JP2005337384A - Method of laying plastic tube underground, and protective sheet for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective sheet easy to be wound or fixed around/to a plastic tube and possible to be cut at a required position thereof without damaging the plastic tube in the case wherein it is necessary to connect a saddle joint or the like to the plastic tube, and capable of preventing the generation of a clearance between the plastic tube due to a contact of the filled-back sand with the plastic tube, in regard to an impact resistant protective sheet to be wound around the plastic tube to prevent the generation of damage in the plastic tube even if a claw of an excavator abuts, by mistake, on the plastic tubes for service water, sewage and gas laid underground when excavating the ground with an excavator. <P>SOLUTION: The protective sheet 16 is structured of a net made of polypropylene formed material, and after winding the protective sheet 6 around the plastic tube 7, both the side edges are connected to each other by a clip 8 made of stainless steel through a mesh. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for embedding a plastic pipe in soil and a protective sheet wound around the plastic pipe in order to improve the impact resistance of the embedded plastic pipe.

  In recent years, plastic pipes have become widespread as liquid transport pipes, such as water and sewage pipes and gas pipes. Among them, polyethylene pipes are flexible, lightweight and easy to install, and do not corrode even when buried in the soil. However, there is a problem that it is weak in impact strength, and when excavating the ground using an excavator for construction performed after burial, for example, water and sewage pipe construction, the claw of the excavator The polyethylene pipe may be damaged by hitting the buried polyethylene pipe. For this measure, for example, in the main pipe of a gas pipe having a high internal pressure, a protective sheet such as a polypropylene sheet is wound to improve the impact resistance of the polyethylene pipe. Specifically, in the case of a polypropylene sheet, a multilayer sheet in which polypropylene sheets are laminated in five layers is used. After the multilayer sheet 2 is wound around the polyethylene tube 1 as shown in FIG. 3 is wound and fastened and fixed, and in order to improve the anti-impact property, the multilayer sheet 2 is further wound thereon and fastened by an insulok and fixed.

For construction with the multilayer sheet 2 described above,
(1) Laminated sheet 2 has a structure in which polypropylene sheets are laminated in five layers, so it is stiff and not easy to wind around a tube.
(2) Since the multilayer sheet 2 is strong as described above, it cannot be temporarily fixed using an adhesive tape or the like in a state of being wound around the tube, and is easily scattered in a state of being wound around the tube. It is not easy to wind and fix the insulation lock 3 around it, and it is particularly difficult to wind and fix the multilayer sheet 2 on it.
(3) In order to connect the branch pipes even after the multilayer sheet 2 is wound and fixed and buried, it may be necessary to dig up later and fuse and connect a saddle joint or service joint to the side of the pipe. When performing such pipe work, it is necessary to cut off the multilayer sheet at the location where the joint is to be attached and to expose the pipe surface of the location, but it is very difficult to cut the multilayer sheet 2, Risk of damaging the tube,
(4) Rolling is carried out by covering with earth and sand at the time of embedding, but a gap is easily formed between the multi-layer sheet 2 and the tube 1, particularly between the double-layered multi-layer sheet 2. There is a risk that earth and sand will be carried along with the rainwater as a rainwater channel, causing local settlement at the buried site,
Etc.

  The present invention provides a method of embedding a plastic pipe into the soil that can solve the above problems, and a protective sheet that is wound around the plastic pipe in order to increase the impact resistance of the embedded plastic pipe. Objective.

  The invention according to claim 1 is a method of embedding a plastic pipe used for a liquid transport pipe or a gas pipe suitable for use as a water and sewage pipe in the ground, and at least a part of the plastic pipe has corrosion resistance, A porous or net-like protective sheet having impact and flexibility and through which earth and sand pass is wound and embedded in the ground.

The invention according to claim 2 is a protective sheet wound around a plastic pipe in order to enhance the impact resistance of the plastic pipe used as a liquid transport pipe or gas pipe buried in the soil, and has a porous or net shape. It is characterized by having earth and sand passing through and having corrosion resistance, impact resistance and flexibility,
The invention according to claim 3 is characterized in that a plastic sheet having no holes is overlapped and integrated with the protective sheet according to claim 2.

