JPH0369793A - Device and method of measuring groundwater - Google Patents

Abstract

PURPOSE:To measure an accurate physical value for a prolonged term by fixing a measuring section with a sensor for measuring a physical value into an excavated pit by upper and lower packers and comparing the physical value measured by the sensor and the physical value of groundwater pumped up by a pump. CONSTITUTION:A boring 4 is lowered into a groundwater measuring device 1, water is injected to upper and lower packers 9, 10, and the packers 9, 10 are expanded, and fastened at the position of measurement in the boring 4. A storage pump 7 is driven, and groundwater in the periphery of a measuring section 6 is sampled while the physical value of groundwater is measured by the measuring section 6. Physical values measured by each measuring section of a pressure measuring section 11, a water-temperature measuring section 12, a conductivity measuring section 13, a pH measuring section 14 and a redox- potential measuring section 15 are frequency-modulated through a control circuit, and transmitted onto the ground. These physical values and the physical value of groundwater sampled are compared. Accordingly, an accurate value can be determined from the displacement of each physical value.

Description

Detailed Description of the Invention "Industrial Application Field" This invention relates to the use of groundwater that is inserted into a borehole such as a poling hole drilled underground to measure the physical properties of groundwater inside the borehole. The present invention relates to a measuring device, and particularly to a groundwater measuring device and a groundwater measuring method capable of measuring accurate physical property values over a long period of time.

"Conventional technology" When conducting a safety assessment (impact assessment) of a structure built deep underground, it is essential to investigate the groundwater flowing around the structure. Holes are drilled and a large number of measurement points are set up to measure various physical properties of groundwater over a long period of time. Therefore, various measurement devices for measuring physical property values of groundwater in boreholes have been proposed and implemented. An example of such a measuring device is a device that samples groundwater from a polling hole through a water sampling port fixed in the polling hole by upper and lower packers, and measures various physical property values using sensors installed above ground. ,
Alternatively, there is a device in which a casing is inserted into a polling hole and fixed with a plurality of packers, and a sensor is placed inside the casing to measure various physical property values inside the polling hole.

``Problems to be Solved by the Invention'' However, with the conventional measuring device in which the water sampling port is installed in a polling hole, the water in the hole in the section partitioned by the packer is not the original in-situ groundwater, so immediately after the water sampling starts. Water (after one to several days) cannot be used as data and requires a long time before it can be measured. Therefore, when continuous water sampling is performed for a long period of time, groundwater that flows from the surrounding ground into the hole can be used as data. As a means of confirming that the groundwater has been replaced with the original in-situ groundwater, judgments were made by constantly monitoring water quality and reading changes in physical property values. However, in such a method, the following problems remain.

■ Even if the hole is partitioned with two packers and water is sampled continuously, the water quality in the space partitioned by these packers may not be completely replaced, and old water may remain in some parts, and the water quality sensor may There are concerns about reliability because even if the space is monitored, it does not necessarily mean that the groundwater is being sampled.

■ If the water pump continues to draw water at a constant rate, the groundwater pressure in the space partitioned off by the packer will drop rapidly if the water sampling speed is higher than the groundwater supply rate from the surrounding ground. , 02, CO2 dissolved in groundwater
etc. will change and the physical property values will no longer be indicated.

■ If groundwater contains many components such as sulfides, these components will adhere to, precipitate, or corrode the electrodes of PH sensors and redox potential sensors, causing them to no longer show correct physical property values. .

■ There are concerns about the reliability of the depth value of the water sampling location.

■ If the hole is bent due to the long overall length of the device,
There is a possibility that it cannot be inserted smoothly into the hole.

In addition, with conventional measuring devices in which the casing is fixed in the polling hole, the diameter of the casing is predetermined, making it difficult to accommodate polling holes of arbitrary diameter. I was unable to provide the sample bottle and had to lower it into the designated space several times.
Since the only method available is to sample water one bottle at a time, it is impossible to sample a large amount of water continuously.Also, some of the physical properties of Sunflu, such as water temperature, may change before being measured at the ground surface. The problem was that there were some things that I ended up doing.

"Means for Solving the Problem" A first aspect of the present invention is a groundwater measuring device that is inserted into an excavation fL excavated underground and measures physical property values of groundwater in the excavation hole. A measuring section equipped with a sensor for measuring physical property values, expandable packers disposed above and below the measuring section, and a pumping system for pumping groundwater flowing into the space partitioned by these packers to the surface. It is characterized by comprising a pump and a transmitting means for transmitting measurement signals from the sensor to the ground.

