Magnetic expanded head anchor rod and construction method thereof

Abstract

The invention provides a magnetic expanded-head anchor rod and a construction method thereof. The expanded head anchor rod comprises a main steel anchor rod, a pull steel anchor rod, a first support steel disc, a magnetic anchor rod expansion head and a plurality of expansion anchor rods; the first supporting steel disc is welded to the main steel anchor rod, and the pull rod anchor rod penetrates through the main steel anchor rod to be connected with the magnetic anchor rod expansion head. The magnetic anchor rod expansion head comprises a second supporting steel disc and a magnet block welded to the side, away from the steel pulling anchor rod, of the second supporting steel disc, a plurality of strip-shaped holes are distributed in the disc face of the second supporting steel disc in the radial direction, and a connecting spring is arranged between the two supporting steel discs. The multiple expansion anchor rods are distributed around the steel pulling anchor rod with the steel pulling anchor rod as the center, one end of each expansion anchor rod is movably connected with the first supporting steel disc, and the other end of each expansion anchor rod penetrates through the corresponding strip-shaped hole of the second supporting steel disc and extends to the outer side of the magnet block. The anchor rod is beneficial to attracting magnetic concrete, so that the concrete is gathered more compactly, excessive air is squeezed out, and the stability and the tensile property of the anchor rod are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of slope treatment, and relates to a magnetic expanded-head anchor rod and a construction method thereof, which is used for a steep slope section in a plateau mountainous area, and can quickly construct and repair a damaged shed-hole section. BACKGROUND

[0002] The mountain slope in a plateau mountainous area is steep, and natural disasters such as rainstorms, floods, landslides and earthquakes are common in the plateau mountainous area. In addition, the stability of the mountain slope is poorer due to the complex geological structure, and disasters such as collapse and landslide are prone to occur. In winter, snow disasters and avalanches are also prone to occur, which brings great challenges to road operation and construction.

[0003] Anchor rod reinforcement is an indispensable engineering means for slope engineering support. The traditional anchor rod is mainly used for high slope rock soil anchoring engineering of highways, railways and foundation pits. Its feature is that the anchor rod is punched into the soil layer, and then grouting is performed to form an integral whole with the soil body. The anchoring capacity of the traditional anchor rod is relatively low, and the tensile property is low. In addition, since the grouting slurry of the anchor rod is generally ordinary concrete slurry, in order to avoid backflow of the slurry during grouting, the existing anchor rod can only be punched downward, and cannot be installed upward, thereby limiting the use range of the anchor rod. SUMMARY

[0004] The present application provides a magnetic expanded-head anchor rod and a construction method thereof, which is beneficial to attract magnetic concrete, makes the concrete more dense, expels excess air, increases the stability and tensile property of the anchor rod, and can realize upward grouting, thereby increasing the construction range of the anchor rod.

[0005] In order to achieve the above technical purpose, the present application provides a magnetic expanded-head anchor rod, which comprises a main steel anchor rod, a pull steel anchor rod, an expansion anchor rod, a first support steel disc and a magnetic anchor rod expansion head. The first support steel disc is welded at one end of the main steel anchor rod near the anchor head, and the pull rod anchor rod is connected with the magnetic anchor rod expansion head through the main steel anchor rod. The magnetic anchor rod expansion head comprises a second support steel disc fixed at the end of the pull steel anchor rod and a magnet block welded on the side of the second support steel disc away from the pull steel anchor rod. The diameter of the second support steel disc is greater than that of the first support steel disc, and a plurality of strip-shaped holes are distributed on the disc surface of the second support steel disc in the radial direction. The plurality of strip-shaped holes are distributed in a ring shape with the connection point of the pull steel anchor rod and the second support steel disc as the center.

