JP3804807B1 - Groundwater sampling device - Google Patents

Abstract

An object of the present invention is to provide a groundwater sampling apparatus that can be used at a deep depth and that can directly collect in situ groundwater from a geological layer that is not disturbed by a boring operation.
A water collection container 11 and a plug 21 are provided. The plug 21 is provided so as to protrude downward in the water sampling container 11 and has a water sampling port 22 and a water conduit 25. Inside the water sampling container 11, there is an inner pipe opening 32 connected to the water sampling port 22 and arranged at the upper part in the water sampling container 11. Moreover, it has the pumping pipe by which the pumping port 42 located in the lower part inside the sampling container 11 is arrange | positioned, and the pumping means by pressurization. Furthermore, the horizontal cross-sectional area of the plug 21 is smaller than the horizontal cross-sectional area of the water sampling container 11.
[Selection] Figure 1

Description

  The present invention relates to a groundwater sampling apparatus for sampling groundwater immediately below a bottom of a vertical hole excavated in the ground such as a borehole.

  When developing a water source well, before starting the drilling of this well, it is possible to obtain groundwater of water quality that meets the purpose of use, such as no harm to health, and if so, from which depth It is desirable to be able to grasp in advance information such as whether it is appropriate. In addition, in the investigation and elucidation of groundwater contamination problems, it is important to understand the pollution status of each groundwater aquifer (by depth).

A conventional groundwater sampling device has an intrusion cone at the tip, and a filter tube for taking groundwater can be slidably inserted into the sampler so that it can enter and exit from the sampler at the tip of the rod. What was inserted freely is known (for example, refer to patent documents 1).
Conventionally, the groundwater collected at the bottom of the borehole has been collected.
Furthermore, as a groundwater sampling device to be inserted into the borehole, a cylindrical casing that is inserted into the borehole and the water sampling hole portion is disposed at a water sampling target position, and a cylinder that is positioned above and below the water sampling port portion There is known a groundwater sampling device provided with an upper packer and a lower packer installed outside the casing, and a pump unit for taking and pumping groundwater from a sampling hole (see, for example, Patent Document 2). .

JP 2002-54382 A Japanese Patent Laid-Open No. 10-18749

  The conventional groundwater sampling device described in Patent Document 1 is a device that pushes or drives a groundwater sampling device from the ground surface toward the ground, and collects groundwater at a relatively shallow depth (for example, 5 m to 10 m) in practice. It is limited to use when watering, and it is impossible to use it for groundwater sampling in deeper places.

  The method of collecting groundwater collected at the bottom of the borehole requires removal of the drilling mud remaining in the hole and cleaning of the hole, and it is not possible to collect groundwater separately for each groundwater aquifer. .

  The conventional groundwater sampling device described in Patent Document 2 is provided with an upper packer and a lower packer for dividing the sampling zone of the borehole, and expands the upper packer, the lower packer and this in the hole. A drive device or the like is required, the device becomes complicated, and durability and reliability are lowered. Furthermore, in addition to the inevitable disturbance of the groundwater aquifer due to the boring operation, the clogging of the hole by the packer, that is, the integrity of the water sampling zone is not guaranteed.

  Therefore, an object of the present invention is to obtain a groundwater sampling apparatus that can be used at a deep depth and can directly collect in-situ groundwater from a stratum that is not disturbed by drilling or other excavation work.

  Other problems of the present invention will become apparent from the description of the present invention.

  The inventor of the present invention temporarily stopped the boring operation with the progress of the depth of the borehole during the borehole investigation, and paid attention to water sampling from a non-disturbed formation located a certain distance below the bottom of the borehole. And even when muddy water used for water shielding, hole wall collapse prevention, slime removal, bit cooling, etc. is present at the bottom of the borehole during boring (ie, removal of muddy water in We have invented a groundwater sampling device that can collect groundwater separately from the muddy water without internal cleaning.

  That is, a groundwater sampling apparatus according to one aspect of the present invention is a groundwater sampling apparatus for sampling groundwater, and projects in a downward direction from a sampling container that is a sealed container and the sampling container. A plug having a water sampling port and an upper opening, and having a water conduit that conducts the water sampling port and the upper opening, and is housed inside the water sampling container and connected to the upper opening, A water guide inner pipe having an inner pipe opening positioned at an upper part in the water sampling container, a water pumping port positioned at a lower part inside the water sampling container, a water pumping pipe conducting to the outside of the water sampling container, and the water sampling port In order to pump the groundwater that is stored in the water sampling container through the inner pipe opening and to the outside of the water sampling container through the water pumping pipe and the water guiding inner pipe. Pumping means, and the horizontal cross-sectional area of the plug is the sampling It is smaller as compared with the horizontal cross-sectional area of the vessel.

