JP2535595Y2 - Rock bolt - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rock bolt for a reinforcing material to be installed on the ground when excavating a tunnel or the like.

[0002]

2. Description of the Related Art Conventionally, when excavating a tunnel or cutting a slope, a borehole 21 as shown in FIG.
2 is injected, and the main body 1 having a circular cross section of a lock bolt made of a bar-shaped steel material is inserted and fixed into the mortar 22 to reinforce the ground 20.

[0003]

The conventional lock bolt can reinforce the ground without using a large steel support, and is excellent as a reinforcing means.

However, there are cases where the adhesive force with the mortar 22 is not sufficient. Also, the main body 1 of the lock bolt
However, it is easy to be eccentric from the center of the borehole 21 and the borehole 2
There is a possibility that the force acting on the inner peripheral surface of 1 becomes uneven, and the reinforcing effect is reduced.

The present invention has been made in view of the above circumstances. The mortar 22 adheres well to the main body 1 of the lock bolt, and the main body 1 of the lock bolt is eccentric from the center of the bore hole 21. A technical object is to prevent the force acting on the peripheral surface from becoming uneven and the reinforcing effect from being reduced.

[0006]

According to the present invention, three or more metal main bodies 1 to be installed in the ground 20 are extended radially and laterally from a longitudinal center line 2 of the main body 1. It was formed from the fixing plate 3 and was bolted.

[0007]

According to the present invention, a borehole 2 formed in the ground 20 is provided.
The mortar 22 is poured into the mortar 1 and the main body 1 of the lock bolt is inserted into the mortar 22.

When the mortar 22 solidifies, the mortar 22
Is fixed in the borehole 21, and the main body 1 of the lock bolt is fixed in the mortar 22 to reinforce the ground 20.

Since the body 1 of the lock bolt is formed of three or more fixing plate-like members 3 extending radially, the surface area of the body 1 is smaller than that of the conventional body 1 having a circular shape. The mortar 22 and the main body 1 do not separate from each other.

Further, since the main body 1 is formed of three or more fixing plate-like members 3 extending radially, the fixing plate-like shape is smaller than that of the circular main body 1 formed in the same sectional area. The outer diameter of the body 3 increases.

Therefore, even if the main body 1 is eccentric in the bore hole 21, the degree of eccentricity is small, and the force of the lock bolt on the inner peripheral surface of the bore hole 21 acts uniformly, so that the main body 1 is securely inserted in the bore hole 21. Fixed to

[0012]

1 to 4 are explanatory views of a lock bolt according to an embodiment of the present invention. In this embodiment, the ground 20
A steel main body 1 to be installed therein is formed by four fixing plate-like bodies 3 extending radially and laterally from a longitudinal center line 2 of the main body 1 and has a cross-shaped cross section. It is.

Then, at the center of the base end of the main body 1,
A vertical space is provided, and the base of the screw rod 10 is inserted into this space and fixed by welding or the like. This lock bolt is
A borehole 21 is drilled in the ground 20 to be reinforced, a mortar 22 is injected into the borehole 21, and the lock bolt body 1 is inserted.

After the mortar 22 is solidified, the seat plate 12 and the like are externally fitted to the screw rod 10, and the nut 11 is screwed into the mortar 22. FIG.
This shows another embodiment. In this embodiment, the corrugated surface 4 is formed on the surface of the fixing plate 3 provided on the main body 1 of the lock bolt, and the adhesion to the mortar 22 is improved. It has been further improved. The corrugated surface 4 can be formed on both sides of the fixing plate-like body 3.

The number of the fixing plate-like members 3 can be three or five or more, but four is most suitable.

[0016]

According to the present invention, the main body 1 of the lock bolt is formed of three or more fixing plate-like members 3 extending in the horizontal direction radially from the center line 2 of the main body 1.

Accordingly, the surface area of the main body 1 is larger than that of a circular body, and the adhesion of the mortar 22 to the main body 1 is increased, so that the mortar 22 and the main body 1 are not separated.

Further, as compared with the circular main body 1 having the same size in cross-sectional area, the outer diameter of the fixing plate-like body 3 is large, and even if the main body 1 is eccentric in the borehole 21, the eccentricity is small. Since it is small, the force of the lock bolt on the inner peripheral surface of the bore hole 21 acts uniformly, the main body 1 is securely fixed in the bore hole 21, and the reinforcing effect is increased.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of one embodiment of the present invention.

FIG. 3 is a view showing a state in which one embodiment of the present invention is installed in the ground.

FIG. 4 is a cross-sectional view of the embodiment of the present invention installed in the ground.

FIG. 5 is a cross-sectional view of another embodiment.

FIG. 6 is a cross-sectional view of a state in which the conventional example is installed on the ground.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Center line 3 Fixing plate 20 Ground

Claims (1)

(57) [Scope of request for utility model registration] 1. A metal body 1 to be installed in a ground 20 is formed by three or more fixing plate-like bodies 3 extending radially and laterally from a longitudinal center line 2 of the body 1. Rock bolt.