[0006] A connecting spring is arranged between the first support steel disc and the second support steel disc, the connecting spring is sleeved outside the main steel anchor rod and the pull steel anchor rod, one end of the connecting spring is connected to the first support steel disc, and the other end of the connecting spring is connected to the second support steel disc; the expansion anchor rods are arranged around the pull steel anchor rod, and each expansion anchor rod is movably connected to the first support steel disc at one end, passes through a corresponding strip-shaped hole of the second support steel disc, and extends to the outside of the magnet block;

[0007] When the magnetic expansion head anchor rod is placed in the anchor hole, the connecting spring is in a normal stretched state, when the pull steel anchor rod is pulled, the second support steel disc is moved towards the first support steel disc, the connecting spring is compressed, and the plurality of expansion anchor rods slide and expand in the corresponding strip-shaped hole.

[0008] The anchor hole comprises an anchor rod hole and an expansion head hole, the anchor rod hole matches the outer diameter of the magnetic anchor rod expansion head when the magnetic anchor rod expansion head is not expanded, and the expansion head hole matches the maximum diameter of the plurality of expansion anchor rods of the magnetic anchor rod expansion head in the expanded state; after the expansion head anchor rod is installed into the anchor hole, the anchor rod hole and the expansion head hole are filled with the magnetic concrete.

[0009] The expansion anchor rod is provided with 3-5 anchor rods, an anchor rod through hole is arranged at the center position of the first support steel disc, a plurality of pull holes are arranged in the annular surface of the first support steel disc and take the anchor rod through hole as the center, the pull steel anchor rod passes through the anchor rod through hole, and the other end is fixedly welded or inserted into the center hole of the second support steel disc; the number of the pull holes and the strip-shaped holes is the same as that of the expansion anchor rods, and the end of each expansion anchor rod is provided with a connecting ring, and the connecting ring is sleeved with the pull hole.

[0010] The magnet block is in the shape of a circular truncated cone or an I-shaped section, the diameter of the end of the magnet block close to the second support steel disc is smaller than the diameter of the end of the magnet block away from the second support steel disc, the outer diameter of the large-diameter end of the magnet block matches the maximum diameter of the plurality of expansion anchor rods in the unexpanded state, the elastic force provided by the connecting spring keeps the expansion anchor rods in the unexpanded state during the process of placing the magnetic expansion head anchor rod into the hole, and the end of the expansion anchor rod away from the first support steel disc is located outside the large-diameter end of the magnet block and in contact with the outer edge of the large-diameter end of the magnet block.

[0011] The main steel anchor rod is slidably sleeved outside the pull rod anchor rod.

[0012] The magnetic concrete comprises the following substances in the following mass percentages: iron ore gravel with a particle size of 5-10 mm 25-35%, iron powder 15-25%, cement 20-30%, SBS modifier 2-4%, glass fiber 6-8% with a length of 15-20 mm, and water 12-17%.

[0013] The application further provides a construction method of the magnetic expanding-head anchor rod.

[0014] S1. Drilling an anchor rod hole from an anchor rod installation point using a drilling machine, the inner diameter of the anchor rod hole being greater than or equal to the outer diameter of the largest diameter part of the magnetic anchor rod expanding head in the unexpanded state;

[0015] S2. Continuing to drill the hole from the deepest part of the anchor rod hole using an expanding drill bit to form an expanding-head hole, the inner diameter of the expanding-head hole being greater than or equal to the outer diameter of the largest diameter part of the magnetic anchor rod expanding head in the expanded state;

[0016] S3. Placing the magnetic expanding-head anchor rod into the drilled anchor rod hole, with the magnetic anchor rod expanding head placed in the expanding-head hole, pulling the steel anchor rod to move the second support steel disc towards the first support steel disc, compressing the connecting spring, and simultaneously sliding and expanding the plurality of expanding anchor rods in the corresponding strip-shaped holes outward, and fixing the position of the steel anchor rod when the expanding anchor rods expand to the maximum diameter of the expanding-head hole;

[0017] S4. Injecting magnetic concrete into the anchor rod hole, and filling the gap of the anchor hole with the magnetic concrete by the magnetic block, and then completing the installation of the magnetic expanding-head anchor rod after the magnetic concrete solidifies.