  In the present invention, a plug portion having a small horizontal cross-sectional area is pressed or driven downward from the bottom of the borehole, and groundwater is collected from a water sampling port provided in the plug. For this reason, in-situ groundwater can be collected directly from a predetermined ground under a minimum disturbance condition. In addition, a water sampling container having a large horizontal cross-sectional area serves as a resistance when the groundwater sampling device is pressed or driven, and helps to move the groundwater sampling device a predetermined distance downward and stop.

  Groundwater flows from above into a water sampling container, which is a sealed container, and is pumped from below. For this reason, when intermittent pumping is performed, replacement of old and new inflow water in the water sampling container is promoted. If mud removal in the borehole is not performed prior to sampling, mud soil present at the bottom of the borehole will be introduced when the plug is driven in, so it is difficult to avoid mixing mud in the groundwater at the beginning of sampling. However, the sampling of raw water is promoted by promoting the replacement of old and new inflow water. However, the groundwater sampling apparatus according to the present invention may be used for sampling from the formation immediately below the bottom of the drilling hole after performing the muddy water removal operation in the drilling hole.

The pumping means uses means such as depressurizing the pumping pipe, opening the pumping pipe inside the water sampling container, providing a pump at the middle of the pumping pipe, or at the end of the pumping pipe, or providing a pressurizing means on the water sampling container. be able to. If the pumping pipe is depressurized, the effect of promoting groundwater leaching can be obtained. Of course, when the purpose is to promote groundwater leaching, a decompression means such as in a water sampling container may be connected to the pumping pipe.
The end of the pumping pipe outside the water sampling container may be outside the water sampling container, but the end is preferably extended to the ground surface.

  The groundwater sampling apparatus according to a preferred embodiment of the present invention is a movable plate that is provided on a side surface of the plug and moves up and down, covers the sampling port at a moving upper end position of the up and down movement, and moves up and down. The movable plate that opens the water sampling port at the moving lower end position may be provided.

In this preferred embodiment, since the movable plate for opening and closing the water sampling port is provided, the water sampling port can be closed until the groundwater sampling device is positioned at the water sampling position. Therefore, contamination of the sampling port and / or the vicinity thereof due to mud at the bottom of the borehole or clay in the formation is reduced, and relatively clean groundwater is sampled from the beginning of the sampling operation.
In using the groundwater sampling apparatus according to this preferred embodiment, after the plug is moved downward from the bottom of the borehole, the plug is moved upward by a distance equal to or slightly longer than the moving distance of the movable plate. Move (pull out). The movable plate is constrained by ground pressure or frictional force and left in the original lower position, and as a result, the water sampling port is opened.

  A groundwater sampling apparatus according to a preferred embodiment of the present invention is provided with a compressed gas air supply pipe connected to the ground opened in the water sampling container, and the pumping means is pressurized derived from compressed gas. May be.

  In this preferred embodiment, the pumping means is pressurized. This enables pumping even if a groundwater sampling device is installed at a deep underground position where pumping or decompression is not possible. In addition, since the compressed gas source and the water sampling container arranged on the ground are connected by the compressed gas air supply pipe, there is no need to arrange a bulky pumping pump in the ground, and even if the borehole diameter is small, the groundwater sampling device can be installed. It also has the effect of being usable.

  In the groundwater sampling apparatus according to a preferred embodiment of the present invention, the inner pipe opening is positioned on a side wall of the water guide inner pipe, the water guide inner pipe extends upward from the inner pipe opening, and the compression The opening of the gas air supply pipe may be in contact with the upper end of the water guide inner pipe.

  In this preferred embodiment, the compressed gas from the compressed gas supply pipe is directly supplied to the water guide inner pipe, the water guide pipe section in the plug, and the water sampling port. By pressing or plugging in the groundwater sampling device plug and / or during sampling operation, compressed gas is supplied to push out mud that has entered the conduit, the conduit tube in the plug, and the sampling port. it can. Therefore, it has the effect that the clogging of the groundwater sampling apparatus can be removed.

  The groundwater sampling apparatus according to a preferred embodiment of the present invention may be provided with a sensor that detects the water level in the sampling container.

In this preferred embodiment, since the water level detection sensor is provided, the timing of intermittent pumping can be optimized, and the groundwater sampling operation time can be shortened. Moreover, the amount of groundwater etc. can be known by measuring beforehand the capacity | capacitance which reaches the specific water level of a water sampling container, and measuring the time and pressure until it reaches the said specific position.
Examples of the water level detection sensor include an ammeter provided with two electrodes at a specific position, a distance sensor that detects a distance from a certain position on the inner surface of the water sampling container to the water surface, and the like. The water level detection sensor may be singular or plural.

