JP5338064B2 - Method for preventing oxidation of groundwater in well and well, method for constructing emergency well and emergency well constructed by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preventing the oxidization of groundwater in a well in the nonuse of the well, and the well for use in the method. <P>SOLUTION: The well 1 comprises: a column pipe 13 for collecting the groundwater inward; an injection section for injecting an inert gas into an upper section with respect to the groundwater in the column pipe 13; a cap 10 which is attached to an upper end of the column pipe 13 and which serves as a sealing member for sealing the inside of the column pipe 13 with the inert gas infilled in the column pipe 13; a concentration meter 9 for measuring the concentration of oxygen in the column pipe 13; and a detector 15 for detecting gas generated from under the ground and having the risk of an explosion etc. or doing harm to the human body. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a method for preventing oxidation of groundwater in a well and a well in which the method is used.

  Conventionally, when excavating the ground by the open-cut method, a well for draining water is constructed and groundwater is pumped to lower the groundwater level. Particularly in recent years, a method of providing a drain well in an underground structure such as soil cement or RC has been used.

  For example, in Patent Document 1, a steel pipe with a lid attached to the tip is inserted into an underground wall structure composed of a plurality of soil cement columns, and the ground is ground from the lower end of the steel pipe to a predetermined depth using this steel pipe as a guide. A method of drilling and constructing a well for draining is disclosed. In this method, the position of the well to be built in the underground wall structure is determined in advance by design, etc., the well is built in the soil cement pillar at this position, and when all construction is completed, earth and sand, cement, etc. are placed in the well. It is backfilled and blocked.

  However, this blockage requires material costs and labor such as backfilling and filling confirmation. In addition, the construction of a well has a problem that it is wasteful to close the well in spite of the time and cost.

Therefore, in recent years, there has been a case where a well is left as it is in order to secure water to be used in an emergency such as a disaster, instead of always using groundwater as domestic water.
JP 2001-115458 A

  However, if the well is not used at all times and left to be used in an emergency, iron contained in the groundwater is oxidized by oxygen in the air to produce insoluble iron hydroxide, Since it settles, there was a problem that when groundwater was pumped up in an emergency, the red water containing iron hydroxide was pumped up and the water could not be used.

  In addition, if the well is left to be used in an emergency, a large amount of oxygen in the air is supplied to the groundwater through the well, so it is inhabited with a low oxygen supply prior to the construction of the well. In addition to the possibility of adversely affecting the ecology of microorganisms, it has the potential to change the underground ecosystem.

  Then, this invention is made | formed in view of the above conventional problems, Comprising: When not using a well, the method of preventing the oxidation of the groundwater in a well and the well by which the method is used are provided. Objective.

In order to achieve the above object, a well according to the present invention is a well for pumping up groundwater, which is installed in the ground, and has a pumping pipe for collecting groundwater, and above the groundwater in the pumping pipe. an injection unit for injecting an inert gas, attached to the riser pipe, and a sealing member for sealing the inert gas injected into the pumping tube from the injection portion into the pumping tube , is under construction is used as a construction for wells, after construction is used as an emergency well characterized Rukoto (first invention).

  According to the well according to the present invention, the pump includes a pumping pipe for collecting groundwater, an injection part for injecting an inert gas, and a sealing member for sealing the inert gas in the pumping pipe. Therefore, it is possible to maintain the full state by injecting the inert gas into the pumping pipe. Moreover, since the inside of the pumping pipe is filled with inert gas and oxygen is not present, iron in the groundwater is not oxidized and microbial ecology is not adversely affected.

According to a second aspect, in the first aspect, the apparatus further comprises a densitometer for measuring the concentration of oxygen in the pumping pipe.
According to the well according to the present invention , since the concentration meter is further provided, the concentration of oxygen in the pumping pipe is periodically measured by the concentration meter, and when oxygen is detected, the concentration is inactive through the injection portion. By injecting the gas into the pumping pipe, the inside of the pumping pipe can be maintained in a reduced state for a long period of time.

According to a third invention, in the first or second invention, the detector further comprises a detector for detecting a gas that is generated from the ground and has a risk of explosion or the like or a gas harmful to the human body.
The well according to the present invention further includes a detector for detecting a gas having a risk of explosion or a gas harmful to the human body, so when methane gas or hydrogen sulfide gas is generated, Can be detected. Therefore, the well can be used and maintained with peace of mind.

