JPH0548328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for measuring the permeability coefficient of ground and an apparatus for carrying out the method.

(Prior art) When injecting grout into the ground to improve the ground, stop water, etc., in order to manage the injection, set the injection pressure, injection amount, select the grout, etc. It is important to understand the strength and hydraulic conductivity of the water. Conventionally, the permeability coefficient is determined by drilling a hole using a boring machine or an excavator with a turret used for digging wells, and drilling to a predetermined target depth using muddy water to prevent collapse of the hole wall after drilling. Alternatively, as the excavation progresses, a casing (collapse prevention pipe) is inserted, the inside of the hole is washed with water, and then measurements are taken using the water pumping method or the water injection method. In the conventional method, it takes a long time to insert the casing after drilling, and the permeability coefficient of the ground varies depending on the depth, so when the measurement range is wide in the vertical direction, the permeability coefficient can be measured several times at each depth. It was necessary to repeat.

In addition, after injecting grout into the ground, a water permeability test is conducted to confirm the injection effect, but conventional methods
Since it cannot be carried out quickly and easily, sufficient confirmation of the injection effect cannot be carried out immediately, resulting in low confidence in the injection results.

(Problems to be Solved by the Invention) The problem of the present invention is to conduct general ground investigation and to measure the hydraulic conductivity of the grouting location before and after grouting in a simple manner, in a short time, and with high precision for any soil layer range. The objective is to provide a method and a measuring device that can.

(Means for Solving the Problems) The present invention was developed to solve these problems, and includes a method for measuring hydraulic conductivity that can be applied to ground having a wide range of hydraulic conductivity, and a method for implementing the method. The aim is to provide a device for this purpose.

The first feature of the hydraulic permeability measurement method of the present invention is to use a mechanical packer that expands with fluid pressure as a packer, and to attach a tip device having the packer and a water injection/discharge portion to the lower end of an inner pipe of a multiple pipe, When the outer pipe of the multiple pipe moves within the ground, the tip device is housed in the outer tube, and prior to water injection for measuring the hydraulic conductivity, the tip device is made to protrude from the outer tube and pressurized fluid is introduced into the packer. The inner pressure of the packer is changed according to the water injection pressure. A pressure fluid higher than the water injection pressure is introduced into the packer to press it against the circumferential wall of the drilled ground, and water is injected from the tip discharge part. Therefore, the packer functions effectively, and the entire amount of water injected is sent to the target ground for measuring the hydraulic conductivity. Therefore, the Lugeon value and hydraulic conductivity of the target ground can be measured with high accuracy using the calculation formulas below. (1 Lugeon has a water injection pressure of 10 kg.
Water injection flow rate per meter of test hole length at f/ ^cm2 /
It is defined as minutes. However, the water injection pressure is 10Kgf/
In many cases, the water injection pressure does not reach 10 kgf/cm ^{2 .}
The reduced Lugeon value Lu', which is expressed in terms of , is generally used. ) Lu'=10・Q/P・L...(1) k=α・Lu/10...(2) (α=1.9/π×10 ^-4 log ₁₀ (100L/r ₀ ) However, Lu' : Lugeon value, Q: Water injection amount (/min) P: Water injection pressure (Kgf/cm ² ) L: Length of water injection section (m) r ₀ : Radius of water injection hole (cm) k: Hydraulic conductivity (cm/sec) ) The second feature of the method of the present invention is that by controlling the water injection pressure used for the permeability test so as to maintain it lower than the resistance pressure of the ground to be tested, and setting the water injection amount to a low value, This prevents ground destruction of the target ground, and allows the entire amount of water to be injected into the ground around the water discharge part at the bottom of the pack car evenly.The third feature of the method of the present invention is that The purpose is to change the water conveyance method.In other words, the permeability coefficient of the ground to be tested is 1×10 ^-3 cm/sec.
If it is larger, for example, to obtain a hydraulic conductivity of 10 ^{-3 cm} /sec with a water injection pressure of 1 Kgf/cm ² and a water injection section length of 50 cm, the water injection flow rate should be 5/sec.
In addition, to measure the general permeability coefficient of 10 ^-5 cm/sec of improved ground after grout injection, assuming the water injection pressure and water injection area are the same values as above, the water injection amount is 0.05 cm/sec. minute and hydraulic conductivity 10 ^-3 cm/sec
The amount of water injected is 1/100th of the amount of water injected, eliminating pulsation.
It is impossible for a water injection pump to satisfy all functions such as high accuracy in a low discharge region and wide variation in discharge amount. The present invention has a hydraulic conductivity of 1 ×
If it is larger than 10 ^-3 cm/sec, the method is to use a variable discharge pump, for example, and control the motor torque by frequency conversion using an inverter, vary the discharge amount over a wide range, and obtain the hydraulic conductivity. If it is smaller than 1×10 ^-3 cm/sec, the water permeability is obtained by filling a pressure vessel-type measuring water tank with water, pressurizing the water in the container with compressed air, and injecting it into a permeability test hole. In order to grasp changes in the liquid level of a small amount of water supplied from a pressure vessel-type measuring water tank, it is preferable to increase accuracy by changing the inner diameter of the cylindrical container that is normally used.