  In the groundwater sampling apparatus according to a preferred embodiment of the present invention, the sensor is composed of an upper ammeter, a middle ammeter, and a lower ammeter each having a pair of electrodes, and one electrode of the upper ammeter is One electrode of the lower ammeter is provided in the vicinity of the lower end of the water guide inner pipe of the water guide inner wall, and is provided immediately below the inner pipe opening of the water guide inner pipe outer wall. May be provided on the outer wall of the water guide pipe at a position that is in a vertical relationship between the position of one electrode of the upper ammeter and the position of one electrode of the lower ammeter.

In this preferred embodiment, since the sensor is composed of an ammeter, the portion disposed in the ground has a simple structure consisting of only an electrode and a lead wire, and there is little failure even if water is present or there is a blow impact. The water level sensor is highly reliable, and as a result, the reliability of the groundwater sampling system increases.
Each of the three ammeters has a pair of electrodes, but each one of the pair of electrodes may be a common (single) electrode.

  In the groundwater sampling apparatus according to a preferred embodiment of the present invention, the outer periphery of the plug is surrounded by the outer periphery of the plug, and is between a lower end position of the sampling container and a lower stop position above the upper end of the sampling port. You may provide the mud prevention board which moves.

  In the present preferred embodiment, the mud prevention plate prevents the muddy water at the bottom of the boring hole from descending through the outer periphery of the plug, reaching the water intake, and being taken into the water sampling container. For example, if the ground at the sampling position is hard, such as a tightly packed gravel layer, the plug is usually driven through a long rod, so the plug vibrates laterally, leaving a gap between the plug periphery and the ground. May occur. This is effective for preventing the flow of muddy water passing through the gap.

  The groundwater sampling apparatus according to a preferred embodiment of the present invention may be provided with a biasing means for biasing the mud prevention plate in the direction of the lower stop position.

In this preferred embodiment, since the mud prevention plate is biased downward, even if the plug is moved downward and then moved upward to open the movable plate, the mud prevention plate remains at the bottom of the borehole. The effect of preventing muddy water flow is enhanced.
The biasing means can list elastic bodies such as springs, weights, urethane foam, and the like. Since urethane foam is an urging means and has an effect of preventing mud, it is effective when used together with other urging means (elastic body, weight, etc.).

  In the groundwater sampling apparatus according to a preferred embodiment of the present invention, the fabric may be fixedly attached to the outer peripheral wall of the plug at a position where the fabric is fixed above the upper end of the sampling port. .

In this preferred embodiment, a part of the fabric is fixed to the outer peripheral wall of the plug, and the other part is attached in such a manner that the position is not restricted. When the plug is moved downward and then moved upward to open the movable plate, the vicinity of the fixed end of the fabric is restrained by ground pressure, frictional force, etc., so that the fabric is fixed in the ground around the plug, The fabric prevents the downward flow of mud.
Cloth and a nonwoven fabric can be illustrated as a fabric.

  The present invention described above, preferred embodiments of the present invention, and components included in these can be implemented in combination as much as possible.

According to the present invention, it is possible to obtain a groundwater sampling apparatus that can be used at a deep depth and can directly collect the groundwater in the original position from a geological layer that is not disturbed by drilling or other excavation work.
Since the groundwater sampling apparatus according to the present invention does not use a filtering means or a fine strainer that covers the sampling port, the sampling port is rarely clogged with mud or the like. Moreover, the groundwater sampling apparatus is easy to handle.

  In ground excavation work by drilling, etc., groundwater can be sampled for each groundwater aquifer by collecting water from groundwater aquifers with different underground depths using this groundwater sampling device.

  Hereinafter, a groundwater sampling apparatus according to an embodiment of the present invention will be further described with reference to the drawings. The dimensions, materials, shapes, relative positions, etc. of the members and parts described in the embodiments of the present invention are not intended to limit the scope of the present invention only to those unless otherwise specified. It is just an illustrative example.

  FIG. 1 is an explanatory diagram of the groundwater sampling apparatus 1 mainly having a basic configuration, and FIG. 2 is an enlarged explanatory diagram of a connecting portion between the compressed gas supply pipe 47 and the water guide inner pipe 31.

