Umbrella-shaped anchor for quick reinforcement of rock mass, and application method

Abstract

The invention provides an umbrella-shaped anchor for rapid reinforcement of rock mass. The umbrella-shaped anchor for rapid reinforcement of the rock mass comprises an umbrella-shaped anchor head and a connecting rod. The umbrella-shaped head comprises the sliding mechanism, bearing block, guide block and main rod of anchor head. The main rod of anchor head is connected with the sliding mechanism after passing through the through-hole located in the middle of the guide block The sliding mechanism is connected with the connecting rod through the main rod of the anchor head. The multiple upper parts of bearing blocks are respectively inserted into the groove of the guide block, and they are fully fitted with the side guide rail of the sliding mechanism During installation, after the umbrella anchor head and connecting rod in the retracted state are extended into the anchor hole, the connecting rod is tensioned to drive the sliding mechanism to extrude the bearing block to open outwards and squeeze with the hole surface. The invention converts the tensile force of the anchor rod into the extrusion pressure on the rock mass, and obtains the larger anchoring force by using the higher compressive strength of the rock mass. The invention has the advantages of large applicable depth, fast construction speed, high efficiency, no grouting, large structural resistance and good stability.

Claims

1. An umbrella-shaped anchor for rapid reinforcement of a rock mass, said umbrella-shaped anchor comprising: an umbrella-shaped anchor head (1), the umbrella-shaped anchor head (1) including: a guide block (7) having a through-hole and a plurality of grooves; a main rod (8) extending through the through-hole of the guide block (7); a reverse anti-sliding device (9) engaging the main rod (8); a sliding mechanism (5) having a plurality of side guide rails, the sliding mechanism (5) being connected to the main rod (8); and a plurality of bearing blocks (6) having a plurality of parts, each of the parts being disposed in a respective one of the grooves of the guide block (7), the bearing blocks (6) engaging the side guide rails of the sliding mechanism (5); a bearing plate (3); a locking device (4) including a sleeve; and a connecting rod (2) connected to the umbrella-shaped anchor head (1) and locked to the bearing plate (3) by the locking device (4), the connecting rod (2) being connected with the sliding mechanism (5) through the main rod (8), the connecting rod (2) being configured to be inserted in an insertion direction along with the umbrella anchor head (1) into an anchor hole of the rock mass while the anchor head (1) is in a retracted state and the sleeve is engaging against the guide block (7), such that when the connecting rod (2) is tensioned in the insertion direction, the connecting rod (2) drives the sliding mechanism (5) to move in the insertion direction, and the bearing blocks (6) move in a radially outward direction along the grooves of the guide block (7) under extrusion pressure of the sliding mechanism (5) until the outer surfaces of the bearing blocks (6) engage a surface of the anchor hole, and such that the reverse anti-sliding device (9) prevents the sliding mechanism (5) from moving in a direction opposite to the insertion direction and from separating from the bearing blocks (6), and such that the bearing blocks (6) maintain tension to exert a predetermined anchor force against the surface of the anchor hole, wherein the slide mechanism (5) is a hexahedron with a first surface facing in the insertion direction and a second surface facing in the direction opposite the insertion direction, the second surface being square-shaped and larger than the first surface, the slide mechanism including two opposite rectangular side surfaces each interconnecting the first surface and the second surface, a respective one of the guide rails being on each of the side surfaces, each of the side surfaces being oriented at an angle of approximately between 70° and 88° relative to a direction perpendicular to the insertion direction, each of the side surfaces having a length between the first surface and the second surface approximately between 100 mm and 400 mm, and wherein said guide block (7) is a cylinder with a groove around a perimeter of the cylinder, the guide block (7) having a central square-shaped hole, the square hole being configured to allow the main rod (8) of the anchor head to extend past the guide block (7), the guide block (7) include four evenly spaced notches, the notches being configured to allow the bearing blocks (6) to slide laterally in directions perpendicular to the insertion direction.

2. The umbrella-shaped anchor of claim 1 wherein the connecting rod (2) includes pre-stressed steel strands.

3. The umbrella-shaped anchor of claim 1 wherein the bearing plate (3) is configured to be sheathed on a portion of the connecting rod (2) protruding from the rock mass, the locking device (4) being configured to lock the bearing plate (3) to the portion of the connecting rod (2) extending out of the rock mass.

4. The umbrella-shaped anchor of claim 1 wherein the outer surfaces of said bearing blocks (6) conjunctively have a cylindrical shape, and inner surfaces of the bearing blocks (6) are engaged with the sliding mechanism (5), the bearing blocks (6) being configured to slide along the guide rails of the sliding mechanism (5), an end of the sliding mechanism (5) that includes the first surface being configured to be inserted into one of the grooves of the guide block (7) and to slide along the groove.