A fourth invention is characterized in that, in any one of the first to third inventions, the invention is constructed in an underground structure.
According to the well according to the present invention, when the underground structure is constructed, the well constructed in the underground structure can be used as it is for the purpose of lowering the groundwater level. Therefore, there is no need to construct a new well.

A fifth invention is characterized in that, in the fourth invention, a manhole is provided around the upper end of the pumping pipe.
According to the well according to the present invention, since the manhole is constructed around the upper part of the pumping pipe, the attachment and detachment of the sealing member, the concentration measurement, the inert gas injection operation, and the like can be easily performed. In addition, the pumping pipe is installed in the manhole, so the landscape is not disturbed.

According to a sixth invention, in any one of the first to fifth inventions, the pumping pipe is made of a stainless steel pipe.
  Since the well according to the present invention is made of stainless steel, damage such as corrosion hardly occurs, and the well can be used for a long time.

A method for preventing oxidation of groundwater in a well according to a seventh aspect of the present invention is a method for injecting an inert gas into a pumping pipe while measuring the concentration of oxygen in the pumping pipe for collecting groundwater. When the oxygen amount in the pumping pipe decreases and oxygen is no longer detected, the pumping pipe is sealed with a sealing member so that the inert gas does not flow out as the pumping pipe is filled with the inert gas. Sealing is performed, and the inert gas is sealed in the pumping pipe.

The method for preventing the oxidation of groundwater in the well of the eighth invention is a method for injecting an inert gas into this pumping pipe while measuring the concentration of oxygen in the pumping pipe installed in the ground for collecting groundwater. Then, as the inert gas is injected into the pumping pipe, the air in the pumping pipe is discharged from the discharge section for discharging the air in the pumping pipe, and the oxygen amount in the pumping pipe is reduced to generate oxygen. If it is no longer detected, the discharge part is sealed with a sealing member so that the inert gas does not flow out because the inside of the pumping pipe is filled with the inert gas, and the inert gas is sealed in the pumping pipe. It is characterized by stopping.

The construction method of the emergency well according to the ninth invention is an underground structure in which a pipe is buried, and a hole reaching a predetermined depth in the ground below the underground structure is inside the pipe. In the construction method of an emergency well in which a well is constructed using the underground structure formed, an installation step of installing a pumping pipe for collecting groundwater in the hole, Injecting an active gas, and sealing the intake pipe so that the inert gas does not flow out when the pumping pipe is filled with the inert gas, and making the pumping pipe a well Features.
According to the method for constructing an emergency well according to the present invention, the inside of the pumped pipe installed in the hole of the pipe is in a reduced state in which oxygen is not present due to filling with inert gas, so that iron in groundwater is oxidized, microorganisms Will not adversely affect the ecology of

In a tenth aspect based on the ninth invention, the hole of the tube is characterized in that it is used as a work for a well with the construction of the underground structure.
According to the construction method of the emergency well according to the present invention, the hole in the pipe buried in the underground wall is used as a construction well, and after the construction is completed, the emergency well is constructed using the hole. Therefore, the construction well can be used effectively.

The emergency well of the eleventh invention is constructed by any one of the ninth and tenth methods.

  By using the method for preventing oxidation of groundwater in a well according to the present invention, oxidation of groundwater in the well can be prevented when the well is not used.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, although the following embodiment demonstrates the case where a well is built in the soil cement pillar row wall which is an underground structure, this invention is applied also when installing in underground structures, such as RC. Can do.

  1 and 2 are a perspective view and a longitudinal sectional view, respectively, showing a state in which a well 1 according to a first embodiment of the present invention is installed on a soil cement column wall 2, and FIG. 3 is a part A of FIG. It is an enlarged view.

  As shown in FIGS. 1 to 3, the soil cement column wall 2 is constructed so as to surround the periphery of a planned excavation site 5 excavated by an open-cut method in order to construct an underground structure or the like, and its lower end is It is installed so as to penetrate the surface layer 14 and reach the upper part of the clay layer 3 which is an impermeable layer. However, the formation is not limited to these, and may be all composed of the sand layer 4.

  In the soil cement column wall 2, a cylindrical guide tube 18 used as a guide when drilling the hole 17 for the well 1 penetrates the soil cement column wall 2 in the depth direction. It is installed in advance such that the lower end protrudes from the lower end of the soil cement column wall 2. A plurality of guide tubes 18 are installed in the soil cement column wall 2 so as to be arranged in the horizontal direction.

  The well 1 is installed in a hole 17 that is vertically drilled so as to reach the sand layer 4 in the guide pipe 18, a pumping pipe 13 for collecting groundwater inward, and groundwater in the pumping pipe 13. An injection part for injecting an inert gas into the upper part, and a sealing member attached to the upper end of the pumping pipe 13 and sealing the inert gas filled in the pumping pipe 13 in the pumping pipe 13 A cap 10, a concentration meter 9 for measuring the concentration of oxygen in the pumping pipe 13, and a detector 15 for detecting a gas that is generated from the ground and has a danger of explosion or harmful to the human body. And.

  The pumping pipe 13 is installed so as to form a gap between the inner circumference of the hole 17 and the inner circumference of the guide pipe 18. Between the outer periphery of the pumping pipe 13 and the inner periphery of the hole 17, which is the portion of the sand layer 4 in the gap, a filter portion 22 is formed that is filled with sand for allowing groundwater to pass through. Further, it is a part of the clay layer 3 above the upper surface of the filter part 22 and between the outer periphery of the pumping pipe 13 and the inner periphery of the hole 17 and between the outer periphery of the pumping pipe 13 and the guide pipe 18. Between the inner periphery, a water stop portion 19 filled with bentonite for preventing inflow of groundwater is formed. Further, a buffer portion 20 filled with earth and sand for preventing contact between the pumping pipe 13 and the guide pipe 18 at the time of an earthquake or the like is formed from the upper surface of the water stopping portion 19 to the vicinity of the upper portion of the pumping tube 13. . The space formed in the upper portion of the buffer portion 20 is used as a manhole 6, and the upper end of the manhole 6 is closed with a lid 7 in normal times. A plurality of pumping pipes 13 are installed in the soil cement column wall 2 at intervals.

  A screen 16 is provided at the lower end of the pumping pipe 13 so that the groundwater that has passed through the filter unit 22 can flow into the pumping pipe 13.

  The pumping pipe 13 is made of stainless steel and is unlikely to be corroded, so that it can be used for a long time.

  The injection part is composed of an injection pipe 8 for injecting an inert gas into a space above the groundwater stored in the pumping pipe 13, and is connected to the upper outer peripheral surface of the pumping pipe 13. The injection pipe 8 is provided with a check valve 11 for preventing gas from flowing out from the pumping pipe 13 to the outside, and an inert gas is injected into the pumping pipe 13 through the check valve 11. .

  The outer peripheral lower end portion of the cap 10 and the inner peripheral upper end portion of the pumping pipe 13 are respectively threaded, and the cap 10 is attached to the upper end of the pumping pipe 13 by being screwed into the pumping pipe 13. In addition, since the O-ring 12 is attached to the screw portion of the cap 10, the inert gas can be sealed in the pumping pipe 13 while being attached to the pumping pipe 13.

  The concentration meter 9 is connected to the outer peripheral surface of the upper end portion of the pumping pipe 13 so as to communicate with the inside of the pumping pipe 13. The densitometer 9 is connected slightly above the injection tube 8 (described later).

  The detector 15 has a function of detecting gas such as hydrogen sulfide harmful to human body and methane gas having danger such as explosion. The detector 15 is installed in the manhole 6 and measures the inside of the water pump 13 and the manhole 6.

  The space above the ground water in the pumping pipe 13 of the well 1 having the above-described configuration is filled with the inert gas injected through the check valve 11 and the injection pipe 28. In the present embodiment, argon is used as the inert gas. Since argon is heavier than air, when it is supplied from the injection pipe 8 into the pumping pipe 13, it sinks to the vicinity of the surface of the groundwater, and is gradually stacked to fill the upper end of the pumping pipe 13. Therefore, if the concentration meter 9 measures the oxygen concentration in the pumping pipe 13 and oxygen cannot be detected, the concentration meter 9 is located above the air inlet 8a of the injection pipe 8 and therefore contains oxygen in the pumping pipe 13. It can be judged that all the air was replaced with argon. When all the air is replaced with argon, the injection of argon is stopped, and the cap 10 is attached to the upper end of the pumping pipe 13 to seal the argon in the pumping pipe 13.