Further, as a second aspect, in the ground water measuring device of the first aspect, a pressure sensor that detects the water pressure around the lift pump, and a detection signal detected by the pressure sensor, a pressure sensor that detects the water pressure around the lift pump. It is characterized by being provided with a control device that controls the amount of drive.

Moreover, as a third aspect, the groundwater measuring device of the first or second aspect is characterized in that a bending member configured to be bendable within a free surface is provided.

Moreover, as a fourth aspect, in the groundwater measuring device according to the first to second aspects, a cleaning mechanism is provided for cleaning the surface of the sensor for measuring physical property values provided in the measuring section. There is.

In addition, as a fifth aspect, when measuring physical property values of groundwater in a borehole drilled underground, physical property values measured by measurement signals from a sensor for measuring physical property values provided in a measurement unit. The method is characterized in that it is compared with the physical property values of groundwater pumped by a water pump.

Furthermore, as a sixth aspect, when detecting the reach depth of a groundwater measuring device that measures the physical property values of groundwater, pressure data detected by a pressure sensor provided in a measuring unit and pressure data from the ground surface to the groundwater measuring device are used. This method is characterized by comparing the cable wire length data obtained by measuring the length of the cable.

"Operation" In the first aspect of the groundwater measuring device of the present invention, the diameter of the groundwater measuring device is reduced by shrinking the packers disposed above and below the measuring section, so that the diameter of the groundwater measuring device can be reduced. It is ready to be inserted into. The groundwater measuring device inserted into the borehole in this state presses the wall surface of the borehole by extending the packer in the radial direction at a predetermined position, and is fixedly supported within the borehole by the reaction force. Then, the measurement unit can measure the physical property values of the groundwater that has flowed between the bunkers.

The measurement signal detected by this measurement unit is then sent to the earth's surface by the transmission means. In the second aspect, the pressure sensor detects the water pressure around the water pump,
Based on the detection signal sent from the pressure sensor, the control device controls the driving amount of the water pump, so that the amount of groundwater flowing between the packers and the amount of groundwater pumped by the water pump are balanced. It will be planned.

In addition, in the third aspect, the groundwater measuring device as a whole is held bendably by the bending member configured to be able to bend freely within the free surface, so that the device is bent in accordance with the bending of the excavation hole. inserted into the borehole.

Further, in the fourth aspect, the bending member allows the device to be freely bent, and the cleaning mechanism cleans the surface of the sensor for measuring physical property values provided in the measurement unit, so that the sensor has good sensitivity. maintained in good condition.

In addition, in the fifth aspect, by comparing the physical property values detected in the borehole with the physical property values measured after the water is pumped by the pump, it is possible to determine the difference between the physical property values and the physical property values. The exact value is easily known.

In the sixth aspect, the pressure data detected by a pressure sensor provided in the measurement unit and the cable line length data obtained by measuring the length of the cable from the ground surface to the groundwater measuring device are combined. By comparing the above, it is easy to determine the more accurate depth reached by the groundwater measuring device from the discrepancies in each data.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 to 5 are diagrams showing a groundwater measuring device according to a first embodiment of the present invention. In these figures, what is indicated by the symbol l in its entirety is a groundwater measuring device (hereinafter simply referred to as a "measuring device") according to an embodiment of the present invention, and this measuring device l is formed as a whole into an elongated rod shape,
As shown in FIG. 1, a wire 5 is suspended from a tower 3 installed on a car 2 into a poling hole (excavation hole) 4 excavated perpendicularly to the ground G. This polling hole 4 is provided around a structure (not shown) built in the ground, and the depth of one polling hole 4 is, for example, 1000 mm.
It is said to have a deep depth of about 1.5 m.

As shown in FIG. 1, the measuring device 1 includes a measuring section 6 equipped with various sensors for measuring physical property values of groundwater, a pump 7 provided on the upper part of the measuring section 6, and a pump 7 provided at the bottom of the pump 7 and a measuring section 6. Each is provided at the bottom of part 6! The two upper packers 9, the lower backer 1O, and a flexible pipe P provided above and below the measuring section 6 to provide flexibility are generally configured to be coaxially connected. In addition, this measuring device 1 includes the measuring section 6, the pump 7, and the upper part.
A control means for controlling the lower backer 9 and IO and storing various physical property values measured by the measuring section 6 is provided.