  The main body of the groundwater sampling apparatus 1 includes a substantially cylindrical sampling container 11 and a substantially cylindrical plug 21. The plug 21 is provided so as to protrude downward from the bottom surface of the water sampling container 11. A water sampling port 22 is opened on the side surface of the plug 21, and an upper opening 24 is opened on the upper end surface of the plug 21. Inside the plug 21, there is provided a water conduit 25 that is a cylindrical cavity of the plug 21 that connects the water sampling port 22 and the upper opening 24.

  Inside the water sampling container 11, the water guide inner pipe 31 is arranged in the vertical direction, and the lower end of the water guide inner pipe 31 is connected to the upper opening 24 of the water guide pipe portion 25. The water guide inner pipe 31 has an inner pipe opening 32 that opens into the water sampling container 11 above the water sampling container 11. The inner pipe opening 32 is a hole opened in the side wall of the water guide inner pipe 31. As another embodiment of the inner pipe opening 32, an upper end opening of the water guide inner pipe 31 can be cited. The inner pipe opening 32 is usually located above half of the height of the water sampling container 11, and preferably above 2/3 of the height.

  Since it is configured as described above, the groundwater flowing from the water sampling port 22 passes through the water guide pipe part 25, the upper opening 24, and the water guide inner pipe 31, and is stored in the water sampling container 11 from the inner pipe opening 32. The

  A pumping pipe 41 is provided through the wall surface of the water sampling container 11. The pumping port 42, which is an opening portion in the water sampling container 11 of the water pumping pipe 41, is normally disposed at the lower part of the water sampling container 11, and is preferably positioned at a position that is substantially in contact with the bottom bottom inner surface of the water sampling container 11. The water collection container outer end 43 of the pumping pipe 41 may be positioned above the outer bottom surface of the normal water collection container 11. This is because pumping through the pumping pipe 41 is usually intended for drainage and rinsing of the initial stored water mixed with mud. Pumping water through the pumping pipe 41 is intermittently performed several times, and then the entire groundwater sampling apparatus is pulled up to the ground surface with the groundwater stored in the sampling container 11, and the stored groundwater is used as a sampling sample.

  However, it is preferable that the water collection container outer end 43 of the water pump 41 is extended to the ground surface. When extended to the ground surface, the progress of rinsing of the initial reservoir water can be visually confirmed. Moreover, the groundwater pumped up through the pumping pipe 41 may be used as a water sample. Further, a drainage container may be attached to the water collection container outer end 43 located in the borehole to hold the groundwater pumped up intermittently.

  The compressed gas supply pipe 47 is one of pumping means. One end of the compressed gas supply pipe 47 is connected to a high pressure gas discharge port such as a high pressure gas cylinder or a compressor placed on the ground surface via a pressure regulator. Nitrogen, helium, argon, carbon dioxide, air, etc. can be used for the kind of gas, and nitrogen, helium, argon, etc. which are inert gas are preferable. Usually, a three-way valve is attached to an appropriate position of the compressed gas supply pipe 47, and the pressure in the water sampling container 11 and the release to the ambient atmospheric pressure are performed by operating the valve.

  With reference to FIG. 2, the water guide inner pipe 31 in the water sampling container interior 11 a extends upward from the position where the inner pipe opening 32 is opened, and has an upper extension portion 33. An upper end portion of the upper extension portion 33 is an upper end 34. On the other hand, the lower end portion of the compressed gas supply pipe 47 has a receiving hole into which the upper extension portion of the water guide inner pipe 31 is inserted. The opening 48 of the compressed gas supply pipe 47 is in contact with the upper end 34 of the water guide inner pipe 31. With such a configuration, since the compressed gas air supply pipe 47 and the water guide inner pipe 31 are in contact with each other, the water sampling container opening of the compressed gas air supply pipe is substantially the inner pipe opening 32. Since the compressed gas supply pipe 47 and the water sampling port 22 are directly connected, mud that has entered the water introduction inner pipe 31, the water conveyance pipe portion 25 in the plug, and the water sampling port 22 can be pushed out by supplying compressed gas. .

  As another pumping means, a decompression source may be placed at the tip 43 of the pumping pipe 41 via a sealed container. For example, an oil rotary pump or a vacuum cleaner may be used as the decompression source. Usually, a four-way valve is attached to the tip 43 of the pumping pipe 41 via a sealed container, and by operating the valve, the water sampling container is decompressed, opened to the surrounding atmospheric pressure, and the pressure is maintained.

  If the water sampling container 11 is depressurized, water sampling from the water sampling port 22 is promoted. When water sampling promotion and intermittent pumping are used in combination, a pressure reducing pipe for connecting the water sampling container 11 and the above-ground part may be provided in addition to the water pumping pipe 41. When the pumping pipe 41 is depressurized as a depressurizing means, the sampling is performed under a reduced pressure. After the sampling, the depressurization is temporarily canceled and the groundwater that has entered the pumping pipe 41 is returned to the sampling container 11, and then the pumping is performed. You may perform operation to do.

  Since the pumping pipe 41 as the pumping means cannot be pumped up to the ground from a position exceeding a depth of 10 m, it can be changed to another pumping means or the other pumping means can be used in combination with the pumping. .

  As other pumping means, a pump may be provided at an appropriate position of the pumping pipe 41 (the pumping port 42, the sampling container outer end 43, and the middle thereof). From the viewpoint of ease of pumping when using the groundwater sampling apparatus 1 at a deep depth, simplifying the groundwater sampling apparatus 1, and the like, the pumping means is preferably a pressurization of the sampling container 11, and the sampling container 11 The pressurization and the decompression of the pumping pipe 41 are more preferable.

  The inside of the water sampling container 11 is sealed, and the outer periphery of the pumping pipe 41, the compressed gas air supply pipe 47 and the like and the wall surface of the water sampling container 11 are airtight. As a sealing mode in the water sampling container 11, the water sampling container 11 is divided into a main body part and an upper lid part, and a compressed gas air supply pipe 47, a pumping pipe 41, an ammeter lead to be described later, etc. It is preferable to arrange the adapter and screw the main body portion and the upper lid portion. The screwing may be performed by providing flanges on the main body part and the upper lid part, providing through holes in these flanges, and screwing them with bolts and nuts, and screwing on the main body part and the upper lid part. These may be screwed to tighten them.

  The water sampling container 11 and the plug 21 are made of a material that can withstand impact force, pressure, and the like. For example, stainless steel (SUS304 as an example), iron with hard plating, and the like. Also, depending on the purpose of analyzing the collected groundwater, for example, in order to avoid elution of iron elements, the inner wall of the water sampling container 11 and the inner surface of the water conduit 25 are treated with an inert metal or synthetic resin, such as a transfer or coating. May be performed. The water guide pipe 31 is made of, for example, a stainless steel pipe (SUS304 as an example) coated with a synthetic resin, a copper pipe coated with a synthetic resin, or the like.

  The horizontal cross-sectional area of the plug 11 is smaller than the horizontal cross-sectional area of the water sampling container 11. For this reason, there is a step in the connecting portion between the water sampling container 11 and the plug 21, and if the entire plug 21 is driven into the formation immediately below the bottom of the borehole, the stepped portion is moved against the downward movement of the groundwater sampling apparatus 1. It becomes a big resistance.

  The distance from the outside of the bottom of the water sampling container to the tip of the shoe 7 is 270 mm. The water sampling port 22 opens at a substantially middle position above and below the plug. The internal volume of the water sampling container 11 is about 200 ml. A shoe 7 is attached to the tip of the plug 21 to facilitate the pushing of the plug 21 and eventually the groundwater sampling container 1.

  The groundwater sampling container 1 is connected to the rod 6 at the joint 2, lowered to the bottom of the borehole, and collected on the ground. The rod 6 is preferably a boring rod.

  The cross section of the water sampling container and the plug is preferably a circle, but may be a triangle, square, ellipse or the like.

  With reference to FIG. 3, the groundwater sampling apparatus 101 provided with the additional structure is demonstrated. In the groundwater sampling apparatus 101, the same members and the same components as those in the groundwater sampling apparatus 1 illustrated in FIG. Moreover, description is abbreviate | omitted about the same part as the groundwater sampling apparatus 1, and the part and structure which are added in the groundwater sampling apparatus 101 are demonstrated below.

  A movable plate 51 is provided to open and close the water sampling port 22 of the plug 21. The movable plate 51 can move up and down between a moving upper end position indicated by an arrow 52 and a moving lower end position indicated by an arrow 53. When the movable plate 51 moves upward and reaches the moving upper end position (arrow 52), the movable plate 51 completely covers the water sampling port and the water sampling port 22 is closed. When the movable plate 51 moves downward to reach the moving lower end position (arrow 53), the movable plate 51 is separated from the water sampling port 22, and the water sampling port 22 opens. In the case of this embodiment, the movable plate has a cylindrical shape and covers the outer periphery of the plug 21. An O-ring 54 and an O-ring 55 are disposed on the outer wall of the plug 21 immediately above and below the upper end of the water sampling port 22, respectively, and assists the closing of the water sampling port 22 by the movable plate 51.

