JP3398270B2 - Underground drilling method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground drilling method for excavating underground without using a casing and an auger. 2. Description of the Related Art As a conventional method of excavating underground using an auger or the like, there is the following method. (A) A method of excavating the ground with a bit using a hydraulic motor as a power source, and laying the pipe in the ground while discharging the excavated earth and sand in the pipe that becomes the casing backward with an auger. (B) A hydraulic motor is the same as (a) except that the ground is excavated with a bit and the soil is propelled using only the auger. After connecting the pipe to the pipe, pull the auger back and pull in and lay the pipe at the same time. (C) A method in which the hydraulic motor in (b) is replaced with an electric motor. [0004] However, the problem to be solved by the invention
(A) and (B) have the drawback that the device is large and heavy since the hydraulic motor is used as power, and the application area is limited. For example, when laying a general building service pipe, the pipe is laid between the vicinity of the ceiling on the first basement floor of the building and the handhole with limited space.
Method (b) cannot be applied. The method (c) has the disadvantage that the rotational torque is small and the allowable excavation distance is short unless a lubricating or muddy material is used. The present invention has been made in view of the above circumstances, and a conventional excavator has a long excavation distance, but the apparatus is large and heavy, or the apparatus is small and lightweight, but the excavation distance is small. It is an object of the present invention to provide an underground drilling method that solves the problem of short length and is small in size and light in weight, and realizes long-distance and high-precision drilling in the ground without using lubricating or muddy materials. [0006] In order to achieve the above object, an underground drilling method according to the present invention uses a first auger, pushes a first casing while excavating a ground, and pushes the auger. At the time when the excavation efficiency is reduced, the outer diameter of the first casing is smaller than the inner diameter of the first casing with respect to the first perforating step performed by pulling out the auger and the perforated portion formed by the first perforating step. A second perforation process performed using a second auger having an outer shape smaller than the inner diameter of the second casing and the second casing;
The third, fourth,... Piercing steps performed using the third, fourth,... Casing and auger until the piercing is completed. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a lateral hole excavation configuration used in an embodiment of the present invention, and FIGS.
(D) is sectional drawing which shows the horizontal hole excavation structure in each process of one Embodiment of this invention. In the figure, 1 is an excavating power unit (for example, a 100 V electric motor of a core boring machine), 2 is a reduction gear, 3 is a vacuum suction plate, 4 is a vacuum pump, 5 is a first large diameter casing, and 6 is a 2 is a middle casing, 7 is a third small casing, 8 is an auger, 9 is a tip bit, 10 is ground, 11 is a building wall, P ₁ is a starting shaft, and P ₂ is a reaching shaft. [0009] That is, the starting pit P ₁ is the attainment pit P ₂ dug in the ground. Wherein during starting pit P ₁ is installed drilling power unit 1. This is the drilling power unit 1 is attached vacuum suction plate 3, the vacuum suction plate 3 is attracted to the inner wall of the starting pit P ₁ is evacuated by a vacuum pump 4. The vacuum suction plate 3 secures a propulsion reaction force for excavation in the soil. At the tip of the excavating power unit 1, a reduction gear 2 for improving rotational torque is attached. [0010] First, as shown in FIG.
The first large-diameter auger 801 through wall holes of the starting pit P ₁
Then, the ground is excavated up to the point where the excavation efficiency, which is the limit of the electric motor rotation torque, which is the excavation ability of the excavation power unit 1, is reduced. Next, as shown in FIG. 2B, the first large-diameter casing 5 is similarly pushed into the first large-diameter auger 801 to the limit distance of the excavating ability, and is propelled. Thereafter, as shown in FIG. 2 (c), while discharging the first large diameter casing 5 in excavated soil rearward (starting pit P ₁ direction), perforated by withdrawing the first large-diameter auger 801 Then, the first perforation step is completed. Next, as shown in FIG.
A second intermediate casing 6 whose outer diameter is smaller than the inner diameter of the first large-diameter casing 5 left in the soil, Using the second medium-diameter auger 802 having a small outer shape, excavation by the second medium-diameter auger 802 from the distal end portion of the first large-diameter casing 5 left in the soil, and the second medium-diameter casing 6 The second perforation process is completed by performing perforation by pushing in. Similarly, the same procedure is followed using the third, fourth,... Casings and augers having diameters that can be accommodated in the casing left in the soil, and the third and fourth drilling and propulsion are performed until drilling is completed. 4 is performed. Next, an example in which construction is actually performed using the underground drilling method will be described. In general clayey ground, 2
When excavating 0m, 100V electric motor, φ12
It could be reached by using three kinds of casings of 8, φ110 and φ77 and augers corresponding to casing diameters. The excavation and propulsion efficiency was 10 min / m, and the arrival error was within 5 cm. As described above, a small and lightweight electric motor does not use a lubricating material or a muddy material, and is a drilling device capable of excavating long distances with high precision. There is the advantage of allowing for a tailored area. The area that is impossible with the conventional excavator is, for example, excavation of an introduction hole at the time of laying a drawing-in conduit between a handhole and a building.
In the case of a building retraction conduit, generally, both the building side and the handhole side duct openings have a narrow construction space, and the building side cannot take a propulsion reaction force. Also, lubricating materials and mud materials cannot be used because they may stain the inside of the building. ADVANTAGE OF THE INVENTION According to this invention, there exists an advantage that the propulsion reaction force for underground excavation can be ensured by an easy-to-handle vacuum suction plate. In addition, since the system does not use lubricating material and muddy material and realizes long-distance excavation, it does not pollute the inside of the building. In addition, since the casing functions as a guide for the auger, the accuracy of arrival is improved as compared with the conventional one. As described above, according to the present invention, the conventional excavator has a long excavation distance, but is large and heavy, or the apparatus is small and light. However, it is possible to provide an underground drilling method that solves the problem that the excavation distance is short, and that is small and lightweight, and realizes long-distance and high-precision underground drilling without using a lubricating material or a muddy material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a side hole excavation structure used in an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a horizontal hole excavation structure in each step of an embodiment of the present invention. [Description of Signs] 1. Excavating power unit (for example, 10 of a core boring machine)
0V electric motor), 2: reduction gear, 3: vacuum suction plate, 4
... vacuum pump, 5 ... first large diameter casing, 6 ... second medium diameter casing, 7 ... third small diameter casing, 8 ... auger, 9 ... tip bit, 10 ... ground, 11 ... building wall, P ₁
… Start shaft, P ₂ … Arriving shaft.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Irie 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Tetsuya Asano 3--19, Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nippon Telegraph and Telephone Corporation (72) Inventor Yusuke Banba 1-6-1, Meguro, Meguro-ku, Tokyo In-house JACOS Co., Ltd. (72) Inventor Toshio Sakuraji 18-18 Motoasakusa, Taito-ku, Tokyo (56) References JP-A-54-33318 (JP, A) JP-A-5-125891 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) E21B 7/04 E21D 9/08 F16L 1/024

Claims (1)

(57) [Claim 1] Using a first auger, pushing in a first casing while excavating a ground, and pulling out the auger when the excavation efficiency by the auger is reduced. A first piercing step performed by the first piercing step, and a second casing having an outer diameter smaller than an inner diameter of the first casing and an inner diameter of the second casing smaller than an inner diameter of the first casing. 2nd with small outer diameter
, A second piercing step performed using the auger, and a third, fourth,... Piercing step performed using the third, fourth,. An underground drilling method, comprising: