JPH0633691A - Direct pushshield drilling method - Google Patents

Abstract

PURPOSE:To protect a steel pipe itself with its coating and prevent the steel pipe from corrosion by sending out a sheet from a sheet outlet installed to a preceding steel and covering the rear end of the preceding steel pipe and the outer wall of the steel pipe accompanied by shielding. CONSTITUTION:Three sheet outlets 1a extending in a circumferential direction are installed to a preceding steel pipe in a lateral direction with an offset. Three sheets 2 wound around each reel 4 are sent out from each of the sheet outlets 1a. Each end 2a of the sheets is fixed with the rear end of the preceding steel pipe in the shielding direction which is the side wall of a shaft 5. Then, each sheet 2 is sent out from the sheet outlets 1a one by one, thereby covering the rear end of the preceding steel pipe 1 ad the outer wall of the steel pipe 3 accompanied by the shield of the preceding steel pipe 1. This construction makes it possible to prevent the outer wall of the steel pipe 3 from the earth and protect the steel pipe itself and its coating or the like from damages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct thrusting method for propelling a steel pipe into the ground.

[0002]

2. Description of the Related Art When laying a steel pipe such as a water pipe or a gas pipe in the ground, there is a case where an excavation method is employed in which the spot to be laid is excavated from the ground to a predetermined depth. However, there are cases where the open-cut method cannot be used because there are roads and structures at the points where the steel pipes are laid. In this case, a vertical shaft is dug at both ends of the point where the steel pipe is laid, a leading steel pipe is dug on the side of one vertical shaft toward the other vertical shaft, and a steel pipe connected longitudinally to the rear end of this leading steel pipe. A propulsion method that promotes is sometimes adopted. In this propulsion method, the steel pipe is normally propelled while contacting the soil with the ground, so the stones and rocks in the ground also damage the coating for corrosion protection covering the outer wall of the steel pipe and the pipe body. Steel pipes may corrode. In order to prevent this, a sheath pipe propulsion method is used in which a pipe called a sheath pipe having a diameter larger than that of the steel pipe is previously propelled to the rear end of the leading steel pipe, and the steel pipe is newly propelled inside this propelled sheath pipe. Many. Also,
Steel pipes that have been prevented from damage by hardening the coating covering the outer wall of the steel pipe or thickening the coating, etc. A direct push propulsion method for propelling may be used.

[0003]

In the conventional sheath tube propulsion method described above, the steel tube must be propelled again after the sheath tube has been propelled, which increases the number of steps and prolongs the construction period. There is. In addition, the steel pipe used in the direct thrusting method has to be harder or thicker for the coating that covers the outer wall of the steel pipe, so the price is higher than for steel pipes with standard coating. There is.

In view of the above circumstances, it is an object of the present invention to provide a direct thrusting construction method which can shorten the construction period and can use a steel pipe coated with standard coating.

[0005]

According to the direct thrusting method of the present invention for achieving the above object, a propulsive force is applied to a steel pipe connected to a rear end of a leading steel pipe to propel the steel pipe into the ground. In the direct push propulsion method, one end is fixed to the outside of the horizontal shaft where the steel pipe is propelled, and the steel pipe is expanded by a sheet that extends into the front end side of the steel pipe in the propulsion direction and extends through the holes in the leading steel pipe or into the steel pipe. It is characterized by propelling a steel pipe while covering the outer wall.

[0006]

In the direct pushing propulsion method of the present invention, one end of the seat is
The steel pipe is fixed to the outside of the horizontal shaft that is propelled, and the other end of the sheet spreads toward the front end side of the steel pipe in the propulsion direction and extends through the hole formed in the leading steel pipe into or into the leading steel pipe. Since the steel pipe is propelled while covering the outer wall of the steel pipe, the steel pipe is propelled in the ground without the outer wall contacting the soil. As a result, even if the steel pipe is coated with a standard coating material, it can be propelled in the ground without being damaged by the coating material or the steel pipe body.

[0007]

EXAMPLES Examples of the present invention will be described below. FIG. 1 is a side view schematically showing a leading steel pipe and a part of an outer wall of the steel pipe in an example of the present invention. The leading steel pipe 1 is provided with three sheet outlets 1a extending in the circumferential direction at different levels in the lateral direction in FIG. 1, and the three sheets 2 partially overlap with each other from the three sheet outlets 1a. The leading steel pipe 1 and the steel pipe 3 are propelled in the ground in a direction indicated by an arrow while covering the outer wall of the rear end portion and also covering the outer wall of the steel pipe 3 connected to the rear end of the leading steel pipe 1.

