JP3433320B2 - Groundwater flow measurement method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groundwater flow measuring method and apparatus for measuring the velocity and direction of groundwater in a borehole by using optical means.

[0002]

2. Description of the Related Art As a groundwater flow measuring method and apparatus of this type, there is one disclosed in the following publication. [Patent Document 1] Japanese Unexamined Patent Publication No. 9-196958 SUMMARY OF THE INVENTION A pressure resistant container to be inserted into groundwater to be detected, a CCD camera housed in the pressure resistant container, a packer provided at the tip of the pressure resistant container, and one end of which is a CCD camera. The image processing apparatus is composed of a rod-shaped rigid endoscope that is connected to the other end and protrudes below the packer at the other end.
An image enhancing function for enhancing contrast by differentiating a video signal from a CD camera, a speed detecting function for calculating a moving velocity of particles in an image processed by the image enhancing function, and a flow direction for detecting a moving direction of particles. With a detection function.

JP, 9-257950, A A measurement case having a circulation part through which groundwater can flow is inserted into water in a boring hole, and air is supplied to the upper part of the measurement case to form an air layer. The float is placed in the flow section of the measurement case, the float is floated between the air layer, the float is positioned in the center of the measurement case with an electromagnetic induction coil, and the video camera installed above the air layer. The movement of the float is photographed to measure the direction and velocity of the groundwater flow.

[0004]

However, in the prior art example, since particles in water are photographed by the CCD camera through the rod-shaped rigid mirror penetrating the packer, the particles can be observed in a narrow photographing field of view, and therefore high accuracy is required. I can't hope.

In the conventional example, an electromagnetic induction coil or the like is required to position the float in the center of the measurement case, and unevenness in measurement accuracy easily occurs depending on the position of the float.

[0006] Also, in both the conventional examples of and, it is difficult to three-dimensionally measure the velocity and direction of the groundwater flow, and
When fixing the case with the built-in camera to a desired measurement position in the boring hole, there is no means for searching for the measurement position, and therefore, a surveillance camera or the like must be used for searching.

The object of the present invention is to make it possible to perform three-dimensional measurement of the velocity and direction of groundwater flow easily and with high accuracy, and to take the measurement and to take a picture for exploring the measurement position in the borehole. An object of the present invention is to provide a groundwater flow measurement method and apparatus capable of simultaneously performing and with one camera.

[0008]

The groundwater flow measuring method of the present invention is a groundwater flow measuring method in which a tracer in groundwater in a boring hole is photographed by an imaging means and the velocity and direction of the groundwater flow are calculated from a moving tracer image. In the method, the peripheral wall image of the borehole is photographed by the same photographing means as an image on a plurality of screens having different parallaxes by the parallax optical system inserted in the borehole, and a three-dimensional groundwater flow is obtained from the tracer image moving on the plurality of screens. It is characterized by calculating various flow velocities and flow directions.

The tracer to be photographed may be an artificial one released into groundwater, or suspended particles existing in groundwater.

Preferably, a prism which is a parallax optical system and a CCD camera which is an image pickup means are built in a probe and inserted into a boring hole, and a lower image in the boring hole and a peripheral wall image of the boring hole are passed through the same prism, Same C
Take a picture with a CD camera.

The position of the probe in the borehole can be determined from the peripheral wall image of the borehole taken by the CCD camera.

Further, the groundwater flow measuring apparatus of the present invention has a CCD camera built in the probe and a plurality of screens which are also built in the probe and have different parallaxes for the lower image in the borehole and the peripheral wall image of the borehole. Parallax optical system leading to the CCD camera as the image of the, the monitoring means for monitoring the image captured by the CCD camera, and the movement of the tracer image on a plurality of screens with different parallax in the lower image to the three-dimensional groundwater flow. It comprises a flow velocity / flow direction calculating means for calculating the flow velocity and the flow direction.

As the parallax optical system, a prism having vertically-symmetrical pyramid portions is preferable.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, according to the present invention, a probe 3 having a prism 1 which is a parallax optical system, a CCD camera 2 which is an image pickup means and the like is inserted into a boring hole 4, and C
The image sent from the CD camera 2 through the cable 5 is measured while being monitored by the ground system 6.

The probe 3 has a prism body 1 and a CCD camera 2 mounted on a probe body 7 which is a pressure-proof and transparent case.
Is arranged right above it to be incorporated therein, and further, an illumination device 8 and an electric power source 9 for illuminating the inside of the boring hole 4 are incorporated therein.

The CCD camera 2 is fixed downward in the center of the probe main body 7, and the prism 1 is installed near the bottom of the probe main body 7. This prism 1
Is two right-angle prisms 1a.1 with a pyramid angle of 90 degrees.
FIG. 3 shows the traveling path of the light when viewed from directly above, where b is overlapped with the upper and lower sides back to back. This prism 1
When viewed from directly above, as shown in FIG. 4, four screen areas having different parallax (viewing angles), that is, lower left and lower right in the center and left and right images on the left and right are four screen areas. They are divided into A, B, C and D and appear side by side at the same time. In addition, the prism 1 may be a cubic one integrally including vertically symmetrical pyramids.

Therefore, the images photographed by the CCD camera 2 through the prism 1 are the images of the lower left image and the lower right image, which have different parallaxes when viewed from the bottom inside the boring hole 4, and the peripheral wall of the boring hole 4 is viewed from the side. Left side wall image and right side wall image with different parallax appear at the same time, and the lower left image and the lower right image overlap each other in a certain area, so that the images of the same object appear simultaneously on the left and right. become.

