Self-drilling type hollow spiral anchor rod

Abstract

The utility model discloses a self-drilling type hollow spiral anchor rod which comprises a nut, a base plate, a connecting sleeve and an anchor rod body, the anchor rod body is of a hollow structure and is provided with external threads, a triangular drilling plate is arranged at the end of the anchor rod body at the foremost end in the drilling direction, and two spiral blades are arranged on a rod body of the anchor rod body and close to the drilling plate. The rotating direction of the spiral blade is the same as that of an external thread of the anchor rod; a first slurry outlet and a second slurry outlet are further formed in a rod body of the anchor rod close to the drilling plate; every two adjacent anchor rods are coaxially connected through a connecting sleeve, the anchor rod at the rearmost end in the drilling direction is sleeved with a base plate, and the end of the anchor rod is in threaded connection with a nut. According to the utility model, drilling is carried out in a manner of not discharging clay, automatic sealing of a hole opening can be realized, high-pressure grouting can be realized, an expanded head structure is formed, meanwhile, clay around a drilled hole is extruded more compactly, the drawing force is further improved, and settlement of a stratum is not caused.

Description

Technical Field

[0001] The utility model relates to the technical field of anchor rods, in particular to a self-drilling hollow spiral anchor rod. Background Art

[0002] In river alluvial plains, the strata are mostly clay strata with high water content. Such strata have poor self-stabilizing ability and must be supported immediately after excavation of foundation pits or slopes.

[0003] Conventional anchor support mainly adopts the form of steel anchor: steel anchor is generally constructed by drilling holes with a drilling rig, then inserting steel bars, and then grouting. Since the drill rod needs to be pulled out after drilling, and the clay layer with a high water content has poor self-stabilization ability after hole formation, the hole wall will shrink and collapse, and the steel anchor will be difficult to insert. Even if it can be inserted, the hole wall is severely deformed. After the rod body is inserted, it is in direct contact with the clay in the drill hole. After grouting, the rod body cannot be effectively wrapped, and the pulling force of the anchor after construction cannot be guaranteed. In addition, the deformation and shrinkage of the borehole also make it impossible to effectively fill the hole with grouting. At the same time, after the steel anchor is grouted, it is necessary to wait for the slurry to initially set before installing it to apply the anchoring force. The clay layer has strong collapsibility. The method of drilling holes first and then installing anchor rods is adopted. When batch construction is carried out, the stratum is easy to settle, which will have an adverse effect on the buildings above. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide a self-drilling hollow spiral anchor rod, which adopts a non-clay-discharging method for drilling, can realize automatic closing of the hole mouth, can realize high-pressure grouting, and form an enlarged head structure. At the same time, the clay around the borehole is squeezed more densely, and the pulling force is further improved. It will not cause settlement of the stratum, and can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a self-drilling hollow spiral anchor rod, comprising a nut, a pad, a connecting sleeve and an anchor rod, the anchor rod being a hollow structure and having an external thread, a triangular drill plate being provided at the front end of the anchor rod in the drilling direction, two spiral blades being provided on the rod body close to the drill plate, the spiral blades having the same rotation direction as the external thread of the anchor rod, a first slurry outlet hole and a second slurry outlet hole being provided on the rod body close to the drill plate; two adjacent anchor rods are coaxially connected by a connecting sleeve, the anchor rod at the rear end in the drilling direction is sleeved with a pad, and a nut is threadedly connected to the end of the anchor rod.

[0006] Preferably, the first slurry outlet hole and the second slurry outlet hole both radially penetrate the anchor rod, the first slurry outlet hole is located between the two spiral blades, and the second slurry outlet hole is close to the drill plate.

[0007] Preferably, an open groove is provided at the end of the anchor rod at the front end in the drilling direction, a drill plate is located in the open groove and fixed by welding, and the drill plate and the corresponding spiral blade are 100 mm apart.

[0008] Preferably, the blade thickness of the spiral blade is 4-10 mm, the inner diameter of the spiral blade is equal to the outer diameter of the anchor rod, the outer diameter of the spiral blade is 2-4 times the outer diameter of the anchor rod, and the spiral line of the spiral blade is 1 pitch, and the pitch is 90 mm.

