JPH0464396B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pipe propulsion method for laying longitudinally curved pipes underground using a trenchless method.

[Conventional technology]

As a method for laying buried pipes, a trenchless method for advancing buried pipes is widely used. In such a trenchless propulsion method, if there are obstacles such as structures at the buried location, it is necessary to lay the pipe in a curved manner to avoid this. FIGS. 8 to 10 show how such a curved pipe 14 is buried.

As a method for laying such a curved pipe, the pipe propulsion method disclosed in Japanese Patent Publication No. 7928/1982 and Japanese Patent Application Laid-open No. 13898/1982 is known.

In the former method, a curved pipe is press-fitted at a predetermined angle, and an auger connected with a universal joint is rotated inside the curved pipe to excavate and remove soil, thereby burying the curved pipe underground. In addition, the latter method uses a hydraulic motor-driven bit attached to the tip of the curved pipe to excavate underground to a diameter larger than the outside diameter of the curved pipe, and propels the curved pipe while discharging soil with circulating water. This is to be buried.

[Problem that the invention seeks to solve]

However, these propulsion systems do not have a direction correction function, and the curved pipe is forced into the ground using only its curvature as a guide, so there is a problem that the directionality is lost as the propulsion distance increases.

The present invention has been made in view of such conventional problems, and it is an object of the present invention to provide a propulsion method that can lay a curved pipe while easily and appropriately correcting the direction.

[Means for solving problems]

For this reason, the present invention includes an outer tube curved in the longitudinal direction;
Using an inner tube that is equipped with a tip-driven drill at the tip and is curved in the longitudinal direction, the outer tube is propelled while drilling with the drill protruding from the tip of the outer tube, and the direction correction during such drilling is carried out by the inner tube. This is done by guiding the guided body provided on the distal end side along a guide provided inside the outer tube near the distal end, thereby making the inner tube distal end eccentric with respect to the outer tube, If the drill is driven with the inner pipe eccentric in this way, the drill will excavate the ground on the eccentric side, and the outer pipe will be propelled by the space created by the excavation and the ground reaction force. The direction is corrected to the eccentric direction of the inner tube.

〔Example〕

Figures 1 to 3 show one implementation situation of the present invention, in which 1 is a curved outer pipe (pipe to be buried), 2 is a bent outer pipe (pipe to be buried);
3 is an inner tube, 3 is a tip-driven drill provided at the tip of the inner tube, and 31 is a rotating part at the tip of the drill. It has a retract bit 5 that can be raised and lowered. This retract bit 5 enlarges the hole excavated by the pilot bit 4 to a diameter larger than the outer diameter of the outer tube. Further, the outer tube 1 has an outer tube shoe 13 at its tip, and the original buried tube is connected to the rear end of the outer tube shoe 13.

In the present invention, the rotating part 31 of the tip-driven drill 3 provided at the tip of the inner tube is made to protrude from the tip of the outer tube,
Its pilot bit 4 and retract bit 5
The inner and outer pipes are propelled while excavating underground. Propulsion of such an inner tube and an outer tube can be achieved by, for example,
This may be carried out either by first propelling the inner tube 2 to excavate a predetermined length with a drill, and then propelling the outer tube 1, or by simultaneously propelling the inner tube 2 and outer tube 1.

Further, excavation water used for such excavation is supplied to the front surface of the pilot bit 4 through the inner pipe 2, and mud water containing removed soil is discharged through the space between the outer pipe 1 and the inner pipe 2.

Stabilizers 9 are protruded from a plurality of locations in the circumferential direction of the outer tube shoe 13, and these stabilizers 9 position the propelled outer tube 1 at the center of the excavated hole expanded by the retract bit 5. , and prevents the end of the outer tube from plunging into the soil.

If it becomes necessary to correct the propulsion direction during such excavation, the tip end of the inner tube is made eccentric with respect to the outer tube by a guide provided inside the outer tube near the tip end.

FIGS. 2 and 3 show an example of the implementation situation, and on both sides of the inner surface near the tip of the outer tube 1,
A pair of guide portions 6 are provided facing each other so as to be inclined with respect to the outer tube axis. In this embodiment, the guide portion 6 is constituted by a guide groove 7. Further, the rear end of the guide groove 7 is configured to have a wide width in order to facilitate the introduction of the guided object 8. Also,
The inner tube 2 (including the casing of the driving drill) has a pair of guided bodies 8 that can be guided by the guide section.
is provided. This guided body 8 is constituted by an arm body that can be slidably fitted into the guide groove 7.

Normally, the outer tube 1 is propelled so that its guide portions 6 are located on both sides in the horizontal direction and are tilted in the vertical direction. When the guided body 8 of the inner tube 2 is located at the center of the guide part 6 as shown in FIG. Excavate the ground along the extension of the pipe axis.

On the other hand, when correcting the excavation direction upward, the inner tube 2 is moved forward in the outer tube axis direction. In this case, as shown in FIG. 2b, the guided body 8 slides while being pushed upward along the guide portion 6, so that the inner tube 2 becomes eccentric upward with respect to the outer tube 1.
The drill excavates the upper side of the ground, and the propelling direction of the outer tube 1 that is propelled is corrected upward due to the space created by the excavation and the reaction force of the ground.