[0018] A further technical solution of the application is that the drilling hole of the magnetic expanding-head anchor rod is inclined downward or upward during installation, and when the drilling hole is inclined upward, the inclination angle is 0-90 degrees, and the grouting method is grouting from the top.

[0019] A further technical solution of the application is that in step S3, when the magnetic expanding-head anchor rod is placed into the anchor rod hole, the connecting spring is in an extended state and provides elastic force to keep the expanding anchor rods in an unopened state, and the end of the expanding anchor rod away from the first support steel disc is located outside the large-diameter end of the magnetic block and is fixed by the magnetic block.

[0020] A further technical solution of the application is that in step S4, the magnetic concrete is prepared by mixing the following substances in the following mass percentages: iron ore crushed stone with a particle size of 5-10 mm 25-35%, iron powder 15-25%, cement 20-30%, SBS modifier 2-4%, glass fiber 6-8% with a length of 15-20 mm, and water 12-17%.

[0021] The application has the following beneficial effects:

[0022] (1) The application welds a magnet at the front end of the expanding head of the expanding-head anchor rod, which is conducive to attracting the expanding anchor rod to the magnet, facilitating the device to extend into the magnetic expanding-head anchor rod hole, and waiting for the bottom to open the magnetic expanding-head anchor rod expanding head by tensioning, and the front-end magnet is also conducive to attracting the magnetic concrete to gather more densely and expel excess air.

[0023] (2) the grouting slurry of the application adopts magnetic concrete, the magnetic concrete cooperates with the magnetic expansion anchor rod to realize the upward grouting, in the grouting process, the front end magnet of the anchor rod expansion head can attract the magnetic concrete, the front pouring magnetic concrete is attracted and contacted with the magnet, then the magnetic concrete also has magnetism, continues to attract the subsequent pouring magnetic concrete, so that the upward pouring is realized;

[0024] (3) the magnetic concrete in the application is mixed with the modifier and the glass fiber, which is conducive to the mutual attraction between the magnets to make the concrete more dense and expel air.

[0025] (4) the first support steel disc is welded in the middle of the magnetic expansion anchor rod, and the connecting ring of the expansion anchor rod is sleeved in the hole of the first support steel disc, which can provide the reinforcing steel of the expansion head for the front end device of the main steel anchor rod; the magnet is welded at the front end of the expansion head of the magnetic expansion anchor rod, which is conducive to attracting the expansion anchor rod on the magnet, facilitating the device to extend into the hole of the magnetic expansion anchor rod, waiting for the bottom to open the expansion head of the magnetic expansion anchor rod by tension, and the front end magnet is also conducive to attracting the magnetic concrete to gather; the magnet block in the application is set to have an I-shaped cross section, which can save cost. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic view of the magnetic expansion anchor rod in the application in an unexpanded state;

[0027] Figure 2 is a schematic view of the magnetic expansion anchor rod in the application in an expanded state;

[0028] Figure 3 is a plan view of the first support steel disc in the application;

[0029] Figure 4 is a plan view of the second support steel disc in the application;

[0030] Figure 5 is a schematic view of the magnetic expansion anchor rod in the application installed in the anchor hole;

[0031] Figure 6 is a schematic view of the magnetic expansion anchor rod in the application installed in the anchor hole after grouting;

[0032] Figure 7 is a schematic view of the magnet block structure in the application with an I-shaped cross section;

[0033] Figure 8 is a schematic view of the magnet block structure in the application with a circular truncated cone-shaped cross section.

