Constant-resistance yield anchor rod and anchor cable

Abstract

The utility model relates to a constant-resistance yield anchor rod and anchor cable, and belongs to the technical field of civil engineering, rock and soil slope treatment and mining engineering supporting. The anchor rod comprises a yield pipe, a rod body, an extrusion head and a force transmission system, the yield pipe is a straight circular steel pipe, periodic indentation lines are arranged on the middle section of the outer wall of the yield pipe, and constant-resistance energy absorption is achieved through gradual buckling deformation of the indentation lines; the rod body penetrates through an inner cavity of the yield pipe, an extrusion head with hardness higher than that of the pipe wall is fixed at the near end, and a birdcage-shaped expanding device is arranged at the far end to enhance anchoring; the force transmission system ensures the load transmission efficiency through a supporting base plate and a force transmission ring. According to the utility model, the contradiction between material strength and ductility is converted into controllable buckling deformation through structural collaborative design, and the controllable buckling deformation anchor rod has the advantages of low cost, long displacement energy absorption (millimeter-meter level), controllable bearing capacity level (yield pipe > extrusion head > rod body), multi-scene adaptation and the like, and is suitable for rock-soil body support under the conditions of earthquake, rock burst and large deformation of surrounding rock.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the supporting technical field in civil engineering, geotechnical slope treatment and mining engineering, and specifically relates to an anchor rod with high tensile strength and long constant resistance yield displacement through structural design, which is suitable for supporting geotechnological body under the conditions of earthquake, high ground stress impact and large deformation of surrounding rock. BACKGROUND

[0002] In geotechnical engineering, anchor rod is a key supporting component for controlling surrounding rock deformation and enhancing structural stability. Traditional anchor rods rely on the mechanical properties of materials themselves (such as the yield strength and ductility of steel) to achieve tensile resistance and deformation function. However, there is an inherent contradiction in material properties: high yield strength materials (such as high carbon steel) often lack ductility and are difficult to adapt to large deformation geological conditions; while materials with excellent ductility (such as titanium alloy) are costly and have limited strength. In addition, existing anchor rods are prone to anchoring failure due to instantaneous load or continuous deformation in the scenarios of earthquake, rock burst or soft rock large deformation. Although some improvement schemes optimize material composition or add auxiliary energy-absorbing structures (such as spring dampers) to alleviate the above problems, there are still defects such as high cost, complex structure or low energy-absorbing efficiency.

[0003] Therefore, there is an urgent need for a new anchor rod structure with high strength, long constant resistance displacement and controllable cost. SUMMARY

[0004] The purpose of the present application is to solve the above-mentioned problems in the prior art, and to provide a constant resistance yield anchor rod and anchor cable. Through the cooperative structural design of the notch lines of the yield pipe and the slip of the extrusion head, the contradiction between material strength and ductility is converted into controllable periodic buckling deformation, realizing constant resistance yield energy absorption and long displacement stable anchoring.

[0005] In order to achieve the above-mentioned application purpose, the following technical scheme is adopted in the present application: a constant resistance yield anchor rod comprises:

[0006] The yield pipe is a straight circular steel pipe, and the outer wall of the middle section is provided with periodic notch lines; the inner cavity of the head end section of the yield pipe is a gradually expanding structure, and the tail end section is provided with a plug;

[0007] The rod body is arranged in the inner cavity of the yield pipe, and the proximal end is fixed with the extrusion head, and the distal end is provided with an anchoring section;

[0008] The extrusion head is a cylindrical body, and the front end is a plow head, which has a hardness greater than that of the pipe wall material of the yield pipe;

[0009] The force transmission system comprises a supporting pad plate fixed to the head end of the yield pipe and a force transmission ring connecting the rod body and the extrusion head;

[0010] The bearing capacity of the yield pipe, the extrusion head and the rod body satisfies: yield pipe > extrusion head > rod body.

[0011] Further, the notch interval of the notch pattern is 10% to 20% of the outer diameter of the yielding pipe, the notch width is 3% to 15% of the outer diameter of the yielding pipe, and the notch depth is 5% to 20% of the wall thickness of the yielding pipe.

[0012] Further, the tapering structure of the head end section of the yielding pipe is a conical surface or a spherical surface, the taper angle of the conical surface is 15° to 45°, and the radius of curvature of the spherical surface is 1.5 to 3 times the outer diameter of the pipe.

[0013] Further, the rod body is a straight long rod body, and the length of the rod body is at least greater than the length of the yielding pipe by a certain margin.

[0014] Further, the rod body is a solid steel rod, a hollow steel pipe or a prestressed steel strand.

[0015] A constant-resistance yielding anchor cable comprises the constant-resistance yielding anchor rod, wherein the rod body is replaced by a steel strand, the force transmission locking piece is replaced by an extrusion head, and the force transmission ring is replaced by a steel strand anchor;

[0016] The steel strand comprises a proximal free section and a distal anchoring section, the anchoring section is provided with a plurality of birdcage type expanding devices, and the tail end is provided with a guide cap; and the free section is a non-bonded steel strand.

[0017] Further, the free section is provided with a plastic sleeve, and lubricating oil is filled between the plastic sleeve and the steel strand.

