An anchor bolt with enhanced anchoring force equipped with an umbrella bone type anchor

Abstract

The present invention discloses an anchor bolt with enhanced anchoring force with an umbrella rib type anchor. The technical solution is as follows: 3 to 5 anchors (1) are uniformly fixed on the rod body (4) through threads. The length of the rod body (4) is L1. The distance L2 between the top of the first anchor (1) and the head of the rod body (4) is L2 = (0.14 to 0.20)L1, and the spacing L3 between each anchor (1) is L3 = (0.15 to 0.25)L1. A tray (2) is provided at the tail end of the rod body (4), and the tray (2) is connected to the rod body (4) through a fixing nut (3). The anchor (1) is an integral body composed of a hexagonal nut (5) and 6 anchor feet (6). The 6 anchor feet (6) are located on the same plane of the hexagonal nut (5). The bottoms of the 6 anchor feet (6) are connected to form a hexagon. The 6 anchor feet (6) are symmetrically inclined outwards. The anchor feet (6) are oblique parallelepipeds, with a rectangular front face and a parallelogram side face. The included angle α of the parallelogram is equal to the outward inclination angle α' of the anchor feet (6). The present invention has the advantages of low installation difficulty, strong anchoring force and high reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of anchor bolts. In particular, it relates to an anchor bolt with enhanced anchoring force with an umbrella rib type anchor. Background Art

[0002] In the field of geotechnical engineering, anchor bolt support is widely used in projects such as foundation pits, slopes, and mine tunnels due to its significant technical and economic advantages. Currently, there are two common types of anchor bolts in engineering: mechanical expanding shell type anchor bolts and pipe-slot type anchor bolts.

[0003] The mechanical expanding shell type anchor bolt is a type of end-anchoring anchor bolt that provides anchoring force through the clamping force between the expanding shell and the hole wall. However, when the surrounding rock mass quality is poor or the rock near the anchoring point is locally deformed or broken, it is easy to cause the anchor bolt to slip, resulting in the failure of the anchoring effect and further causing engineering disasters.

[0004] The pipe-slot type anchor bolt is a type of full-length anchoring anchor bolt. When installed in a borehole slightly smaller than the pipe diameter, it can exert radial pressure on the hole wall and frictional force to prevent the surrounding rock from sliding throughout the entire length. Together with the supporting force of the tray, the surrounding rock is thus in a triaxial stress state to achieve rock layer stability. However, its initial anchoring force is low, and it has strict requirements for the borehole diameter. If the diameter is slightly larger, the anchoring force is low; if the diameter is slightly smaller, installation is difficult. Its length is also limited (it is difficult to install when generally exceeding 1500 mm), and its applicable range has significant limitations. In addition, the high elastic alloy steel used is expensive.

[0005] Therefore, those skilled in the art have continuously explored and developed new anchor bolt technologies.

[0006] "An anti-deformation ratchet type soil anchor bolt" (CN 205530246 U), in which through holes are arranged on the anchor bolt and steel wire ratchets are inserted, improving the bonding force between the anchor bolt and the soil layer; and a round nut is provided to prevent the ratchet from deforming. However, the arrangement of the ratchets destroys the integrity of the anchor bolt, reducing the tensile capacity of the anchor bolt itself, and the arrangement of the through holes and grouting holes has high construction requirements for the anchor bolt, and it is difficult to achieve large-scale production in a short time. In addition, the stiffness and strength of the ratchets are limited, and they can only play a certain role in soil layer support. In the surrounding rock that needs to be supported in roadway construction, most of them are relatively hard rocks. Obviously, this anchor bolt is no longer applicable at this time.

