JPH06287948A - Installing method of lock bolt - Google Patents

Abstract

PURPOSE:To prevent draw-out of a lock bolt together with a casing by slidably fitting a hollow bolt in the casing of an automatic boring type drilling tool provided with bits on the extreme end, and drawing out the casing only while pouring consolidating material through the shaft passage of the bolt after drilling. CONSTITUTION:An automatic boring type drilling tool to drill by being given with rotation and a shock is constituted by slidably fitting a hollow bolt 2 having a bit 1 on the extreme end into a casing 4 having bits 3 on the extreme end. A seal material 32 is mounted on the contact face between the hollow bolt 2 and the casing 4. Next, fluid for drilling such as water or air is fed through the shaft passage 21 of the bolt 2 for drilling. After drilling, the the base end of the hollow bolt 2 is held down, the casing 4 only is drawn out while pouring consolidating material such as mortar through the shaft tunnel 21, and the hollow bolt 2 is fixed in the hole. Hereby, draw-out of the lock bolt together with the casing can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for installing a rock bolt suitable for collapsible ground.

[0002]

2. Description of the Related Art As a method of installing a rock bolt on a ground that is likely to collapse, a drilling device comprising a lock bolt having an inner bit mounted on its tip and a casing having an outer bit on the tip, which is exterior to the lock bolt, is provided. After making a hole by rotating and striking both bits, the casing is pulled out while pouring mortar or other solidifying material between the lock bolt and the peripheral surface of the casing, and the lock bolt is fixed in the hole. Are known.

[0003]

The above-mentioned conventional lock bolt installation technique has the following problems.

<A> Since the solidifying material interposed between the lock bolt and the peripheral surface of the casing has adhesiveness, the lock bolt is likely to come out together when the casing is pulled out. If the installation position of the lock bolt is retracted, the proof stress is unavoidable.

<B> The casing extracted from the lock bolt is filled with a solidifying material inside. The solidified material remaining in the casing is uneconomical because it is lost, and it is necessary to clean the inside of the casing for the next drilling work.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and an object of the present invention is to prevent the lock bolt from coming off together and to impart design strength to the lock bolt. It is to provide the installation method.

[0007]

According to the present invention, there is provided a casing having a bit at its tip, and a casing inserted in the casing.
While using a lock bolt that has a bit at the tip and an axial path in the shaft core, while rotating and striking the casing and the lock bolt to make a hole, while filling the hole with the solid material through the axial path of the lock bolt. This is a method for installing a lock bolt, characterized in that only the casing is pulled out and the hollow bolt is left in the hole.

[0008]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

<A> Drilling tool FIG. 1 shows an example of a self-piercing drilling tool for drilling by rotating and hitting. The drilling tool comprises a hollow bolt 2 having an inner bit 1 at its tip and a casing 4 having an outer bit 3 at its tip.

<B> Hollow Bolt The hollow bolt 2, which is a lock bolt, has a plate-shaped inner bit 1 fixed to the tip thereof. The plate thickness of the inner bit 1 is thinner than the inner diameter of the shaft passage 21 of the hollow bolt 2, and the discharge port 22 is formed at the tip of the hollow bolt 2. Hollow bolt 2
The rotating force and the striking force may be applied through the inner bit 1 and the casing 4 or may be applied independently of the casing 4.

<C> Casing The outer bit 3 provided at the tip of the casing 4 is
A slit 31 is opened from the tip to the base.
The slit 31 is for accommodating the inner bit 1, and its opening width and depth are set to be substantially equal to the size of the inner bit 1. Further, a sealing material 32 that is in contact with the outer peripheral surface of the inner bit 1 is attached to the inner peripheral surface of the tip end portion of the casing 4.

[0012]

Next, a method of installing the lock bolt will be described.

<A> Drilling (FIG. 1) Drilling is performed by applying a rotating force and a striking force to the base ends of the hollow bolt 2 and the casing 4. When drilling holes, the shaft 2 of the hollow bolt 2
A fluid for drilling (water or air) is supplied through 1.

<B> Extraction of Casing and Filling of Consolidation Material (FIG. 2) After completion of drilling, only the casing 4 is retracted while pouring the consolidation material 5 such as mortar from the base end of the hollow bolt 2. At this time, the base end of the hollow bolt 2 is pressed to prevent the hollow bolt 2 from coming off together with the casing 4, and the casing 4 is pulled out. The solidified material 5 is discharged into the hole from the discharge port 22 via the shaft passage 21 of the hollow bolt 2. The sealing material 32 at the tip of the casing 4 prevents the solidifying material 5 from entering the casing 4 while slidingly contacting the outer peripheral surface of the hollow bolt 2. In this way, only the casing 4 is extracted while filling the binder 5 in the hole, and the extracted casing 4 is used for the next work without cleaning. The hollow bolt 2 left in the hole is tensioned and fixed by a known method.

[0015]

Since the present invention is as described above, the following effects can be obtained.

<A> The solidifying material is filled in the hole through the shaft of the hollow lock bolt. Therefore, it is not necessary to clean the removed casing, and the loss of the solidifying material can be avoided.

<B> Since the casing is pulled out while there is no solidifying material between the casing and the peripheral surface of the lock bolt and the base end of the lock bolt is pressed, it is possible to prevent the lock bolt from coming off together when the casing is pulled out. .

<C> The construction procedure is simple and efficient construction is possible.

<D> In the collapsible ground, the rock bolt can be reliably installed, and since the solidifying material can be densely filled over the entire length of the rock bolt, a high fixing effect can be obtained and the collapsible ground can be efficiently reinforced. it can.

[Brief description of drawings]

FIG. 1 is an explanatory view of a drilling tool at the time of drilling

FIG. 2 is an explanatory diagram when the casing is removed.

Claims (1)

[Claims] 1. A casing having a bit at its tip,
Use a lock bolt that is inserted in the casing and has a bit at the tip and an axial path in the shaft core.Rotate and hit the casing and the lock bolt to drill a hole, and then through the axial path of the lock bolt A method for installing a lock bolt, characterized in that only the casing is pulled out while filling the solidifying material, and the hollow bolt is left in the hole.