JPH11343800A - Execution method of self-drilling rock bolt and its anchor body structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure both excellent execution and high tensile strength by integrally forming a self-drilling rock bolt and PC steel material fixed on its inside as an anchor body under grout solidification. SOLUTION: A prescribed PC steel material 34 is inserted and innerly provided in a bolt inside 10b from the bolt head of a self-drilling lock bolt 10 to the bolt edge part. The PC steel material 34 and the self-drilling rock bolt 10 are integrally formed as an integral anchor body under solidification of grouts 14, 14 in the bolt inside. Tensile strength of the PC steel material 34 inserted in the bolt inside 10b is reflected as the tensile strength of the anchor body as it is. Thus, both the excellent execution of the self-drilling rock bolt 1 and the high tensile strength of the PC steel material 34 can be secured in the anchor body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-drilling rock bolt which is set and placed in a ground or the like under drilling with a bit at the tip of the bolt and is fixed to the ground or the like by filling and solidifying grout material. The present invention relates to a construction method and an anchor structure thereof.

[0002]

2. Description of the Related Art In the case of earth retaining strut, tunnel strutting, etc., in a stratum of a stratum where the hole wall is not self-supporting, it is usually directly driven into the stratum by drilling with a bit at the tip of a bolt. A so-called self-drilling lock bolt which can be arranged is used as the anchor body.

[0003] This type of self-drilling lock bolt is usually made of a so-called all-threaded pipe-shaped hollow steel having a thread portion over its entire length on its peripheral surface, and a bit for drilling is integrally provided at the tip. Have been. And the self-drilling lock bolt is usually constructed as follows.

A self-drilling rock bolt is set in a corresponding drilling machine, and the self-drilling lock bolt is inserted into the ground while the target ground or the like is drilled with a bit under the impact of the drilling machine or the like. Place and place only the corresponding length on the etc. After cleaning the inside of the bolt, insert an exhaust pipe into the anchor hole, caulk the mouth of the anchor hole with caulking material, inject grout material into the inside from the head of the self-drilling lock bolt, pass through the bit, Fill continuously. After disposing a plate (also referred to as a bearing plate), a nut is fastened to the bolt head to fix the bolt head, and the bolt head fixing part is rust-proofed by being covered with an oil cap or the like.

[0005]

This type of self-drilling lock bolt is a hollow bolt made of pipe-shaped hollow steel such as a full screw, and since this bolt itself cannot be expected to have a very high tensile strength, it is usually used. The self-drilling lock bolt is used as an anchor body of a part that requires a low tensile strength. However, since the self-drilling rock bolt has excellent workability on a ground or the like of a stratum where the hole wall is not self-supporting, it is desired to expand the range of use by increasing the tensile strength and the like.

For example, reinforcement by increasing the thickness of the bolt itself is considered as a configuration for increasing the strength of the self-drilling lock bolt. However, since the self-drilling lock bolt is a pipe-shaped bolt, it cannot be said that a sufficiently high tensile strength can be obtained even by increasing the wall thickness. Further, since increasing the thickness of the bolt itself involves increasing the weight and size of the self-drilling lock bolt, a reduction in workability and a significant increase in cost cannot be avoided.

In many cases, self-drilling lock bolts are used by connecting a plurality of them in a straight line with a joint coupler or the like. Higher strength cannot be expected in the connection part.

Further, in this self-drilling lock bolt, the bolt itself is an anchor body, and the rust on the bolt itself cannot be sufficiently performed. Is inevitable. Such rust, corrosion, etc. reduce the strength of the self-drilling lock bolt, and eventually the proof strength of the anchor body, so the self-drilled lock bolt cannot be used as a permanent anchor, and is not used as a temporary anchor. It is the current situation. Therefore, also from this point, it is inevitable to limit the range of use of the self-drilling lock bolt.

The present invention provides a method of constructing a self-drilling rock bolt, which achieves both excellent workability and high tensile strength and can maintain a permanent strength, and provides an anchor structure thereof. The purpose is.

[0010]

In order to achieve this object, in the present invention, the self-drilling lock bolt itself is made of pipe-shaped hollow steel, and the inside of the bolt is filled with a grout material and solidified. We are paying attention. According to the method for constructing a self-drilling lock bolt of the present invention, a predetermined PC steel material is inserted and installed inside the bolt from the head of the bolt to the tip of the bolt, and the solidification of the grout material inside the bolt is performed. Thus, the PC steel material and the self-drilling lock bolt are integrally formed as an integral anchor body.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

In the method for constructing a self-drilling lock bolt according to the present invention, as shown in FIG. 1, a self-drilling lock bolt 10 is cast as an anchor body on a target ground such as ground.
It is arranged and can be fixed to the ground or the like by solidifying the grout material 14 and tightening the bolt head with the nut 16.

