleeve, the expansion shell plates installed on the inner tapered sleeve and the end tapered sleeve expand to achieve two-way anchoring. It is worth noting that in this solution, the anchor rod body is a hollow anchor rod to achieve the grouting function. When installing the steel expansion shell sheet, the steel expansion shell sheet is fixed to the inner conical sleeve and the end conical sleeve by fixing the binding wire, and an anti-slip steel sheet is provided to prevent the steel expansion shell sheet from falling off during the process of pushing the anchor rod body into the anchor hole. A grouting exhaust pipe is also provided on the wedge-shaped groove pad of this solution to discharge the gas in the anchor hole during the grouting process.

[0006] Furthermore, the end conical sleeve includes a first cylindrical hollow sleeve and a first conical hollow sleeve which are fixedly connected, wherein the first conical hollow sleeve is placed on a side close to the middle section of the rod body with the conical surface facing the middle section of the rod body; a first outer limit and an inner limit are provided on the side of the first cylindrical hollow sleeve away from the first conical hollow sleeve, wherein the first outer limit is arranged around the outer wall of the first cylindrical hollow sleeve, the inner limit is arranged on the inner wall of the first cylindrical hollow sleeve, and the inner limit is provided with a center hole connected to the interior of the first cylindrical hollow sleeve.

[0007] Furthermore, the outer wall of the first conical hollow sleeve is provided with three first extended convex arcs and three first small concave arcs, wherein the three first extended convex arcs are distributed around the first conical hollow sleeve array, and the three first small concave arcs are spaced between the three first extended convex arcs.

[0008] Furthermore, the internal conical sleeve includes a second cylindrical hollow sleeve and a second conical hollow sleeve fixedly connected, wherein the second conical hollow sleeve is placed on a side close to the outer rod body with the conical surface facing the outer rod body; a second outer limit is provided on a side of the second cylindrical hollow sleeve away from the second conical hollow sleeve, and the second outer limit is arranged around the outer wall of the second cylindrical hollow sleeve.

[0009] Furthermore, the outer wall of the second conical hollow sleeve is provided with three second extended convex arcs and three second small concave arcs, wherein the three second extended convex arcs are distributed in an array around the second conical hollow sleeve, and the three second small concave arcs are spaced between the three second extended convex arcs.

[0010] Furthermore, an extended concave arc and a large concave arc are provided on the inner side of the steel expansion shell sheet, wherein the extended concave arc matches the first extended convex arc and / or the second extended convex arc, and the large concave arc matches the outer contour of the first cylindrical hollow sleeve and / or the outer contour of the second cylindrical hollow sleeve.

[0011] Furthermore, the barb angle of the steel shell expansion piece is greater than 45°.

[0012] Furthermore, the shell-expanding anchor described in the present application also includes a positioning steel sheet, the two ends of which are respectively fixed to the inner conical sleeve and the end conical sleeve by fixing screws, and the positioning steel sheet is fixed to the steel shell-expanding sheet by fixing screws. The present application provides a positioning steel sheet when installing the steel shell-expanding sheet, and connects the steel shell-expanding sheet to the inner conical sleeve and the end conical sleeve by fixing screws and the positioning steel sheet.

[0013] In a second aspect, the present application further provides a construction method of an expansion shell anchor, characterized in that the expansion shell anchor as described above is used, comprising the following steps:

[0014] S1: Screw the inner conical sleeve into the middle rod body, screw the end conical sleeve into the outer rod body, and install steel shell expansion plates on the inner conical sleeve and the end conical sleeve;

[0015] S2: Install the nut, anti-friction washer, spherical washer and the pad with wedge groove on the inner rod body in sequence;

[0016] S3: Determine the target rock mass, drill the anchor hole, and push the anchor rod to the bottom of the anchor hole;

[0017] S4: Tighten the nut to a predetermined torque;

[0018] S5: Grouting is performed through the anchor body to complete the anchor installation.