FIG. 2 is a side view showing the leading steel pipe and the steel pipe in a cross section with a part omitted in an example of the present invention.
A reel 4 is rotatably attached to the inner wall of the leading steel pipe 1, a sheet 2 is wound around the reel 4, and one end 2a of the sheet 2 passes through a sheet outlet 1a provided in the leading steel pipe 1. It is fixed to the side wall of the vertical shaft 5, that is, to the rear end side of the leading steel pipe 1 in the propulsion direction. A water blocking wall 6 is provided between the leading steel pipe 1 and the steel pipe 3. Sheet 2 for promotion
While covering the rear end portion of the leading steel pipe 1 and the outer wall of the steel pipe 3, the leading steel pipe 1 and the steel pipe 3 are propelled in the ground in the direction indicated by the arrow.

One end 2a of the seat 2 is fixed to the side wall of the vertical shaft 5 before the leading steel pipe 1 is propelled. Therefore, when the leading steel pipe 1 and the steel pipe 3 are propelled, the sheet 2 wound around the reel 4 is unwound from the reel 4 and the sheet outlet 1
It goes out from a and covers the rear end part of the leading steel pipe 1 and the outer wall of the steel pipe 3. As a result, the outer wall of the steel pipe 3 does not come into contact with the soil, and the coating of the steel pipe 3 and the steel pipe 3 are prevented from being damaged. Further, since the water blocking wall 6 is provided at the connecting portion between the leading steel pipe 1 and the steel pipe 3, even if a water nozzle penetrates into the inside of the leading steel pipe 1 through the seat outlet 1a, it does not reach the inside of the steel pipe 3. Intrusion is prevented.

FIG. 3 is a side view showing a leading steel pipe and a steel pipe in a sectional view with a part omitted in another example of the present invention. Elements having the same configurations as those of the above-described example (see FIGS. 1 and 2) are designated by the same reference numerals. A reel 4 is rotatably attached to the inner wall of the steel pipe 3, and a sheet 2 is wound around the reel 4. One end 2a of the sheet 2 passes through a sheet outlet 1a provided in the leading steel pipe 1 to form a vertical shaft. The sheet 2 is fixed to the side wall of the steel pipe 5, and the sheet 2 covers the rear end of the steel pipe 1 and the outer wall of the steel pipe 3, while the steel pipe 1 and the steel pipe 3 are propelled in the ground in the direction indicated by the arrow.

As in the above-mentioned example, since the one end 2a of the sheet 2 is fixed to the side wall of the vertical shaft 5 before the leading steel pipe 1 is propelled, when the leading steel pipe 1 and the steel pipe 3 are propelled, the reel 4 is moved to the reel 4. The wound sheet 2 is rewound to the sheet exit 1
It goes out from a and covers the rear end part of the leading steel pipe 1 and the outer wall of the steel pipe 3. As a result, the outer wall of the steel pipe 3 does not come into contact with the soil, and the coating of the steel pipe 3 and the steel pipe 3 are prevented from being damaged.

Here, the steel pipe 3 used in the present invention may be a standard coated pipe, for example, a polyethylene lined steel pipe, or a steel pipe provided with concrete for covering the coated pipe. Further, between the steel pipe 3 and the sheet 2, the steel pipe 3
It is more effective to provide a lubricant or the like for reducing friction between the sheet 2 and the sheet 2.

[0013]

As described above, in the direct pushing propulsion method of the present invention, the steel pipe is propelled while the sheet covers the outer wall of the steel pipe, and therefore the steel pipe is propelled without the outer wall of the steel pipe coming into contact with the soil. . As a result, the coating of the steel pipe and damage to the steel pipe itself can be avoided, and corrosion of the steel pipe is prevented, so that a standard coated steel pipe can be used. Moreover, since the steel pipe is directly propelled, the construction period can be shortened.

[Brief description of drawings]

FIG. 1 is a side view showing a leading steel pipe and a part of an outer wall of the steel pipe in an example of the present invention.

FIG. 2 is a side view showing a leading steel pipe and a steel pipe in a cross section with a part omitted in an example of the present invention.

FIG. 3 is a side view showing a leading steel pipe and a steel pipe in a sectional view with a part omitted in another example of the present invention.

[Explanation of symbols]

 1 Leading steel pipe 2 Sheet 3 Steel pipe 4 Reel 5 Vertical shaft 6 Water stop wall

Claims (1)

[Claims] 1. A direct push propulsion method in which a propulsive force is applied to a steel pipe connected to the rear end of a leading steel pipe to propel the steel pipe into the ground, one end of which is fixed to the rear end side in the propulsion direction of the steel pipe. Direct pressing, characterized in that the steel pipe is propelled while covering the outer wall of the steel pipe by a sheet that extends to the front end side in the propulsion direction of the steel pipe and extends through the holes provided in the leading steel pipe into the steel pipe or into the steel pipe. Propulsion method.