[0009] Preferably, the connecting sleeve is provided with an internal thread adapted to the anchor rod.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows: the drill plate acts as a drill bit, drilling into the clay layer and stirring, and at the same time plays a guiding role; the spiral blade plays a role similar to a self-tapping screw during drilling, driving the anchor rod into the clay, and after drilling to a predetermined depth, since its diameter is much larger than the anchor rod, it can provide a certain pull-out resistance without grouting; since the clay is not discharged during the anchor rod drilling process, the entire self-drilling spiral anchor rod is wrapped by clay, and the first anchor rod is in a confined space deep in the stratum. High-pressure grouting is performed through the inner hole of the hollow anchor rod body, and the slurry is discharged from the slurry outlet hole of the first spiral anchor rod. The high-pressure cement slurry can squeeze the surrounding rock and soil to form a large-diameter cement bag, and make the surrounding clay denser. After the slurry solidifies, the anchoring force of the rod body can be greatly improved. Drilling without discharging clay can realize automatic closure of the orifice, and can realize high-pressure grouting to form an enlarged head structure. At the same time, the clay around the borehole is squeezed more densely, further improving the pull-out force, and will not cause settlement of the stratum. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the utility model;

[0012] Figure 2 It is an enlarged schematic diagram of the local structure of the utility model;

[0013] Figure 3 This is a state diagram used in the present utility model.

[0014] In the figure: 1 nut, 2 pad, 3 connecting sleeve, 4 anchor rod, 5 spiral blade, 6 drill plate, 7 first slurry outlet hole, 8 second slurry outlet hole. DETAILED DESCRIPTION

[0015] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction.

[0016] See also Figure 1-2The utility model provides a technical solution: a self-drilling hollow spiral anchor, comprising a nut 1, a pad 2, a connecting sleeve 3 and an anchor 4, wherein the anchor 4 is a hollow structure and has an external thread, and a triangular drill plate 6 is provided at the end of the anchor 4 at the front end in the drilling direction, and two spiral blades 5 are provided near the drill plate 6 on the rod body of the anchor 4, and the spiral blades 5 have the same rotation direction as the external thread of the anchor 4, and a first slurry outlet hole 7 and a second slurry outlet hole 8 are also provided near the drill plate 6 on the rod body of the anchor 4; two adjacent anchors 4 are coaxially connected by a connecting sleeve 3, and the anchor 4 at the rear end in the drilling direction is sleeved with a pad 2, and a nut 1 is threadedly connected to the end of the anchor 4;

[0017] A drill plate 6 and a spiral blade 5 are added to the anchor rod 4 at the front end of the drilling direction. The drill plate 6 acts as a drill bit, drilling into the clay layer and stirring it, and also plays a guiding role. The spiral blade 5 plays a drilling role similar to a self-tapping screw during drilling, driving the anchor rod 4 into the clay. After drilling to a predetermined depth, it can provide a certain pull-out resistance without grouting. By installing the nut 1 and the pad 2 to press the working surface, the slope deformation can be prevented and prestress can be applied. Since the anchor rod 4 is directly screwed into the clay layer through the spiral blade 5 and the drill plate 6, the anchor rod 4 does not need to discharge the clay during drilling, which will not cause the settlement of the stratum and will not affect the buildings above.

[0018] The first slurry outlet hole 7 and the second slurry outlet hole 8 both radially penetrate the anchor rod 4, the first slurry outlet hole 7 is located between the two spiral blades 5, and the second slurry outlet hole 8 is close to the drill plate 6; the end of the anchor rod 4 at the front end of the drilling direction is provided with an open groove, the drill plate 6 is located in the open groove and is welded and fixed, and the drill plate 6 and the corresponding spiral blade 5 are 100 mm apart;

[0019] Specifically, the blade thickness of the spiral blade 5 is 4-10 mm, the inner diameter of the spiral blade 5 is equal to the outer diameter of the anchor rod 4, the outer diameter of the spiral blade 5 is 2-4 times the outer diameter of the anchor rod 4, and the spiral line of the spiral blade 5 is 1 pitch, and the pitch is 90 mm;

[0020] It should be noted that high-pressure grouting is performed through the hollow anchor rod 4, and the grout is discharged from the first grout outlet hole 7 and the second grout outlet hole 8 of the anchor rod 4 at the front end in the drilling direction. The high-pressure cement slurry can squeeze the surrounding rock and soil and form a large-diameter cement bag at the end of the anchor rod 4, and make the surrounding clay denser. After the grout solidifies, the anchoring force of the rod body can be greatly improved;

[0021] In addition, the connecting sleeve 3 is provided with an internal thread matched with the anchor rod 4 .