[0018] Compared with the prior art, the utility model has the following advantages:

[0019] 1. Low cost and high energy absorption: the constant-resistance yielding characteristics are controlled by notch parameters of ordinary steel pipes, and no expensive alloy materials are needed.

[0020] 2. Long displacement stability: the periodic buckling expansion of the notch pattern can consume impact kinetic energy, and achieve millimeter to meter level large deformation adaptation under constant resistance.

[0021] 3. Multi-scene adaptability: compatible with different rod body forms such as solid rods and steel strands, and suitable for earthquakes, mine impact ground pressure and soft rock tunnel large deformation support.

[0022] 4. Structural reliability: the hierarchical design (yielding pipe > extrusion head > rod body) ensures that the deformation sequence is controllable, and the overall failure of the anchoring system is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The head structure of the constant-resistance yielding anchor rod;

[0024] Figure 2 The elevation sectional view of the constant-resistance yielding anchor cable;

[0025] Figure 3 It is the structure diagram of the notch pattern.

[0026] In the figure, 1, yield pipe; 2, rod body; 3, extrusion head; 4, support pad; 5, force transmission ring; 11, middle section; 12, tail end section; 13, head end section; 14, plug; 21, free section; 22, anchoring section; 23, birdcage type expansion device; 24, guide cap; 31, plow head; 101, score interval; 102, score width; 103, score depth. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0028] Those skilled in the art should understand that in the disclosure of the present application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above terms cannot be understood as a limitation on the present application.

[0029] Embodiment 1

[0030] As shown in Figure 1 and Figure 3 , the constant resistance yield anchor rod comprises a constant resistance yield pipe 1, a rod body 2, a support pad 4 and a force transmission ring 5.

[0031] The rod body 2 is an elongated force-bearing rod, and the anchor head proximal end of the rod body 2 is fixed with an extrusion head 3, which is coaxial with the yield pipe 1, penetrates into the lumen of the head end section 13 of the yield pipe 1, and extends to the distal end from the tail end section 12.

[0032] The yield pipe 1 is a straight circular steel pipe, the middle section 11 has an equal wall thickness, and the outer wall surface of the section has regular score lines perpendicular to the pipe center axis; the inner cavity of the head end section 13 is slightly larger than that of the middle section 11 and forms a gradual change surface such as a conical surface or a spherical surface to cooperate with the inner cavity of the middle section 11; the tail of the tail end section 12 has a plug 14 to prevent the extrusion head 3 from sliding out of it.

[0033] The extrusion head 3 is a cylindrical body, and the front end part has a plow head 31 which cooperates with the inner cavity of the middle section 11 of the yield pipe 1 and can slide from the head end section 13 to the tail end section 12 of the yield pipe 1 along the inner cavity of the yield pipe 1 under the action of sufficient load.

[0034] The plough head 31 of the extrusion head 3 is harder than the yielding pipe 1; the bearing capacity of the yielding pipe 1 is greater than that of the extrusion head 3 and the rod body 2, and the bearing capacity of the extrusion head 3 is greater than that of the rod body 2.

[0035] The rod body 2 is a straight long rod body, including a solid rod, a hollow and a flexible cable, and the length is at least greater than the length of the yielding pipe 1 by a certain margin.

[0036] As shown in Figure 3 The outer surface of the middle section 11 of the yielding pipe 1 is regularly notched, including a notching interval 101, a notching width 102 and a notching depth 103, and the notching of the middle section is uniformly arranged in cycles.

[0037] The notching interval 101 is 10% to 20% of the outer diameter of the yielding pipe 1, the notching width 102 is 3% to 15% of the outer diameter of the yielding pipe 1, and the notching depth 103 is 5% to 20% of the wall thickness of the yielding pipe 1.

[0038] Example 2

[0039] The constant-resistance yielding energy-absorbing anchor rod of the embodiment comprises the following components:

[0040] The yielding pipe 1 is a Q235B straight-welded pipe with an outer diameter of 50 mm, a wall thickness of 5 mm and a length of 2 m. The outer wall of the middle section 11 is processed with an annular notching pattern, the notching interval 101 is 15% of the outer diameter of 7.5 mm, the width 102 is 8% of the outer diameter of 4 mm, and the depth 103 is 10% of the wall thickness of 0.5 mm. The inner cavity of the head end section 13 is processed as a tapering expanding structure, the tapering angle is 30°, the tail end section 12 is welded with a circular plug 14, and the center of the plug is opened with a hole with a diameter of 12 mm.

[0041] The rod body 2 is an HRB400 solid steel rod with a diameter of 10 mm and a length of 2.5 m. The proximal end is connected with the extrusion head 3 through threads, and the distal end is processed with threads and installed with a birdcage-shaped expanding device 23, which has an expanded outer diameter of 3 times the rod diameter of 30 mm, and the surface is welded with barbs.

[0042] The extrusion head 3 is made of 45# steel quenched and treated, with a hardness of HRC50, and the front end is a plough head 31 with a tapering angle of 60° and a diameter of 15 mm, which is matched with the head end tapering surface of the yielding pipe 1 with an interval distance of 3 mm, which is 0.6 times the wall thickness.