  The outer wall of the movable plate 51 is formed with horizontal stripe-like irregularities 56 to assist the restraint of the movable plate 51 by ground pressure or frictional force. The movable plate 51 plays a role as long as the pumping port 22 is opened and closed, and does not necessarily have a shape covering the entire periphery of the plug cross section. However, when the sampling port 22 is opened by using the restraint due to the earth pressure of the movable plate 51, that is, by pushing the plug 21 downward and pulling it upward by a certain distance, the shape covering the entire periphery of the plug cross section is formed. It is preferable that The vertical dimension of the movable plate 51 is preferably 25 mm or more, more preferably 35 mm or more. This is to facilitate restraint of the movable plate 51 due to ground pressure or frictional force. Although there is no restriction | limiting in particular in the upper limit of the vertical dimension of the movable plate 51, From a viewpoint of making a plug moderate length, the vertical length of the movable plate 51 is 100 mm or less normally, Preferably it is 75 mm or less, More preferably, it is 50 mm or less. is there.

  In order to know the water storage status in the water sampling container 11, three ammeters which are sensors for detecting the water level are provided. An upper ammeter 61, a middle ammeter 62, and a lower ammeter 63 are arranged on the ground, and electrodes connected to these ammeters by lead wires are provided in the water sampling container 11. That is, one electrode 64 communicated with the upper ammeter 61 is disposed on the outer wall side of the water guide inner pipe 31 and immediately below the inner pipe opening 32. One electrode 65 communicated with the middle ammeter 62 is arranged on the outer wall side of the water guide inner pipe 31 and at a height position near the middle of the height of the water sampling container 11. One electrode 66 communicated with the lower ammeter 63 is disposed on the inner wall side of the water guide inner pipe 31 and below the inner wall bottom surface of the water sampling container 11. In addition, a common electrode 67 which is a pair of electrodes of the three ammeters is attached to the wall surface of the water sampling container. A voltage is applied to a pair of electrodes of the three ammeters from a power supply device (not shown).

  Here, changes in the instructions of the three ammeters will be described as groundwater is sampled, the water is stored in the water sampling container 11, and the stored water is reduced by pumping.

  Water sampling starts with the inside of the water sampling container 11 being empty. At this time, the upper ammeter 61, the middle ammeter 62, and the lower ammeter 63 each indicate a minimum value. When the water level of the water conduit 25 increases and reaches the electrode 66, the lower ammeter 63 indicates the maximum value. When the water level further rises and the ground water overflows due to the opening of the inner pipe 31 of the water guide pipe 31, the electrode 64 gets wet, and the upper ammeter 61 indicates an intermediate value, or the indicated value changes irregularly. When the water storage proceeds and the water level in the water sampling container 11 reaches the electrode 65, the middle ammeter 62 indicates the maximum value. When the water storage further proceeds and the water level reaches the electrode 64, the upper ammeter 61 indicates the maximum value.

  When pumping is started using the pumping pipe 41 at this time, the indicated value of the upper ammeter 61 first decreases as the water level decreases. Subsequently, the indicated value of the middle ammeter 62 decreases. Furthermore, when the pressure in the water sampling container is adopted or used in combination as the pumping means, the water level in the water guide inner pipe 31 is also reduced, and the indicated value of the lower ammeter 63 is lowered.

  Since the water level in the water sampling container 11 can be known as described above, if the capacity corresponding to the height of the electrode 64 and the electrode 65 of the water sampling container is obtained in advance, the time and pressure required for the water level increase. From the above, it is possible to estimate the amount of groundwater and the permeability of the groundwater layer.

  A mud prevention plate that surrounds the outer periphery of the plug 21 on the outside of the plug 21 and moves between a lower end position (indicated by an arrow 12) of the outer wall of the water sampling container and a lower stop position that is a fixed position above the upper end of the water sampling port 22 71 is provided. In the present embodiment, a fabric fixing position 92 to be described later is a lower stop position.

  The mud prevention plate 71 prevents mud staying at the bottom of the borehole from passing through the vicinity of the outer periphery of the plug 21 and reaching the water sampling port 21. The distance between the outer periphery of the plug 21 and the inner periphery of the mud prevention plate 71 is preferably narrow, and more preferably they slide. In the present embodiment, the mud prevention plate 71 has a disc shape with a hole in the center. The mud prevention plate 71 is made of a material such as rubber, hard rubber, synthetic resin, wood or metal.

  The mud prevention plate 71 is urged downward by a coil spring 81 as urging means. The urging means acts to press the mud prevention plate against the hole bottom when the plug 21 moves downward and then moves upward for a short distance. As the biasing means, an elastic body such as a plate spring or urethane foam, a weight, or the like can be used. If foamed urethane is placed in contact with the outer wall of the plug, it can also prevent mud.

