JP7057582B1 - Underground construction method for large pipes and bottomed buried pipes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly and surely carry out a buried construction work of a buried pipe by a combination of simple processes, and to surely prevent water leakage or the like after the construction. SOLUTION: The method of laying a large pipe in the ground is a preceding excavation pipe having a diameter larger than that of the pipe to be buried, and the buried pipe is buried so as to have a pipe wall position including the plan view buried outer diameter of the buried pipe. The process of press-fitting the preceding excavation pipe into the ground prior to the ground, the process of discharging the excavated soil in the pipe at the same time as excavating the preceding excavation pipe, and the process of pressing the preceding excavation pipe to the planned depth and then inside the excavation pipe. Includes a step of inserting a bottomed buried pipe into the space and arranging it in a double tubular shape with the preceding excavation pipe and the buried pipe, and a step of pulling out the preceding excavation pipe after inserting the buried pipe to a predetermined depth position. .. In addition to being able to accurately perform interior work and equipment according to the purpose of use in this buried pipe by ground work, it is possible to simplify the work process, shorten the work, and improve the water blocking performance. [Selection diagram] Fig. 3

Description

The present invention is a shelter for temporary evacuation of people and things in the event of a natural disaster such as an earthquake, tsunami, typhoon, or man-made disaster, a storage for goods and food storage, a land for large pipes that can form leisure and other multipurpose spaces. Regarding the method of building in the middle and the buried pipe with a bottom.

Applicants can install a shelter for temporary evacuation of people and goods, shelters for storing goods and food, leisure and other multipurpose spaces underground in a relatively short period of time at low cost in the event of a natural disaster such as an earthquake, tsunami, or typhoon. Patent Document 1 proposes a large bottomed tube that can be easily constructed and has a small occupied flat space and is not easily affected by above-ground structures and equipment.

Japanese Patent No. 6585787

In Patent Document 1, after a large pipe is press-fitted into the ground, underwater concrete is supplied from the upper end opening of the pipe and poured into a recess below the lower end of the large pipe to form a concrete base outside the lower end of the pipe. After this, the inside of the pipe is lowered to place a bottom lid with a filling hole at the lower end of the pipe, and mortar is injected into the gap between the lower surface of the bottom lid and the concrete base outside the pipe through the filling hole to bottom. The purpose is to construct the bottom of the pipe by integrating the lid and the concrete base outside the pipe.

In this method, it is possible to weld and join the end of the bottom lid to the inner wall of the pipe while suppressing the ingress of water into the pipe on the lower end side of the pipe after the underground injection of the pipe for the underground construction of the large pipe. can. However, after the pipe body is press-fitted into the ground, concrete is supplied, the concrete is once put into the recess below the lower end of the large pipe body, and then mortar is injected from the filling hole of the bottom lid arranged on the lower end side of the pipe body. Since the mortar is injected into the gap between the lower surface of the bottom lid and the concrete base outside the pipe, the work must be performed without confirming the condition of the concrete base on the lower surface side of the bottom lid. Further, the mortar injection work from the filling hole of the bottom lid is a narrow space work in a limited space, and the work setup and the injection work take time and the work cost is high. In addition, since it is not possible to confirm the filling of the gap between the lower surface of the bottom lid and the concrete base outside the pipe after injection, there is a problem that mortar is injected more than necessary and the entire work or the material is unnecessarily costly. On the other hand, the applicant has a process of press-fitting the pipe body in the vertical direction in the ground while discharging the soil inside the pipe body having a rib portion attached to the inner wall of the pipe, and a pipe after pressing the pipe body to the planned depth. The process of pouring ready-mixed concrete to the height corresponding to the rib part in the main body, the process of hanging the bottom lid inside the pipe body and placing it on the top of the hardened concrete after the ready-made concrete is hardened, and the outer edge and pipe of the bottom lid. Japanese Patent Application No. 2020-192207 proposed a method for constructing a large bottomed pipe body including a step of welding the inner wall surface of the main body to join the pipe body and the bottom lid.

In this method, the filling work can be performed while visually observing the state of the concrete to be poured up to the rib portion in the pipe body, so that there is an advantage that the work state and the end of the work can be surely confirmed. On the other hand, in this method, after the pipe body is press-fitted up to a dozen meters underground, ready-mixed concrete is poured into the pipe and filled to the required height at the lower end of the pipe. Therefore, it is necessary for the operator to perform auxiliary work in the pipe. In addition, it takes a long time to work, and it is difficult to surely confirm the presence or absence of water leakage because it is one of the concrete cast-in-place construction methods. Further, there is a problem that the work cost is significantly increased.

The present invention has been made in view of the above-mentioned conventional problems, and one of the purposes thereof is to smoothly and surely carry out the burying work of the buried pipe by a combination of simple steps, and to cause water leakage or the like after the construction. The purpose is to provide an underground construction method for large pipes and a bottomed buried pipe that can be reliably prevented. Another object of the present invention is to provide a method for underground construction of a large pipe and a bottomed buried pipe that can complete the burying work of the buried pipe in a short time and at low cost.

In order to solve the above problems, the present invention is a method for constructing a large buried pipe that is vertically buried in the ground so that the space inside the pipe can be used for various purposes. 20 is a step of press-fitting the preceding excavation pipe 20 into the ground prior to burying the buried pipe 1 so as to be a pipe wall position including the plan view buried outer diameter of the buried pipe 1, and a preceding excavation pipe. At the same time as the excavation of 20 It is composed of a step of arranging the buried pipe 1 in a double tubular shape and a step of pulling out the preceding excavation pipe 20 after inserting the buried pipe 1 to a predetermined depth position, and a method of building a large pipe in the ground. To.

At that time, the inner bottom portion of the bottomed buried pipe 1 which is inserted and lowered into the pipe inner space 100 of the preceding excavation pipe after the preceding excavation pipe 20 is press-fitted to the planned depth has an anti-buoyancy weight portion 3 against buoyancy from the underground side. Should be provided.

Further, a swivel biting device 4 with the tip side facing downward is provided outside the bottom of the bottomed buried pipe 1, and the bottomed buried pipe 1 is buried under the bottom after being inserted into the in-pipe space 100 of the preceding excavation pipe 20. It is even more preferable to include a step of turning the tube 1 itself around the vertical axis.

Further, the present invention is a bottomed buried pipe 1 in which the preceding excavation pipe 20 is press-fitted to a planned depth and then inserted and lowered into the pipe inner space 100 of the preceding excavation pipe 20. It is composed of a bottomed buried pipe provided with an embedding device 4.

At that time, the inner bottom portion may be provided with an anti-buoyancy weight portion 3 against buoyancy from the underground side.

According to the method for building a large bottomed pipe body and the bottomed buried pipe of the present invention, the work process can be greatly simplified by improving the pipe body, and each work itself is simple, clear and can greatly reduce the work time. Furthermore, it is possible to significantly reduce the work cost.

It is a plane explanatory view which showed the underground burial positional relationship of the preceding excavation pipe and the burial pipe which concerns on the underground building method of the large-sized pipe of this invention, and the embodiment of a bottomed burial pipe. It is a front explanatory view which shows the state which presses the leading excavation pipe which concerns on embodiment of this invention into the ground using a tubing apparatus. It is a perspective explanation of the tubing device which carries out underground press-fitting of the preceding excavation pipe of FIG. (A) is an explanatory diagram showing a state in which a bottomed buried pipe is inserted and lowered into a pipe of a preceding excavation pipe that has been excavated. (B) is a partially omitted front explanatory view of the bottomed buried pipe. (A) is an explanatory view showing a state in which the buried pipe is arranged in a double tubular shape in the pipe of the preceding excavation pipe. (B) is an explanatory view showing a double tubular gap set between the preceding excavation pipe and the buried pipe. It is explanatory drawing which shows the state which pulls out the outer leading excavation pipe to the ground side after arranging the buried pipe in the pipe of the leading excavation pipe in a double tubular shape. It is explanatory drawing which shows the state which formed the solidified part by pouring cement milk around the buried pipe after pulling out the preceding excavation pipe.

Hereinafter, a method of underground construction of a large pipe of the present invention and an embodiment of a bottomed buried pipe will be described with reference to the accompanying drawings.

The large-sized bottomed buried pipe used in the method for building a large-sized pipe in the ground according to the present invention is buried and built in order to use the space inside the pipe for various purposes. For example, it is used as an evacuation shelter from earthquakes and other natural disasters, wars and other human disasters. It can also be used as a storage for documents, jewelry, magnetic tapes, films and other electronic recording media. It is also used as a warehouse for chemicals, chemicals, water, other liquids, and other valuable materials, and as a space utilization tube for any other purpose. The large bottomed buried pipe according to the present invention is a hollow bottomed pipe body having a space inside and having a closed bottom. The pipe body is a pipe body buried at a depth of, for example, 2 meters or more to 5 meters and an underground depth of, for example, 5 meters to 20 meters or more, and is made of volcanic ash soil or clay. It is effectively used not only in the soil but also in areas where there is a lot of water and boulders in the ground. The method of underground construction of a large pipe of the present invention can be effectively utilized in these areas.

Since the structure of the member of the large bottomed pipe body of the present invention differs depending on the building process, the large bottomed pipe body will be described together with each step.

[First step]
1 to 7 show an embodiment of the method for building a large pipe in the ground of the present invention. FIG. 1 is a plan explanatory view showing the press-fitting positional relationship between the preceding excavation pipe 20 to be press-fitted into the ground in a substantially vertical direction and the buried pipe 1, and the inner one-dot chain line-showing pipe is finally buried and built. It is a buried pipe 1 to be embedded, and the pipe shown by the solid line on the outside indicates the preceding excavation pipe 20. In this method, the leading excavation pipe 20 is pressed into the ground G where the building position is set and the soil is discharged, and the buried pipe 1 to be finally built is inserted and lowered into the space 100 inside the leading excavation pipe 20. After that, a large pipe is built by pulling out the preceding excavation pipe 20 to the ground.

As shown in FIGS. 2, 4 and 5, the preceding excavation pipe 20 is a so-called casing tube made of a steel cylindrical pipe having both ends (upper and lower in the drawing) open. When a single steel pipe can reach the target underground depth, it is composed of one steel pipe, but it is usual to use multiple steel pipes in combination. Normally, a unit tube having a diameter of several meters and an axial length of several meters is gripped by a tubing device and pressed into the ground while rotating in the axial direction. While the press-fitting and lowering of one unit pipe is not completed in the tubing device, the pipe ends of the other unit pipes are welded or connected by any fastening means in a watertight holding state inside and outside the pipe, and the press-fitting and lowering is sequentially performed. For example, the pipe ends of unit pipes that are vertically opposed to each other are screwed together using a coupling member, and a plurality of pipe bodies are connected to form an integrated leading excavation pipe having a length of, for example, about 20 m, and press-fitted and lowered. You may. In this embodiment, as shown in FIG. 4B, the inside and outside of the pipe are welded and connected in advance at the welded portion 10 on the ground to maintain watertightness. The preceding excavation pipe 20 has a plurality of excavation bit portions 21 attached to the lower ends thereof, and digs downward while rotating or swiveling as the tubing device 40 rotates around the axis. As a result, even in the ground with a lot of boulders, the excavation bit 21 can surely dig downward while crushing the bedrock and the like. The excavation bit portion 21 is configured by fixing a plurality of excavation bits 21a in an annular shape to the lower end edge of the pipe body at intervals. As will be described later, in order to press-fit the pipe body 1 into the ground, the pipe body 1 is press-fitted while rotating in the direction around the longitudinal axis of the pipe body by a dedicated mechanical device, but by attaching the excavation bit portion 21 to the lower end edge of the pipe body 1. Even if a hard bedrock layer is present during the press-fitting, it is possible to cut it down and let it enter the ground while rotating the pipe body.

In FIGS. 2 and 3, the tubing device 40 is installed on the ground. Push it into the ground. In FIG. 2, the tubing device 40 has a rotating body for rotating a tube (not shown) supported by a machine frame 41, an elevating frame that rotatably supports the rotating body, an elevating device, a chuck member, a chuck cylinder, and the like. It is a rotary tubing device. A receiving plate 42 is preliminarily placed on the ground on the lower surface of the tubing device 40. Further, the counterweight 43 is arranged so as to sandwich the tubing device 40 from both sides. The counterweight 43 stabilizes the entire tubing device 40 so that the tubing device 40 does not move due to reaction during the press-fitting operation of the large tube.