[0034] In the figure: 500, main steel anchor rod, 501, pull steel anchor rod, 502, expansion anchor rod, 503, first support steel disc, 504, second support steel disc, 505, magnet block, 506, connecting spring, 507, pull hole, 508, strip hole, 509, connecting ring, 510, anchor hole, 511, magnetic concrete. DETAILED DESCRIPTION

[0035] The application will be further described below in conjunction with the drawings and examples. The drawings that are all examples of the application are drawn in a simplified manner and are only used for the purpose of clearly and concisely illustrating the embodiments of the application. The technical solutions shown in the drawings below are specific solutions of the embodiments of the application, and are not intended to limit the scope of the claimed application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the application. Figures 1 to 8

[0036] In the description of the application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only used for the purpose of facilitating the description of the 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, and therefore cannot be understood as limiting the application. In addition, the terms "first", "second", etc. are only used for differentiation and cannot be understood as indicating or implying relative importance.

[0037] A magnetic expansion anchor rod provided in the embodiment is as shown in the figure Figures 1 to 8 ​, the magnetic expansion anchor rod comprises a main steel anchor rod 500, a pull steel anchor rod 501, an expansion anchor rod 502, a first supporting steel disc 503 and a magnetic anchor rod expansion head; the magnetic anchor rod expansion head comprises a second supporting steel disc 504 fixed at the end of the pull steel anchor rod 501 and a magnet block 505 welded on the side of the second supporting steel disc 504 away from the pull steel anchor rod 501, and the diameter of the second supporting steel disc 504 is greater than that of the first supporting steel disc 503; the expansion anchor rod 502 is provided with four, the first supporting steel disc 503 is welded at one end of the main steel anchor rod 500 close to the anchor head, an anchor rod through hole is formed at the center position of the first supporting steel disc 503, the annular surface of the first supporting steel disc 503 is distributed in a ring shape with four pull holes 507 with the anchor rod through hole as the center, the pull steel anchor rod 501 passes through the anchor rod through hole, and the other end is fixedly welded or inserted into the center hole of the second supporting steel disc 504, and the main steel anchor rod 500 is slidingly sleeved outside the pull rod anchor rod 501. Four strip-shaped holes 508 are radially distributed on the disc surface of the second supporting steel disc 504, and the four strip-shaped holes 508 are distributed in a ring shape with the connection point of the pull steel anchor rod 501 and the second supporting steel disc 504 as the center; a connecting spring 506 is arranged between the first supporting steel disc 503 and the second supporting steel disc 504, the connecting spring 506 is sleeved outside the main steel anchor rod 500 and the pull steel anchor rod 501, one end of the connecting spring 506 is connected to the first supporting steel disc 503, and the other end of the connecting spring 506 is connected to the second supporting steel disc 504; each expansion anchor rod 502 is provided with a connecting ring 509, the connecting ring 509 of each expansion anchor rod 502 is sleeved at the pull hole 507 and can move, the other end of each expansion anchor rod 502 passes through the corresponding strip-shaped hole 508 of the second supporting steel disc 504 and extends to the outside of the magnet block 505. When the magnetic expansion anchor rod is put into the anchor hole 510, the connecting spring 506 is in a normal stretched state, when the pull steel anchor rod 501 is pulled, the pull steel anchor rod 501 drives the second supporting steel disc 504 to move towards the first supporting steel disc 503, the connecting spring 506 is compressed, and the four expansion anchor rods 502 slide and expand in the corresponding strip-shaped holes 508.

