JPH0344632B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to civil engineering work, when a horizontal hole is being constructed by a buried pipe propulsion method in order to bury a sewer pipe, cable laying pipe, etc. underground. This invention relates to a method for temporarily backfilling the excavation site of a pilot tube when it becomes necessary to pull out the pilot propulsion tube for drilling.

[Conventional technology]

When constructing a horizontal hole using the underground pipe propulsion method in order to bury a small-diameter sewage pipe of approximately 250 to 1000 mmφ, a propulsion device is installed in the starting shaft, a hammer is attached to the tip of the pilot pipe, and the pilot The auger is inserted into the tube, and the pilot tube and auger are fed while rotating in opposite directions to propel the pilot tube.

If a failure of the impact hammer occurs during propulsion of the pilot tube, it is necessary to pull out the pilot tube and re-propulsion after the failure is recovered. In such a case, it is very possible to restore the original condition by temporarily backfilling the excavation site where the pilot pipe was pulled out with sand, etc., and then re-propelling while removing this sand, etc. It's easy. However, if the pilot pipe was pulled out and then backfilled, the hole wall would collapse and sufficient backfilling could not be achieved.

The present inventors first used an auger with a hollow shaft inside a pilot tube, installed a plurality of down-the-hole hammers in parallel at the tip, created a hollow space in the center of the group of hammers, and installed a light source in this hollow space. In Japanese Patent Application No. 59-240983 (Japanese Unexamined Patent Publication No. 61-122394), we proposed a propulsion device that can correct hole bending by observing this light source from behind with a transit through the auger's hollow shaft. There is.

This device incorporates multiple down-the-hole hammers in parallel, and a light-emitting diode is arranged in the central space surrounded by the hammer group so that it can be observed from the starting end of the propulsion device.A target with a light-emitting diode attached near the drill bit By setting this section, if the axis of the tip of the propulsion tube is even slightly eccentric, the movement of the diode away from the center of the transit can be immediately detected. Therefore, it is an excellent device that can quickly correct hole bending by operating the eccentric tube housing the hammer group.

The inventors of the present invention utilized the hollow part of this auger shaft to supply backfilling sand etc. to the tip of the pilot tube while retracting the pilot tube toward the starting end of the propulsion device. After repeated research on backfilling, the method of the present invention was completed.

[Problem that the invention seeks to solve]

If it becomes necessary to pull out the pilot propulsion tube for drilling while constructing a horizontal hole using the buried tube propulsion method, backfilling after pulling out the pilot tube will cause the hole wall to collapse and insufficient backfilling. Can not. The present invention aims to solve the above-mentioned drawbacks by providing a method that enables sufficient backfilling by backfilling the excavation site with sand or the like as the pilot pipe retreats.

[Means for solving problems]

The method of the present invention will be explained with reference to FIG.

The present invention is a technical means applied to a pilot pipe propulsion method using a plurality of down-the-hole hammers 3, and consists of the following steps a) to d).

a) The target section 2 to be attached to the tip of the pilot tube 1 is fixed in advance so that it can be extracted from the propulsion device starting end, and b) A rod for extracting the target section 2 from the propulsion device starting end into the hollow tube of the auger 4. Insert 5,
The tip of this extraction rod 5 is attached to the target section 2.
c) Next, insert the backfilling material feeding screw 6 into the hollow pipe of the auger 4 (or a pressure feeding pipe may be used instead of the screw), and d) insert the backfilling material into the excavation site 7. While feeding the backfilling material 8, the pilot pipe 1 is retreated and pulled out.

[Effect]

By using the hollow part of the center of the multiple down-the-hole hammers and the hollow part of the auger that follows them, it is possible to backfill the excavation site at the same time as the pilot pipe is withdrawn and retreated. Since sufficient backfilling can be performed without causing collapse of the hole wall, collapse of the hole wall or ground subsidence due to poor backfilling will not occur.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is (a) a longitudinal cross-sectional view of an embodiment of the device showing the vicinity of the tip of the pilot tube used for carrying out the present invention;
(b) A perspective view of the target case, and (c) a partial perspective view of the target storage section.