The apparatus for carrying out the method of the present invention is characterized by a tank for storing water, a pump for delivering water from the tank, and in response to a received signal, the amount of water injected from the pump is continuously or continuously up to a set pressure. A water injection amount adjustment means that adjusts in stages, a pressure vessel type measuring water tank, a level converter that detects the amount of water fed from this tank and generates a signal according to the detected flow rate, and a swivel part at the upper end of the multiple pipe. A pressure transducer that detects water injection pressure using an installed pressure detector and generates a signal according to the detected pressure, a tank that stores pressurized fluid to inflate the pump car, and a pressure fluid pressure that detects the pressure fluid pressure to the pump car. A pressure transducer that generates a signal according to the detected pressure, and a pressure fluid automatic regulator connected to the pressure fluid tank to receive the signal from the pressure transducer and control the Paccar inflation pressure according to the signal. It memorizes the means for controlling the discharge valve and the arithmetic processing formula for the permeability coefficient, and based on the values of the length of the water injection section, the radius of the water injection hole, the amount of water injection, and the water injection pressure, which are input continuously and in stages. and a means for calculating the hydraulic permeability coefficient using the above calculation processing formula, and after the tip device is protruded by pressure fluid, the expansion pressure to the packer is adjusted to a pressure according to the water injection pressure and the state of the hole wall. Adjust the expansion pressure with a pressure converter that converts the water into a signal, and convert the difference between the set water flow rate and the instructed water flow rate into a signal so that the water injection pressure is less than the resistance pressure of the ground where water is being poured. The amount of water supplied is adjusted by means of a microcomputer that has been programmed with parameters and arithmetic processing formulas for measuring the permeability coefficient to detect changes in the water injection pressure and amount over time. The hydraulic conductivity coefficient is continuously calculated and displayed on a CRT display.

(Function) The method for measuring the permeability coefficient according to the present invention involves attaching a tip device having a packer and a water discharge part to the lower end of the inner pipe of a multiple pipe, and operating the tip device after drilling a hole with the multiple pipe, prior to a water permeability test. The tip device is made to protrude from the outer pipe, and the packer is inflated to define the range of water injection from the multiple pipes, and then water is supplied and detected by pressurizing the water injection pump or pressure vessel type metering water tank with compressed air. The system measures the pressure and flow rate of water, sends the measured values to a central processing unit, and immediately measures the hydraulic conductivity in relation to the water injection area. The above water injection range mainly indicates the diameter of the water injection hole and the length of the hole in the direction from the tanker, and the relational expression between this value and the above pressure and flow rate is based on the central processing unit (CPU), keyboard, printer, A floppy disk in a microcomputer consisting of a floppy disk peripheral device (hereinafter referred to as a CPU and a peripheral device) is programmed in advance.

(Example) Examples of the present invention will be specifically described below with reference to the accompanying drawings.

In the figure, reference numeral 1 indicates a multiple tube for testing the permeability coefficient, which is normally attached to a boring machine (not shown) in a predetermined manner. Reference numeral 2 denotes a tip device having a packer 1a attached to the lower end of the inner pipe of the multiple pipe 1 and a water discharge part 1b, 3 a water pump for supplying water to the water discharge part 1b, and 4 directly connected to the water supply pump 3. 5 is a water tank for temporarily storing water used for permeability tests; 5 is a pressure vessel type measuring water tank used when the permeability coefficient of the ground to which water is injected is smaller than 1×10 ^-3 cm/sec; 6 is a water tank sent from pump 3; a detector for measuring the flow rate of water; 7
is a flow rate converter that converts the water flow rate detected by the detector 6 into a signal. 8 is a microcomputer that programs hydraulic conductivity parameters (length of water injection section, radius of water injection hole, water injection amount, and water injection pressure) and arithmetic processing formulas, detects fluctuations in water injection pressure and water injection amount, and performs calculation processing. 9 is a CRT display that displays water injection pressure, water injection amount, and hydraulic conductivity over time.