The first step in the method for laying a large pipe in the ground according to the present invention is a preceding excavation pipe having a diameter larger than that of the pipe to be buried, so that the pipe wall position includes the outer diameter of the buried pipe 1 in a plan view. Prior to burying the buried pipe 1, the preceding excavation pipe 20 is press-fitted and excavated with respect to the ground. That is, for example, in FIG. 1, the rotation center of the tubing device 40 is set for the center position Q corresponding to the above-ground plane position of the pipe 1 to be finally buried and built, and the diameter is larger than that of the pipe 1 to be buried therein. The center position of the preceding excavation pipe 20 is set, and the preceding excavation pipe 20 is press-fitted and buried. The preceding excavation pipe 20 and the buried main pipe 1 do not necessarily have to be set at concentric positions. After the press-fitting excavation of the preceding excavation pipe 20, it is sufficient that there is an interval margin for inserting and arranging the main burial pipe 1 in the pipe 20. In the embodiment, in order to facilitate understanding, the buried main pipe 1 and the preceding excavation pipe 20 to be descent-inserted into the preceding excavation pipe have a required distance D (FIG. 5 (b)) on both ends when longitudinally crossed along the diameter line. ) Is formed and is press-fitted like a circle with different diameters at concentric positions so as not to contact the preceding excavation pipe 20. As a result, as shown in FIG. 1, the press-fitting and burying position of the preceding excavation pipe 20 is prior to the burying of the buried pipe 1 so as to be the pipe wall position of the preceding excavation pipe including the plan view buried outer diameter of the buried pipe 1. The preceding excavation pipe 20 is press-fitted and excavated with respect to the ground.

The preceding excavation pipe 20 drains the inside of the pipe while excavating in advance in order to form an underground gap for inserting and arranging the buried pipe 1 prior to the buried construction of the buried main pipe 1, and a space is provided in the pipe. Form 100. Then, it functions as a collapse prevention pipe so that the peripheral wall of the vertical hole formed when the buried main pipe is inserted and arranged in the pipe inner space after excavation does not collapse.

[Second step]
At the same time as the rotary press-fitting excavation by the tubing device 40 of the preceding excavation pipe 20, the excavated soil generated by excavation through the excavation bit 21 at the lower end of the preceding excavation pipe is discharged into the pipe. That is, in FIG. 30, when the tubing device 40 rotates the preceding excavation pipe 20 and press-fits it into the ground, the soil inside the preceding excavation pipe 20 is simultaneously discharged to the ground side by the excavator 44. In the embodiment, as the earth removal machine, a known large-diameter excavation machine such as a grab hammer, which is suspended by a heavy machine such as a crawler crane and is driven into the ground by a falling force to grab the earth and sand, is used. When excavating the preceding excavation pipe, water usually seeps out from the ground on the lower end side of the pipe body to the inside of the pipe as the depth is gradually increased. Water leaching can be several meters or tens of meters deep.

[Third step]
In FIG. 4, the preceding excavation pipe 20 is press-fitted to the planned depth while the inside of the pipe is discharged by the earth removal machine 44, and then the bottomed buried pipe 1 as the buried main is inserted and lowered into the pipe space of the preceding excavation pipe 20. The leading excavation pipe and the buried pipe are arranged in a double tubular shape (see FIG. 5). In FIG. 4B, the bottomed buried pipe 1 arranged inside the preceding excavation pipe 20 is a steel pipe called a casing tube, which is made of a steel cylindrical pipe having an opening at one end side, which is the upper end side. be. It is composed of connecting multiple steel pipes.

The bottom wall 2 of the bottomed buried pipe 1 is preliminarily attached to the ground side so that the lower end maintains a watertight state and closes the inside and outside. Further, an anti-buoyancy weight portion 3 is provided inside the buried pipe 1 and above the bottom wall 2, that is, at the inner bottom portion of the bottomed buried pipe 1. When the bottomed buried pipe 1 is inserted and lowered into the pipe inner space of the preceding excavation pipe after the preceding excavation pipe is press-fitted to the planned depth, the anti-buoyancy weight portion 3 is seepage water from the underground side at the lower end of the pipe. The bottomed buried pipe 1 is prevented from rising against the buoyancy of the above. The anti-buoyancy weight portion 3 may be any tangible material having gravity capable of countering the buoyancy, and may be a steel material, concrete, waste material thereof, or the like. The upper surface of the anti-buoyancy weight portion 3 is provided with arbitrary flooring according to the usage pattern of the in-pipe space.

