JPH0959974A - Manufacture of removal type anchor unbonded pc-steel stranded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a substance innoxious to underground environment by coating the surfaces of PC-steel stranded wires with vegetable oil biodegradable grease and covering the surfaces of the stranded wires with polyethylene sheets. SOLUTION: The surfaces of PC-steel stranded wires 1 are coated with vegetable oil biodegradable grease 2, and the surfaces of the stranded wires 1 are covered with polyethylene sheets 3. A drilled pit is drilled to the ground, the unbonded PC-steel stranded wires are inserted into the pit in a shape that the front end of a load- withstand body is folded back in the character of a fulcrum U while the pit is filled with mortar, etc., and the unbonded PC-steel stranded wires are moored to the ground, and both tips projected to the outside of the pit of the unbonded PC-steel stranded wires are stretched and fixed. Only the PC-steel stranded wires as existing obstructions can be removed from the ground by extracting one tips of the PC-steel stranded wires 1 in the unbonded PC-steel stranded wires, by which the object of the execution of works is attained previously and which are unnecessitated. The PC-steel stranded wires 1 are taken off, and vegetable oil biodegradable grease 2 adhering on the polyethylene sheets 3 left in the ground is biodegraded instantaneously by the culture action of microorganisms when the grease 2 is brought into contact with organic matter in the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a removable anchor construction method for supporting mountain retaining walls, retaining walls and the like. The ground anchor method or the rock anchor method is usually used to support the mountain retaining wall and retaining wall. In these methods, a hole is drilled in the ground and a PC steel stranded wire is used in the hole. The material is inserted and filled with mortar and the like, the strip material is moored to the ground, and the tension of this strip material supports the retaining wall and retaining wall. Furthermore, these construction methods can be roughly divided into permanent type and removal type.One of the removal types considers that the strip material which has already been achieved the construction purpose and is no longer needed is removed from the ground and does not become an existing obstacle. It is of the type used. The unbonded PC stranded steel wire of the present invention is a strip material used in this removal type anchor construction method.

[0002]

2. Description of the Related Art An unbonded PC steel twisted wire used in a conventional removable anchor construction method has a surface of a PC steel twisted wire coated with a mineral oil-based grease and a polyethylene sheath covering the surface. Unbonded P using this manufacturing method
The C steel stranded wire is manufactured and sold by a plurality of PC steel stranded wire manufacturing companies.

[0003]

However, this has the following drawbacks. The unbonded PC steel stranded wire used in the strip material of the removable anchor construction method can remove only the PC steel stranded wire from the ground when the construction purpose has already been achieved and is no longer necessary, but polyethylene left in the ground Since the mineral oil-based grease remains attached to the sheath, residual mineral oil-based grease in the ground causes environmental pollution such as soil and groundwater pollution.

[0004]

Means for Solving the Problems A removal formula characterized in that a surface of a PC steel stranded wire (1) is coated with a vegetable oil biodegradable grease (2) and the surface is covered with a polyethylene sheath (3). Provided is a method for manufacturing an unbonded PC steel stranded wire for an anchor.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A ground hole is bored in a ground (4), and the unbonded PC steel twisted wire of the present invention is folded into a U shape with the tip of a load bearing body (7) as a fulcrum. Inserting and filling mortar etc. (5) mooring unbonded PC steel stranded wire to the ground (4), tightening both ends of the unbonded PC steel stranded wire outside the hole and fixing it with the elasticity Supports retaining walls (6) and retaining walls. The unbonded PC steel stranded wire which has already achieved the purpose of construction and is no longer needed can be removed from the ground (4) only the PC steel stranded wire (1) which is an existing obstacle by pulling out one end of the PC steel stranded wire (1).

[0006]

[Example] Unbonded PC steel twist for removable anchor characterized in that the surface of PC steel twisted wire (1) was coated with vegetable oil biodegradable grease (2) and the surface was covered with polyethylene sheath (3) Manufacture wire.

[0007]

EFFECT OF THE INVENTION After removing the PC steel twisted wire (1), the vegetable oil-based biodegradable grease (2) attached to the polyethylene sheath (3) remaining in the ground (4) comes into contact with organic substances in the ground. Immediately biodegradable by the culture action of microorganisms, it becomes a substance harmless to the underground environment. Therefore, the present invention solves the problem of environmental pollution due to residual mineral oil-based grease in the ground, which is a drawback of the unbonded PC steel twisted wire used in the conventional removable anchor.

[Brief description of drawings]

FIG. 1 is a diagonal diagram of the present invention.

FIG. 2 is a sectional view of the present invention.

FIG. 3 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 1 PC steel stranded wire 2 Vegetable oil-based biodegradable grease 3 Polyethylene sheath 4 Ground 5 Mortar 6 Yamadome wall 7 Load-bearing body

Claims (1)

[Claims] 1. An unbonded PC steel for a removable anchor, characterized in that a surface of a PC steel stranded wire (1) is coated with a vegetable oil-based biodegradable grease (2) and the surface is covered with a polyethylene sheath (3). Manufacturing method of stranded wire.