The multi-pipe 1 for hydraulic permeability testing is configured as at least a double pipe, and the tip of the inner pipe has a packer 1a that can be expanded by pressure fluid and a water discharge part 1b.
is provided so that it can freely appear and retract from the outer tube. As this multiplex tube, the one disclosed in Japanese Patent Application No. 58-67784 (Japanese Unexamined Patent Publication No. 59-195918) can be used.

Note that the water pump 3 may be either a variable discharge type pump or a constant discharge type pump. For example, when a variable discharge type pump is used, the discharge amount is varied by the automatic adjustment discharge valve 22 until a set pressure is obtained according to instructions from the central processing unit by frequency conversion using an inverter. On the other hand, in the case of a constant discharge type pump, the pressure detector 12 measures the water supply pressure while maintaining a set constant flow rate.

In the case of ground with high permeability, it is necessary to send a large amount of water, so it is preferable to use a variable discharge pump.For ground with low permeability, a small amount of water is required, so a constant discharge pump is recommended. It is preferable to detect the water supply pressure while supplying a certain amount of water.

The water discharge portion 1b has a large number of discharge holes on its circumferential surface so that the water sent therein is spouted laterally. This water discharge portion 1b is also used for grout injection.

A packer 1a is installed between the inner tube and the outer tube of the multiplex tube 1.
A pressure fluid supply path is provided to inflate the pressure fluid, and this pressure fluid may be either gas or liquid, but water is usually used due to ease of handling.

10 is a pressure fluid storage tank, which is usually a water tank.
A pump 11 sends water in the first storage tank 10 to the liquid feeding path. In addition, the set inflation pressure of the pack car is determined by the pressure converter 12 that converts the water injection pressure into a signal.
It is controlled by the CPU 8 and adjusted by the automatic adjustment discharge valve 13, and the inflation pressure is checked over time by the pressure transducer 14.

The pack car 1a, which is inflated after drilling the hole, defines the range of water injection during the water permeability test. This water injection range is as described above. The hydraulic permeability coefficient is calculated from the above equation (2) using the factors related to the water injection range and the flow rate and pressure values obtained by the flow rate converter 7 and pressure converter 12.
It is calculated by Note that the variable discharge pump 3 is usually used when the hydraulic conductivity of the ground is greater than 1×10 ^-3 cm/sec, and the hydraulic conductivity is greater than 1×10 ^-3 cm/sec.
If it is smaller, the pressure vessel type measuring water tank 5 is pressurized with compressed air from the compressor 15 and water is supplied. The amount of water fed from the metered water tank 5 is determined by a level converter 16, and the water injection pressure is determined by a pressure converter 12, which controls the CPU and CRT in the microcomputer 8.
Display on display 9. The water injection pressure is adjusted by the automatic pressure control valve 23 based on instructions from the pressure converter 12.
Do it with Note that the dotted lines in the figure indicate the electrical signal system. Further, in the figure, 17 is a flow rate indicator attached to the flow rate converter 7, 18 is a flow rate indicator attached to the level converter 16, 19 is a pressure indicator detected by the pressure converter 12, and 20 is a pressure converter. 21 is an automatic continuous recorder for each value detected by the converters 7, 12, 14, and 18.

Microcomputer 8 is the main memory CPU
It consists of a keyboard as an input device, a CRT display 9 as an output device, peripheral devices such as a printer, and a floppy disk as an auxiliary storage device.The functions of the microcomputer according to the present invention can be summarized as follows. It is as follows.

(1) It has a function of adjusting the expansion pressure of the packer 1a to be higher than the water injection pressure according to the water injection pressure and the condition of the hole wall. That is, it is connected to the pressure fluid tank 10 in order to receive a signal about the water injection pressure detected by the pressure detector 12 installed at the swivel portion at the upper end of the multiple pipe 1, and to control the expansion pressure of the packer according to the signal. The pressure fluid automatically regulating discharge valve 13 is controlled.