The self-drilling lock bolt 10 is formed, for example, of a so-called fully-threaded pipe-shaped hollow steel having a threaded portion 10a over its entire length on its outer peripheral surface, and a bit 18, for example, a reverse blow bit, is provided at the tip of the bolt. It is provided integrally.

Incidentally, this kind of self-piercing lock bolt itself is the same as a known configuration, and the basic configuration itself of this self-piercing lock bolt 10 is not the purpose of the present invention, and therefore will not be described in detail here.

As shown in FIG. 1, in the embodiment of the present invention, a configuration in which a plurality of, for example, two self-drilling lock bolts 10 are connected linearly via a joint coupler 20 will be described below. I do. In addition, the joint coupler 20 is formed as a substantially pipe body having a screw portion corresponding to the screw portion 10a of the self-drilling lock bolt on its inner surface, and the corresponding bolt terminal is screwed to the joint coupler. The plurality of self-drilling lock bolts 10 can be connected to each other via a joint coupler.

This type of self-drilling lock bolt 10 is cast, for example, for fixing the formation to a ground 12 or the like where the hole wall is not self-supporting.

As shown in FIG. 2 (A), in the method for installing a self-drilling lock bolt according to the present invention, a drilling machine 22 such as a leg drill is used to attach a That is, it is set on the head at the rear end with respect to the front end where the bit 18 is provided, and is installed at a location corresponding to the target ground 12 or the like. Then, under a so-called inverter chisel or the like by transmission of a striking force from the drilling machine 22, a corresponding anchor hole 24 is drilled to a predetermined depth in the ground or the like 12 by the bit 18, and at the same time, In the anchor hole,
The self-drilling lock bolt 10 is driven and arranged by a corresponding length (see FIG. 2B).

After the installation of the self-piercing lock bolt 10 shown in FIG. 2 (B), the inside (the inside of the bolt) 10b of the self-piercing lock bolt is cleaned by blowing or the like.

Next, as shown in FIG.
After inserting the exhaust pipe 26 from the mouth of the inside 24, that is, around the self-drilling lock bolt 10, and caulking the mouth of the anchor hole with a caulking material such as a water stopping material 28, through the injection adapter 30 A hose 32 from a grout pump or the like is connected to the head (bolt head) of the self-drilling lock bolt, and the grout material 14 is injected from the hose into the bolt interior 10b.

In the self-drilling lock bolt 10, the grout material 14 moves from the bolt inside 10b to the outside, ie, the anchor hole, through the blow hole 18a provided in the bit 18 at the tip.
The grout material is continuously filled into and out of the bolt under the injection from the bolt head to the inside of the bolt because it flows into the inside of the bolt. The air inside the bolt 10b and the air inside the anchor hole 24 is discharged to the outside of the anchor hole under the injection of the grout material 14 from the exhaust pipe 26 provided at the mouth of the anchor hole.

Here, as shown in FIG. 3B, in the present invention, a predetermined PC steel material having a higher tensile strength than a self-drilling lock bolt 10 made of hollow steel, for example, one PC
After the grout material 14 is injected, for example, the steel strand 34 is inserted into the bolt interior 10b from the bolt head to the bolt tip, and is internally provided. Then, under the solidification of the grout material 14 in the bolt interior 10b, this PC steel stranded wire (PC steel material) 34
And the self-drilling lock bolt 10 are integrally formed as an integral anchor body.

In the case of inserting the wound long PC steel stranded wire 34, the PC steel stranded wire is linearly stretched and inserted into the bolt interior 10b. It is sufficient to cut the PC strand together.

Inserting a PC steel strand 34 into the bolt interior 10b,
After the internal installation, as shown in FIG. 1, a plate (bearing plate) 36 is disposed around the head of the bolt and facing the surface of the ground 12 or the like, and, for example, a substantially ring-shaped joint plate 38 is attached. By arranging it on top of this and tightening the bolt head with the nut 16, the self-drilling lock bolt 10
Is fixed on the ground 12 or the like. Then, the head fixing portion formed by the nut 16 is covered with an oil cap 40, and is fixed by being screwed to a thread portion on a peripheral surface of the joint plate 38, and the oil cap is filled with the rust preventive oil 42 and the like. The self-drilling lock bolt 10 as the anchor body is completed by performing the rust prevention treatment on the head fixing portion.