[0019] In summary, compared with the prior art, the present invention has the following beneficial effects: the present invention changes the traditional expansion shell anchoring that is only one-way anchoring and cannot give full play to the deficiency of the expansion shell plate anchoring performance, and adopts an internal conical sleeve and an end conical sleeve respectively arranged on the middle rod body and the outer rod body, and a steel expansion shell plate is arranged on the internal conical sleeve and the end conical sleeve, and the barbs of the steel expansion shell plate arranged on the internal conical sleeve and the end conical sleeve are in opposite directions, so that during anchoring, bidirectional anchoring is achieved by the steel expansion shell plate arranged on the internal conical sleeve and the end conical sleeve, while the structural force is better, and the anchoring reliability and anchoring performance are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0021] Figure 1 It is a structural cross-sectional view of a specific embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of a specific embodiment of the present invention during anchoring;

[0023] Figure 3 It is a structural schematic diagram of a specific embodiment of the present invention;

[0024] Figure 4 for Figure 1 A schematic diagram of the structure of the tapered sleeve at the middle end;

[0025] Figure 5 for Figure 1 Schematic diagram of the structure of the shell expansion plate made by China Steel.

[0026] The names corresponding to the reference numerals in the accompanying drawings are: 10, anchor body; 11, inner rod body; 12, middle rod body; 13, outer rod body; 20, inner tapered sleeve; 30, end tapered sleeve; 31, center hole; 32, inner limit; 33, first outer limit; 34, first small concave arc; 35, first extended convex arc; 38, first conical hollow sleeve; 39, first cylindrical hollow sleeve; 41, anti-slip steel sheet; 42, fixing wire; 43, positioning steel sheet; 44, fixing screw; 50, steel expansion sheet; 55, extended concave arc; 56, large concave arc; 57, expansion sheet; 5, spherical washer; 6, grouting exhaust pipe; 7, nut; 8, pad with wedge groove; 9, anti-friction washer. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary implementation modes of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0028] Example:

[0029] like Figure 1 to Figure 5As shown, an expansion shell anchor comprises an anchor body 10, a nut 7, a friction-reducing washer 9, a spherical washer 5 and a pad 8 with a wedge groove, wherein the nut 7, the friction-reducing washer 9, the spherical washer 5 and the pad 8 with a wedge groove are sequentially arranged on the anchor body 10, and further comprises an inner tapered sleeve 20 and an end tapered sleeve 30; the anchor body 10 is a variable thread direction rod body, comprising an inner, middle and outer three-section threaded rod body, wherein the thread direction of the middle section rod body 12 is the same as that of the inner section rod body 1 1 and the outer rod body 13 have opposite thread directions; the inner conical sleeve 20 is threadedly connected to the middle rod body 12, the end conical sleeve 30 is threadedly connected to the outer rod body 13, and one end of the end conical sleeve 30 is placed outside the outer rod body 13; the inner conical sleeve 20 and the end conical sleeve 30 are both provided with steel shell expansion pieces 50, and the barb directions of the steel shell expansion pieces 50 provided on the inner conical sleeve 20 and the end conical sleeve 30 are opposite. In the prior art, the inventors found that most shell expansion type anchor rods are anchored in the form of "single-sided" anchoring, that is, the barb directions of the shell expansion pieces are all facing the same side, which makes the anchoring reliability of the shell expansion type anchor rod poor, especially in tunnels affected by impact loads, the anchoring force reduction is very common and obvious. Based on this, the inventor invented an expansion shell anchor to solve the shortcomings of the expansion shell anchor, which has poor anchoring capacity in the form of "single-side" anchoring and a general and obvious decrease in anchoring force in tunnels affected by impact loads. In this solution, in addition to the nut 7, anti-friction washer 9, spherical washer 5 and pad 8 with wedge grooves arranged in sequence on the anchor body 10, the anchor body 10 is set to three sections, namely the inner rod body 11, the middle rod body 12 and the outer rod body 13, and the thread direction on the middle rod body 12 is opposite to the thread direction on the inner rod body 11 and the outer rod body 13, wherein, during installation, the nut 7, anti-friction washer 9, spherical washer 5 and pad 8 with wedge grooves are installed on the inner rod body 11, and the outer rod body 13 faces the inside of the anchor hole. In this solution, the middle rod body 12 and the outer rod body 13 are respectively provided with an inner conical sleeve 20 and an end conical sleeve 30, and a steel shell expansion piece 50 is provided on the inner conical sleeve 20 and the end conical sleeve 30, and the barbs of the steel shell expansion piece 50 provided on the inner conical sleeve 20 and the end conical sleeve 30 are in opposite directions, so that during anchoring, bidirectional anchoring is achieved by the steel shell expansion piece 50 provided on the inner conical sleeve 20 and the end conical sleeve 30, thereby improving the anchoring reliability and anchoring performance. Preferably, the inner conical sleeve 20 and the end conical sleeve 30 are symmetrically arranged with the connection point of the middle rod body 12 and the outer rod body 13 as the symmetry center.Different from the prior art in which the anchor rod body 10 is set as a single-section form, this solution innovatively sets the anchor rod body 10 as a three-section form, wherein the thread direction of the middle section rod body 12 is opposite to the thread direction of the inner section rod body 11 and the outer section rod body 13, and an inner conical sleeve 20 and an end conical sleeve 30 are respectively provided on the middle section rod body 12 and the outer section rod body 13, and a steel expansion shell sheet 50 is respectively provided on the inner conical sleeve 20 and the end conical sleeve 30, so that when the anchor rod body 10 is installed, when the anchor rod body 10 is pushed to the bottom of the anchor hole At this time, since one end of the end tapered sleeve 30 is placed outside the outer rod body 13, the end tapered sleeve 30 reaches the bottom of the anchor hole. When the internal tapered sleeve 20 and the end tapered sleeve 30 are installed and the nut 7 is screwed, in the process that the outer rod body 13 reaches the bottom of the end tapered sleeve 30, the internal tapered sleeve 20 also approaches the end tapered sleeve 30. When the outer rod body 13 reaches the bottom of the end tapered sleeve 30, the expansion shell pieces installed on the internal tapered sleeve 20 and the end tapered sleeve 30 expand to achieve bidirectional anchoring. It is worth noting that in this solution, the anchor body 10 is a hollow anchor to achieve the grouting function. When installing the steel expansion piece 50, the steel expansion piece 50 is fixed to the inner conical sleeve 20 and the end conical sleeve 30 by fixing the binding wire 42, and an anti-slip steel sheet 41 is provided to prevent the steel expansion piece 50 from falling off during the process of pushing the anchor body 10 into the anchor hole. A grouting exhaust pipe 6 is also provided on the wedge-shaped groove pad 8 of this solution to discharge the gas in the anchor hole during the grouting process.