(2) A function that adjusts the difference between the set water flow rate and the instructed water flow rate so that the water injection pressure is less than the resistance force of the ground where water is being poured. In other words, the water injection pressure before injecting grout into the ground is usually the soil cover 1 at the location where the permeability coefficient is measured.
Set from 0.1 to 0.15 Kgf/cm ² per meter, and 0.15 to 0.2 Kgf/cm ² per meter after injection, and adjust the increase or decrease within this water injection pressure range so that the specified water flow rate reaches the set water flow rate. Control.

(3) A function for adjusting the amount of water injected into the water pump 3, for example, a variable discharge type pump, until a set water injection pressure is obtained.

(4) A function in which the water injection pressure for the pressure vessel type metering water tank 5 is specified according to (2) above, and the water injection amount is inputted by the level converter 16.

(5) Length of injection section of permeability test, radius of injection hole,
The four factors of water injection amount and water injection pressure and the programming of the calculation formula for hydraulic conductivity are stored on the floppy disk, and the function is to calculate the above four values input continuously and step by step using the CPU.

(6) About water injection pressure and water injection amount for water permeability test 4-6
The signal values from the pressure transducer 12 and the flow rate transducer 7 or 16 are read at intervals of once per second, and the horizontal axis shows the time, and the vertical axis shows the water injection pressure.
A function that simultaneously plots the amount of water injected and displays the permeability coefficient on the CRT display 9 using the above calculation formula at intervals of 4 to 6 seconds.

(7) Function to memorize and print the contents on the CRT display.

Next, the procedure for measuring the hydraulic conductivity will be explained with reference to FIG.

The hydraulic conductivity is correlated with the soil (geological) classification.
The hydraulic conductivity k of soil in its natural state is k = 10 ^-1 to ^{10 -3} cm/sec for fine sand, coarse sand, medium sand, and fine sand.
For very fine sand, silty sand, and loose silt, k = 10 ^-3 to ^{10 -5} cm/sec, and for compact silt, clayey silt, and clay, k = 10 ^-5 to ^{10 -7} cm/sec.
Therefore, from the results of a preliminary soil investigation by depth of the ground to be injected with water, it is possible to obtain a numerical guideline for the permeability coefficient of the ground to be injected with water, and based on this, it is possible to determine whether to use the water pump 3 or the pressure vessel type metering water tank 5.
A choice is made as to whether to use If grout is injected into the ground, the permeability coefficient is 10 ^-5 cm/
sec, the pressure vessel type metering water tank 5 is often selected. This selection is normally made artificially using the permeability coefficient corresponding to the soil quality, but by inputting the permeability coefficient for each soil type when programming the permeability test parameters and arithmetic processing formula into the microcomputer, it is possible to It is also possible to make selections using a microcomputer based on soil survey results by depth.

First, data regarding the water injection range and the calculation of the hydraulic conductivity are programmed and stored in the floppy disk in the microcomputer 8, together with an instruction as to which of the above options to select (step). Next, a hole is drilled to a predetermined depth using a multi-tube 1 set in a boring machine (step). After drilling, the multiple pipe 1 is pulled upward by at least the length of the tip device attached, and then the tip device is discharged to expose the packer 1a and the water discharge portion 1b (step), and pressurized fluid is supplied to the packer 1a. Then, it is inflated and pressed against the hole wall, completely separating the water injection range deeper than the packer, that is, the area ahead of the packer, from the area behind the packer (step). Next, the permeability coefficient of the ground to be measured is 1×10 ^-3
If it is larger than cm/sec, the water pump 3 is activated and water injection into the water injection range is started (step).
The water injection pressure is measured by the pressure transducer 12, and the water injection amount is measured by the flow rate converter 7, and the measured values are continuously input to the CPU (step). The CPU controls the automatic adjustment discharge valve 22 in response to the signal from the flow rate converter 7 so that the water injection pressure is below the resistance force of the water-injected ground, and adjusts the difference between the set water flow rate and the instructed water flow rate. . The CPU also controls the pressure fluid automatic adjustment discharge valve 13 in response to a signal from the pressure transducer 12 to adjust the inflation pressure of the packer 1a to be higher than the water injection pressure (step). Then the CPU is 4, for example.
~Reads signal values at intervals of once every 6 seconds, performs arithmetic processing based on the programmed formula,
Calculate the hydraulic conductivity (step). The calculated permeability coefficient is determined by the water injection pressure over time and the CRT display based on the values of the central processing unit (CPU).
A graph of changes in water injection amount and hydraulic conductivity are displayed.
After measuring the hydraulic conductivity over a specified period of time,
The water injection is stopped, the pressure fluid supply to the packer 1a is also stopped, and the packer is then deflated.