A plurality of down-the-hole hammers 3 are built into the tip of the pilot tube 1, and a target section 2 is attached to the center thereof. Target part 2
The main body 20 has the necessary parts built into the target case 11 and holds the down-the-hole hammer.
It is housed in a hollow hole (accommodating part) 21 bored in the center of the pilot tube 1, and is attached so that it can be extracted from the propulsion device side of the pilot tube 1.

In the structural example shown in Fig. 2, target case 11
The tip side (hereinafter simply referred to as the tip side) of the pilot tube is supported by the cover 13 via the spring 14, and the propulsion device side (hereinafter referred to as the tail end side) is engaged by the case side hook 17 and the main body side hook 22. It is stopped and fixed.

The cover 13 supports the tip side of the target case 11, and supports the tip of a plate-shaped or chrysanthemum-shaped leaf spring 15 attached to the back of the cover 13.
It is inserted and fixed into a ring-shaped recess provided in the target storage section 21.

As shown in FIG. 2b, the target section 2 has a hook 17 on the outer periphery of the target case 11 on the case side.
A guide plate 18 is provided in a protruding manner, and a pull-out engaging portion 19 is provided on the tail end side. The case side hook 17 has a circumferential length shorter than 1/4 of the outer circumference of the case 11,
Two pieces are provided at symmetrical positions on the circumference. The tail end side surface 17a of the case side hook 17 engages with the tip side surface 22a of the main body side hook 22 protruding from the inner surface of the target storage section 21 shown in FIG. 2c.
They are formed so as to engage with each other through unevenness.

The circumferential length of the body-side barbs 22 is also shorter than 1/4 circumference, and two of them are provided symmetrically at 180° positions on the circumference.

The outer diameter of the case-side barb 17 is such that it fits loosely into the hole diameter of the housing portion 21, and the inner diameter of the main body-side barb 22 is such that the outer diameter of the target case 11 fits loosely therein.

The guide plate 18 of the target case 11 also has a circumferential length shorter than 1/4 circumference, and is two protrusions arranged symmetrically on the circumference, and its outer diameter is the same as that of the storage part 21.
The target case is held approximately concentrically within the storage portion 21 with dimensions that fit loosely into the hole diameter.

The extraction engaging portion 19 engages with the tip of the extraction rod 5 in the target portion extraction process described later,
The rod 5 has a shape that allows it to push the target case 11 toward the distal end, rotate it 90 degrees, and then carry it toward the caudal end. Although an L-shaped notch is shown in FIG. 2b, it is also possible to provide an L-shaped or T-shaped groove or protrusion on the end face or inside diameter of the case.

The target portion extraction step of the method of the present invention using this embodiment apparatus will be explained with reference to FIG. Under normal conditions, target case 11 is the third
As shown in FIG. They are each supported by their outer diameters and fixed and held within the storage section 21 .

To remove the target part, insert the extraction rod 5 from the tail end side as shown in FIG. Extraction engagement part 19
The target case 11 is pushed toward the distal end side against the spring 24, the engagement between the case side hook 17 and the main body side hook 22 is released, and then a twisting force is applied to the rod 5 to push the target case 1
1 by 90 degrees so that the case-side hook 17 and the main body-side hook 22 are in a non-interfering state, the target case can be pulled out toward the tail end. Then the third
As shown in Figure c, insert the backfilling screw 6 into the hole 2.
1, and use the tip of this screw to close cover 1.
When the center of the cover 3 is pressed, the locking of the leaf spring 15 is released, and the cover 13 can be pushed outward toward the distal end, and the spring 14 is also pushed out.

In this way, the screw 6 can feed sand or the like from the propulsion machine side to the excavation trace on the tip side of the pilot pipe.

FIG. 4 shows another embodiment of the fixing structure of the target case 11.
A screw 31 is provided on the outer diameter of the case 1, and is screwed together with a female screw provided on the inner diameter of the storage part 21. When removing the target case 11, a drawing rod with a taper tap 33 having a screw 32 attached to the tip is used. 5
Using a, pull out the target case 11 toward the tail end. One of the screws 31 and 32 has a right-hand thread, and the other has a left-hand thread.