[0038] In the embodiment, the anchor hole 510 comprises an anchor rod hole and an expansion head hole, the anchor rod hole matches the outer diameter of the magnetic anchor rod expansion head when the magnetic anchor rod expansion head is not expanded, and the expansion head hole matches the maximum diameter of the expanded state of the plurality of expansion anchor rods 502 of the magnetic anchor rod expansion head; after the expansion anchor rod is installed into the anchor hole 510, the anchor rod hole and the expansion head hole are filled with magnetic concrete. Figure 7 and Figure 8 As shown in the drawings, the magnet block 505 is in the shape of a circular truncated cone or an I-shaped section, and the I-shaped section is more cost-saving, and the diameter of the magnet block 505 close to one end of the second supporting steel disc 504 is smaller than the diameter of the magnet block 505 away from the other end of the second supporting steel disc 504; during the process of putting the magnetic expansion anchor rod into the hole, as shown in the drawings, Figure 1As shown, the connecting spring 506 is in an extended state, and the provided elastic force keeps the expanded anchor rod 502 in an unexpanded state, at which the end of the expanded anchor rod 502 away from the first support steel disc 503 is located outside the large-diameter end of the magnet block 505 and in contact with the outer edge of the large-diameter end of the magnet block 505. The magnetic anchor rod expansion head is provided with a magnet, which is used to facilitate the attraction of the expanded anchor rod 502 to the magnet, facilitate the insertion of the device into the magnetic expansion head anchor rod hole, and wait until the bottom of the magnetic expansion head anchor rod is opened by tension. The front-end magnet is also used to attract magnetic concrete. The designed spring is used to provide elastic force to the magnetic expansion head anchor rod during insertion, generate a rebound force when encountering an obstacle, and rebound when not subjected to resistance, thereby ensuring that the magnetic expansion head anchor rod is placed in the designed position of the hole.

[0039] The magnetic concrete used in the implementation is prepared from the following substances in the following mass percentages: 30% of iron ore gravel with a particle size of 5-10 mm, 20% of iron powder, 25% of cement, 3% of SBS modifier, 7% of glass fiber with a length of 19 mm, and 15% of water.

[0040] The construction method of the magnetic expansion head anchor rod provided in the embodiment includes the following specific steps:

[0041] S1. A drill is used to drill an anchor rod hole from an anchor rod installation point, and the inner diameter of the anchor rod hole is greater than or equal to the outer diameter of the largest diameter part of the magnetic anchor rod expansion head in the unexpanded state.

[0042] S2. A reamer bit is used to continue drilling from the deepest part of the anchor rod hole to form an expansion head hole, and the inner diameter of the expansion head hole is greater than or equal to the outer diameter of the largest diameter part of the magnetic anchor rod expansion head in the expanded state.

[0043] S3. The magnetic expansion head anchor rod is placed in the drilled anchor rod hole, and the magnetic anchor rod expansion head is placed in the expansion head hole; as shown, when the magnetic expansion head anchor rod is placed in the anchor rod hole, the connecting spring is in an extended state and provides elastic force to keep the expanded anchor rod in an unexpanded state. The end of the expanded anchor rod away from the first support steel disc is located outside the large-diameter end of the magnet block, and is fixed by the magnet block. Figure 3 Figure 4 As shown, the second support steel disc is moved toward the first support steel disc by pulling the steel anchor rod, the connecting spring is compressed, and the plurality of expanded anchor rods simultaneously slide outward in the corresponding strip-shaped holes to expand, and the position of the steel anchor rod is fixed when the expanded anchor rods expand to the maximum diameter of the expansion head hole.

[0044] S4. Magnetic concrete is injected into the anchor rod hole, and the magnetic concrete is filled into the gap of the anchor hole by the magnet block. After the magnetic concrete solidifies, the installation of the magnetic expansion head anchor rod is completed.

[0045] ​The magnetic expansion anchor rod in the application is inclined downward or upward when installed; when the drilling is inclined upward, the inclination angle is 0-90 degrees, and the grouting mode is upward grouting. In order to achieve upward grouting by using magnetic concrete and magnetic anchor rod, the inventor of the application has carried out experiments in the laboratory, and the elevation angle can reach 90 degrees to achieve vertical elevation pouring; in specific construction, the magnetic force of the magnet can be changed according to the depth of the anchor rod on the site to realize the upward grouting. The experiment proves that the viscosity of the magnetic slurry is 12464mpa / s, and under the adsorption of the 12000GS magnetic field strength magnetic rod, the 420cm 3 The inverted container is filled. After filling the container, stand still for 10 min, and after the excess slurry flows out under gravity, remove the top magnet and the transparent container. Observe the adhesion of the slurry on the rod-shaped magnet, and measure the maximum adsorption diameter of 4 cm. Provide technical support for large-scale upward hole grouting in later engineering.

