JPH0326279B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a buried pipe propulsion method and device using a boring machine for burying pipes for sewage, cables, etc. underground in civil engineering work, and particularly when excavating and propulsion through a gravel layer, etc. This relates to technology that ensures straight-line propulsion by correcting the bend in the hole.

The conventional buried pipe propulsion method, which uses an auger shaft as the inner pipe inside the outer pipe, is used to bury small diameter pipes of about 400φ to 1000φ. , a power swivel type with an outer tube that can rotate and propel is used)3
Install the outer tube 4a and inner tube 4b (auger shaft) at a.
are simultaneously propelled in opposite directions to dig the pilot hole, b connects the pilot pipe 4, c attaches the enlargement bit 5 after reaching the hole, d and e enlarge the hole, entrain the sheath pipe or fume pipe, and reach the hole. The jack 6 provides auxiliary propulsion from the second side. However, buried pipes
If the diameter is about 400φ, the step of expanding the hole to a diameter of c or less may not be necessary. However, if a bend occurs during the pilot hole excavation, it cannot be corrected, so a buried pipe propulsion device as shown in Figure 1 has been used to correct the bend. In Fig. 2, 7 is an outer tube, 8 is an inner tube, and the front side of the inner tube is a screw shaft 8b, and the tip side is an inclined head 8a, and the inclined head 8a has a center riser 8c inside the outer tube. Prevents the tip from wobbling. During normal excavation, the outer tube 7 and the inner tube are rotated in opposite directions to propel both, but if the hole bends, the rotation is stopped and the outer tube 7 and inner tube 8 are propelled as they are. Then, in the case of this figure, the tilting head 8a is eccentrically corrected diagonally upward in the figure, so that it is rotated and propelled again. The excavated soil passes between the outer pipe 7 and the inner pipe 8 and is discharged to the starting shaft by the screw shaft 8b. However, correction of hole bending using the conventional buried pipe propulsion device as shown in Figure 2 is difficult when the ground to be excavated is a gravel layer mixed with cobbles.
If the boulders are large, not only is it difficult to excavate without crushing the boulders while digging, but it is also difficult to excavate with a screw, making construction impossible. When using the buried pipe propulsion method for burying sewage pipes, the sewage treatment plant is often installed downstream and near the river, and the ground near the river is not only a layer of sand and gravel, but also a natural environment for the buried pipes. Since it is necessary to create a slope, correction of the bend in the hole is a necessary condition, but this could not be done using the conventional construction method using a buried pipe propulsion device.

It is an object of the present invention to provide a buried pipe straight propulsion method that can correct hole bending and propel straight forward even when propagating through a sand and gravel layer mixed with cobbles, and to provide a device used to carry out this method.

The method of the present invention for achieving the above object is a construction method in which a boring machine installed in the starting shaft is used to install a buried pipe in the ground between the reaching shaft and the outer pipe, in which a whipstock is fixed to the tip of the circular pipe on the reaching shaft side. The whipstock has a cylindrical shape with an eccentric hole that slopes forward from the axis of the circular tube, and a cutting tip is fixed to the cutting part at the tip, and the inner tube has an auger at its base end on the side of the starting shaft. A down-the-hole drill is fixed to the tip of the shaft, and a center riser is provided on the outer periphery of the cylinder liner of the down-the-hole drill. Using a drilling device that operates a down-the-hole drill while rotating the inner and outer tubes in opposite directions and propelling them, the axis of the eccentric hole of the whipstock was corrected in order to correct the bend in the hole. Therefore, set the hole in the direction in which it should be eccentric, operate the down-the-hole drill while rotating only the inner tube with the outer tube stopped, and drill eccentrically until the bent hole is corrected. Next, drill only the outer tube a specified distance. A process of retreating to the starting shaft side without rotation, a process of rotating and propelling the outer tube halfway through the down-the-hole drill that previously excavated eccentrically and stopped, and then a state of normal propulsion again without rotation to the outer tube. This is a buried pipe straight advancement construction method that is characterized by the process of advancing the buried pipe to the position and correcting the hole bend.

Further, an apparatus of the present invention capable of suitably implementing the above method has the following configuration.