As described above, in the method for constructing a self-drilling lock bolt according to the present invention, a PC steel wire 34 is inserted into the inside 10b of the self-drilling lock bolt that is cast into the ground 12, etc. Under the solidification of the grout material 14 (14I) inside the bolt, the PC steel strand and the self-drilling lock bolt 10 are integrally formed as an integral anchor body.

The anchor structure of the self-drilling lock bolt of the present invention, comprising the self-drilling lock bolt 10 and the PC steel strand 34 integrally formed under such solidification of the grout material 14 (14I). According to the PC installed inside the bolt inside 10b
Since the tensile strength of the steel strand is directly reflected on the tensile strength of the anchor body, the tensile strength obtained from the anchor body having this structure is significantly improved as compared with the case of using only the self-drilling rock bolt. That is, self-drilling lock bolt 10
It is possible to easily increase the tensile strength of the self-drilling rock bolt, and to achieve both high workability and high tensile strength.

Further, since the self-drilling lock bolt 10 itself is not reinforced by increasing the wall thickness or the like, the weight and the size are not increased, and a reduction in workability and a significant increase in cost can be reliably prevented. . Furthermore, after the grout 14 is injected, etc., it is sufficient to insert and internally install the PC steel strand 34 into the bolt interior 10b, so that the self-drilling lock bolt 10 can be used without complicating the work and complicating the configuration. It is easy to increase the tensile strength.

Also, since the PC steel strand 34 is inserted and installed inside the bolt 10b from the bolt head to the bolt tip, the self-piercing lock bolt 10 can be reinforced over the entire length. That is, even in a form in which a plurality of self-piercing lock bolts 10 are connected linearly in the joint coupler 20, strength reduction in the joint coupler can be prevented, and regardless of the connection with the joint coupler, the tension in the self-piercing lock bolt can be reduced. High strength can be easily secured.

Here, even when the PC steel strand 34 is provided inside, the head of the self-drilling lock bolt 10 is fixed by tightening the nut 16. In other words, since the nut 16 can be used for anchoring an anchor body having a tensile strength as high as that of the PC steel strand 34, it is possible to achieve both high tensile strength and easy anchoring work. It can be easily secured according to the body.

By the way, as shown in FIG. 1, the PC steel stranded wire 34 inserted and installed inside the bolt inside 10b by the construction method of the present invention is covered by the self-drilling lock bolt 10. And, inside the bolt 10b,
Since the grout material 14 (14I) is filled around the PC steel strand 34 and solidified, the PC steel strand is double-rusted by the self-drilling rock bolt 10 and the grout material inside the bolt. Will be.

That is, the grout material 14 (14U) outside the bolt
Rust on the self-drilling lock bolt 10 due to moisture etc.
Even if corrosion or the like occurs, the penetration of moisture or the like into the PC steel stranded wire 34 is reliably prevented by the grout material 14 (14I) inside the bolt, so that a decrease in the tensile strength of the PC steel stranded wire is prevented. Therefore, according to the anchor body having the structure in which the PC steel stranded wire is integrated into the bolt interior 10b, the high tensile strength of the PC steel stranded wire can be permanently maintained. Utilization becomes fully possible.

Here, in the embodiment of the present invention, after the grout material 14 is injected, the PC steel stranded wire 34 is connected to the inside of the bolt.
10b, but not limited to this, for example,
Before injecting the grout material, a PC steel stranded wire may be inserted and installed inside the bolt in advance. However, as in this embodiment, if the PC steel stranded wire is inserted into the bolt interior 10b after the grout material 14 is injected, the PC steel stranded wire does not hinder the grout material injection. Smooth and appropriate injection and filling can be easily ensured.

In the embodiment of the present invention, one PC steel strand 34 is provided inside the bolt 10b.
Although it is embodied as a PC steel material, the present invention is not limited to this, and a configuration in which a plurality of PC steel strands are provided inside the bolt may be adopted. Further, the present invention is not limited to the PC steel strand 34.
It may be configured to be installed inside 10b.

In the embodiment of the present invention,
Although a configuration in which a plurality of (two) self-piercing lock bolts 10 are connected by a joint coupler 20 is illustrated, the invention is not limited to this, and a configuration in which three or more self-piercing lock bolts may be connected may be employed. Needless to say, only one (one) self-drilling lock bolt may be driven and placed on the ground or the like in accordance with the depth to be driven into the ground 12 or the like.

In the embodiment of the present invention, the self-drilling lock bolt 10 is embodied as a full screw. However, it is sufficient if at least the front and rear ends have the threaded portions 10a. For example, the self-drilling lock bolt may be formed from hollow steel having a partially threaded portion.