[0046] The above is only one embodiment of the application, which is described in more detail and in more detail, but it cannot be understood as a limitation on the scope of the application. It should be noted that for those skilled in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are within the scope of the application. Therefore, the protection scope of the application should be subject to the appended claims.

Claims

1. A magnetic expanded-head anchor rod, characterized by: The expanded head anchor rod comprises a main steel anchor rod (500), a pull steel anchor rod (501), an expansion anchor rod (502), a first supporting steel disc (503) and a magnetic anchor rod expansion head; the first supporting steel disc (503) is welded at one end of the main steel anchor rod (500) near the anchor head, the pull rod anchor rod (501) passes through the main steel anchor rod (500) and is connected with the magnetic anchor rod expansion head; the magnetic anchor rod expansion head comprises a second supporting steel disc (504) fixed at the end of the pull steel anchor rod (501) and a magnet block (505) welded on the side of the second supporting steel disc (504) away from the pull steel anchor rod (501), the diameter of the second supporting steel disc (504) is greater than that of the first supporting steel disc (503), a plurality of strip-shaped holes (508) are distributed on the disc surface of the second supporting steel disc (504) in the radial direction, and the plurality of strip-shaped holes (508) are distributed in a ring shape with the connecting point of the pull steel anchor rod (501) and the second supporting steel disc (504) as the center; A connecting spring (506) is arranged between the first supporting steel disc (503) and the second supporting steel disc (504), the connecting spring (506) is sleeved outside the main steel anchor rod (500) and the pull steel anchor rod (501), one end of the connecting spring (506) is connected to the first supporting steel disc (503), and the other end of the connecting spring (506) is connected to the second supporting steel disc (504); the expansion anchor rod (502) is provided with a plurality of expansion anchor rods (502) distributed around the pull steel anchor rod (501) with the pull steel anchor rod (501) as the center, one end of each expansion anchor rod (502) is movably connected to the first supporting steel disc (503), the other end of each expansion anchor rod (502) passes through the corresponding strip-shaped hole (508) of the second supporting steel disc (504) and extends to the outside of the magnet block (505); When the magnetic expansion head anchor rod is placed in the anchor hole (510), the connecting spring (506) is in a normal stretched state, when the pull steel anchor rod (501) is pulled, the pull steel anchor rod (501) drives the second supporting steel disc (504) to move towards the first supporting steel disc (503), the connecting spring (506) is compressed, and the plurality of expansion anchor rods (502) slide and expand in the corresponding strip-shaped holes (508).

2. A magnetic upset anchor according to claim 1, characterized in that: The anchor hole (510) comprises an anchor rod hole and an expanded head hole, the anchor rod hole matches the outer diameter of the magnetic anchor rod expansion head when the magnetic anchor rod expansion head is not expanded, and the expanded head hole matches the maximum diameter of the plurality of expansion anchor rods (502) of the magnetic anchor rod expansion head in the expanded state; after the expanded head anchor rod is installed into the anchor hole (510), the anchor rod hole and the expanded head hole are filled with the magnetic concrete (511).

3. A magnetic oversize anchor according to claim 1 or 2, characterized in that: The expansion anchor rod (502) is provided with 3-5 anchor rods, and an anchor rod through hole is formed at the center of the first support steel disc (503). The annular surface of the first support steel disc (503) is provided with a plurality of pull holes (507) in a ring shape with the anchor rod through hole as the center. The pull steel anchor rod (501) passes through the anchor rod through hole, and the other end is fixedly welded or inserted into the center hole of the second support steel disc (504). The number of the pull holes (507) and the strip-shaped holes (508) is the same as that of the expansion anchor rods (502). Each expansion anchor rod (502) is provided with a connecting ring (509) at one end, and the connecting ring (509) is sleeved with the pull hole (507).