  Since the inside of the pumping pipe 13 filled with argon and free of oxygen is in a reduced state, iron in the groundwater is not oxidized and the ecology of microorganisms is not adversely affected. Even if air enters the pumping pipe 13 in this state for some reason, the air is lighter than argon and is laminated on the argon in a state separated from the argon, so that oxygen in the air comes into contact with the groundwater. There is nothing.

  When groundwater is needed in the event of an emergency, the lid 7 of the manhole 6 is opened. First, the detector 15 confirms that no methane gas or hydrogen sulfide is generated, and then the cap 10 is removed, and the pump is connected to the pump. Insert in 13 to pump up the groundwater.

  At the time of periodic inspection, the lid 7 of the manhole 6 is opened, and first, it is confirmed that no methane gas or hydrogen sulfide is generated by the detector 15, and then the concentration of oxygen in the pumping pipe 13 is measured by a concentration meter. Measured at 9, the filling state of argon in the pumping pipe 13 is confirmed. If oxygen is detected in this measurement, the cap 10 is removed, a portable argon supply device is connected to the injection pipe 8 via the check valve 11, and oxygen is injected into the pumping pipe 13 while oxygen is injected. Measure the concentration. Then, when oxygen is no longer detected, it is assumed that all the oxygen-containing air in the pumping pipe 13 has been replaced with argon, and argon injection is stopped, and the cap 10 is attached to the pumping pipe 13 to seal the argon.

  The thickness and installation depth of the soil cement column wall 2 and the diameter and installation depth of the well 1 are drilled around the planned drilling site 5 and after the hydraulic survey to investigate the geology and hydraulic conditions such as permeability, It is determined in advance by the design performed based on the result of the hydraulic survey.

  Next, a second embodiment of the present invention will be described. In the following description, portions corresponding to the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described. In this embodiment, a case where helium is used as an inert gas will be described.

  FIG. 4 is a longitudinal sectional view showing a state in which the well 21 according to the second embodiment of the present invention is installed on the soil cement column wall 2, and FIG. 5 is an enlarged view of a portion B in FIG. 4.

  As shown in FIGS. 4 and 5, the well 21 includes an injection tube 28 for injecting helium therein, a densitometer 9, a detector 15, a cap 10, and a discharge part.

  The injection pipe 28 penetrates the upper side surface of the pumping pipe 13 from the outside of the pumping pipe 13, and the intake port 28 a at the lower end thereof is located on the pumping pipe 13 so as to be located slightly above the groundwater surface in the pumping pipe 13. It is attached.

  A check valve 11 is attached to the upper end of the injection pipe 28, and helium is injected into the pumping pipe 13 through the check valve 11.

  The concentration meter 9 is installed at a position slightly above the surface of the groundwater in the well 21 and below the air supply port 28a at the lower end of the inner pipe 29b. The densitometer 9 is movable in the vertical direction in consideration of the fluctuation of the groundwater level.

  The discharge part is composed of an exhaust pipe 29 for discharging the air in the pumping pipe 13, penetrates the upper side surface of the pumping pipe 13 from the outside of the pumping pipe 13, and the suction port 29 a at the lower end thereof is inside the pumping pipe 13. Is connected to the pumping pipe 13 so as to be located slightly above the groundwater surface.

  When helium is injected into the injection pipe 28, helium is lighter than air. Therefore, when helium is supplied from the air supply port 28a of the injection pipe 28 into the pumping pipe 13, the helium rises to the vicinity of the cap 10 and is gradually stacked. To fill up near the surface of the groundwater. Helium is supplied into the pumping pipe 13 and air containing oxygen in the pumping pipe 13 is discharged to the outside through the exhaust pipe 29. Accordingly, when the concentration meter 9 measures the oxygen concentration in the pumping pipe 13 and oxygen cannot be detected, the concentration meter 9 is located below the air supply port 28a of the inner pipe 29b and therefore contains oxygen in the pumping pipe 13. It can be determined that all the air has been replaced with helium. When all the air is replaced with helium, the helium injection is stopped.

  Since the inside of the pumping pipe 13 filled with helium and free of oxygen is in a reduced state, iron in groundwater is not oxidized or adversely affects the ecology of microorganisms.

  When groundwater is needed in an emergency, as in the first embodiment, the lid 7 of the manhole 6 is opened, and first, it is confirmed that no methane gas or hydrogen sulfide is generated by the detector 15, and then the cap 10 And the pump is inserted into the well 21 to pump up the groundwater.

  Further, at the time of periodic inspection, as in the first embodiment, the lid 7 of the manhole 6 is opened, and it is first confirmed that the detector 15 does not generate methane gas or hydrogen sulfide. The concentration of oxygen in the inside is measured with a densitometer 9 to check the helium filling state in the pumping pipe 13. At this time, since it is impossible to measure if the densitometer 9 is submerged, it is first checked whether or not the densitometer 9 is submerged. When the concentration meter 9 is submerged and cannot be measured, the concentration meter 9 is pulled up to a measurable state while measuring the concentration, that is, lifted above the surface of the groundwater, and then as much as possible. Measure the oxygen concentration near the surface of the groundwater. If oxygen is detected by this measurement, a portable helium supply device is connected to the injection pipe 28 with the cap 10 attached, and helium is introduced into the pumping pipe 13 while measuring the oxygen concentration. It injects and the inside of the pumping pipe 13 is filled with helium. Then, when oxygen is no longer detected, helium injection is stopped assuming that all the air containing oxygen in the pumping pipe 13 is replaced with helium.

  According to the wells 1 and 21 in the present embodiment described above, the pumping pipe 13 that is installed in the ground and collects groundwater inward, and the injection pipes 8 and 28 for injecting argon or helium, Since the concentration meter 9 for measuring the oxygen concentration in the pumping pipe 13 and the cap 10 for sealing argon or helium in the pumping pipe 13 are provided, the pumping pipe 13 is filled with argon or helium. Can be maintained. Moreover, since the inside of the pumping pipe 13 is a reduced state in which argon or helium is filled and oxygen is not present, iron in the groundwater is not oxidized and the ecology of microorganisms is not adversely affected. Therefore, the wells 1 and 21 may be used as emergency wells that are used only in an emergency such as an earthquake or fire.

  Then, the concentration meter 9 periodically measures the oxygen concentration in the pumping pipe 13, and when oxygen is detected, argon or helium is injected into the pumping pipe 13 through the injection pipes 8 and 28. Thereby, the inside of the pumped-up pipe 13 can be maintained in a reduced state in which oxygen does not exist over a long period of time.

  Further, since the pumping pipe 13 is a stainless steel pipe, damage such as corrosion hardly occurs, and the wells 1 and 21 can be used for a long time.

  Furthermore, since the upper part of the pumping pipe 13 is provided in the manhole 6, the detachment of the concentration meter 9 and the cap 10, the measurement of the oxygen concentration, the operation of injecting argon or helium, etc. can be easily performed. Furthermore, since the pumping pipe 13, the injection pipes 8 and 28, and the concentration meter 9 are installed in the manhole 6, the landscape is not disturbed.

  In addition, because it is equipped with a detector 15 for detecting gas such as hydrogen sulfide, which is generated from the ground and has a danger of explosion and harmful to the human body, the wells 1 and 21 can be used with peace of mind, Can be maintained.

  And when constructing an underground structure, the construction well constructed in the soil cement column wall 2 for the purpose of lowering the groundwater level can be used as it is. Therefore, there is no need to construct new wells 1 and 21.

  In addition, in each embodiment mentioned above, although the case where the injection pipes 8 and 28 and the concentration meter 9 were attached to the pumping-up pipe 13 main body was demonstrated, it is not limited to this, For example, when filling with argon, FIG. 6 and when filling with helium, the injection pipes 8 and 28 and the concentration meter 9 may be attached to the cap 10 as shown in FIG.

  In each of the above-described embodiments, the case where argon or helium is used as the inert gas has been described. However, the present invention is not limited to these gases. For example, a gas such as neon, krypton, xenon, or radon is used. It may be used.

  Furthermore, in each embodiment mentioned above, although the case where the injection pipes 8 and 28 were attached to the pumping pipe 13 was demonstrated, it is not limited to this, The injection hole is provided in the pumping pipe 13 as an injection part. Alternatively, an inert gas may be injected by attaching a portable injection tube connectable to the injection hole during maintenance or the like.