  A part of the fabric 91 is fixedly attached to the outer peripheral wall of the plug 21 at a fabric fixing position 92 above the upper end of the water sampling port 22. When the plug 21 is pressed downward and then moved upward for a short distance, the fabric 91 is curled up and clings to the outer peripheral wall of the plug 21, so that the downward flow of muddy water staying at the bottom of the borehole can be prevented. The fabric 91 may be a fabric or a non-woven fabric.

  Next, a groundwater sampling method using the groundwater sampling apparatus 101 will be described with reference to FIG. The groundwater aquifer 97 is shown in the figure. The bore wall 96 is protected by muddy water, the slime at the bottom of the hole is removed, and the ground is mined by mechanical boring to a predetermined depth. Here, the ground excavator is lifted to the ground.

  The groundwater sampling device 101 is connected to the tip of the rod 6 and lowered to the bottom of the hole. At this time, the movable plate 51 is positioned at the upper end position of movement and the water sampling port 22 is closed. Further, nitrogen gas having a pressure corresponding to the depth is sent from the nitrogen cylinder 46 to the groundwater sampling apparatus 101 via the three-way valve 49 and the compressed gas supply pipe 47 to infiltrate the groundwater into the sampling container 11. To prevent.

  Next, the plug 21 is penetrated into the ground by hitting the drive hammer 9 through the knocking block 8 attached to the upper part of the rod 6. Thereafter, the groundwater sampling apparatus 101 is moved upward (extracted) by a distance corresponding to the vertical movement distance of the movable plate 51. By this operation, the movable plate 51 is moved downward relative to the plug 21 and the water sampling port 22 is opened.

  Here, the three-way valve 49 is operated to release the pressurization in the water sampling container 11. Thereby, inflow of groundwater into the water sampling container is started. The water level of the stored groundwater in the water sampling container 11 is monitored by three ammeters, and pumping is performed when the water in the water sampling container 11 becomes full.

  Pumping is performed by operating the three-way valve 49 to pressurize the water sampling container and simultaneously operating the four-way valve 44 to reduce the pressure by the decompression pump 45 to the sealed container 5 and the pumping pipe 41. Normally, mud is mixed in the water pumped into the sealed container 5 by the first pumping operation.

  When the inside of the water sampling container 11 becomes empty and the first pumping is completed, the above water sampling and pumping are repeated several times. Thereby, the part which touches groundwater, such as the inside of the water sampling container 11 of the groundwater water sampling container 101, is rinsed.

  Subsequently, water sampling work is performed. When the inside of the water sampling container 11 is full, the four-way valve 44 is operated to close the water sampling container outer end 43 of the pumping pipe 41. The three-way valve 49 is operated to gently lift the rod 6 while collecting nitrogen gas at the same pressure as when the groundwater sampling apparatus 101 descends, and collect the groundwater sampling apparatus 101 on the ground. During this work, the stored water in the water sampling container 11 enters the pumping pipe 41, but after collecting the groundwater sampling apparatus 101 on the ground, the four-way valve 44 and the three-way valve 49 are operated to enter the pumping pipe 41. What is necessary is just to return water to the water collection container 11. After performing appropriate operations such as washing away mud adhering to the outer wall of the groundwater sampling apparatus 101, the groundwater in the sampling container 11 is taken out. Thus, the water sampling operation in the groundwater aquifer 97 is completed.

  Thereafter, ground mining by mechanical boring is resumed, and groundwater is sampled in the same manner as described above when a predetermined depth has been reached. By repeating this operation, groundwater can be sampled for each groundwater aquifer.

  In the water sampling method using the groundwater sampling apparatus according to the present invention, rinsing of the water sampling container 11 by intermittent pumping is preferable, but intermittent pumping is not always necessary. For example, in groundwater aquifer sampling with a large amount of spring water, groundwater is continuously blown out from the pumping pipe, and therefore, after the initial pumping is discarded, the pumped water may be used as a sample. In addition, in the case where water is collected after washing the muddy water accumulated at the bottom of the borehole, the initial stored water may be used as a sample.

  The embodiment of the groundwater sampling apparatus described above is suitable for a boring hole having a diameter of 86 mm. By changing the design such as changing the dimensions without changing the basic configuration, it is possible to obtain a groundwater sampling apparatus that fits into a 66 mm diameter borehole. A groundwater sampling device that fits into a small diameter borehole can further contribute to savings in survey costs.

  The groundwater sampling apparatus according to the present invention can be used for sampling groundwater in a sampling zone (by depth) used for the development of water source wells, investigation and elucidation of groundwater contamination problems, and the like.

