JPH10205259A - Method for well excavation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bury an embedding pipe having a larger diameter by using a compressor of the same capacity with a compressor for a smaller diameter pipe. SOLUTION: A drilling rod 8 provided with a drilling bit 13 is inserted into the front end of the inside of an embedding pipe 7 to excavate the ground while discharging the excavated soil to the ground surface by compressed air supplied to the nearby position of the drilling bit. An auxiliary pipe 23 positioned to contact the inner peripheral face of the embedding pipe 7 or the outer peripheral face of the rod 8 at the lower end thereof, is arranged at the gap between the embedding pipe 7 and the drilling rod 8 and the gap Sa between the rod 8 and the auxiliary pipe 23 or the embedding pipe 7 is used for the discharging passage of the excavated soil. The lower end of the auxiliary pipe 23 is arranged to contact the lower part than the water flow opening 26 formed in the embedding pipe 7 to separate the discharging passage of the excavated soil, formed between the auxiliary pipe 23 and the rod 8 from the water flow opening 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a well excavation method for burying a well to a predetermined depth while sequentially adding a buried pipe for pumping groundwater or the like. More specifically, the present invention relates to a well drilling method that has been improved to enable burying work of a buried pipe having a larger diameter using the same drilling equipment.

[0002]

2. Description of the Related Art As for well excavation, there have been known excavation methods utilizing various excavation principles. According to the present invention, a drilling rod having a drill bit at the tip is inserted inside the buried pipe, and the soil generated by the drilling action of the drill bit is passed through a ground compressor. The buried pipe is sequentially buried in the ground to a predetermined depth while being sent to the ground by compressed air supplied near the tip of the drill bit, and after the burial is completed, the drilling rod is buried. The present invention relates to a well drilling method for drilling a well having a predetermined depth in the ground by removing the well from a pipe. The present invention has a technical feature in that it is possible to bury a buried pipe having a larger diameter on the assumption that the same drilling equipment used in the conventional well drilling method is used. Hereinafter, a specific example of the related art as the base technology will be described in detail.

FIGS. 3 to 7 show an example of a conventional well drilling technique. FIG. 3 is a schematic configuration diagram showing a main part of a ground drilling rig, and FIG. It is explanatory drawing which showed the middle part. As shown in FIG. 3, the excavator 1 on the ground is provided with a base portion 2, a column portion 3 arranged to be tiltable with respect to the base portion 2, and arranged to be able to move up and down on the column portion 3. As a main element. A rotary motor 6 such as a geared motor is disposed on the lifting block 5 of the lifting head unit 4, and a drilling rod 8 inserted into the buried pipe 7 via the rotation motor 6 is provided for each. A rotary chuck section 9 for applying a low-speed rotational force of about several tens of rotations is provided. The bearing portion of the rotary chuck portion 9 is provided with an air connection port 11 for supplying compressed air to the vicinity of the drill bit through an air supply passage 10 formed in the rod 8 itself. Air connection port 1
1, a compressor 12 having a predetermined capacity corresponding to the scale of the drilling equipment is connected.