[0007] "A combined barbed type anchor bolt" (CN 110387882 A) and "A flexible self-anchoring prestressed anchor bolt with reverse barbs" (CN 209510357 U) use the structures of barbs and reverse barbs to enhance the anchoring force, but have the following deficiencies: such structures have high construction requirements and low economic applicability; such structures cannot provide a large anchoring force, and are prone to breakage when the rock layer undergoes large displacements; the barbed and clawed types have safety hazards and are prone to causing injuries to workers during construction. Summary of the Invention

[0008] The present invention aims to overcome the deficiencies of the prior art, and the purpose is to provide an anchor rod with enhanced anchoring force of an umbrella-bone type anchor, which has low installation difficulty, strong anchoring force and high reliability.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is:

[0010] The anchor rod with enhanced anchoring force of the umbrella-bone type anchor is composed of K anchors, 1 tray, 1 fixing nut and 1 rod body. The rod body is a threaded rod member, and the length and major diameter of the thread of the threaded rod member are represented by the letters L1 and D in sequence; the K anchors are uniformly fixed on the rod body through threads, and a tray 2 is arranged at the tail end of the rod body 4, and the tray 2 is connected to the rod body 4 through the fixing nut 3.

[0011] The K anchors are numbered starting from the head of the rod body, and the serial numbers are the 1st, the 2nd,..., the kth in sequence, and K is a natural number from 3 to 5.

[0012] The distance L2 between the top end of the 1st anchor and the head of the rod body is L2=(0.14 - 0.20)L1;

[0013] The spacing L3 between each anchor is L3=(0.15 - 0.25)L1.

[0014] The anchor is of the umbrella-bone type, and each anchor is an integral body composed of 1 hexagonal nut and 6 anchor feet; the 6 anchor feet are located on the same plane of the hexagonal nut, the bottoms of the 6 anchor feet are connected to form a hexagon, and the bottom side of each anchor foot is parallel to the corresponding side of the hexagonal nut; the 6 anchor feet are symmetrically inclined outwards, and the outward inclination angle α' of each anchor foot is 30 - 60°.

[0015] The major diameter of the thread of the hexagonal nut is the same as the major diameter D of the thread of the rod body, the circumradius R of the hexagonal nut is R=(1 - 1.2)D, and the thickness a3 of the hexagonal nut is a3=(0.35 - 0.55)R.

[0016] The anchor foot is an inclined parallelepiped, and the geometric shape of the inclined parallelepiped is: the front is a rectangle, the width a1 of the rectangle is a1=(0.65 - 0.85)R, and the length a2 of the rectangle is a2=(1.25 - 1.55)a1; the side is a parallelogram, the bottom side length b of the parallelogram is b=(0.35 - 0.55)a2, and the included angle α of the parallelogram is equal to the outward inclination angle α' of the anchor foot.

[0017] The using method of the anchor rod with enhanced anchoring force of the umbrella-bone type anchor is:

[0018] (1) According to the surrounding rock conditions and construction requirements, determine the number K of the anchors, and install the K anchors at the corresponding positions of the rod body.

[0019] (2) Drive the head of the rod with the anchor into the rock mass at the bottom of the anchor hole, and then pull the rod outwards until the anchor feet are embedded into the rock wall around the anchor hole.

[0020] (3) Insert a grouting pipe into the gap between the anchor feet, grout. After the grout solidifies and the anchor is stable, install a tray and a fixing nut at the tail of the rod, and the fixing nut fixes the tray at the orifice of the anchor hole.

[0021] Due to the above technical solutions, the present invention has the following beneficial effects:

[0022] Since the present invention evenly arranges 3 to 5 anchors on the rod of the anchor bolt, the anchoring force is provided by the anchoring force between the anchor feet on the anchors and the surrounding rock, and the required anchoring force is borne on the entire length of the rod. It is easier to install compared to the split-set anchor bolt and has a greater initial anchoring force. Also, because the anchor feet on the anchors have high strength, the provided anchoring force is the resistance provided by the rock layer after the anchor feet are embedded into the rock layer. The anchoring force is greater and more firm compared to the mechanical expanding shell anchor bolt, and the structural strength is higher than that of the hook-type and claw-type structures, which can provide better support for the rock and make the service life of the rod of the anchor bolt longer.

[0023] The present invention connects 3 to 5 anchors to the rod by thread, with a simple structure. The tray and fixing nut used during installation are standard parts, effectively reducing the processing difficulty and production cost, suitable for industrial production, and can significantly improve the economic effect of construction enterprises.

[0024] The present invention adopts a threaded connection between the anchor and the rod. Not only can the length of the rod and the number of anchors be replaced in a timely manner according to the surrounding rock conditions and actual situations, and the length of the rod is 2000 - 2500 mm, with high flexibility and the anchoring force can meet the actual on-site requirements. At the same time, the anchor, tray, fixing nut, and rod are separately packaged when leaving the factory, which is convenient for transportation, storage, and installation, and has strong applicability.

[0025] Therefore, the present invention has the advantages of low installation difficulty, strong anchoring force, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is Figure 1 a schematic structural diagram of the anchor 1 in

[0028] Figure 3 is Figure 2 the right view schematic diagram;

[0029] Figure 4 is Figure 2 or Figure 3 a three-dimensional view of the anchor foot 6 in DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, which is not a limitation on its protection scope.

[0031] As Figure 1 shown, the anchoring force enhanced bolt with umbrella rib type anchor is composed of K anchors 1, 1 tray 2, 1 fixing nut 3 and 1 rod body 4. The rod body 4 is a threaded rod member, and the length and major diameter of the thread of the threaded rod member are represented by the letters L1 and D respectively; the K anchors 1 are uniformly fixed on the rod body 4 by threads, and a tray 2 is arranged at the tail end of the rod body 4, and the tray 2 is connected to the rod body 4 through the fixing nut 3.

[0032] The K anchors 1 are numbered starting from the head of the rod body 4, and the serial numbers are the 1st, the 2nd,..., the kth in sequence, and K is a natural number from 3 to 5.

[0033] The distance L2 between the top end of the 1st anchor 1 and the head of the rod body 4 is L2=(0.14 - 0.20)L1;

[0034] The spacing L3 between each anchor 1 is L3=(0.15 - 0.25)L1.

[0035] As Figures 1 to 3 shown, the anchor 1 is of umbrella rib type, and each anchor 1 is an integral body composed of 1 hexagonal nut 5 and 6 anchor feet 6. The 6 anchor feet 6 are located on the same plane of the hexagonal nut 5, and the bottoms of the 6 anchor feet 6 are connected to form a hexagon, and the bottom edge of each anchor foot 6 is parallel to the corresponding edge of the hexagonal nut 5; the 6 anchor feet 6 are symmetrically inclined outwards, and the outward inclination angle α' of each anchor foot 6 is 30 - 60°.

[0036] The major diameter of the thread of the hexagonal nut 5 is the same as the major diameter D of the thread of the rod body 4, the circumradius R of the hexagonal nut 5 is R=(1 - 1.2)D, and the thickness a3 of the hexagonal nut 5 is a3=(0.35 - 0.55)R.

[0037] As Figure 4 shown, the anchor foot 6 is an inclined parallelepiped, and the geometric shape of the inclined parallelepiped is: the front ( Figure 3 the surface of the anchor foot 6 facing the reader in the figure) is a rectangle, the width a1 of the rectangle is a1=(0.65 - 0.85)R, and the length a2 of the rectangle is a2=(1.25 - 1.55)a1; the side surface is a parallelogram, the base length b of the parallelogram is b=(0.35 - 0.55)a2, and the included angle α of the parallelogram is equal to the outward inclination angle α' of the anchor foot 6.

[0038] Embodiment 1

[0039] An anchor bolt with enhanced anchoring force with an umbrella bone type anchor. The anchor bolt with enhanced anchoring force with an umbrella bone type anchor in this embodiment is used in a certain mine roadway. The surrounding rock of the roadway is relatively stable, the cross-sectional shape is semi-circular arch, the range of the loosening zone is 1500 mm, the net width of the cross-section is 4300 mm, and the net height of the roadway is 2150 mm. According to the surrounding rock conditions and construction requirements, the anchor bolts are arranged in a three-flower pattern, with a spacing of 800×800 mm.