In addition, when the excavation direction is corrected downward, the inner tube 2 is moved backward to make the inner tube 2 eccentrically downward with respect to the outer tube 1 as shown in FIG. 2c. As a result, the drill excavates the lower part of the ground, and the direction of movement of the outer pipe 1 is corrected downward.

To move the inner tube 2 back and forth during such vertical correction, as shown in FIG. (hydraulic cylinder), and the cylinder device 12 moves the inner tube.

The above is a correction in the vertical direction of the propulsion direction,
When making corrections in the left and right direction (horizontal direction), the fifth
As shown in Figures a and b, the length of the guided body 8 is changed on the left and right sides, and by doing so, the inner tube 2 is eccentric with respect to the outer tube 1 in the horizontal direction. Due to such eccentricity, the propulsion direction is corrected in the left-right direction based on the same principle as described above. Therefore, by adjusting the length of the guided body and selecting the position of the guided body in the longitudinal direction of the guide length described above, the propulsion direction can be corrected in any direction.

In addition, when making corrections in the left and right direction, the third
The inner tube as shown in the figure (the inner tube with guided bodies of the same length on the left and right sides) is once removed, the guided body 8 is replaced with one like that shown in Figure 5 a or b, and then reinserted. It is.

The above is the basic and preferred correction method, but
For example, the outer tube 1 may be rotated by 90 degrees from the state shown in FIGS. 2 and 3, that is, the guide portion 6 may be positioned vertically.
The mode of use thereof is not limited to the above embodiment. FIG. 6 shows an example (horizontal cross-sectional view), in which the guide portion 6 is located above and below the guided object 8.
By being guided by the guide portion 6, the inner tube 2 is horizontally eccentric with respect to the outer tube 1, and the propulsion direction is corrected in the horizontal direction. Regarding correction in the vertical direction, as shown in FIGS. 7a and 7b, the guided body 8
This can also be done by making the lengths of the upper and lower portions different and eccentrically centering the inner tube in the vertical direction.

In addition to the above embodiments, for example, a structure in which a guide portion in the form of a guide rail is provided and the guide rail is sandwiched from both sides as a guided object, or a structure in which the guide portion is simply slid on the upper surface of the guide rail may be used. Can be used.

Further, as the drive motor of the tip drive type drill 3, a water pressure motor, a hydraulic motor, an electric motor,
Although an air hammer or the like can be used, when a hydraulic motor is used, there is an advantage that the excavation water can be used as driving water. Further, the soil may be discharged by suction using a vacuum pump.

Moreover, the above-mentioned direction correction is performed based on the detection result of the position detection device sent through the inner tube.

The construction method of the present invention is applicable not only to ordinary buried pipes but also to piles, underground measurement boreholes, etc.

〔Effect of the invention〕

According to the present invention described above, it is possible to install a curved pipe while easily and appropriately correcting the direction.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is an overall explanatory diagram, and FIGS. 2 a to c.
3 is an explanatory diagram showing a method of correcting the propulsion direction, and FIG. 3 is a cross-sectional view taken along the line 2-a in FIG. 2. FIG. 4 is an explanatory view showing an example of a mechanism for moving the inner tube forward and backward relative to the outer tube in carrying out the present invention. FIGS. 5a and 5b are explanatory diagrams showing a method of eccentricizing the inner tube in the left-right direction. FIG. 6 is an explanatory view showing another example of a method for correcting the propulsion direction, and FIGS. 7a and 7b are explanatory views showing a method for vertically eccentricizing the inner tube in the correction method. FIG. 8, FIG. 9a, b, and FIG. 10 are explanatory diagrams showing an example of laying a curved pipe. In the figure, 1 is an outer tube, 2 is an inner tube, 3 is a tip-driven drill, and 6 is a guide portion.

Claims (1)

[Claims] 1. Using an outer tube that is curved in the longitudinal direction and an inner tube that is curved in the longitudinal direction and has a tip-driven drill at its tip, the outer tube is drilled while drilling with the drill protruding from the tip of the outer tube. At the same time, the direction correction during cutting can be carried out by guiding the guided body provided on the tip side of the inner tube along a guide provided inside the outer tube near the tip. A curved propulsion method characterized in that it is carried out by making it eccentric to the outer pipe. 2 By slidably engaging the guided body provided in the inner tube with a guide portion inside the outer tube that is non-parallel to the outer tube axis, the tip of the inner tube can be biased with respect to the outer tube. The curved propulsion construction method according to claim 1, characterized in that it is cored. 3 In the guide part provided opposite to the inner surface of the outer tube,
The curved propulsion construction method according to claim 2, characterized in that guided bodies on both sides of the inner tube are guided. 4. The curved propulsion construction method according to claim 3, characterized in that the lengths of the guided bodies on both sides are made different, and the inner tube is eccentric to the shorter guided body side with respect to the outer tube.