[0004] As shown in FIG. 4, at the time of a drilling operation, an upper end is connected to the rotary chuck portion 9 at a lower speed inside a buried pipe 7 buried in the ground via a rotary motor 6. The rod 8 for possible drilling is in the inserted state,
Drilling is performed to a predetermined depth by the drilling action of the drill bit 13 provided at the tip of the rod 8. The drill bit 13 is configured to be set in the expanded state shown in FIG. 5 or the contracted state shown in FIG. 6 according to the rotation direction of the rod 8. That is, during the drilling operation, the drill bit 13 is set to the expanded state shown in FIG.
5 provides a drilling action. In this case, the interval between the tips of the expanded blade portions 14 and 15 is set slightly larger than the outer diameter of the buried pipe 7, and a hole is formed that is larger than the outer diameter of the buried pipe 7. Have been. On the other hand, when the rod 8 is pulled up and removed from the buried pipe 7 after the completion of the excavation work, the rotation of the rod 8 is stopped or reversely rotated so that the drill bit 13 is set to the reduced state of FIG. And the diameter of the drill bit 13 is
Is returned to a state smaller than the inner diameter of the rod 8 so that the rod 8 can be easily pulled out. As shown in the cross-sectional view of FIG. 7, the drill bit 13 has an air supply passage 16 at the center portion thereof, which communicates with the blade portions 14, 15, and a longitudinal groove portion at its outer peripheral surface which constitutes a passage for excavating soil. 17 and 18 are formed, and shavings generated by the cutting portions 14 and 15 of the drill bit 13 are cut through the longitudinal grooves 17 and 18 to generate a gap between the buried pipe 7 and the rod 8 by compressed air. It is configured to be able to flow out to the part side. In front of the drill bit 13 of the rod, an impact generating portion 19 such as a known air hammer driven by compressed air supplied through the air supply path 10 is incorporated. The drill bit 13 is mounted so as to move back and forth through an output shaft 20 that moves back and forth by the operation of the generating unit 19. Further, a locking member 21 is fixed to the output shaft 20, and a locking collar 22 is fixed to the inside of the lower end of the buried pipe 7 so as to be lockable with the locking member 21. The engagement between the locking member 21 and the locking collar 22 allows the impact force to be transmitted to the buried pipe 7.

When the above-mentioned equipment is used for excavation according to a conventional excavation method, the drilling rod 8 is first inserted into the buried pipe 7 as shown in FIG. Then, the upper end of the rod 8 is connected to the rotary chuck 9
After that, the following operation will be performed. That is, the rod 8 is rotated forward via the rotary motor 6 and the compressed air from the compressor 12 is supplied to the tip of the drill bit 13 via the air supply path 10 formed in the rod 8. By the forward rotation of the rod 8, the blade portions 14, 15 of the drill bit 13 are set in the expanded state shown in FIG. At that time,
As a result of the compressed air being blown out from the tip of the drill bit 13, the soil produced by the drilling action of the drill bit 13 is removed together with the compressed air into the vertical grooves 17, 18 and the gap between the buried pipe 7 and the rod 8. It will be sent up to the ground. In this case, if groundwater or the like is springing in the drilled portion, the water is also sent to the ground in a state of being sprayed from the longitudinal grooves 17, 18 by compressed air together with the shaved soil. Further, the compressed air supplied through the air supply passage 10 is supplied to a known air hammer or the like constituting the impact generating portion 19 on the way to generate an impact force, and the impact force is transmitted to the drill bit 13. At the same time, it is transmitted to the buried pipe 7 through the engagement between the locking member 21 and the locking collar 22, so that the buried pipe 7 is smoothly lowered.

As described above, a predetermined length, for example, 2.75 m
When the buried pipe 7 and the drilling rod 8 are buried, the next buried pipe 7 is further connected to the upper end of the buried pipe 7 by welding or the like, and the upper end of the rod 8 Then, the next rod is connected by an appropriate connecting means and the above-mentioned drilling operation is executed, and the excavation operation is repeated, so that the excavation is continued to the target depth. In this case, it is needless to say that a strainer pipe having a water inlet formed therein is inserted as a buried pipe 7 in a portion corresponding to the depth of the formation where the groundwater or the like in which the groundwater flows according to the excavation site. Nor. When the buried pipe 7 can be buried to the target depth, the rotation of the rod 8 is stopped or reversed by the rotation motor 6 so that the blade portions 14 and 15 of the drill bit 13 are moved to the position shown in FIG. The excavation work is completed by reducing the rod 8 and drilling bit 13 part upward and removing it from the buried pipe 7 as shown in FIG. Thereafter, a submersible pump or the like is inserted inside the buried pipe 7 to be used as a well.