5. The umbrella-shaped anchor of claim 1 wherein said reverse antisliding device (9) is disposed between the main rod of the anchor head (8) and the guide block (7), between an end of the bearing block (6) and the guide block (7), and between the sliding mechanism (5) and the bearing blocks (6), the antisliding device (9) being configured to function as a spring limit device, the bearing blocks (6) and the sliding mechanism (5) being slidable relative to each other, the reverse anti-sliding device (9) being configured to limit the movement of the sliding mechanism (5) in the direction opposite the insertion direction and away from the bearing blocks (6) after the bearing blocks (6) have engaged the surface of the anchor hole.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is the structural view of the umbrella-shaped anchor for rapid reinforcement of rock mass in the present invention.

(2) FIG. 2 is the side view of the umbrella-shaped anchor used for rapid reinforcement of rock mass in the present invention.

(3) FIG. 3 (a) is the top view of the retracted state of the umbrella-shaped anchor for rapid reinforcement of rock mass, and FIG. 3 (b) is the bottom view of the umbrella-shaped anchor used for rapid reinforcement of rock mass in the present invention.

(4) FIG. 4 (a) is the section view of the retracted state of the umbrella-shaped anchor head used for rapid reinforcement of rock mass in the retracted state, and FIG. 4 (b) is the section view of the expansion state of the umbrella type anchor head for rapid reinforcement of rock mass in the present invention.

(5) FIG. 5 is the stress schematic view of the umbrella-shaped anchor for rapid reinforcement of rock mass in the present invention.

(6) In the view, 1—the umbrella-shaped anchor head;

(7) 2—the connecting rod;

(8) 3—the bearing plate;

(9) 4—the locking device;

(10) 5—the sliding mechanism

(11) 6—the bearing block;

(12) 7—the guide block;

(13) 8—the main rod of the anchor head;

(14) 9—the reverse anti-sliding device;

(15) 10—the connecting device;

(16) 11—the groove of the guide block;

(17) 12—the guide rail with the rectangular section

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(18) The technical scheme of the invention will be described clearly and completely in combination with the views in the invention as below:

(19) Referring to FIG. 1, the present invention provides an umbrella-shaped anchor for rapid reinforcement of rock mass, including the umbrella-shaped anchor head 1, the connecting rod 2, the bearing plate 3 and the locking device 4.

(20) Furthermore, referring to FIG. 2 to FIG. 4, the umbrella-shaped anchor head 1 includes the sliding mechanism 5, the bearing block 6, the guide block 7 and the main rod of the anchor head 8. The main rod of the anchor head 8 passes through the through-hole in the middle of the guide block 7, and the eliding mechanism 5 is connected with the connecting rod 2 through the main rod of the anchor head 8. The upper parts of each bearing block 6 are respectively inserted into the groove of the guide block 11, and the eliding mechanism 5 is completely wrapped and contacted. The diameter of the anchor head is smaller than the diameter of the anchor hole in the retracted state, so it is easy to extend into the hole.

(21) The sliding mechanism 5 is a hexahedron with a small upper and a large square cross-section at the bottom. There is a rectangular section guide rail 12 in the middle of the inclined plane. The elope angle is 70° to 88° and the height is 100 mm to 400 mm.

(22) The upper part of bearing block 6 can be inserted into groove of guide block 11 (as shown in FIG. 2) and can be slid in groove of guide block 11. The outer surface of the bearing block 6 is circular arc, and the middle part of the inner surface is provided with a rectangular groove (as shown in FIG. 3 (b)), which fits with the guide rail with the rectangular section 12 of the eliding mechanism 5, and can be slid relative to the guide rail of the eliding mechanism 5.

(23) The guide block 7 is a cylinder with grooves around and the hole in the middle. The hole is square and can allow the connecting rod 2 to pass through (as shown in FIG. 2 (a)). There are four grooves of the guide block 11 and they are evenly distributed. The notch matches the shape of the upper part of the bearing block 6. After the bearing block 6 is inserted into the guide block 7, the notch only allows the bearing blocks to slide laterally.

(24) The reverse anti-sliding device 9 is arranged between the main rod of the anchor head 8 and the guide block 7, between the top of the bearing block 6 and the guide block 7, and between the sliding mechanism 5 and the bearing block 6 with the model of spring limit device etc. After the bearing blocks 6 and the sliding mechanism 5 slide relative to each other, the reverse anti-sliding device 9 (as shown in FIG. 4 (b)) can limit the downward movement of the sliding mechanism 5 and separate from the bearing blocks 6 after opening and contacting extrusion with the hole surface.