As shown in FIG. 2, the measuring section 6 includes a pressure measuring section 11, a water temperature measuring section 12, a conductivity measuring section 13, and a pi-1 measuring section 14.
and an oxidation-reduction potential (El+) measuring section 15. The configurations of each measuring section 11-15 are approximately the same, and are housed in a cylindrical casing in which a water intake is formed, a sensor is provided protruding from a pressure-resistant case housing a circuit section, and It has a configuration in which a common direct current M, a source, and a cable for transmitting signals are connected (not shown). Therefore,
In the following explanation, only the TL 4 degree measuring section 13 will be explained. In this embodiment, the casing is divided into two parts along the axial direction, and the circuit section and the sensor are fixed to one of the divided casings. In addition, a control circuit is incorporated in the circuit section, and this control circuit 1 performs measurements using a sensor in response to remote control signals from the ground, and performs frequency modulation (FM) on various physical property values measured by the sensor. It has the function of being placed in the DC power supply and carried on the cable.

As shown in FIG. 3, the conductivity measuring section 13 includes a circuit section 37.
It is comprised of a pressure-resistant case 38, a sensor portion 39 protruding from the pressure-resistant case 38, and a common DC power cable 40 connected to this circuit section. This sensor section 39 is a so-called electromagnetic induction type liquid conductivity measurement sensor, and has an annular core 42 made of a highly permeable material such as permalloy inside a cylindrical case 41 made of a non-conductive, non-magnetic material. Four cores are arranged with the same axis, and a through hole 43 is bored in the case 41 so as to pass through the central opening of these cores 42. Conductive wires (not shown) are wound around the cores 42, . connected to an amplifier) and an amplifier. Therefore, an alternating current voltage is applied to the primary coil by an oscillator within the circuit section. −Next coil,
The secondary coil and the groundwater in the through hole 43 and the sensor N
In the loop formed by the groundwater surrounding the outer circumference of 39,
Since a current proportional to the conductivity of the groundwater is generated by electromagnetic induction, the conductivity of the groundwater in the through hole 43 can be measured by detecting this with the secondary coil and extracting it as a voltage signal.

Here, since the conductivity measurement sensor portion 39 of this embodiment is provided with four cores 42 (that is, coils),
Even substances with low conductivity such as groundwater can be measured with high precision, and the overall configuration can be made compact. In other words, a normal electromagnetic induction type conductivity sensor has a configuration including one primary coil and one secondary coil, and the principle of the electromagnetic induction type sensor is to measure conductivity using voltage as described above. Therefore, the voltage of the secondary coil becomes low when measuring a substance with a low current of 4 degrees, such as groundwater. Therefore, in order to improve the measurement accuracy of conduction disease, it is necessary to increase the saturation magnetic flux of the primary coil and increase the number of turns of the secondary coil. This makes it difficult to apply it to narrow places such as the polling hole 4. Therefore, in this embodiment, the accuracy of measuring conductivity is improved by providing four coils without increasing the outer diameter of the sensor part 39, and it is possible to measure conductivity in groundwater within the polling hole 4. This is what I did.

On the other hand, as shown in FIG. 4, the water pump 7 includes a cylinder 20 formed in a cylindrical shape and open at both ends, and a disk-shaped piston 2 disposed in a liquid-tight manner within the cylinder 20.
1, a piston rod 22 protruding from the upper and lower surfaces of the piston 21, a drive mechanism 23 that reciprocates the piston 21 within the cylinder 20 by reciprocating the piston rod 22 in the axial direction, and the cylinder 21. It is generally composed of suction and discharge mechanisms 24 and 24 provided at both open ends of the pump 20.

A communication hole 20 is provided in the side surface of the cylinder 20 to communicate with the inside.
b, 201+ are drilled and serve as holes for venting air when the water pump 7 is started. Further, the piston 21
is formed by carving grooves with a cylindrical cross section on the side surface of a disc-shaped member having a diameter slightly narrower than the inner diameter of the cylinder 20,
An O-ring 25 is fitted into this groove to ensure liquid tightness with the inner surface of the cylinder 20. Further, the piston rod 22 extends from the center of the upper and lower surfaces of the piston 21 along the axial direction of the cylinder 20, and is disposed to pass through the suction and discharge mechanisms 24 and 24.