Although FIG. 4 shows a tapered female thread 34 that screws into the inner diameter of the target case 11 with the taper tap 33, this tapered female thread is not necessarily necessary, and even if omitted, the taper tap 33 can be engaged with the target case. is possible.

5 to 7 show other embodiments of the fixing structure and extraction structure of the target case 11.

In FIG. 5, the target part 11 is fixed in the storage part 21 using a snap ring 41, and a ring-shaped groove 43 that engages with the extraction tool 50 is provided on the inner diameter of the target part. Ingredients 50
The extraction engaging portion 51 of is adapted to engage.

The snap ring 41 holds the target part 11 in the storage part 21, and has enough strength to shear when a strong force is applied to pull out the target part 11, so that the target part can be pulled out. It's summery.

As shown in FIG. 5b, the extractor 50 has a distal end 52 shaped so that it can be easily inserted into the inner diameter of the target 11, and has a longitudinally long through hole in the distal end 52. 53 is bored. A extraction engaging portion 51 is attached within this through hole 53. As shown in FIG. 6, this extracting engaging portion 51 is constructed by combining symmetrical V metal fittings 54 and 56 via a spring 55, storing them in a through hole 53, and using a pin 57 and a snap ring 58 to attach the extracting tool 50.
is attached to the main body of the 2 V hardware 54,
56 repel each other due to the action of the spring 55 and swing about the pin 57 in the direction of protruding from the through hole 53.

When the extraction tool 50 is inserted into the storage section 21, the V hardware 54, 56 of the extraction engagement section 51 slides on the inner diameter of the storage section 21 and moves forward, and when the extraction tool 50 is inserted in the state shown in FIG. , 56 engage with the groove 43 in the inner diameter of the target portion 21. In this state, when the extraction tool 50 is pulled to the right in FIG. 5, the snap ring 41 is sheared and the target portion 11 can be extracted.

FIG. 7 shows a protruding piece 42 protruding from the outer diameter of the target portion 11 in place of the snap spring shown in FIG.
It is of a structure that is fitted into a recess in the storage section 21 to restrain and lock the target section from moving in the longitudinal direction. The protruding piece 42 has a hemispherical head that fits into the recess, and can be unlocked by applying a strong axial force to the target 11.

Although sand or the like is preferable as the backfilling material used in the present invention, even more dense backfilling can be achieved by using foamed mortar or the like in some cases.

〔Effect of the invention〕

Since the present invention is constructed as described above, (1) ground subsidence does not occur due to pulling out of the pilot pipe;

(2) If the pilot tube needs to be pulled out due to a failure during propulsion, the failure can be repaired without collapsing the hole wall, and the original state can be easily restored. .

It has excellent effects such as

[Brief explanation of drawings]

Fig. 1 is a process diagram of an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing the fixing structure of a removable target part used in carrying out the present invention, b is a perspective view of the target case, and c is a portion of the storage hole. A perspective view, FIG. 3 is an explanatory diagram of the extraction process of the device in FIG. FIG. 6 is an exploded perspective view of the extractor of the extractor of FIG. 5; 1... Pilot pipe, 2... Target part, 3... Down-the-hole hammer, 4... Auger, 5... Rod, 6... Screw, 7... Excavation trace, 8... Backfill material,
11...Target case, 13...Cover, 14...
Spring, 15... Leaf spring, 17... Case side hook, 18... Guide plate, 19... Extraction engagement part, 20...
Main body, 21... Storage section, 22... Main body side hook, 3
1, 32...Screw, 33...Tap, 41...Snap spring, 42...Protruding piece, 43...Groove 50...Extraction tool,
51...Extraction engagement part, 52...Tip part, 53...Through hole,
54, 56...V hardware, 55...spring, 57...
pin.

Claims (1)

[Claims] 1. Fix the target part to the tip of the pilot tube so that it can be extracted from the starting end of the propulsion device, and insert the extraction rod into the auger hollow tube from the propulsion device side.
The tip of the extraction rod is engaged with the target portion to extract the target portion toward the propulsion machine, and then the backfilling material is fed into the excavation site using a backfilling material feeding means into the auger hollow pipe. A method for backfilling a pilot pipe excavation site, characterized by pulling out the pilot pipe at the same time.