  In addition, in each embodiment mentioned above, although the case where the wells 1 and 21 were constructed | assembled vertically was demonstrated, it is not limited to this, It constructs diagonally to such an extent that it does not protrude from the side surface of the soil cement column wall 2 May be.

It is a perspective view which shows the state which installed the well which concerns on 1st embodiment of this invention in the soil cement column row wall. It is a longitudinal cross-sectional view which shows the state which installed the well which concerns on 1st embodiment of this invention in the soil cement column row wall. It is the A section enlarged view of FIG. It is a longitudinal cross-sectional view which shows the state which installed the well which concerns on 2nd embodiment of this invention in the soil cement column row wall. It is the B section enlarged view of FIG. It is a figure which shows the other Example of the arrangement | positioning method of an injection tube and a concentration meter. It is a figure which shows the other Example of the arrangement | positioning method of an injection tube and a concentration meter.

Explanation of symbols

1 well, 2 soil cement column wall, 3 clay layer, 4 sand layer, 5 drilling site,
6 Manhole, 7 Lid, 8 Injection tube, 8a Air supply port, 9 Densitometer,
10 cap, 11 check valve, 12 O-ring, 13 pumping pipe,
14 ground layer, 15 detectors, 16 screens, 17 holes, 18 guide tubes,
19 water stop, 20 buffer, 21 well, 22 filter,
28 Inlet tube, 28a Inlet port, 29 Exhaust tube, 29a Inlet port

Claims (11)

A well for pumping up groundwater,
A pumping pipe installed in the ground to collect groundwater,
An injection part for injecting an inert gas above the groundwater in the pumping pipe;
A sealing member attached to the pumping pipe, for sealing the inert gas injected into the pumping pipe from the injection portion into the pumping pipe ,
During construction are used as a construction for wells, after construction is used as an emergency wells wells, wherein Rukoto.   The well according to claim 1, further comprising a densitometer for measuring the concentration of oxygen in the pumping pipe.   The well according to claim 1 or 2, further comprising a detector for detecting a gas that is generated from the ground and has a danger of explosion or a gas harmful to a human body.   The well according to any one of claims 1 to 3, wherein the well is constructed in an underground structure.   The well according to claim 4, wherein a manhole is provided around the upper end of the pumping pipe.   The well according to any one of claims 1 to 5, wherein the pumping pipe is made of a stainless steel pipe. In a method for preventing oxidation of groundwater in a well,
While measuring the oxygen concentration in the pumping pipe installed in the ground and collecting groundwater, injecting inert gas into this pumping pipe,
When the oxygen amount in the pumping pipe decreases and oxygen is no longer detected, the pumping pipe is sealed with a sealing member so that the inert gas does not flow out as the pumping pipe is filled with the inert gas. And the method of preventing the oxidation of the groundwater in a well characterized by sealing an inert gas in the said pumping pipe. In a method for preventing oxidation of groundwater in a well,
While measuring the oxygen concentration in the pumping pipe installed in the ground and collecting groundwater, injecting inert gas into this pumping pipe,
As the inert gas is injected into the pumping pipe, the air in the pumping pipe is discharged from the discharge section for discharging the air in the pumping pipe, and the amount of oxygen in the pumping pipe is reduced to detect oxygen. When it is gone, the discharge part is sealed with a sealing member so that the inert gas does not flow out because the inside of the pumping pipe is filled with the inert gas, and the inert gas is sealed in the pumping pipe. A method for preventing oxidation of groundwater in a well characterized by: An underground structure in which a pipe is embedded, and using the underground structure in which a hole reaching a predetermined depth in the ground below the underground structure is formed inside the pipe In the construction method of the emergency well to construct the well,
An installation step of installing a pumping pipe for collecting groundwater in the hole;
Injecting an inert gas into the pumping pipe, and sealing the pumping pipe so that the inert gas does not flow out when the pumping pipe is filled with the inert gas,
A construction method of an emergency well, wherein the pumping pipe is a well.   The method for constructing an emergency well according to claim 9, wherein the hole in the pipe is used as a construction well associated with construction of the underground structure.   An emergency well constructed by the method according to claim 9.

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