JPS5938399B2 - lock bolt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a steel pipe body having a protrusion and a vertically elongated injection hole along the generatrix direction in the peripheral wall of the steel pipe having a slit extending in the generatrix direction, and A rock bolt is characterized in that it is made of an elastic hollow steel pipe having a slit along the entire length in the generatrix direction of a steel pipe having a large outer diameter and a conical part at the tip, and its purpose is to improve the structure. The object of the present invention is to provide an improved lock bolt that is simple to use, can maintain initial supporting force, and can provide stable supporting force over a long period of time.

Since the rock bolt according to the present invention is configured as described above, in use, after drilling a hole in the rock, the steel pipe body is penetrated into the drilled hole, and the injection material or injection material is inserted into the hollow part of the steel pipe body. After the filled capsules are filled, the inner steel pipe is press-fitted, and as mentioned above, the inner steel pipe has slits along the entire length in the generatrix direction, so it has elasticity, and therefore, the inside diameter of the steel pipe body is When an inserted steel pipe with a large outer diameter is inserted into a steel pipe body, the steel pipe body having a slit in the generatrix direction also expands elastically in the circumferential direction, is crimped against the inner circumferential wall of the drilled hole, and is anchored in the same drilled hole. Ru.

Moreover, as the steel pipe is injected, the injection material inside the steel pipe body is compressed by the conical end thereof, and passes through the injection hole and slit made in the steel pipe body to the inner peripheral wall of the drilled part and the outer peripheral wall of the steel pipe main body. It is loaded between the

Therefore, when the injection material is not hardened, the steel pipe body is supported in the drilled part by friction between the outer circumferential wall of the steel pipe body having the protrusion expanded in the circumferential direction by the press-fitting of the inserted steel pipe and the inner circumferential wall of the drilled part. After the injection material has hardened, the shearing force generated between the protrusion provided on the outer peripheral wall of the steel pipe body and the hardened injection material loaded between the steel pipe main body and the drilled part, The steel pipe body is firmly supported by the drilled part.

In this way, the rock bolt according to the present invention can secure the initial supporting force, and after the injection material hardens, it is anchored in the drilled part in a stable state for a long period of time, and as described above, The part of the injection material consolidated in the tube is press-fitted between the outer circumferential wall and the inner circumference wall of the drilled part through a vertically elongated injection hole provided in the circumferential wall of the steel pipe body in the generatrix direction, and the injection material is hardened. Not only is the steel pipe main body anchored in the drilled part, but also the steel pipe main body is supported in the drilled part by the shear force acting between the hardened injection material and the protrusion provided on the outer peripheral wall of the steel pipe main body. As a result, the steel pipe body is stably supported in the drilled part without being affected by the hole diameter of the drilled part, and the steel pipe body can obtain the shear support force of the full-surface adhesive type from friction on the entire surface, and the steel pipe itself The rock bolt of the present invention prevents earth and sand from collapsing into the hole on the inner circumferential wall of the drilled hole, can be installed even in areas with severe hole roughness, and eliminates variations in pulling force. The present invention has many advantages such as cost reduction.

The present invention will be described below with reference to the illustrated embodiments.

Reference numeral 1 denotes a steel pipe body constituting the main body of the rock bolt, the tip of which is formed into a conical shape, with a slit 2 cut out over its entire length in the generatrix direction, and a large number of protrusions 4 protruding from the peripheral wall. An injection hole 3 is provided on the outer peripheral surface of the protrusion 4 and extends vertically in the generatrix direction, and a ring 5 is integrally fixed to the outer periphery of the proximal end.

When using the rock bolt of the present invention, after drilling a hole in the rock, the plate 6 is fitted to the steel pipe main body 1 and penetrates into the drilled part 7 (see Figs. 7 and 8). (See Figure 9) Insert the cement milk capsule 8 into the hollow part of the steel pipe main body 1 (see Fig. 9), and then insert the steel pipe main body 1 with a conical shoe formed at the tip and a slit 9 cut out along the generatrix direction. An inserted steel pipe 10 having an outer diameter larger than the inner diameter is inserted into the steel pipe main body 1.
When the inserted steel pipe 10 is elastically expanded in the circumferential direction due to the presence of the slit 9, the steel pipe main body 1 having the slit 2 is also expanded in the circumferential direction and is inserted into the drilled hole 7. The cement milk capsule 8 inside the steel pipe main body 1 is crushed as the inner steel pipe 10 is press-fitted, and the cement milk 11 inside the capsule 8 is compressed.
It passes through the injection hole 3 and slit 2 provided in the steel pipe body 1 and is filled between the inner circumferential wall of the drilled part 7 and the outer circumferential wall of the steel pipe body 1.

(See Fig. 10) When press-fitting the steel pipe 10, the slit 9 and the slit 2 of the steel pipe body 1 are positioned on the opposite side, and the cement milk 1 is inserted through the slit 9 of the steel pipe 10.
1 to prevent leakage.

When the cement milk 11 filled between the steel pipe main body 1 and the drilled part T has not hardened yet, the drilled part 7
The steel pipe main body 1 is supported in the hole by friction between the inner circumferential wall of the steel pipe main body 1 and the steel pipe main body 1 expanded in the circumferential direction by press-fitting the inserted steel pipe 10.

At this time, the presence of the projections 4 further improves this frictional effect.

After the cement milk 11 has hardened, the steel pipe body is hardened by the shearing force acting between the cement milk 11 filled between the inner wall surface of the drilled hole 7 and the protrusion 4 provided on the outer wall of the steel pipe body 1. 1 force Zp+'' is supported within the hole 1.

Furthermore, if a large initial bearing capacity is not required,
Cement mortar may be placed in the steel pipe main body 1 in advance, the steel pipe main body 1 is inserted into the drilled hole 7, and the intermediate steel pipe 10 may be press-fitted into the steel pipe main body 1.

Note that resins may be used instead of cement mortar.

Also, without using cement milk capsule 8, steel pipe 1
If the entire area is filled with the injection material, a fixing method using grout may be used.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various designs without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1 is a vertical side view showing one embodiment of a rock bolt according to the present invention, FIG. 2 is a vertical cross-sectional view thereof, FIG. 3 is a side view of an inserted steel pipe, FIG. 4 is a vertical cross-sectional view thereof, and FIG. Figure 6 is a side view of the cement milk capsule, Figure 6 is a plan view of the plate, and Figure 7 is a side view of the cement milk capsule.
Figures 10 to 10 are longitudinal side views showing the steps of the rock bolt construction method using the rock bolt according to the present invention, and Figures 11 and 12 are enlarged longitudinal views showing the anchoring part for the hole drilled on the outer periphery of the rock bolt, respectively. FIG. 1...Steel pipe body, 2...Slit, meter...Injection hole for injection material, 4...Protrusion, 4'
-... Concave groove, 10... Inner steel pipe, 11.
·····slit.

Claims (1)

[Claims] 1. On the peripheral wall of a steel pipe having slits in the generatrix direction,
A steel pipe body having a protrusion and a vertically elongated injection hole along the generatrix direction, a slit extending over the entire length in the generatrix direction of the steel pipe having an outer diameter larger than the inner diameter of the steel pipe body, and a conical part at the tip. A rock bolt characterized by being made of an elastic cored steel pipe.