  As a protective sheet made of a material having corrosion resistance, impact resistance and flexibility used in each of the above inventions, for example, a multilayer formed by laminating a plastic net such as stainless steel or polypropylene, or a plastic sheet such as stainless steel or polypropylene. Examples of the sheet include a perforated sheet having numerous holes, and the above-described net is usually formed by punching with a press when made of stainless steel, and may be a molded product when made of plastic. It may also be a woven product.

  Further, the pores of the porous sheet may not be uniform in shape and size, but are preferably uniform.

  As a method for integrating plastic sheets having no holes, for example, fastening with a fastener, and in the case of a plastic sheet, welding, adhesion, sewing, or the like can be used.

  According to the embedding method of the plastic pipe of the present invention and the protective sheet used in the method, since the protective sheet has impact resistance, the claw of the excavator hits the plastic pipe when excavating using the excavator after embedding. The tube can be prevented from being damaged even if there is a thing, the protective sheet has flexibility, the winding work around the plastic tube can be easily performed, the protective sheet is wound around the plastic tube, A protective sheet that is easily wrapped around a plastic tube by fastening it with a string-like object such as a wire or rope having corrosion resistance and strength through a hole or through a mesh of a net, or by connecting with a fastener such as a clip. When it is necessary to connect a saddle joint or service joint to the side of the plastic pipe, It can be cut without damaging the pipe by checking the surface, and the backfilled soil will enter the pipe surface even if it is brazed with multiple layers as well as a single layer, causing subsequent local settlement. There are effects such as difficulty.

  In addition, in a protective sheet in which sheets with no holes are stacked and integrated, a sheet without holes reinforces the protective sheet, and when the protective sheet is hooked with a claw of an excavator to try to tear it down, Excavator operators tend to notice the protective sheet because resistance increases as unseen sheets are pulled out together. Therefore, the buried pipe is also noticed to make it difficult to damage the pipe.

  In addition, when a protective sheet in which sheets with no holes are overlapped and integrated is attached to the pipe, the end of the protective sheet overlaps to form a gap that can serve as a water or earth and sand channel between the pipe and the pipe. The width of the protective sheet wound around the pipe is preferably shorter than the outer peripheral length of the pipe.

FIG. 2 shows an example of the protective sheet 6 according to the present invention, which is composed of a net made of a molded product made of polypropylene, and is cut to be the same or slightly wider than the outer periphery of the plastic pipe around which the width M is wound. ing.

  FIG. 3 shows a cross section in which the protective sheet 6 is wound around a polyethylene pipe 7 as a plastic pipe, and the side edges of the sheet 6 are fixed by connecting them through a mesh with a stainless steel clip 8. Yes.

  FIG. 4 shows another example of the protective sheet, in which the protective sheet 6 described above is partially welded and integrated with a polypropylene sheet 9 having no holes.

  The protective sheet of the present invention is used to increase the impact resistance of a liquid transport pipe or gas pipe embedded in the soil, and a water and sewage pipe is suitable as the liquid transport pipe.

Sectional drawing which shows the prior art example of the protection sheet wound around a plastic pipe | tube. The top view of the protection sheet which concerns on this invention. Sectional drawing which shows the state which wound and fixed the protection sheet shown in FIG. 2 around the plastic pipe | tube. The fragmentary perspective view of another example of the protection sheet which concerns on this invention.

Explanation of symbols

1, 7 ... Polyethylene pipe 2. Multi-layer sheet 3. Insulok 6. Protective sheet 8. Clip 9. Sheet with no holes

Claims (3)

  A method of embedding a plastic pipe used as a liquid transport pipe or a gas pipe in the ground, wherein at least a part of the plastic pipe has corrosion resistance, impact resistance and flexibility, and a porous or net through which earth and sand can pass. A plastic pipe embedding method characterized by winding a protective sheet in the shape of a tube and embedding it in the ground.   A protective sheet wrapped around a plastic pipe to increase the impact resistance of a plastic pipe used as a liquid transport pipe or a gas pipe. A protective sheet for a plastic tube, characterized by having flexibility.   The protective sheet for a plastic tube according to claim 2, wherein sheets having no holes are stacked and integrated.

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