[0030] In a possible implementation, the inner rod body 11, the middle rod body 12 and the outer rod body 13 are connected by welding. In this solution, after the inner tapered sleeve 20 is installed in the middle rod body 12, the inner rod body 11 and the middle rod body 12 are welded. The middle rod body 12 and the outer rod body 13 can be welded after the end tapered sleeve 30 is installed on the outer rod body 13, or before the end tapered sleeve 30 is installed on the outer rod body 13.

[0031] Furthermore, the end conical sleeve 30 includes a first cylindrical hollow sleeve 39 and a first conical hollow sleeve 38 which are fixedly connected, wherein the first conical hollow sleeve 38 is placed on a side close to the middle section of the rod body 12, and the conical surface faces the middle section of the rod body 12; the first cylindrical hollow sleeve 39 is provided with a first outer limit 33 and an inner limit 32 on the side away from the first conical hollow sleeve 38, wherein the first outer limit 33 is arranged around the outer wall of the first cylindrical hollow sleeve 39, the inner limit 32 is arranged on the inner wall of the first cylindrical hollow sleeve 39, and the inner limit 32 is provided with a center hole 31 which is connected to the interior of the first cylindrical hollow sleeve 39. The end conical sleeve 30 of the present embodiment includes a first cylindrical hollow sleeve 39 and a first conical hollow sleeve 38. A first outer limit 33 is arranged on the first cylindrical hollow sleeve 39. The first outer limit 33 is used to limit the upward displacement of the steel shell expansion piece 50, so that after one end of the steel shell expansion piece 50 reaches the first outer limit 33, the steel shell expansion piece 50 and the end conical sleeve no longer have relative displacement; an inner limit 32 is arranged on the inner side of the first cylindrical hollow sleeve 39, so that the anchor body 10 and the end conical sleeve 30 do not rotate relative to each other after the outer section rod body 13 reaches the inner limit 32; the center hole 31 on the inner limit 32 is used as a grouting outlet for the grouting liquid, so that the grouting liquid can be injected into the anchor hole.