By attaching the pack car 1a above and below the water discharge portion 1b, it is possible to measure the permeability coefficient of the ground at a limited depth.

In addition, if the water injection pressure and water injection amount for the hydraulic conductivity measurement test can be performed under the same conditions, each value must be stored in ROM (Read Only Memory) in advance, or the values in RAM (Random Access Memory) can be stored using a power supply. If you create a structure that always holds,
Once each numerical value is inserted, it can be carried out using the same control method all the time, making it possible to perform water permeability tests more quickly.

(Effects of the Invention) The effects of the present invention are that the measurement of the permeability coefficient of the target ground can be carried out easily and quickly with high accuracy by selecting the water supply method using the advanced device that has a packer and a water discharge part; By installing it above and below the water discharge part, it is possible to grasp the permeability coefficient of any soil layer range, and at the same time the central processing unit and CRT
Since the permeability coefficient is displayed immediately on the display, the permeability test method and permeability test apparatus of the present invention can be used in a wide range of areas such as urban civil engineering and dams.

[Brief explanation of the drawing]

In the accompanying drawings, FIG. 1 is a diagram showing an outline of an embodiment of the present invention, and FIG. 2 is a flow sheet showing the test procedure. DESCRIPTION OF SYMBOLS 1...Multi-tube for hydraulic permeability test, 1a...Packer, 1b...Water discharge part, 2...Tip device, 3...
Water pump, 4...Water tank, 5...Pressure vessel type measuring water tank, 6...Flow rate detector, 7...Flow rate converter, 8...Microcomputer, 9...
CRT display, 10...pressure fluid tank,
11... Pressure fluid water supply pump, 12... Pressure transducer, 13... Pressure fluid automatic adjustment discharge valve, 14...
Pressure transducer, 15... Compressor, 16...
Level converter, 17, 18...Flow rate indicator, 19
... Pressure indicator, 20 ... Pressure indicator for advanced equipment, 21 ... Automatic continuous recorder, 22 ... Automatic adjustment discharge valve, 23 ... Automatic pressure control valve, 24 ... Three-way cock.

Claims (1)