[0007]

However, in the above-mentioned conventional drilling method, there is a limitation on the size of the diameter of the existing drilling equipment, particularly the buried pipe 7 which can be buried as long as the existing compressor is used. That is, for example, when the discharge pressure is 13.5
In the case of using a compressor having a capacity of 20 m ³ / min with a discharge rate of 20 m ³ / min in kg / cm ² , in this type of conventional excavation method, the upper limit is to bury a buried pipe 7 having a diameter of 150 mm about 100 m. I generally know that. If this compressor is used to bury a buried pipe 7 having a diameter of, for example, 250 mm according to the conventional excavation method described above, it can be buried only to a depth of at most 20 to 30 m, which is not practical. It has been experimentally confirmed that there is none. This is because, when the diameter of the buried pipe 7 is increased, the flow area of the soil excavation passage formed by the gap between the buried pipe 7 and the rod 8 is enlarged, and the ascending flow of the soil by compressed air is correspondingly increased. It is considered that because the flow velocity of the soil decreases, it becomes impossible to send the excavated soil smoothly to the ground. In general, a buried pipe 7 having a diameter of 150 mm is used.
When water is used, the amount of water discharged is 1 ton /
min submersible pump can be inserted, 250mm
When the buried pipe 7 having a diameter of
A submersible pump of about n / min can be inserted. That is, the size of the submersible pump that can be inserted is determined according to the diameter of the buried pipe 7, and the pumping amount is determined. Therefore, in order to increase the pumping rate to about 3 ton / min in the previous example, a large compressor that is one size larger is required as the compressor, which not only increases the cost but also increases the load to the site and the excavation position. Movement becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional technical circumstances, and has been made to enable the burial of a buried pipe having a larger diameter using the same drilling equipment, particularly, a compressor having the same capacity. An object of the present invention is to provide an improved well drilling method.

[0009]

According to the present invention, in order to solve the above-mentioned problems, a drilling rod having a drill bit at its tip is inserted inside a buried pipe to cut the drill bit. The burial pipe is buried in the ground to a predetermined depth sequentially while sending excavated soil generated by the hole action to the ground by compressed air supplied near the drill bit through an air supply path formed in the rod. Then, after the burial is completed, by removing the drilling rod from the buried pipe, in a well drilling method for drilling a well of a predetermined depth in the ground, in the method of drilling the buried pipe and the drilling rod, The lower end of the gap abuts against the inner peripheral surface of the buried pipe or the outer peripheral surface of the rod, and an auxiliary pipe is disposed in a state that can be removed after the burying of the buried pipe is completed, and the auxiliary pipe and the rod or The gap with the buried pipe is used as the delivery path for the excavated soil Ri, was adopted well drilling method of delivering a form obtained by reducing the flow passage area. By adopting this auxiliary pipe, the flow path area of the soil excavation passage can be reduced to the flow area that can obtain the flow velocity necessary to send the earth excavation with the same compressor capacity. Compressors can accommodate larger diameter buried pipes. That is, it is possible to bury a large-diameter buried pipe with a small-capacity compressor. Further, the auxiliary pipe is disposed such that the lower end outer peripheral portion thereof is in contact with the inner peripheral surface of the buried pipe below a water passage portion formed in the buried pipe, and the auxiliary pipe is connected to the auxiliary pipe via the auxiliary pipe. If it is configured to separate the delivery path formed between the drilling rod and the water supply port formed in the buried pipe, the air for delivery is dispersed through the water supply port, Conversely, groundwater or the like flows in through the water inlet during excavation work, thereby greatly reducing the adverse effect of the air on the sending action of the soil excavation. It is to be noted that an impact generating portion is disposed at the tip of the drilling rod so as to perform excavation while applying an impact force to the drilling bit and the buried pipe, or to rotate the drilling rod itself. The drilling bit may be configured to be rotated via a hole.