[0032] Furthermore, the outer wall of the first conical hollow sleeve 38 is provided with three first extended convex arcs 35 and three first small concave arcs 34, wherein the three first extended convex arcs 35 are distributed in an array around the first conical hollow sleeve 38, and the three first small concave arcs 34 are spaced between the three first extended convex arcs 35.

[0033] Furthermore, the internal conical sleeve 20 includes a second cylindrical hollow sleeve and a second conical hollow sleeve which are fixedly connected, wherein the second conical hollow sleeve is placed on a side close to the outer rod body 13, and the conical surface faces the outer rod body 13; a second outer limit is provided on a side of the second cylindrical hollow sleeve away from the second conical hollow sleeve, and the second outer limit is arranged around the outer wall of the second cylindrical hollow sleeve.

[0034] Furthermore, the outer wall of the second conical hollow sleeve is provided with three second extended convex arcs and three second small concave arcs, wherein the three second extended convex arcs are distributed in an array around the second conical hollow sleeve, and the three second small concave arcs are spaced between the three second extended convex arcs.

[0035] It should be noted that in the present application, the end tapered sleeve 30 and the internal tapered sleeve 20 are basically the same in structure, the difference is that the internal thread direction is different, and the end tapered sleeve 30 also includes an internal limit 32 and a center hole 31 compared to the internal tapered sleeve 20.

[0036] Furthermore, an extended concave arc 55 and a large concave arc 56 are provided on the inner side of the steel expansion shell plate 50, wherein the extended concave arc 55 matches the first extended convex arc 35 and / or the second extended convex arc, and the large concave arc 56 matches the outer contour of the first cylindrical hollow sleeve 39 and / or the outer contour of the second cylindrical hollow sleeve.

[0037] Furthermore, the barb angle of the expansion piece 57 of the steel expansion piece 50 is greater than 45°.

[0038] Furthermore, it also includes a positioning steel sheet 43, the two ends of which are respectively fixed to the inner conical sleeve 20 and the end conical sleeve 30 by fixing screws 44, and the positioning steel sheet 43 is fixed to the steel shell expansion sheet 50 by fixing screws 44. The present application is provided with a positioning steel sheet 43 when installing the steel shell expansion sheet 50, and the steel shell expansion sheet 50 is connected to the inner conical sleeve 20 and the end conical sleeve 30 by fixing screws 44 and the positioning steel sheet 43.

[0039] In a second aspect, the present application further provides a construction method of an expansion shell anchor, characterized in that the expansion shell anchor as described above is used, comprising the following steps:

[0040] S1: Screw the inner conical sleeve 20 into the middle rod body 12, screw the end conical sleeve 30 into the outer rod body 13, and install the steel shell expansion piece 50 on the inner conical sleeve 20 and the end conical sleeve 30;

[0041] S2: Install the nut 7, the friction-reducing washer 9, the spherical washer 5 and the washer plate with wedge groove 8 on the inner rod body 11 in sequence;

[0042] S3: Determine the target rock mass, drill the anchor hole, and push the anchor rod to the bottom of the anchor hole;

[0043] S4: Tighten the nut 7 to a predetermined torque;

[0044] S5: Grouting is performed through the anchor body 10 to complete the anchor installation.

[0045] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An expansion shell anchor, comprising an anchor body (10), a nut (7), a friction-reducing washer (9), a spherical washer (5) and a pad with a wedge-shaped groove (8), wherein the nut (7), the friction-reducing washer (9), the spherical washer (5) and the pad with a wedge-shaped groove (8) are sequentially arranged on the anchor body (10), characterized in that: It also includes an inner tapered sleeve (20) and an end tapered sleeve (30); the anchor rod body (10) is a variable thread direction rod body, including three sections of threaded rod bodies, namely, inner, middle and outer sections, wherein the thread direction of the middle section rod body (12) is opposite to the thread directions of the inner section rod body (11) and the outer section rod body (13); the inner tapered sleeve (20) is threadedly connected to the middle section rod body (12), the end tapered sleeve (30) is threadedly connected to the outer section rod body (13), and one end of the end tapered sleeve (30) is placed outside the outer section rod body (13); the inner tapered sleeve (20) and the end tapered sleeve (30) are both provided with steel expansion shell sheets (50), and the barb directions of the steel expansion shell sheets (50) provided on the inner tapered sleeve (20) and the end tapered sleeve (30) are opposite.