Further, in the embodiment of the present invention, a case where the head of the self-drilling lock bolt 10 is not inclined and fixed to the ground 12 or the like is exemplified. On the other hand, in the case where the fixing is performed in an inclined manner, it can be easily dealt with by interposing a pair of so-called adjust plates (not shown) having different angles between the plate 36 and the joint plate 38 (see FIG. 1). .
Since the adjustment plate itself is known,
Detailed description here is omitted.

The embodiments of the present invention described above are intended to explain the present invention, and do not limit the present invention in any way. It goes without saying that all are included in the present invention.

[0037]

As described above, according to the present invention, since the tensile strength of the PC steel material inserted and installed inside the bolt is directly reflected as the tensile strength of the anchor body composed of the self-drilling lock bolt, Both the excellent workability of the self-drilling rock bolt and the high tensile strength of the PC steel material can be secured in this anchor body. Therefore, excellent workability,
Higher tensile strength is compatible.

Since it is sufficient to insert and internally install a PC steel material inside the bolt, it is easy to increase the tensile strength of the self-drilling rock bolt without complicating the work and complicating the configuration. Peel off.

Further, since the PC steel material is inserted and provided inside the bolt from the bolt head to the bolt tip, the self-drilling lock bolt can be reinforced over the entire length. Accordingly, regardless of the presence or absence of the connection by the joint coupler, it is possible to easily secure a high tensile strength in the self-drilling lock bolt.

Further, the head fixing of the self-drilling lock bolt is as follows.
Since the nut is tightened, the nut can be used for anchoring an anchor body having a tensile strength as high as that of PC steel. Accordingly, it is also possible to easily ensure both high tensile strength and easy fixing work.

Since the PC steel material provided inside the bolt is double rust-prevented by the self-drilling rock bolt and the grout material inside the bolt, the reduction in tensile strength of the PC steel material is ensured. Is prevented. Therefore, according to the anchor body having a structure in which the PC steel material is integrated into the bolt in the present invention, the high tensile strength of the PC steel wire can be maintained permanently. Utilization becomes fully possible.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing an anchor body structure of a self-drilling lock bolt of the present invention.

FIG. 2 is a schematic process drawing in the method for constructing a self-drilling lock bolt of the present invention.

FIG. 3 is a schematic process drawing in the method of constructing a self-drilling lock bolt of the present invention.

[Explanation of symbols]

 10 Self-drilling lock bolt 10b Bolt inside 14 Grout material 16 Nut 18 bit 34 PC steel strand (PC steel material)

Claims (4)

[Claims] 1. A self-drilling lock bolt made of pipe-shaped hollow steel having at least a partial thread portion on a peripheral surface thereof.
Drilled into the ground or the like under drilling with the bit at the tip of the bolt,
In the construction method of self-drilling rock bolts, which are arranged and continuously filled with grout material inside and outside of the bolts through a bit from the inside of the bolts and tighten the bolt heads with nuts to transmit the introduction force to the ground or the like, Insert the PC steel into the bolt from the bolt head to the bolt tip, install it inside, and solidify the grout inside the bolt, and use this PC steel and self-drilling lock bolt as an integral anchor body. A method for constructing a self-drilling rock bolt characterized by being integrally formed. 2. A self-drilling lock bolt made of pipe-shaped hollow steel having at least a partial thread portion on its peripheral surface,
Drilled into the ground or the like under drilling with the bit at the tip of the bolt,
The grout material is continuously filled into the inside and outside of the bolt through the bit from the inside of the bolt, and the bolt head is tightened with a nut to transmit the introduced force to the ground or the like. After injecting and filling the material, stretch the wound long PC steel wire straight, insert it inside the bolt from the bolt head to the bolt tip, install it inside, and adjust the position according to the position of the bolt head. Self-drilling characterized by cutting a PC steel stranded wire and forming the PC steel stranded wire and self-drilling lock bolt as an integral anchor body under solidification of the grout material inside the bolt Construction method of lock bolt. 3. A pipe-shaped hollow steel having at least a part of a threaded portion on its peripheral surface, which is driven into a ground or the like under drilling with a bit at the tip, and is disposed inside a bolt from inside. The grout material is continuously filled inside and outside through the hole, and the self-drilling lock bolt that can transmit the introduced force generated by tightening the bolt head with the nut to the ground, etc. Self-piercing, characterized in that a predetermined PC steel material inserted and installed inside the drilling lock bolt is integrated with the self-piercing lock bolt under the solidification of the grout material filled in the bolt. Lock bolt anchor structure. 4. An anchor structure for a self-drilling lock bolt according to claim 3, wherein the PC steel material is a stranded PC steel wire of a corresponding length.