[0010]

According to the first aspect of the present invention, the lower end of the auxiliary pipe may be brought into contact with the inner peripheral surface of the buried pipe or the outer peripheral surface of the rod. It may be. In short, by adopting the auxiliary pipe, a gap between the auxiliary pipe and the buried pipe or a gap between the auxiliary pipe and the rod forms a delivery path for excavating soil, and the flow path area is the same as that of the compressor. Any capacity can be used as long as it can reduce the flow passage area to obtain the flow velocity necessary for smoothly sending the soil excavation to the ground with the above capacity. However, in the second aspect of the present invention, the lower end portion of the auxiliary pipe is limited to the case where the lower end of the auxiliary pipe is in contact with the buried pipe side, because it is necessary to separate the delivery path of the earth shaving from the water inlet formed in the buried pipe. become. In this case, the gap between the auxiliary pipe and the buried pipe or rod is set to have a flow area equal to the flow area formed between the buried pipe and the rod set in the conventional excavation method. If it is set, the same excavation performance can be obtained, and a good sending action of the ground excavation to the ground can be obtained. However, since the amount of compressed air supplied near the drill bit is constant, the amount of excavation increases as the drill hole diameter increases, and as a result, the burying speed itself decreases.

The present invention can be applied to various types of drill bits, and supplies compressed air to an appropriate portion near the drill bit, for example, to a tip portion or a side portion of the drill bit. However, if the excavation method is to send the excavated soil to the ground using the compressed air, the excavation method can be applied by arranging the auxiliary pipe and reducing the flow path area of the delivery path. That is, when the above-mentioned impact generating portion is provided, when excavating while applying an impact force to the drill bit and the buried pipe, or when rotating the drill bit through rotation of the drilling rod itself. Although it is applicable, the present invention is not limited to this. Even if no impact force is applied or the drill bit is configured to be rotated using another mechanism, compressed air is supplied near the drill bit. In addition, any excavation method that sends excavated soil to the ground by the compressed air can be applied.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is an explanatory diagram showing a state of an underground portion during excavation work according to an embodiment of the present invention. As shown, the present invention differs from the above-described conventional excavation method only in that an auxiliary pipe 23 is used. The same reference numerals are given to the parts common to the conventional excavation method. In the excavation work, a rod 8 having a drill bit 13 at the distal end inside the buried pipe 7 is used similarly to the conventional method. In this case, in the present invention,
It is characterized in that the rod 8 is inserted into the buried pipe 7 with the rod 8 also inserted through the auxiliary pipe 23.

In this embodiment, the lower block 24 formed in the auxiliary pipe 23 is supported on a suitable number of hook members 25 provided on the inner peripheral surface of the buried pipe 7.
In this case, as for the joining state of the lower closing portion 24 to the inner peripheral surface of the buried pipe 7, a completely sealed state is desirable, but a slight leak hardly hinders the excavation work. Thus, as described above, the gap Sa between the outer peripheral surface of the rod 8 and the inner peripheral surface of the auxiliary pipe 23 forms a soil excavation passage, and the flow passage area is reduced. The hook member 2
Reference numeral 5 denotes a water inlet 2 formed in the buried pipe 7 in the present embodiment.
6, the water inlet 26 is separated from the soil excavation passage composed of the gap Sa by the auxiliary pipe 23, and the influence of the dispersion of the compressed air from the water inlet 26 and the inflow of groundwater as described above. It is constituted so that it may be shut off from. Therefore, not only the slit type water inlet 26 but also various types having a large water flow area do not hinder the excavation work. In addition, since water is not passed during excavation work, the tightening action based on a change in the stratum in contact with the buried pipe 7 that is likely to be caused by the water flow is reduced, and the advanced welding technology required for the connection portion of the buried pipe 7 is also reduced. It is reduced compared to the conventional case.

FIG. 2 is an explanatory view showing a state of an underground portion during excavation work according to another embodiment of the present invention. As shown in the drawing, in the present embodiment, a lower closing portion 28 formed at a lower portion of the auxiliary pipe 27 is supported on an appropriate number of hooking members 29 provided on the outer peripheral surface of the rod 8. Have been. In this example, the gap Sb between the outer peripheral surface of the auxiliary pipe 27 and the inner peripheral surface of the buried pipe 7 serves as a soil excavation delivery path, and the passage area is reduced. However, in the case of this example, since the soil excavation passage composed of the gap Sb is in communication with the water inlet 26, the influence is affected, but the passage area is reduced by the form of the water inlet 26. Therefore, the effect of being able to cope with the buried pipe 7 having a larger diameter can be effectively obtained. Also,
When the rod 8 rotates, the auxiliary pipe 27 also rotates. Therefore, it is desirable to apply to a type in which the rod 8 does not rotate.