Further, in the present embodiment, a swivel biting device 4 with the tip end side facing downward is provided outside the bottom wall 1 of the bottomed buried pipe 1. In the swivel biting device 4, after the bottomed buried pipe 1 is inserted into the pipe inner space of the preceding excavation pipe 20 and landed, the bottomed buried pipe 1 itself is swiveled around the vertical axis to cause the ground outside the bottom wall 2. It is a means to bite the bottom of the bottomed buried pipe 1 into the ground G and integrate it into the ground G. In this embodiment, as shown in FIGS. 4 to 7, the screw shaft 5 and the spiral blade 6 around the outer circumference of the screw shaft 5 It is composed of a screw blade 7 to which the screw blade 7 is attached. As the swivel biting device 4, a device having any structure can be adopted as long as it is a mechanism that bites into the ground by swiveling the main body side. Further, a screw blade long downward may be used depending on the ground condition of the planned depth portion. In the embodiment, the upper part of the preceding excavation pipe arranged in the double pipe state and the bottomed buried pipe 1 inserted inside the pipe is connected, and both pipes are integrally swiveled by a tubing device to cause the bottomed buried pipe 1. I try to secure the state of biting into the ground.

When the bottomed buried pipe 1 is inserted and lowered into the inside of the preceding excavation pipe 20 at a concentric position, the unit pipe having a required axial length may be held by the tubing device 40 and lowered as it is. It may be inserted and lowered while being supported by a suspension device such as a heavy machine crane. At that time, the bottomed buried pipe 1 is smoothly and quickly inserted and arranged inside the preceding excavation pipe 20 while maintaining the gap D between the two pipes.

[Fourth step]
After inserting the buried pipe 1 to a predetermined depth position, the preceding excavation pipe 20 is pulled out. Regarding the work of pulling out the preceding excavation pipe 20 to the ground side, it is also possible to hold it by the tubing device 40 and pull it out into the ground while rotating it in the opposite direction around the axis. In this case, there is no need to change the setup of the main equipment until the press-fitting excavation of the preceding excavation pipe 20, the insertion arrangement of the buried pipe 1 inside the pipe 20, and the pulling-out operation of the preceding excavation pipe 20. Therefore, the work man-hours can be significantly reduced, the work time can be shortened, the work labor can be reduced, and the work cost can be significantly reduced. The preceding excavation pipe 20 may be pulled out by using a crane or other heavy equipment having a lifting function.

In the embodiment, a fluidized solidifying material such as a grout material is injected into a gap formed in the trace where the preceding excavation pipe 20 is pulled out to the ground side to form a solidifying portion 12, which is integrated with the ground. It should be noted that the solidification portion 12 does not necessarily have to be formed depending on the size of the distance between the two pipes and the state of the ground.

As described above, the storage space for the bottomed buried pipe 1 is formed inside the preceding excavation pipe 20 in the ground, and the bottomed buried pipe 1 is inserted and lowered into the storage space with the peripheral wall retained. Since it is fixed to the ground side, it is possible to install, construct, construct, deploy interiors, and other equipment for using the space inside the bottomed buried pipe 1 on the ground. In addition, since the entire construction and confirmation for stopping the water in the bottomed buried pipe 1 can be performed on the ground side, it is possible to take all possible measures against the intrusion of water into the buried pipe 1. For example, the construction of powered lift racks, ventilation equipment, equipment, equipment, food, storage equipment for goods, shelters for disaster evacuation, and other usage patterns for any purpose are designed on the ground side and specifically installed in the pipe. It is possible to use the buried pipe by inserting and descending in the state of being inserted.

By constructing a large pipe in the ground by the above steps 1 to 4, the assembly equipment construction according to the purpose of use in the bottomed buried pipe 1 is performed in advance on the ground side in the pipe, so that the equipment accuracy is good. Not only can the completed state be maintained, but the work process is simple and the number of processes is small, which contributes to shortening the work time, shortening the construction period, and significantly reducing the work cost. In particular, it is possible to maintain stable and safe use in the pipe by taking thorough measures to prevent the intrusion of groundwater from the bottom of the pipe on the ground side.

Further, an anti-buoyancy weight portion against buoyancy from the underground side is provided at the inner bottom portion of the bottomed buried pipe that is inserted and lowered into the pipe inner space of the preceding excavation pipe after the preceding excavation pipe is press-fitted to the planned depth. As a result, when the bottomed buried pipe 1 is inserted and lowered into the pipe space of the preceding excavation pipe, the buried main pipe 1 does not become unstable due to the buoyancy of the leachate from the underground side at the lower end of the pipe and is stable. It can be placed in the pipe space of the preceding excavation pipe.