[Claims] 1. Using multiple pipes with packers, using a mechanical packer that expands with fluid pressure as the packer, and attaching a tip device having the packers and a water discharge part to the lower end of the inner tube of the multiple pipes. However, when the outer tube of the multiple tube is moved in the ground, the tip device is housed in the outer tube, and the tip device is made to protrude from the outer tube prior to measuring the permeability coefficient, and pressurized fluid is supplied to the packer. The internal pressure of the pack car is changed according to the water injection pressure, and the water injection pressure is controlled so as to be maintained lower than the resistance pressure of the ground to be watered, and the hydraulic conductivity of the ground to be watered is increased. If it is larger than 1 x 10 ^-3 cm/sec, use a water pump to send water to the permeability test hole, and if the permeability coefficient of the ground to which water is poured is smaller than 1 x 10 ^-3 cm/sec,
A ground permeability coefficient characterized by using a pressure vessel type measuring water tank, pressurizing the water in the container with compressed air, injecting the water into a permeability test hole, and calculating the permeability coefficient based on the amount of water injection and the water injection pressure. Measuring method. 2. Use a multiple pipe with a packer, use a mechanical packer that expands with fluid pressure as the packer, attach a tip device having the packer and a water discharge part to the lower end of the inner pipe of the multiple pipe, and When the outer tube is moved in the ground, the tip device is housed in the outer tube, and prior to measuring the permeability coefficient, the tip device is made to protrude from the outer tube, and a pressure fluid is introduced into the packer to inflate it, Furthermore, the internal pressure of the pack car is changed according to the water injection pressure, and the water injection pressure is controlled so as to be maintained lower than the resistance pressure of the water-injected ground, and the hydraulic conductivity of the water-injected ground is 1 × 10 ^- If it is larger than ³ cm/sec, use a water pump to send water to the permeability test hole, and if the permeability coefficient of the ground to be injected is smaller than 1 x 10 ^-3 cm/sec, use a pressure vessel type metering water tank and A device used to carry out a method for measuring the permeability coefficient of the ground, which is characterized by pressurizing the water inside with compressed air, injecting it into a permeability test hole, and performing a permeability test of the ground based on the relationship between the amount of water injected and the water injection pressure. (a) a tank 4 that stores water; (b) a pump 3 that delivers water from the tank; and (c) a system that continuously increases the amount of water injected from the pump up to a set pressure in response to a received signal. or a water injection amount adjusting means 22 that adjusts in stages; (d) a pressure vessel type measuring water tank 5; and (e) a level converter that detects the amount of water fed from the tank 5 and generates a signal according to the detected flow rate. vessel 16
(f) A pressure transducer 12 that detects the water injection pressure with a pressure detector installed at the swivel section at the upper end of the multiple pipe and generates a signal according to the detected pressure; (g) A pressure transducer 12 for inflating the pack car 1a. (h) a pressure transducer 14 that detects the pressure fluid pressure to the pack car and generates a signal according to the detected pressure; (i) a pressure transducer 14 that receives the signal from the pressure transducer 12 and means for controlling the pressure fluid automatic adjustment discharge valve 13 connected to the pressure fluid tank 10 in order to control the Paccar expansion pressure according to the signal; , means for calculating the hydraulic conductivity using the above calculation formula based on the values of the length of the injection section, the radius of the water injection hole, the water injection amount, and the water injection pressure that are input in stages. Device. 3. Using a multiple pipe with a packer, using a mechanical packer that expands by fluid pressure as the packer, attaching the tip device having the packer and a water discharge part to the lower end of the inner pipe of the multiple pipe, When the outer tube is moved in the ground, the tip device is housed in the outer tube, and prior to measuring the permeability coefficient, the tip device is made to protrude from the outer tube, and a pressure fluid is introduced into the packer to inflate it, Furthermore, the internal pressure of the pack car is changed according to the water injection pressure, and the water injection pressure is controlled so as to be maintained lower than the resistance pressure of the water-injected ground, and the hydraulic conductivity of the water-injected ground is 1 × 10 ^- If it is larger than ³ cm/sec, use a water pump to send water to the permeability test hole, and if the permeability coefficient of the ground to be injected is smaller than 1 x 10 ^-3 cm/sec, use a pressure vessel type metering water tank and A device used to carry out a method for measuring the permeability coefficient of the ground, which is characterized by pressurizing the water inside with compressed air, injecting it into a permeability test hole, and performing a permeability test of the ground based on the relationship between the amount of water injected and the water injection pressure. (a) a tank 4 that stores water; (b) a pump 3 that delivers water from the tank; and (c) a system that continuously increases the amount of water injected from the pump up to a set pressure in response to a received signal. or a water injection amount adjusting means 22 that adjusts in stages; (d) a pressure vessel type measuring water tank 5; and (e) a level converter that detects the amount of water fed from the tank 5 and generates a signal according to the detected flow rate. vessel 16
(f) A pressure transducer 12 that detects the water injection pressure with a pressure detector installed at the swivel section at the upper end of the multiple pipe and generates a signal according to the detected pressure; (g) A pressure transducer 12 for inflating the pack car 1a. (h) a pressure transducer 14 that detects the pressure fluid pressure to the pack car and generates a signal according to the detected pressure; (i) receives a signal from the pressure transducer 12; (j) means for controlling a pressure fluid automatic regulating discharge valve 13 connected to the pressure fluid tank 10 in order to control the Patsuker expansion pressure in accordance with the signal; (k) sending a signal to the water injection amount adjusting means 22 to adjust the water injection amount from the water injection pump 3 until the set water injection pressure is obtained; (l) Means for instructing the water injection pressure for the pressure vessel type measuring water tank 5 according to (j) above, and inputting the water injection amount by the level converter 16; (m) Calculating the hydraulic conductivity coefficient. means for storing the formula and calculating the permeability coefficient by the above calculation formula based on the values of the length of the injection section, the radius of the water injection hole, the amount of water injection, and the water injection pressure that are input continuously and stepwise; ) About water injection pressure and water injection amount for water permeability test 4-6
The signal values from the pressure transducer 12 and flow rate transducers 7 and 16 are read at intervals of once every second, and the time is plotted on the horizontal axis and the water injection pressure and water injection amount are plotted on the vertical axis on the CRT display, and at the same time, every 4 to 6 seconds. A permeability coefficient measuring device characterized by comprising means for displaying a permeability coefficient on a CRT display using the above-mentioned arithmetic processing formula.