4. A magnetic oversize anchor according to claim 1 or 2, characterized in that: The magnet block (505) is in the shape of a circular truncated cone or an I-shaped section, and the diameter of the magnet block (505) near one end of the second support steel disc (504) is smaller than that far from the other end of the second support steel disc (504). The outer diameter of the large-diameter end of the magnet block (505) matches the maximum diameter of the expansion anchor rod (502) in the non-expanded state. In the process of placing the magnetic expansion head anchor rod into the hole, the elastic force provided by the connecting spring (506) keeps the expansion anchor rod (502) in the non-expanded state. At this time, the end of the expansion anchor rod (502) far from the first support steel disc (503) is located outside the large-diameter end of the magnet block (505) and touches the outer edge of the large-diameter end of the magnet block (505).

5. A magnetic oversize anchor according to claim 1 or 2, characterized in that: The main steel anchor rod (500) is slidably sleeved on the pull rod anchor rod (501).

6. A magnetic upset anchor according to claim 2, wherein: The magnetic concrete is prepared from the following substances in the following mass percentages: iron ore gravel with a particle size of 5-10 mm 25-35%, iron powder 15-25%, cement 20-30%, SBS modifier 2-4%, glass fiber 6-8% with a length of 15-20 mm, and water 12-17%.

7. A method of constructing a magnetic expanded anchor rod according to any one of claims 1 to 5, characterized in that The specific steps are as follows: S1. Use a drilling machine to drill an anchor rod hole from the anchor rod installation point, and the inner diameter of the anchor rod hole is greater than or equal to the outer diameter of the maximum diameter part of the magnetic anchor rod expansion head in the non-expanded state; S2. Use a reamer to continue drilling from the deepest part of the anchor rod hole to form an expansion head hole, and the inner diameter of the expansion head hole is greater than or equal to the outer diameter of the maximum diameter part of the magnetic anchor rod expansion head in the expanded state; S3. Place the magnetic expansion head anchor rod into the drilled anchor rod hole, and the magnetic anchor rod expansion head is placed in the expansion head hole. Pull the pull steel anchor rod to move the second support steel disc towards the first support steel disc, compress the connecting spring, and simultaneously expand the plurality of expansion anchor rods in the corresponding strip-shaped holes. When the expansion anchor rod expands to the maximum diameter of the expansion head hole, the position of the pull steel anchor rod is fixed; S4. Inject magnetic concrete into the anchor rod hole, and use the magnet block to attract the magnetic concrete to fill the gaps in the anchor hole. After the magnetic concrete solidifies, the installation of the magnetic expansion head anchor rod is completed.

8. A method of construction of a magnetic expanded anchor rod according to claim 7, characterized in that: When the magnetic expansion head anchor rod is installed, the drilled hole is inclined downward or upward. When the drilled hole is inclined upward, the inclination angle is 0-90 degrees, and the grouting method is grouting from the top view.

9. A method of construction of a magnetic expanded anchor rod according to claim 7, characterized in that: In the S3 step, the magnetic expanding anchor rod is put into the anchor rod hole, the connecting spring is in the stretched state, and the elastic force keeps the expanding anchor rod in the unopened state, and the end of the expanding anchor rod away from the first supporting steel disc is located outside the large diameter end of the magnet block and is fixed by the magnet block.

10. A method of construction of a magnetic expanded anchor rod according to claim 7, characterized in that: In the S4 step, the magnetic concrete is prepared by mixing the following substances in the mass percentage: 25-35% of iron ore gravel with a particle size of 5-10 mm, 15-25% of iron powder, 20-30% of cement, 2-4% of SBS modifier, 6-8% of glass fiber with a length of 15-20 mm, and 12-17% of water.

Images