It is explanatory drawing of the groundwater sampling apparatus 1 mainly provided with the basic composition. 4 is an enlarged explanatory view of a connection portion between a compressed gas supply pipe 47 and a water guide inner pipe 31. FIG. It is explanatory drawing of the groundwater sampling apparatus 101 provided with the additional structure. It is explanatory drawing of the groundwater sampling method which uses the groundwater sampling apparatus 101. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 Groundwater sampling apparatus 2 Joint part 5 Sealed container 6 Rod 7 Shoe 8 Knocking block 9 Drive hammer 11 Sampling container 11a Sampling container inside 12 Lower end 21 of sampling container Plug 22 Sampling port 24 Upper opening 25 Water guide pipe part 31 Water guide inner pipe 32 Inner pipe opening 33 Upper extension 34 of water guide inner pipe 31 Upper end 41 of water guide inner pipe 31 Water pump pipe 42 Water pumping port 43 Water sampling container outer end 44 Four-way valve 45 Pressure reducing pump 46 Nitrogen cylinder 47 Compressed gas feed Trachea 48 Compressed gas air pipe opening 49 Three-way valve 51 Movable plate 52 Moving upper end position 53 Moving lower end position 54 O ring 55 O ring 56 Concavity and convexity 61 Upper ammeter 62 Middle ammeter 63 Lower ammeter 64 Upper electrode 65 Middle electrode 66 Lower electrode 67 Common electrode 71 Mud prevention plate 81 Energizing means 91 Fabric 92 Fabric fixing position 96 Boring hole 9 Groundwater aquifers

Claims (8)

A groundwater sampling device for sampling groundwater,
A water sampling container which is a sealed container;
A plug that protrudes downward from the water sampling container, has a water sampling port and an upper opening, and has a water conduit pipe part that conducts the water sampling port and the upper opening;
A water guide inner pipe that is housed inside the water sampling container, connected to the upper opening, and having an inner pipe opening positioned at an upper part in the water sampling container;
A pumping pipe that is connected to the outside of the water sampling container and a water pumping port positioned in the lower part inside the water sampling container;
Groundwater that flows in from the water sampling port, passes through the water conduit and the water conduit inner pipe, passes through the inner pipe opening, and accumulates in the water sampling container is pumped to the outside of the water sampling container through the water pump. Equipped with pumping means for
The water sampling port is open on the side of the plug ,
Horizontal cross-sectional area of the plug, rather small compared to the horizontal cross-sectional area of the water sampling container,
A movable plate that is provided on a side surface of the plug and that moves up and down, covers the water sampling port at a moving upper end position of the vertical movement, and opens the water sampling port at a moving lower end position of the vertical movement. Groundwater sampling device provided . The groundwater sampling system according to claim 1, wherein a compressed gas air supply pipe that opens into the water sampling container and is electrically connected to the ground is provided, and the pumping means is pressurized derived from the compressed gas. Water equipment. The inner pipe opening is located on a side wall of the water guide inner pipe;
The water guide inner pipe extends upward from the inner pipe opening,
The groundwater sampling apparatus according to claim 2, wherein the opening of the compressed gas supply pipe is in contact with an upper end portion of the water guide inner pipe. The groundwater sampling apparatus according to any one of claims 1 to 3, further comprising a sensor for detecting a water level in the sampling container. The sensor is composed of an upper ammeter having a pair of electrodes, a middle ammeter, and a lower ammeter,
One electrode of the upper ammeter is provided immediately below the inner tube opening of the outer wall of the water guide inner tube,
1 electrode of the lower ammeter is provided in the vicinity of the lower end of the water guide inner pipe of the water guide inner pipe inner wall,
One electrode of the middle ammeter is provided at a position on the outer wall of the water guide inner pipe in a vertical relationship between the position of the first electrode of the upper ammeter and the position of the first electrode of the lower ammeter. The groundwater sampling apparatus according to any one of claims 1 to 4, wherein the groundwater sampling apparatus is provided.   A mud prevention plate surrounding the outer periphery of the plug and moving between a lower end position of the water sampling container and a lower stop position above the upper end of the water sampling port is provided outside the plug. The groundwater sampling apparatus according to any one of claims 1 to 5.   The groundwater sampling apparatus according to claim 6, further comprising an urging means for urging the mud prevention plate toward the lower stop position.   The groundwater according to any one of claims 1 to 7, wherein a part of the fabric is fixedly attached to the outer peripheral wall of the plug at a fabric fixing position above the upper end of the sampling port. Water sampling device.

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