This suction/discharge mechanism 24 includes a main body 24a having a cylindrical external appearance and a suction check valve 26 and a discharge check valve 27 coaxially provided therein. That is, in the main body 24j,
A through hole 28 having a slightly larger diameter than the piston rod 22 is bored in the center thereof, and a through hole 29 is also bored along this axis at a position slightly offset from the axis. , the water pump 7 is arranged in the polling hole 4 and has a three-stage configuration whose diameter narrows as it goes downward. This through hole 29 has a communication hole 3 in the middle thereof which communicates with the through hole 28 in the center of the main body 24.
0 is formed, and each step 29 of the through hole 29!
, 29b are arranged with poles 31, 32 that fit therewith, and these poles 31, 32 are arranged above the poles 31, 32.
The suction check valve 26 and the discharge check valve 27 are closed by disposing springs 33 and 34 in the through hole 29, respectively, to bias the suction check valve 26 and the discharge check valve 27 downward. In the case of this embodiment, the check valve located at the upper part of the suction and discharge mechanism 24 is used as the discharge check valve 27, and the check valve located at the lower part is used as the suction check valve 26. The open end of the suction check valve 26 is opened to the outside through the measuring section 6 equipped with various sensors, and the pressure feed pipe 35 is connected to the open end of the discharge check valve 27. The tip of No. 35 is connected to a water quality meter on the ground.

The drive mechanism 23 connected to the piston rod 22 is waterproof and
It is housed in a casing 36 having a pressure-resistant structure. The drive mechanism 23 includes a motor 37 as a drive source, a control circuit 38 that supplies power to the motor 37 in response to a remote control signal from the ground, and a control circuit 38 connected to the output end of the motor 37.
-H, speed @39 and the rotating shaft 40 which is the output end of the reducer 39
and engages with a screw 40 formed at the tip of the rotating shaft 40,
Moreover, it is approximately separated from the threaded portion 41 connected to the tip of the piston rod 22.

In FIG. 4, reference numeral 42 is an underwater connector to which a power source is connected, reference numeral 43 is a connecting member that connects the casing 36 and the suction/discharge machine tR24 located above, and reference numeral 44 is a suction/discharge unit located below. It is a rod cover provided at the lower end of the mechanism 24, and a through hole (not shown) is bored at a position facing the open end of each of the check valves 26 and 27 of the connecting member 43 and rod cover 44, respectively. . Similarly, through holes (not shown) are formed at positions facing the open ends of each of the check valves 26 and 27 of the cylinder 20, respectively.

Further, the upper backer 9 and the lower backer IO are roughly constructed from a stretchable bag body and an injection mechanism (both not shown) for injecting water into the bag body.

Furthermore, the flexible pipe P is a pipe formed from an elastically deformable material, and is configured to be freely bendable within a free surface.

Next, with reference to FIG. 1, a method for measuring groundwater in the polling hole 4 using the groundwater measuring device 1 having the above configuration will be described.

First, using a poling device, poling holes 4, . . . are excavated around a structure (-not shown) to be constructed in the ground. In this case, the poling holes 4, . . . the poling device for excavation may be of a well-known type, and no special device is required.

Next, the measuring section 6, the water pump 7, and the upper and lower packers 9.10. A groundwater measuring device 1 is assembled by connecting flexible pipes P on the ground, suspended by a tower 3 via a wire 5, and gradually lowered into a polling hole 4. When the measuring device 1 reaches the depth to be measured, water is injected into the upper and lower backers 9 and 10 to expand the upper and lower backers 9 and 10 so that they contact the inner wall surface of the polling hole 4. Let them come into contact with you. As a result, the entire measuring device l is fixed within the polling hole.

In this state, the operation of the water pump 7 is started, and the measuring device l
Groundwater will be sampled in the area where the area is located. That is, after the water pump 7 is fixed, the motor 37 is driven via the control circuit 38 in response to a command from the ground. This motor 3
The driving force of 7 is decelerated by the speed reducer 39, then transmitted as the rotational force of the rotating shaft 40, and converted into a linear motion by the screw 40 at the tip of the rotating shaft 40 and the threaded part 41, and the piston ron F 22 It moves back and forth.