Thus, according to the present invention, as described above, the delivery path for delivering the excavated soil resulting from the drilling action of the drill bit 13 to the ground is formed by the inner peripheral surface of the auxiliary pipe 23 and the rod 8. The gap Sa between the outer pipe and the auxiliary pipe 27
Is formed by the gap Sb between the outer peripheral surface of the buried pipe 7 and the inner peripheral surface of the buried pipe 7, so that the passage area is reduced to a flow passage area which can obtain a flow velocity necessary for smoothly and accurately sending the soil excavation to the ground. By reducing the size, it becomes possible to easily cope with the work of excavating a buried pipe having a diameter larger than the conventional upper limit using the same capacity compressor.

[0016]

According to the present invention, the following effects can be obtained. (1) By using a compressor having the same capacity, a buried pipe having a diameter larger than that of the conventional one can be buried, and the applicable range as a compressor is expanded. (2) Since only a small capacity compressor is required, the cost can be reduced, and it is easy to carry into the site or move according to the excavation position. (3) The configuration is extremely simple because only an auxiliary pipe is added.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a state of an underground portion during excavation work according to an embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a state of an underground portion during excavation work according to another embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a main part of a conventional ground excavator.

FIG. 4 is a schematic explanatory view showing an underground portion during a drilling operation in a conventional excavation method.

FIG. 5 is a bottom view of the drill bit portion in an expanded state when FIG. 4 is viewed from below.

FIG. 6 is a bottom view of the drill bit portion in a reduced state when FIG. 4 is viewed from below.

FIG. 7 is a cross sectional view showing a cross section of a drill bit part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ground excavator, 2 ... Base part, 3 ... Support part, 4 ...
Elevating head part, 5 ... Elevating block, 6 ... Rotary motor, 7
... Buried pipe, 8 ... Rod, 9 ... Rotating chuck part, 10 ... Air supply path, 11 ... Air connection port, 12 ... Compressor, 1
3 ... drill bit, 14 and 15 ... blade part, 16 ... air supply path, 17 and 18 ... vertical groove part, 19 ... impact generation part, 20 ... output shaft, 21 ... locking member, 22 ... locking collar 22 , 23
... Auxiliary pipe, 24 ... Lower closing part, 25 ... Hanging member, 26 ...
Water inlet, 27 ... Auxiliary pipe, 28 ... Lower closing part, 29 ... Hanging member

Claims (4)

[Claims] 1. A drilling rod having a drill bit at its tip is inserted inside a buried pipe, and the soil produced by the drilling action of the drill bit is supplied to the rod by an air supply. The buried pipes are sequentially buried in the ground to a predetermined depth while being sent out to the ground by compressed air supplied in the vicinity of the drill bit through a road, and after the burial is completed, the drilling rod is removed. In the well excavation method of excavating a well having a predetermined depth in the ground by removing from a buried pipe, a lower end portion is formed in a gap between the buried pipe and a rod for drilling, and an inner peripheral surface of the buried pipe or the An auxiliary pipe is disposed so as to be in contact with the outer peripheral surface of the rod and to be removable after the burying of the buried pipe is completed, and a gap between the auxiliary pipe and the rod or the buried pipe is used as a delivery path for the soil excavation. To reduce the area of the flow path. The well drilling method to be considered. 2. The auxiliary pipe is disposed such that the lower end outer peripheral portion thereof is in contact with the inner peripheral surface of the buried pipe below a water passage portion formed in the buried pipe, and the auxiliary pipe is provided through the auxiliary pipe. The well excavation method according to claim 1, wherein the delivery path formed between the auxiliary pipe and the drilling rod is separated from the water passage formed in the buried pipe. 3. An excavation unit is provided at an end of the drilling rod, and excavation is performed while applying an impact force to the drilling bit and the buried pipe. The well drilling method described. 4. The well according to claim 1, wherein the drilling operation is performed by rotating the drilling bit through rotation of the drilling rod itself. Drilling method.