[0040] The structure of the anchor bolt with enhanced anchoring force with an umbrella bone type anchor is as described in the specific implementation manner. Among them:

[0041] The length L1 of the rod body 4 is 2100 mm, and the major diameter D of the thread of the rod body 4 is 20 mm.

[0042] The number K of the anchors 1 is 3.

[0043] The distance L2 between the top of the first anchor 1 and the head of the rod body 4 is L2 = 0.2L1 = 0.2×2100 = 420 mm;

[0044] The spacing L3 between each anchor 1 is L3 = 0.25L1 = 0.25×2100 = 525 mm;

[0045] The outward inclination angle α' of each anchor leg 6 is 60°;

[0046] The circumradius R of the hexagonal nut 5 is R = 1.2D = 1.2×20 = 24 mm;

[0047] The thickness a3 of the hexagonal nut 5 is a3 = 0.55D = 0.55×20 = 11 mm.

[0048] The anchor leg 6 is an inclined parallelepiped, and the geometric dimensions of the inclined parallelepiped are:

[0049] The width a1 of the rectangle is a1 = 0.85R = 0.85×24 = 20.4 mm;

[0050] The length a2 of the rectangle is a2 = 1.55a1 = 1.55×20.4 = 31.6 mm;

[0051] The base length b of the parallelogram is b = 0.55a2 = 0.55×31.6 = 17.4 mm;

[0052] The included angle α of the parallelogram is α = α' = 60°.

[0053] The usage method of the anchor bolt with enhanced anchoring force with an umbrella bone type anchor in this embodiment is as follows:

[0054] (1) According to the surrounding rock conditions and construction requirements, determine that the number K of the anchors 1 is 3, and install the 3 anchors 1 at the corresponding positions of the rod body 4.

[0055] (2) Drive the head of the rod body 4 with the anchor 1 into the rock mass at the bottom of the anchor hole, and then pull the rod body 4 outwards until the anchor feet 6 are embedded into the rock wall around the anchor hole.

[0056] (3) Insert a grouting pipe into the gap of the anchor feet 6, grout. After the grout solidifies and the anchor is stable, install a tray 2 and a fixing nut 3 at the tail of the rod body 4, and the fixing nut 3 fixes the tray 2 at the orifice of the anchor hole.

[0057] Example 2

[0058] An anchor rod with enhanced anchoring force with a ribbed umbrella-shaped anchor. The anchor rod with enhanced anchoring force with a ribbed umbrella-shaped anchor in this example is used in a track decline in a mining area. The decline is located in the interlayer of sandy shale and medium sandstone, with small compressive strength of the surrounding rock, long-term rheology of the roadway, large deformation and difficult maintenance. The cross-sectional shape of the roadway is a semi-circular arch, with a net width of 4300 mm and a net height of 2150 mm. According to the surrounding rock conditions and construction requirements, the anchor rods are arranged in a five-flower pattern, with a spacing of 800×800 mm.

[0059] The structure of the anchor rod with enhanced anchoring force with a ribbed umbrella-shaped anchor is as described in the specific implementation manner. Among them:

[0060] The length L1 of the rod body 4 = 2400 mm, and the major diameter D of the thread of the rod body 4 = 22 mm.

[0061] The number K of the anchors 1 = 4.

[0062] The distance L2 between the top of the first anchor 1 and the head of the rod body 4 = 0.18L1 = 0.18×2400 = 432 mm;

[0063] The spacing L3 between each anchor 1 = 0.20L1 = 0.20×2400 = 480 mm;

[0064] The outward inclination angle α' of each anchor foot 6 is 45°;

[0065] The circumradius R of the hexagonal nut 5 = 1.1D = 1.1×22 = 24.2 mm;

[0066] The thickness a3 of the hexagonal nut 5 = 0.5D = 0.5×22 = 11 mm.