As the piston rod 22 reciprocates, the piston 21 also reciprocates within the cylinder 20, which causes the measuring section 6 to move back and forth.
Surrounding groundwater can be sampled. Specifically, the piston 21
Due to the reciprocating movement of the piston 21, the cylinder chambers 45 and 45 formed above and below the piston 21 are alternately compressed and expanded. Groundwater flows in through the gap between the cylinder chamber 45 and the hole 28, and the cylinder chamber 45 is filled with groundwater. Next, the cylinder chamber 45 filled with groundwater
When the groundwater contracts, this groundwater passes through the gap between the main body 24a and the through hole 28 and the communication hole 30, reaches the discharge check valve 27, and is pumped from the check valve 27 toward the pressure feed pipe 35. Therefore, due to the reciprocating motion of the piston 21, the groundwater around the measuring section 6 is forced to be sent to the water quality meter on the ground via the pressure feeding pipe 35, and various physical property values are measured by this water quality meter.

On the other hand, the pump 7 samples groundwater through the measuring section 6, and at the same time, the measuring section 6 measures the physical property values of the groundwater. First, a remote control signal is sent from the ground, and physical property values are measured by each predetermined measuring section 11-15. The physical property values measured by each measuring section 11-15 are
It is frequency modulated via the control circuit in the circuit section 15, superimposed on the DC power supply, and transported to the ground via cable.

A method of conveying commands and physical property values using remote control signals will be specifically explained. Each measuring section 11-15 has its own unique calling frequency, and the control means installed on the ground superimposes a frequency signal corresponding to each measuring section 11-15 to be activated on the DC power supply and sends it via a cable. and polling (calling) each measuring section 11-15. Each of the polled measurement units 11-15
Correspondingly, the physical property values measured by the sensor are transmitted in frequency modulated form. A specific frequency band is assigned to each physical property value, and the physical property value is exited in a range corresponding to the band width.

In this case, unless the plurality of measuring units 11 to 15 are polled simultaneously, the frequency bands for transmitting the physical property values may be set to overlap, and may be appropriately determined in consideration of the characteristics of the cable and the like.

After measuring the physical property values of groundwater for a predetermined period, the upper and lower backers 9 and 10 are contracted, the measuring device fit1 is pulled out from the polling hole 4, and the measuring device 1 is inserted into the next polling hole 4. In this way, the physical property value of groundwater around the building m! j is determined.

Therefore, in the measuring device 1 of this embodiment, since the measuring section 6 equipped with a sensor is provided between the upper and lower packers 9 and 10, when the measuring device 1 is inserted into the polling hole 4, the measuring device 1 is placed at that position. Physical property values of groundwater can be directly determined in+1, and measurement errors are small. Furthermore, since the measuring device 1 is fixed in the polling hole 4 by the packers 9 and 10, which can be freely compressed, reliable measurement can be performed regardless of the diameter of the polling hole 4. In addition, as shown in FIG. 5, when the inside of the hole into which the measuring device L is to be inserted is bent, the flexible vibe P is bent as appropriate according to the bent state and the entire measuring device is bent. A measuring device l can also be inserted into the hole 4.

Furthermore, the water pump 7 of this embodiment has a configuration in which suction/discharge machines gt24, 24 are provided at both ends of the cylinder 20, so unlike conventional pumps, groundwater is pumped during the entire process of the reciprocating movement of the piston 21. This makes it possible to sufficiently increase the pumping efficiency. This makes it possible to collect groundwater from deep depths of around 1000a+ or more, while also making it possible to collect groundwater from a depth of about 1000a+ or more.
Even if the outer shape of the cylinder 20 is limited so that it can be inserted into the cylinder 20 at a distance of about 100 mm, it is possible to realize a water pump 7 that can ensure sufficient pumping capacity. In addition, when using the measuring device fl of this embodiment, when there is no bend in the excavation hole,
It is also possible to adopt a configuration in which 13 flexible pipes P are omitted.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. In this embodiment, parts having the same configuration as those in the previous embodiment are given the same reference numerals, and the explanation thereof will be omitted.

The measuring device 1 of this embodiment includes a pressure sensor 11 for detecting the water pressure around the water pump 7, and a pressure sensor 11 for detecting the water pressure around the water pump 7.
A control device is provided to control the driving amount of the water pump 7 based on the detection signal detected by the pump.

In FIG. 6, the symbol ■ indicates a control system placed inside the polling hole 4, and the symbol ■ indicates a control system installed on the ground surface.

