JPH0447100A - Rock bolt - Google Patents

Abstract

PURPOSE:To prevent a hindrance to excavation by integrally forming a core composed of a rigid member on one side and a soft member on the other side, in such a way that the core is surrounded by a skin in which yarns that are formed of bound thin wires having a large tensile strength, are braided into a hollow braided rope. CONSTITUTION:A core 1 is composed of a rigid member 1a made of resin impregnated fibers, propylene or the like on one side and a soft member 1b made of foamed mortar, foamed resin or the like. Further, yarns 3 formed of thin wires 2 such as carbon wires or the like having a large tensile strength are braided into a hollow braided rope, and the thin wires 2 are bound together so as to form a skin 4. Further, the core 1 is surrounded by the skin 4, and they are integrally incorporated with each other by a binder.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rock bolt used to prevent surface rock from collapsing during construction such as tunneling or rock cutting.

(Prior Art) As this type of lock bolt, a lock bolt made of a rigid material such as steel is known.

(Problems to be Solved by the Invention) However, although the conventional structure has no problem in reinforcing effect, it has the disadvantage that its rigidity becomes an obstacle during excavation.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such conventional drawbacks and to provide a rock bolt that has a sufficient reinforcing effect and does not interfere with excavation work during excavation.

(Means for Solving the Problems) The rock bolt of the present invention has a core body composed of a rigid material on one side and a soft material on the other side, and a hollow braided body made of fine wires with high tensile strength. It is characterized by surrounding and integrating these thin wires with an outer sheath formed by bonding them together.

(Function) The rock bolt as a whole exhibits a sufficient reinforcing effect, and the core portion made of soft material is easily sheared and broken.

(Examples) Examples of the present invention will be described below with reference to the accompanying drawings.

In the figure, reference numeral 1 indicates a core body composed of a rigid material 1as on one side and a soft material 1b on the other side, and in this example, it is formed into a round bar shape, but its shape is not particularly limited, and it has an irregular shape. is optional, including

In addition, in the illustrated example, the rigid material 1a and the soft material 1b are the core body 1.
However, the ratio is arbitrary depending on the excavation work conditions and the like.

As the rigid material 1a constituting the core body 1, for example, a steel material, a resin-impregnated fibrous material formed by binding together carbon fiber, aramid fiber, vinylon fiber, etc. with a binder, a propylene material, etc. are used.

Further, as the soft material 1b constituting the core body 1, for example, foamed mortar, foamed resin such as foamed polystyrene, foamed epoxy, etc. are used.

The core body 1 is surrounded and integrated with a sheath 4 formed by knitting a bunched thread 3 of fine wires 2 having high tensile strength into a hollow braid shape and binding these fine wires 2 to each other.

The fine wires 2 with high tensile strength constituting the outer sheath 4 include, for example, inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers, aromatic polyamide fibers, polyester fibers, high-strength polyolefin fibers, strong polyamide fibers, and strong polyvinyl fibers. Organic fibers such as alcohol fibers, metal fibers, etc. can be used alone or in combination.

In order to bond these thin wires 2 with high tensile strength to each other, organic binders such as epoxy, polyester, vinyl ester, phenol, and polyimide, alkali metal silicate, colloidal silica, phosphate, etc. Use an inorganic binder such as a cement type or cement type.

The outer sheath 4 may be formed in a hollow braid shape, such as a round braided cord, a square braided cord, a hand-strung cord, or the like, as required.

In order to integrate the core body 1 and the jacket 4, the bonding agent used to bind the thin wires 2 to each other may be used.

For example, if the core 1 is inserted into the jacket 4 with the binder uncured and the binder is cured in that state, the fine wires 2 can be bound together and the jacket 4 and the core 1 can be integrated. Can be done at the same time.

Figure 2 shows the state in which the rock bolt of the present invention is used to cut out a tunnel. First, the rock bolt is driven into the small diameter tunnel 10 that has already been excavated, with the rigid material 1a at the tip. After reinforcing the tunnel, the tunnel is excavated including the soft material 1b, and a large diameter tunnel 11 is cut out as shown by the imaginary line in the figure.

(Effects of the Invention) As described above, according to the rock bolt of the present invention, the core body made of a rigid material on one side and a soft material on the other side is knitted into a hollow braid-like body by collecting fine wires with high tensile strength. However, since these thin wires are surrounded by a jacket formed by bonding them together and are integrated, it is possible to provide a rock bolt which has a sufficient reinforcing effect and does not interfere with excavation work during excavation.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of one embodiment of the lock bolt of the present invention, and FIG. 2 is an explanatory diagram showing the state of use thereof. 1...Core body 1a...Rigid material b...Soft material 2...Thin wire 3...Collected yarn 4...Outer cover 3 people

Claims (1)

[Claims] 1. A core body made of a rigid material on one side and a soft material on the other side is surrounded by an outer jacket made by knitting aggregated threads of fine wires with high tensile strength into a hollow braid shape and binding these fine wires together. A rock bolt characterized by being integrated.