[0043] The force transmission system: the head end of the yielding pipe 1 is installed with a Q235 supporting pad plate 4 with a size of 200 mm x 200 mm x 20 mm, and the rod body 2 and the extrusion head 3 are bolted through the force transmission ring 5.

[0044] Working principle: when the rod body 2 is pulled, the extrusion head 3 slides along the inner cavity of the yielding pipe 1, forcing the middle section notching pattern to expand and curve ring by ring, with a single ring deformation displacement of about 8 mm, and the whole can provide a constant resistance displacement of 0.5-2 m, and the constant resistance value is stably maintained at 80-100 kN.

[0045] Embodiment 3

[0046] As Figure 2 shown, based on the same concept, the rod body 2 of the embodiment adopts the embodiment of steel strand. A constant resistance yielding anchor cable includes a constant resistance yielding pipe 1, a steel strand (instead of a rod body 2), a supporting pad 4, a force transmission locking piece (instead of a pressing head 3), and a steel strand anchor (instead of a force transmission ring 5). The steel strand includes a free section 21 at a proximal end and an anchoring section 22 at a distal end, and has a prestress function. The anchoring section 22 has a plurality of birdcage type expansion devices 23, and has a guide cap 24 at a tail end for lifting and anchoring adhesion with a hole of an anchor rod and surrounding rock of a stratum. The proximal end free section 21 of the steel strand is a non-adhesion steel strand, and preferably a low plastic sleeve is filled with lubricating oil between the steel strand.

[0047] The working principle is that the head end section 13 of the yielding pipe 1 is fixed by the force transmission locking piece and the supporting pad 4, and the tensile load from the steel strand is transmitted to the stratum; when the steel strand above can bear sufficient tensile load, the steel strand slips in the lumen of the yielding pipe 1 through the steel strand anchor, thereby realizing the function of constant resistance tensile energy absorption of the anchor rod.

[0048] The part of the present application not described in detail is prior art, so the present application does not describe it in detail.

[0049] It can be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of one element can be one, and in another embodiment, the number of the element can be multiple, and the term "one" cannot be understood as a limitation on the number.

[0050] Although professional terms are used more frequently herein, the possibility of using other terms is not excluded. The use of these terms is only for the convenience of describing and explaining the essence of the present application; any interpretation as any kind of additional limitation is contrary to the spirit of the present application.

[0051] The present application is not limited to the above best embodiment, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any change in shape or structure, any technical solution having the same or similar technical solution as the present application falls within the protection scope of the present application.

Claims

1. A constant resistance yielding anchor, characterized in that, The utility model relates to a constant-resistance yielding anchor rod, comprising: a yielding pipe (1) which is a straight circular steel pipe, and a periodic array of score lines is arranged on the middle section (11) of the outer wall of the pipe; the inner cavity of the head end section (13) of the pipe is gradually expanded, and a plug (14) is arranged on the tail end section (12) of the pipe; a rod body (2) which is arranged in the inner cavity of the pipe and has a fixed extrusion head (3) at the proximal end and an anchoring section at the distal end; the extrusion head (3) is a cylindrical body, and the front end of the body is a plow head (31) which has a greater hardness than the pipe wall material of the yielding pipe (1); a force transmission system which comprises a support pad (4) fixed on the head end of the yielding pipe (1) and a force transmission ring (5) connecting the rod body (2) and the extrusion head (3); the bearing capacities of the yielding pipe (1), the extrusion head (3) and the rod body (2) satisfy the following relationship: yielding pipe (1) > extrusion head (3) > rod body (2).

2. A constant resistance yielding rock bolt according to claim 1, characterised in that, The score interval (101) of the score lines is 10% to 20% of the outer diameter of the yielding pipe (1), the score width (102) is 3% to 15% of the outer diameter of the pipe, and the score depth (103) is 5% to 20% of the wall thickness of the pipe.

3. A constant resistance yielding rock bolt according to claim 1, characterised in that, The gradually expanded structure of the head end section (13) of the yielding pipe (1) is a conical surface or a spherical surface, the conical surface has an inclination angle of 15° to 45°, and the spherical surface has a radius of curvature of 1.5 to 3 times the outer diameter of the pipe.

4. A constant resistance yielding anchor according to claim 1, characterised in that, The rod body (2) is a straight long rod body which has a length greater than the length of the yielding pipe (1) by a certain amount.

5. A constant resistance yielding anchor according to claim 1, characterised in that, The rod body (2) is a solid steel rod, a hollow steel pipe or a prestressed steel strand.

6. A constant resistance yielding anchor, characterized in that, The utility model relates to a constant-resistance yielding anchor rod, comprising: The steel strand comprises a free section (21) at the proximal end and an anchoring section (22) at the distal end, the anchoring section (22) is provided with a plurality of birdcage-shaped expansion devices (23), and a guide cap (24) is arranged at the tail end; the free section (21) is a non-bonded steel strand.

7. A constant yield anchor according to claim 6, wherein, The free section (21) is provided with a plastic sleeve, and lubricating oil is filled between the steel strand and the plastic sleeve.

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