In addition, a swivel bite device with the tip side facing downward is provided on the outside of the bottom of the bottomed buried pipe, and the bottomed buried pipe itself is displayed on the vertical axis after the leading excavated pipe is inserted into the pipe space and descended. By including the step of turning around, after landing in the pipe inner space of the preceding excavation pipe 20, the bottomed buried pipe 1 itself is swiveled around the vertical axis to reach the ground outside the bottom wall 22 via the swivel bite. It is possible to bite into the bottom of the bottomed buried pipe 1 and integrate it into the ground G.

Further, the bottomed buried pipe of the present invention is a bottomed buried pipe used in the method of underground construction of a large pipe by the above method, and is inside the pipe of the preceding excavation pipe after the preceding excavation pipe is press-fitted to the planned depth. It is a bottomed buried pipe that is inserted and lowered into the space, and the inner bottom is provided with an anti-buoyant weight for buoyancy from the underground side, so that it is buried in the pipe space of the preceding excavation pipe. When the pipe 1 is inserted and lowered, the buried main pipe 1 can be stably arranged in the pipe space of the preceding excavated pipe without becoming unstable due to the buoyancy of the leachate from the underground side at the lower end of the pipe.

Further, the above-mentioned bottomed buried pipe is provided with a swivel bite device facing downward to the outside of the bottom, so that the bottomed buried pipe 1 is after landing in the pipe inner space of the preceding excavation pipe 20. By turning around the vertical axis of itself, it is possible to bite the bottom portion of the bottomed buried pipe 1 into the ground outside the bottom wall 2 via the swivel bite device and integrate it into the ground G.

The method for laying a large pipe in the ground and the bottomed buried pipe described above are not limited to the configuration of only the above-described embodiment, and are not deviating from the essence of the invention described in the claims. In, other embodiments may be used.

The method for laying a large pipe in the ground and the underground pipe of the present invention can be used as a shelter in an earthquake, a tsunami, a landslide disaster, a wartime danger situation, etc. can do. It is also possible to form a mushroom cultivation space where the growing conditions for light and air are not so severe.

1 Bottomed buried pipe (buried main)
2 Bottom wall 3 Anti-buoyancy weight part 4 Swirling bite 5 Screw shaft 6 Spiral blade 7 Screw blade 20 Leading excavation pipe 21 Excavation bit part 21a Excavation bit 40 Tubing device 44 Excavator D Gap between both pipes G Ground

Claims (5)

It is a method of building a large buried pipe that is buried vertically in the ground so that the space inside the pipe can be used for various purposes.
It is a preceding excavation pipe with a diameter larger than that of the pipe to be buried, and the preceding excavation pipe is press-fitted and excavated into the ground prior to burying the buried pipe so that the pipe wall position includes the outer diameter of the buried pipe in a plan view. Process and
The process of excavating the excavated soil in the pipe at the same time as excavating the preceding excavation pipe,
After the preceding excavation pipe is press-fitted to the planned depth, the bottomed buried pipe is inserted and lowered into the space inside the excavation pipe, and the preceding excavation pipe and the buried pipe are arranged in a double tubular shape.
A method for underground construction of a large pipe, which comprises a step of inserting a buried pipe to a predetermined depth position and then pulling out a preceding excavation pipe. After the preceding excavation pipe is press-fitted to the planned depth, the inner bottom of the bottomed buried pipe that is inserted and lowered into the pipe space of the preceding excavation pipe is provided with an anti-buoyancy weight portion against buoyancy from the underground side. The method for underground construction of a large pipe according to claim 1, which is characteristic. A swivel biting device with the tip side facing downward is provided outside the bottom of the bottomed buried pipe, and after the bottomed buried pipe is inserted into the in-pipe space of the preceding excavation pipe and descends, the bottomed buried pipe itself is rotated around the vertical axis. The method for laying a large pipe in the ground according to claim 1 or 2, which comprises a step of turning. It is a bottomed buried pipe in which the preceding excavation pipe of claim 2 is press-fitted to the planned depth and then inserted and lowered into the pipe space of the preceding excavation pipe.
A bottomed buried pipe characterized in that a swivel biting device with the tip side facing downward is provided on the outside of the bottom. The bottomed buried pipe according to claim 4, wherein the inner bottom portion is provided with an anti-buoyancy weight portion against buoyancy from the underground side .

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