That is, the device of the present invention is composed of an outer tube having a whipstock fixed to the distal end of the circular tube, and an inner tube inserted from the proximal end side of the outer tube, and the whipstock extends forward from the axis of the circular tube. It has a cylindrical shape with an eccentric hole that is inclined towards the direction, and a cutting tip is fixed to the cutting part at the tip, and the inner tube consists of an auger shaft at the proximal end and a down-the-hole drill fixed to the tip, A center riser is provided on the outer periphery of the cylinder liner, and the center riser slidably abuts on the inner surface of the eccentric hole of the whipstock, and allows the outer tube to rotate, non-rotate, advance, and retreat independently of the inner tube. This is a buried pipe straight propulsion device that is characterized by the following.

A detailed explanation will be given below based on FIG. 3 and subsequent figures.

In the buried pipe propulsion device of the present invention, as shown in FIG.
b has a cylindrical shape with an eccentric hole that slopes forward from the axis of the circular tube, and a cutting tip 10a is fixed to the cutting part at the tip. The one on the left) is an auger shaft 11a having a spiral blade on the outer periphery of the shaft, and the inner tube 11, which is a down-the-hole drill 9, is inserted through the tip of the auger shaft 11a. FIG. 4 is a partially cutaway perspective view of a conventionally used down-the-hole drill, and FIG. 5a is a perspective view of the down-the-hole drill used in the present invention. This is different from the commonly used down-the-hole drill 17 as described below.

The conventionally used down-the-hole drill 17 shown in FIG. 4 has the same internal structure as an air hammer used in civil engineering work, etc., and has a valve 15 for controlling air, a cylinder liner 14, a piston 13, and a piston 12. This is a drill bit, and the pressurized air supplied in the direction of arrow A passes through the valve 15 to move the piston 13 back and forth, then passes through the hole at the tip of the drill bit 12, passes through the groove 12a on the outer periphery, and is released to the near side (left side in the drawing). be done. When the piston 13 moves back and forth, it hits the shank 12b of the drill bit 12 to apply an impact force.

The town-the-hole drill used in the present invention shown in FIG. 5a is a down-the-hole drill 17 shown in FIG. 4 in which a center riser 14a is provided on the outer periphery of the cylinder liner 14.

The excavated soil and rocks excavated by the drill bit 16 of the drill 9 pass through the groove 16a on the outer periphery of the drill bit 16, and pass through the gap between the outer pipe 10 and the cylinder liner 14 shown in FIG. 3 (this gap is filled by the center riser 14a shown in FIG. 5a). The auger shaft 11a is configured to discharge the auger shaft through the starting shaft (1 in FIG. 1) in the direction of the boring machine by the helical blade of the auger shaft 11a. The drill bit 16 has the same shape as a conventional drill 17, and as shown in FIG. 5B, a drilling surface 16c at the tip of the drill bit 16 is perpendicular to the axis and has a large number of carbide tips 16b implanted therein. In Fig. 5b, 16e is an air hole, 16d is a groove through which air passes, and the air used in the drill is passed through hole 16e.
The pulverized powder is emitted from the hole, passes through the groove 16d, and exits into the excavation hole via the groove 16a on the outer periphery, but when large boulders or rocks are crushed, the crushed powder is led out together with air.

Figures 3a to 3d are explanatory diagrams of an embodiment of the construction method of the present invention. During normal excavation, the starting shaft (see Figure 1)
Rotate the inner tube 11 to the right and rotate the outer tube 10 to the left as shown in a with a boring machine (usually a power swivel type is used) installed in the hole. The down-the-hole drill 9 is operated by supplying pressurized air through the auger shaft center to drill the drill bit 1.
At step 6, the ground is struck in the direction of excavation, and the inner and outer pipes are propelled. In this case down the hole drill 9
is inserted through the eccentric hole of the whipstock 10b at the tip of the outer tube 10, but since the whipstock 10b rotates while changing the axis C-D of the eccentric hole around the excavation axis E-D, as shown in Fig. 3a. The drill bit 16 also drills while changing the axis C-D around the drilling axis E-D, and the whipstock 10
This is to drill a hole with the same outer diameter as b. In addition, the third
In the case of normal excavation shown in Figure a, the hole is drilled with the drill bit 16 of the down-the-hole drill 9, and the outer pipe 1
Tip 10a of whip stock 10b at the tip of 0
So don't dig.

If a hole bends during normal excavation, set the axis of the eccentric hole of the whipstock 10b in the direction in which it should be eccentric (upward in Fig. 3) to correct it.
With the outer tube 10 stationary as shown in b, the inner tube 1
The down-the-hole drill 9 is operated to excavate eccentrically while rotating only the inner pipe 11, and when a predetermined amount of eccentricity is reached, the inner pipe 11 is stopped.