[0067] The anchor foot 6 is an inclined parallelepiped, and the geometric dimensions of the inclined parallelepiped are:

[0068] The width a1 of the rectangle = 0.75R = 0.75×24.2 = 18.2 mm;

[0069] The length a2 of the rectangle = 1.45a1 = 1.45×18.2 = 26.4 mm;

[0070] The base length b of the parallelogram is b = 0.45a2 = 0.45×26.4 = 11.9 mm;

[0071] The included angle α of the parallelogram is α = α' = 45°.

[0072] The usage method of the anchoring force enhanced bolt with umbrella rib type anchor is the same as that in Embodiment 1.

[0073] Embodiment 3

[0074] An anchoring force enhanced bolt with an umbrella rib type anchor. The anchoring force enhanced bolt with an umbrella rib type anchor described in this embodiment is used in the return airway of a certain coal mine. The roof of the return airway is fine sandstone, and the floor is grayish-black siltstone, with massive structure and a sliding surface. The cross-sectional shape is a semi-circular arch, the net width of the cross-section is 4400 mm, and the net height of the roadway is 3400 mm. According to the surrounding rock conditions and construction requirements, the bolts are arranged in a three-flower pattern, with a spacing of 800×800 mm.

[0075] The structure of the anchoring force enhanced bolt with an umbrella rib type anchor is as described in the specific implementation manner. Among them:

[0076] The length L1 of the rod body 4 is L1 = 2000 mm, and the major diameter D of the thread of the rod body 4 is D = 20 mm.

[0077] The number K of the anchors 1 is K = 5.

[0078] The distance L2 between the top of the first anchor 1 and the head of the rod body 4 is L2 = 0.14L1 = 0.14×2000 = 280 mm;

[0079] The spacing L3 between each anchor 1 is L3 = 0.15L1 = 0.15×2000 = 300 mm;

[0080] The outward inclination angle α' of each anchor leg 6 is 30°;

[0081] The circumradius R of the hexagonal nut 5 is R = 1.0D = 1.0×20 = 20 mm;

[0082] The thickness a3 of the hexagonal nut 5 is a3 = 0.35D = 0.35×20 = 7 mm.

[0083] The anchor leg 6 is an oblique parallelepiped, and the geometric dimensions of the oblique parallelepiped are:

[0084] The width a1 of the rectangle is a1 = 0.65R = 0.65×20 = 13 mm;

[0085] The length a2 of the rectangle is a2 = 1.25a1 = 1.25×13 = 16.3 mm;

[0086] The base length b of the parallelogram is b = 0.35a2 = 0.35×16.3 = 5.7 mm;

[0087] The included angles α = α' of the parallelogram are 30°.

[0088] The usage method of the anchoring force enhanced bolt with umbrella rib type anchor in this embodiment is the same as that in Embodiment 1.

[0089] This specific implementation mode has the following beneficial effects:

[0090] Since 3 - 5 anchors 1 are evenly arranged on the rod body 4 of the bolt in this specific implementation mode, and the anchoring force is provided by the embedding force of the anchor feet 6 on the anchor 1 with the surrounding rock, the required anchoring force is borne on the entire length of the rod body 4. It is easier to install compared with the slit - type bolt and has a greater initial anchoring force. Also, because the anchor feet 6 on the anchor 1 have a higher strength, the provided anchoring force is the resistance provided by the rock layer after the anchor feet 6 are embedded into the rock layer. The anchoring force is greater and more firm compared with the mechanical expanding shell type bolt, and has a higher structural strength compared with the hook - type and claw - type structures, which can provide better support for the rock, making the service life of the rod body 4 of the bolt longer.