[0022] When implementing this utility model:

[0023] When using

[0024] 1) Select anchor rods 4 and other accessories of appropriate length and quantity according to design requirements;

[0025] 2) After the drilling rig is debugged and the hole position is determined, the anchor rod 4 at the front end of the drilling direction is connected to the drilling rig;

[0026] 3) Start the drilling rig to rotate and advance, and the drill plate 6 of the anchor rod 4 at the front end of the drilling direction first contacts the clay at the part to be supported, then penetrates into the clay and rotates and stirs; then the spiral blade 5 contacts the clay and is screwed into the clay like a screw;

[0027] 4) Remove the connection between the drilling rig and the anchor 4;

[0028] 5) Install the connecting sleeve 3 and connect the anchor rod 4, tighten the anchor rod 4 and the connecting sleeve 3, and then connect them to the drilling rig;

[0029] 6) Use the drilling rig to perform rotary drilling until the drilling reaches the corresponding position;

[0030] 7) Remove the connection between the drilling rig and the anchor 4;

[0031] 8) Repeat 5), 6), and 7) to continuously extend the anchor rod 4 until the drilling reaches the required depth of the anchor rod 4;

[0032] 9) Install nut 1 and gasket 2, and apply pre-tightening force with a wrench.

[0033] The parts of the present invention that are not described in detail are prior art. It is obvious to those skilled in the art that the present invention is not limited to the details of the above-mentioned exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and it is intended to include all changes that fall within the meaning and scope of equivalent elements in the content of the present invention.

Claims

1. A self-drilling hollow spiral anchor, comprising a nut (1), a backing plate (2), a connecting sleeve (3) and an anchor (4), characterized in that: The anchor rod (4) is a hollow structure and has an external thread. The end of the anchor rod (4) at the front end in the drilling direction is provided with a triangular drill plate (6). The rod body of the anchor rod (4) is provided with two spiral blades (5) near the drill plate (6). The spiral blades (5) have the same rotation direction as the external thread of the anchor rod (4). The rod body of the anchor rod (4) is also provided with a first slurry outlet hole (7) and a second slurry outlet hole (8) near the drill plate (6). Two adjacent anchor rods (4) are coaxially connected via a connecting sleeve (3). The anchor rod (4) at the rear end in the drilling direction is sleeved with a pad (2), and the end of the anchor rod (4) is threadedly connected with a nut (1).

2. A self-drilling hollow spiral anchor according to claim 1, characterized in that: The first slurry outlet hole (7) and the second slurry outlet hole (8) both radially penetrate the anchor rod (4); the first slurry outlet hole (7) is located between the two spiral blades (5), and the second slurry outlet hole (8) is close to the drill plate (6).

3. A self-drilling hollow spiral anchor according to claim 1, characterized in that: An end of the anchor rod (4) at the front end in the drilling direction is provided with an open groove, a drill plate (6) is located in the open groove and is fixed by welding, and the drill plate (6) and the corresponding spiral blade (5) are 100 mm apart.

4. A self-drilling hollow spiral anchor according to claim 1, characterized in that: The blade thickness of the spiral blade (5) is 4-10 mm, the inner diameter of the spiral blade (5) is equal to the outer diameter of the anchor rod (4), the outer diameter of the spiral blade (5) is 2-4 times the outer diameter of the anchor rod (4), and the spiral line of the spiral blade (5) is 1 pitch, and the pitch is 90 mm.

5. The self-drilling hollow spiral anchor according to claim 1, characterized in that: The connecting sleeve (3) is provided with an internal thread adapted to the anchor rod (4).

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