The position of the whipstock 10b shown in FIG. 3b is close to the down-the-hole drill 16, and in this state the whipstock 10b cannot rotate.
After the outer tube 10 is moved back without rotation (toward the left in the drawing) by a predetermined distance that the whipstock can rotate, the outer tube is rotated and fed to the middle of the down-the-hole drill 9 that has previously excavated eccentrically, as shown in c. . In this state, the outer diameter of the borehole excavated by the whipstock 10b is
It is larger than the outer diameter of 0b by L.

Next, as shown in d, the eccentricity can be corrected by feeding the outer tube 10 in a non-rotating state to a state where normal excavation is performed again, and the normal excavation after the correction is returned again. In addition, when correcting hole bending as shown in FIGS. 3b to 3d, when rotating and propelling the whip stock 10b with the down-the-hole drill 9 stationary, unlike the normal drilling described above, drilling is performed with the tip 10a at the tip. It is.

As explained in detail above, according to the method of the present invention, when a hole bends, the inside of the outer pipe having an eccentric hole is kept stationary and only the down-the-hole drill moves forward. Even if the ground contains soil, it is now possible to use a down-the-hole drill to fracture it, correct the bend in the hole, and drill a buried pipe straight through the hole.

The device of the present invention, with the above configuration, can suitably carry out the buried pipe straight advancement method, and it has become easy to construct a straight buried pipe in the ground including a gravel layer.

[Brief explanation of drawings]

Figures 1 a to e are explanatory diagrams of a conventional buried pipe construction method, Figure 2 is an explanatory diagram of a conventional eccentric buried pipe propulsion device, and Figures 3 a to d are explanatory diagrams of an embodiment of the construction method of the present invention. FIG. 4 is a partially cutaway perspective view of a conventional down-the-hole drill, FIG. 5a is a perspective view of a down-the-hole drill used in the present invention, and FIG. 5b is a perspective view of a drill bit used in the down-the-hole drill. 1... Starting shaft, 2... Arrival shaft, 3... Boring machine, 4a, 7, 10... Outer pipe, 4b, 8,
11...Inner tube, 8b...Screw shaft, 8c, 1
4a...center riser, 10a...chip,
10b... Whip stock, 11a... Auger shaft, 9... Down-the-hole drill, 14... Cylinder liner, 12, 16... Drill bit, 16b... Carbide tip 16c... Excavation surface.

Claims (1)

[Claims] 1. In a construction method in which a boring machine installed in a starting shaft is used to install a buried pipe in the ground between the reaching shaft and the reaching shaft, a whipstock is fixed to the tip of the outer pipe on the reaching shaft side, and the whipstock is fixed to the tip of the circular pipe on the reaching shaft side. It has a cylindrical shape with an eccentric hole that slopes forward from the axis of the tube, and a cutting tip is fixed to the cutting part at the tip.The inner tube has an auger shaft at its base end on the starting shaft side, and its tip A down-the-hole drill is fixed to the down-the-hole drill, and a center riser is provided on the outer periphery of the cylinder liner of the down-the-hole drill, and the inner tube is inserted into the outer tube, and during normal excavation, the inner tube and outer tube are When using a drilling device that excavates by operating a down-the-hole drill while rotating them in opposite directions to correct a hole bend, the axis of the eccentric hole of the whipstock should be adjusted in the direction in which it should be eccentric for correction. Then, with the outer pipe stationary, only the inner pipe is rotated and the down-the-hole drill is operated to drill eccentrically until the hole bending is corrected.Then, only the outer pipe is started a predetermined distance without rotating. a step of rotating and propelling the outer tube halfway through the down-the-hole drill that previously excavated eccentrically and stopped, and then propelling the outer tube to a position where normal propulsion is performed again without rotation. A buried pipe straight advancement construction method characterized by correcting hole bending, which consists of a process. 2. Consisting of an outer tube with a whipstock fixed to the distal end of the circular tube, and an inner tube inserted from the base end side of the outer tube, the whipstock is eccentrically tilted forward from the axis of the circular tube. It has a cylindrical shape with a hole, and a cutting tip is fixed to the cutting part at the tip, and the inner tube consists of an auger shaft at the base end and a down-the-hole drill fixed to the tip, and the outer periphery of the cylinder liner of the down-the-hole drill is A center riser is provided, and the center riser slidably abuts on the inner surface of the eccentric hole of the whip stock, allowing the outer tube to rotate, non-rotate, advance, and retreat independently of the inner tube. Buried pipe straight propulsion device.