[0091] In this specific implementation mode, 3 - 5 anchors 1 are thread - connected to the rod body 4, and the structure is simple. The tray 2 and the fixing nut 3 used during installation are standard parts, effectively reducing the processing difficulty and production cost, being suitable for industrial production, and significantly improving the economic effect of construction enterprises.

[0092] In this specific implementation mode, the anchor 1 is thread - connected to the rod body 4. Not only can the length of the rod body 4 and the number of anchors 1 be replaced in a timely manner according to the surrounding rock conditions and actual situations, and the length of the rod body 4 is 2000 - 2500 mm, with high flexibility and the anchoring force can meet the actual requirements on - site. At the same time, when leaving the factory, the anchor 1, the tray 2, the fixing nut 3 and the rod body 4 are separately packaged, which is convenient for transportation, storage and installation, and has strong applicability.

[0093] Therefore, this specific implementation mode has the advantages of low installation difficulty, strong anchoring force and high reliability.

Claims

1. An anchoring force enhanced bolt with an umbrella rib type anchor, characterized in that: The anchoring force enhanced bolt with umbrella rib type anchor is composed of K anchors (1), 1 tray (2), 1 fixing nut (3) and 1 rod body (4); the rod body (4) is a threaded rod member, and the length and major diameter of the thread of the threaded rod member are represented by the letters L1 and D respectively; the K anchors (1) are uniformly fixed on the rod body (4) by threads, a tray (2) is arranged at the tail end of the rod body (4), and the tray (2) is connected to the rod body (4) through the fixing nut (3). The K anchors (1) are numbered starting from the head of the rod body (4), and the serial numbers are the 1st, the 2nd, ……, the Kth in sequence, and K is a natural number from 3 to 5; The distance L2 from the top end of the 1st anchor (1) to the head of the rod body (4) is L2 = (0.14~0.20)L1, The spacing L3 between each anchor (1) is L3 = (0.15~0.25)L1, and L1 is 2000~2500mm; The anchor (1) is of umbrella rib type, and each anchor (1) is an integral body composed of 1 hexagonal nut (5) and 6 anchor feet (6). The 6 anchor feet (6) are located on the same plane of the hexagonal nut (5). The bottoms of the 6 anchor feet (6) are connected to form a hexagon, and the bottom side of each anchor foot (6) is parallel to the corresponding side of the hexagonal nut (5); the 6 anchor feet (6) are symmetrically inclined outwards, and the outward inclination angle α' of each anchor foot (6) is 30~60°; The major diameter of the thread of the hexagonal nut (5) is the same as the major diameter D of the thread of the rod body (4). The circumradius R of the circumscribed circle of the hexagonal nut (5) is R = (1~1.2)D, and the thickness a3 of the hexagonal nut (5) is a3 = (0.35~0.55)R; The anchor foot (6) is an inclined parallelepiped, and the geometric shape of the inclined parallelepiped is: the front is a rectangle, the width a1 of the rectangle is a1 = (0.65~0.85)R, and the length a2 of the rectangle is a2 = (1.25~1.55)a1; the side is a parallelogram, the bottom side length b of the parallelogram is b = (0.35~0.55)a2, and the included angle α of the parallelogram is equal to the outward inclination angle α' of the anchor foot (6).

2. A method for using an anchor bolt with enhanced anchoring force having an umbrella rib type anchor, characterized in that: The method is as follows: (1) According to the surrounding rock conditions and construction requirements, determine the number K of the anchors (1), and install the K anchors (1) at the corresponding positions of the rod body (4); (2) Drive the head of the rod body (4) with the anchor (1) into the rock mass at the bottom of the anchor hole, and then pull the rod body (4) outwards until the anchor feet (6) are embedded into the surrounding rock wall of the anchor hole; (3) Insert a grouting pipe into the gap of the anchor feet (6), grout. After the grout solidifies and the bolt is stable, install the tray (2) and the fixing nut (3) at the tail of the rod body (4), and the fixing nut (3) fixes the tray (2) at the orifice of the anchor hole.

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