The control system I includes a pressure sensor 11 that detects the groundwater pressure in the polling hole 4, a pump 7, a motor that drives the pump 7, and a control circuit that controls the amount of drive of the motor. It becomes.

In addition, the control system (2) includes a transmitting/receiving section that receives the detection signal (2) from the pressure sensor 11, and a control converting section that receives the pressure data (2) from this transmitting/receiving section and calculates the optimal drive amount of the water pump 7. and a voltage control section that receives the conversion signal (2) from the control conversion section and transmits the drive data (2) to the control circuit in the polling hole 4.

In the measurement device #l equipped with such a control system, the pressure gauge in the polling hole 4 detects the absolute pressure of the groundwater between the backers, and sends the data to the ground surface via a cable. The pressure gauge signal is received by the transmitter/receiver, converted into a digital signal, and displayed or printed out by the control converter. The control conversion unit is composed of a personal computer, a display device such as a CRT or LCD, a printer, an input keyboard, and the like.

On the other hand, the center value and allowable variation range of pressure are input from the keyboard. The pump drive motor is driven by a DC voltage supplied from the voltage control unit via a cable.

The DC power supply voltage is set within the set range (
The voltage is increased or decreased by the voltage control unit so that the voltage falls within the range (PQ-JP-P, +JP).

That is, as shown in FIG. 7, P×P. When the voltage is 10 JP, the voltage is maintained as it is, but when P<20 JP, the voltage is gradually increased, and when P=P, the voltage is fixed. Further, when P>P, +JP0, the voltage is gradually lowered, and when P=P, -), the voltage is fixed. This determination is made within the control converter and instructs the voltage controller to increase or decrease.

Next, a third embodiment of the groundwater measuring device 1 of the present invention will be described with reference to FIG. 8. In this embodiment, parts having the same configuration as those in the previous embodiment are given the same reference numerals, and the explanation thereof will be omitted.

The measuring device 1 of this embodiment is configured to include a cleaning mechanism 50 that cleans the surface of a sensor for measuring physical property values provided in the measuring section 6.

As shown in Figure VgB, this cleaning mechanism 50 includes a polishing member 51 made of circular ceramic, for example, and a worm wheel 52 that supports the polishing member 51 rotatably around its central axis. This worm wheel 52
It is generally constituted by a worm gear 53 and a drive motor 54 that are screwed together to provide driving force, and a control circuit 55 that controls the amount of drive of the drive motor 54.

The drive motor 54, the control circuit 55, and the lower end of the worm wheel 52 are covered by a substantially sealed casing 56, and the worm wheel 52 is held in close contact with the upper part of the casing 56 so as to be rotatable. A bearing portion 57 is provided. Also, casing 5
6, a position detection sensor 59.59 is installed below the worm wheel 52. Further, the polishing member 51 is urged upwardly by the worm wheel 52 by a spring 58. This cleaning mechanism 50 is
It is arranged below the electrode section of the sensor provided in the measurement section 6.

When using this cleaning mechanism 50, a polishing member 5 is used as appropriate to remove impurities that have adhered to or precipitated on the senna.
However, especially in the case of a large depth, more force is required to make the polishing member 51 protrude, so a drive method using two drive motors may be used.

Measuring device of this example! ! In l, when measuring the physical property values of groundwater in the polling hole 4, if sulfides etc. adhere to or precipitate on the sensor, these substances are removed by operating the cleaning machine t, η50. can do. At this time, when the electrode tip is polished, it becomes very slightly shortened, but the spring 5 provided on the polishing member 51
8, so there is no problem. By using the cleaning mechanism 50 of this embodiment in this way, the surface of the sensor can always be maintained in a good condition.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 9. The measuring device 1 of this embodiment is further provided with a measuring section 60 installed on the ground surface. This measuring section 60 includes a measuring section main body 61 that sucks in and discharges groundwater pumped by the pump 7, and a measuring circuit 65 provided in the measuring section main body 61 with sensor sections 62, 63, and 64 protruding from the measuring section main body 61. It is roughly composed of:

The measurement unit main body 61 is an airtight container with an approximately box-like appearance, and a suction hole 66 for sucking groundwater pumped by the water pump 6 is formed at the lower side of the main body 61, and a suction hole 66 is formed at the upper side of the side opposite to the above-mentioned side. A discharge hole 67 is formed in which drains the groundwater sucked in from the suction hole 66. The shape and internal volume of the measuring section main body 61 are taken into consideration in consideration of the relationship with the amount of spring water from the pump 7, so that underground water can flow easily, and the capacity is as small as possible. Further, it is desirable that the measurement section main body 61 be constructed using a transparent material so that the inside can be seen through.