2. The expansion shell anchor according to claim 1, characterized in that: The end conical sleeve (30) comprises a first cylindrical hollow sleeve (39) and a first conical hollow sleeve (38) which are fixedly connected, wherein the first conical hollow sleeve (38) is placed on a side close to the middle rod body (12) and the conical surface faces the middle rod body (12); a first outer limit (33) and an inner limit (32) are provided on the side of the first cylindrical hollow sleeve (39) away from the first conical hollow sleeve (38), wherein the first outer limit (33) is arranged around the outer wall of the first cylindrical hollow sleeve (39), the inner limit (32) is arranged on the inner wall of the first cylindrical hollow sleeve (39), and the inner limit (32) is provided with a center hole (31) which is connected to the inside of the first cylindrical hollow sleeve (39).

3. The shell-expanding anchor bolt according to claim 2, characterized in that: The outer wall of the first conical hollow sleeve (38) is provided with three first extended convex arcs (35) and three first small concave arcs (34), wherein the three first extended convex arcs (35) are distributed in an array around the first conical hollow sleeve (38), and the three first small concave arcs (34) are arranged between the three first extended convex arcs (35) at intervals.

4. The expansion shell anchor according to claim 1, characterized in that: The internal conical sleeve (20) comprises a second cylindrical hollow sleeve and a second conical hollow sleeve which are fixedly connected, wherein the second conical hollow sleeve is placed on a side close to the outer rod body (13) with the conical surface facing the outer rod body (13); a second outer limit is arranged on a side of the second cylindrical hollow sleeve away from the second conical hollow sleeve, and the second outer limit is arranged around the outer wall of the second cylindrical hollow sleeve.

5. The expansion shell anchor according to claim 4, characterized in that: The outer wall of the second conical hollow sleeve is provided with three second extended convex arcs and three second small concave arcs, wherein the three second extended convex arcs are distributed in an array around the second conical hollow sleeve, and the three second small concave arcs are spaced between the three second extended convex arcs.

6. The shell-expanding anchor according to claim 3 or 5, characterized in that: An extended concave arc (55) and a large concave arc (56) are arranged on the inner side of the steel expansion shell plate (50), wherein the extended concave arc (55) matches the first extended convex arc (35) and / or the second extended convex arc, and the large concave arc (56) matches the outer contour of the first cylindrical hollow sleeve (39) and / or the outer contour of the second cylindrical hollow sleeve.

7. The expansion shell anchor according to claim 1, characterized in that: The barb-shaped angle of the shell expansion piece (57) of the steel shell expansion piece (50) is greater than 45°.

8. The expansion shell anchor according to claim 1, characterized in that: It also includes a positioning steel sheet (43), the two ends of which are respectively fixed to the inner conical sleeve (20) and the end conical sleeve (30) by fixing screws (44), and the positioning steel sheet (43) is fixed to the steel shell expansion sheet (50) by fixing screws (44).

9. A method for constructing an expansion shell anchor, characterized in that: The method of using an expansion shell anchor as claimed in any one of claims 1 to 8 comprises the following steps: S1: Screw the inner conical sleeve (20) into the middle rod body (12), screw the end conical sleeve (30) into the outer rod body (13), and install the steel shell expansion sheet (50) on the inner conical sleeve (20) and the end conical sleeve (30); S2: Install the nut (7), the friction-reducing washer (9), the spherical washer (5) and the washer with a wedge-shaped groove (8) on the inner rod body (11) in sequence; S3: Determine the target rock mass, drill the anchor hole, and push the anchor rod to the bottom of the anchor hole; S4: Tighten the nut (7) to a predetermined torque; S5: Grouting is performed through the anchor body (10) to complete the installation of the anchor.

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