(25) The connecting rod 2 is a thick wall steel pipe which can bear the tensile force required for anchoring. The pre-stressed steel strand is set inside according to the needs, and the single length of the strand is 1-2 m. The umbrella-shaped anchor head 1 is connected with the connecting rod 2 by a connecting device 10. The connecting device 10 is arranged at the end of the main rod 8 of the anchor head. When only steel pipe is used to connect with anchor head 1, connection device 10 can be threaded connection. When the steel strand is used, the connection device 10 can be used as the anchorage device of the steel strand.

(26) The bearing plate 3 is a square or circular metal component that bears the pressure required for anchoring. The bottom surface of bearing plate 3 (the side in contact with rock mass) is a smooth plane. The top surface of the bearing plate 3 can be ribbed according to the stress requirements. The bending deformation of bearing plate 3 should not exceed 1% under the design stress condition.

(27) The locking device comprises a sleeve and a pipe slip. The sleeve is a ring made of metal, and the middle part is an inverted circle-shaped cavity for passing through the connecting rod 2. The pipe slips are installed in the wedge gap between the sleeve and the connecting rod, and locks the connecting rod 2 and the sleeve with the bearing plate 3 and forms a whole.

(28) In the initial state, the four bearing blocks 6 are completely embedded in the groove of the guide block 11 and are close to the periphery of the sliding mechanism 5. When used, the umbrella-shaped anchor head 1 in the retracted state and the connecting rod 2 are extended into the drilled anchor hole and are reached the design position. Then the sleeve is used to resist the guide block 7. When the connecting rod 2 is tensioned upward, the sliding mechanism 5 is driven to move upward, and the bearing block 6 opens outward along the groove of the guide block 11 under the extrusion force of the sliding mechanism 5 (as shown in FIG. 4 (b)), until the outer wall of the bearing block 6 contacts the hole wall. The reverse anti-sliding device 9 works to prevent the sliding mechanism 5 from moving downward and separating from the bearing block 6. Take out the sleeve and continue to stretch to reach the predetermined anchor force.

(29) Referring to FIG. 5, the load-bearing principle of the invention is that the tensile force Ton the connecting rod 2, which is used to reinforce the rock mass to prevent its sliding, causes the sliding mechanism 5 to move upward and extrude the bearing block 6, thus producing a squeezing force F. on the interface. The bearing block opens outward and extrudes the rock mass to produce squeezing force N, and the rock mass prevents the anchor rod from moving upward and produces static friction force f, and f=T in steady state. Within the range of compressive strength of rock mass, the tensile force T is proportional to the extrusion force N. When the wedge ratio of sliding mechanism 5 is appropriate, the tensile force T is always less than the limit value AN of sliding between bearing block 6 and rock mass. The μ is the sliding friction coefficient, that is, the umbrella-shaped anchor and the rock mass will only become more and more tight, and there will be no relative slide. Theoretically, as long as the rock mass and umbrella-shaped anchor do not destroy, the anchoring force is infinite. Due to the high compressive strength of rock mass, the present invention can make full use of its compressive strength to obtain larger anchoring force.

(30) The present invention provides an application method of umbrella-shaped anchor for rapid reinforcement of rock mass, including the following steps (taking slope as an example):

(31) Step 1. Turn on the drilling equipment and drill into the rock body until the predetermined depth is reached. Remove the drilling equipment. The umbrella-shaped anchor head 1 is connected with the connecting rod 2, the umbrella-shaped anchor head 1 in the retracted state and the connecting rod 2 are extended into the anchor hole, and the second connecting rod 2 is connected until the design anchorage depth is reached.

(32) Step 2. Put the sleeve out of the connecting rod 2 into the anchor hole until it is against the guide block 7. The connecting rod 2 is tensioned outwards, and the sliding mechanism 5 moves upward to squeeze the bearing blocks 6 to open like an umbrella until the outer wall of the bearing block 6 contacts with the hole surface.

(33) Step 3. Take out the sleeve and the reverse anti-sliding device 9 makes the sliding mechanism 5 not to be separated from the bearing blocks 6 downward. Install the bearing plate 3 and the locking device 4. Then the jack with large stroke hollow is installed on the construction platform and the bearing plate 3, and the jack is clamped with the connecting rod 2 with the pipe slips.

(34) Step 4. Start the jack and tension the connecting rod 2 at the end. When the tension indicated by the jack pressure gauge reaches the predetermined anchoring force, the connecting rod 2 and the bearing plate 3 are locked with the locking device to form a whole, and the installation is completed.

(35) The above-mentioned content is only a detailed description of the preferred embodiment provided by the present invention. However, the protection scope of the invention is not limited to that. Any change or replacement that can be easily thought of by a person skilled in the technical field within the scope of the present invention disclosed shall be included in the scope of protection of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claim.