The sensor sections 62, 63, 64 extending from the measurement circuit 65 are
It is set so that it penetrates the upper surface of the measuring section main body 61 and its tip protrudes into the measuring section main body 61. At this time, the sensor units 62, 63, and 64 are arranged so as to obtain more accurate measurement values. In other words, water temperature and conductivity are closely related, so they are made to be as close as possible. The hole 68 in the middle of the conductivity sensor section 63 is oriented in a direction through which groundwater can easily pass. It is preferable that the electrode sensors (PH, 0RP), etc., where the internal liquid oozes out, be placed in positions where they are measured in the rear order.

In the measuring device 1 of this embodiment, the physical property values measured at the measurement unit 6 position in the polling hole 4 are compared with the physical property values measured by the measurement unit 60 on the ground surface after spring water is pumped by the spring water pump 7. By doing so, the reliability of measuring the physical property values of groundwater can be improved.

Next, a fifth embodiment of the present invention will be described with reference to FIG. 10. The measuring device of this embodiment uses a measuring device 70 for measuring the cable line length of the cable 5 from which the measuring device 1 is fed out in order to accurately grasp the depth reached by the measuring section 6.
It is configured with the following.

As shown in FIG. 10, this jllll measuring device 70 includes a winch drum 71 for winding the cable 5, a measurement pulley 72 provided near the winch drum 71, and a winch drum 71 and measurement pulley 72. It is composed of a base 73 that is rotatably held.

The cable 5 is wound around the winch drum 71 via this measuring pulley 72, and the cable 5 is also let out. Then, the number of rotations of the measurement pulley 72 is integrated by a calculation means (not shown) to obtain the cable length. Moreover, the feeding speed of the cable 5 can be calculated by differentiating the rotation of the measuring pulley 72.

Further, the depth position of the measuring unit 6 is calculated based on data from a pressure sensor provided in the measuring unit 6, and the accurate depth position is grasped by comparing it with the depth position calculated by the measuring device 70. I can do it.

Note that the details of the groundwater measuring device of the present invention are not limited to the above embodiments, and various modifications are possible. For example, the configuration of each measuring section 11-15 is an example, and it is also possible to add a measuring section capable of measuring other physical property values, or to delete any one of the measuring sections 11-15.

Furthermore, the water pump 7 may also be provided between the upper packer and the lower puff car. Furthermore, in the above embodiment,
It is also optional to transmit the measurement data and control signals as frequency signals, or to serially transmit them as digital signals based on FSK or PSK. Furthermore, fpl No. 1
A combination of any of the embodiments 1 to 5 may be used.

"Effects of the Invention" As explained in detail above, according to the groundwater measuring device and groundwater measuring method of the present invention, the groundwater measuring device and the groundwater measuring method of the present invention are inserted into a borehole excavated underground and can be used to measure the physical property values of groundwater in the borehole. A device that performs measurements, including a measurement section equipped with a sensor for measuring physical property values, expandable packers placed above and below the measurement section, and groundwater flowing into the space partitioned by these bunkers. The structure consists of a water pump that pumps water to the ground, and a transmitting means that sends the measurement signal from the sensor to the ground, so if the measuring device is inserted into a borehole, it can directly measure the physical properties of groundwater at that location. The measurement error is small. In particular, among the physical properties, water is 7! ,
Since PH can be directly measured at the location, highly accurate data can be collected. Furthermore, the measuring device is fixed in the borehole using a retractable packer.
Since it is an I-type structure, reliable measurements can be made regardless of the diameter of the borehole.

Further, the measuring device is configured to include a pressure sensor that detects the water pressure around the water pump, and a control device that controls the driving amount of the water pump based on the detection signal detected by the pressure sensor. , it is now possible to balance the amount of groundwater flowing between the bunkers and the amount of groundwater pumped by the pump, and the groundwater pressure in the space partitioned by the packer is reduced by the amount of water pumped by the pump. This eliminates the possibility of water pressure changes.
There will be no change in the values of 02, CO2, etc. dissolved in groundwater.

In addition, since the measurement device is equipped with a bending member that can be bent freely within the free plane, even if the borehole is curved, the device will bend according to the bend, so it will not fit inside the borehole. It becomes possible to insert it smoothly.

In addition, the configuration is equipped with a cleaning mechanism that cleans the surface of the sensor for measuring physical property values provided in the measuring section of the measuring device, so it can be used even if there are many components such as sulfides in the groundwater in the borehole. Therefore, even if there is a risk that components may adhere to, precipitate, or cause corrosion on the electrode portion of the PH sensor or redox sensor, the cleaning mechanism can constantly clean the surface of the sensor, so good sensitivity can be maintained. Accurate physical property values can be obtained.

In addition, since the measuring device is equipped with a cleaning mechanism that cleans the surface of the bending member and the sensor for measuring physical property values provided in the measuring section, it can be inserted smoothly into an excavation hole that has a bend. , the sensitivity of the sensor can always be maintained at a good level, and accurate physical property values can be obtained.

In addition, when measuring the physical property values of groundwater in a borehole drilled into groundwater, the physical property values calculated by a total of 2111J based on the measurement signal from the sensor for measuring physical property values provided in the measurement unit, and the physical property values obtained by the pumping pump. Since this is done by comparing the physical property values of the pumped groundwater, more accurate values of these physical property values can be easily determined from the discrepancies between the respective physical property values.

In addition, in order to detect the reach depth of a groundwater measuring device that measures the physical properties of groundwater, we use the pressure data detected by the pressure sensor installed in the measurement unit and the length of the cable from the ground surface to the groundwater measuring device. Since we decided to compare the cable length data obtained by measurement, it is easy to understand the more accurate depth reached by the groundwater measuring device from the discrepancy between each data.

[Brief explanation of drawings]

1 to 4 are diagrams showing a groundwater measuring device that is a first embodiment of the present invention, in which FIG. 1 is a cross-sectional view showing the overall configuration, and FIG. 2 is a diagram showing the configuration of the measuring section. Cross section, 3rd
The figure is a cross-sectional view showing only the conductivity measurement part, No. 4
The figure is a sectional view showing only the water pump, Figure 5 is a state diagram showing the usage state of the measuring device, Figures 6 and 7 are
The figures show a second embodiment of the present invention, in which Fig. 6 is a schematic diagram for explaining a control system that controls the drive amount of the pump, Fig. 7 is a state diagram showing the control state, and Fig. 7 is a state diagram showing the control state. Figure 8 is a diagram showing a third embodiment of the present invention, and is an enlarged sectional view of the cleaning mechanism part, and Figure 9 is a diagram showing a fourth embodiment of the present invention, which is installed on the ground. Enlarged sectional view of total l1lq part, No. 10
The figure is an overall view showing a fifth practical example of the present invention. 1 ... 4 ... 6 ... 7 ... 9 , 1 Groundwater measuring device, poling hole (excavation hole), measuring section, water pump, ... Packer

Claims (1)

[Scope of Claims] 1) A groundwater measuring device that is inserted into a borehole drilled underground to measure the physical property values of groundwater in the borehole, the equipment comprising a sensor for measuring the physical property values. A measurement unit, expandable packers disposed above and below the measurement unit, a pump for pumping groundwater flowing into the space partitioned by these packers to the ground, and a measurement signal from the sensor. 1. A groundwater measuring device comprising: a transmitting means for transmitting to the ground. 2) A pressure sensor that detects the water pressure around the water pump;
The groundwater measuring device according to claim 1, further comprising a control device that controls the amount of drive of the pump based on the detection signal detected by the pressure sensor. 3) The groundwater measuring device according to claim 1 or 2, further comprising a bending member configured to be bendable within a free surface. 4) The groundwater measuring device according to any one of claims 1 to 3, further comprising a cleaning mechanism for cleaning the surface of a sensor for measuring physical property values provided in the measuring section. 5) When measuring the physical property values of groundwater in a borehole drilled underground, the physical property values measured by the measurement signal from the sensor for measuring the physical property values provided in the measurement unit and the water pumped by the pump are used. A groundwater measurement method characterized by comparing measured groundwater physical property values. 6) In detecting the reach depth of a groundwater measuring device that measures the physical property values of groundwater, the pressure data detected by the pressure sensor provided in the measuring unit and the length of the cable from the ground surface to the groundwater measuring device are used. A groundwater measurement method characterized by comparing the cable line length data obtained by measurement.