The transparent bottom portion 7a of the probe body 7 has 4
As shown in FIG. 2, four connecting rods 10 are arranged vertically in a square arrangement, and a circular tip jig 11 is fixed to the lower ends of these four connecting rods 10. This tip jig 1
In the middle of the outer periphery of the probe body 7 and in the middle of the outer periphery of the probe main body 7, expander / contractor packers 12 and 13 are provided, respectively. By expanding these packers 12 and 13 and bringing them into pressure contact with the peripheral wall of the boring hole 4, The boring hole 4 can be stably fixed at a desired position.

The lower end of the outer periphery of the probe body 7 and the tip jig 1
Ring-shaped blocking plates 14 and 15 made of an elastic material such as rubber are fixed to the upper end of the outer periphery of the upper and lower insulating plates 14.
A space partitioning portion 17 is formed on the bottom portion 7a of the probe body 7 and the upper surface of the tip jig 11 to vertically partition the floating space of the tracer 16 in the boring hole 4. The groundwater that has entered the space division portion 17 is blocked from the downward flow above the space division portion 17 and the upward flow below. The tracer 16 is, for example, an artificial granular material made of agglomerated protein of milk or the like having a specific gravity close to 1.0, and is put into the space compartment 17 from inside the probe main body 7 or from another device.
If there are any airborne particles that can be photographed in the groundwater, they can be used as a tracer.

As shown in FIG. 2, a scale 18, which is an extremely thin transparent plate, is provided on the upper surface of the tip jig 11, for example, 2
Two sets are attached in a cross shape as one set for each book. Two sets of similar scales 19 are also attached in a cross shape on the upper surface of the bottom portion 7a of the probe body 7, but do not overlap with the scale 18 on the tip jig 11 when viewed from above. Thus, for example, there is an angle difference (phase difference) of 45 degrees. As shown in an enlarged scale in FIG. 5, the scale points 20 are provided on a single scale in a plurality of rows at a pitch P of equal intervals of about several mm, and the distance between the rows is set as an interval D of about several mm. The two scales in each set are offset by a half pitch (P / 2).

On the other hand, although not shown, the ground system 6 includes an azimuth indicator for instructing the azimuth of the probe 5, a depth indicator for instructing the depth, and an image processing system for processing a captured image of the CCD camera 2. It includes a personal computer incorporating (hardware and software) and a display for monitoring and displaying measurement data.

The image processing system has the CCD as described above.
The imaged images of the four screen areas captured by the camera 2 are divided into a lower image in the boring hole and a peripheral wall image of the boring hole for image processing.

Next, a measuring method using the groundwater flow measuring device thus constructed will be described. The probe 3 is suspended and inserted into the boring hole 4, the CCD camera 2 takes an image through the prism 1, and while monitoring the peripheral wall image of the boring hole 4 displayed on the display on the ground, the crack position (water channel) of the rock mass Check the geological condition, etc. and select the measurement point. Reference numeral 21 in FIG. 1 indicates a water channel.

Once the measurement point is determined, the packer 12.13
Is expanded to fix the probe 3 in the boring hole 4,
The tracer 16 is put into the space partitioning portion 17, and this is photographed by the CCD camera 2 through the prism 1. The tracer 16 that moves due to the groundwater flow simultaneously appears on two left and right screens with different parallax in the captured lower image, and scales 18 and 19 also appear on the same screen.

FIG. 6A shows the transmission path of the light beam of the prism 1 and the movement trajectory of the tracer 16 during the passage of time from time t1 to time t2, and FIG. 6B shows the plane of the movement. Shows a typical trajectory. In addition, in FIG.
Images of two screens having different parallaxes of the lower images at the time point are shown, and (B) shows images of the same two left and right screens at the time point t2. Since the tracer 16 moves slowly along with the movement of groundwater, the image of the tracer 16 appears on two left and right screens with different parallax at the same time as shown in FIG. appear. Figure 7
As can be seen from the above, since the two left and right screens have different parallax, the same tracer 16 appears in different positions of the image. If the tracer 16 moves, the movement is as shown in FIG. It can be seen three-dimensionally from the correlation with B).

Therefore, at any time t1, t2, t3 ...
The imaging is repeated at tn, the three-dimensional coordinates of the image of the tracer 16 are calculated by the personal computer at each time point, and the movement amount is grasped at each time, whereby the three-dimensional flow velocity can be obtained. Moreover, since the movement of the image of the tracer 16 can be grasped in the vertical direction as well as in the plane, the three-dimensional flow direction can be calculated.

The above operation is repeated for each required position and depth by changing the installation position of the probe 3.

In addition to the above-described embodiment, the present invention can be modified and applied as follows. The prism 1, which is an optical system, is composed of two right-angle prisms 1 each having a pyramid angle of 90 degrees.
Although a and 1b are combined, since the visible area changes depending on the angle of the pyramid, a prism having an appropriate angle may be used in consideration of the positional relationship between the CCD camera 2 and the tracer 16. Further, the parallax optical system is not limited to the prism as long as it is a parallax optical system capable of simultaneously guiding the lower image in the boring hole 4 and the image of the peripheral wall of the boring hole 4 to the CCD camera 2.

If the tip jig 11 is hollow and the illuminating device is installed therein, and the stay 10 is hollow and a power supply line to the illuminating device is passed through the hollow, the space from the tip jig 11 to the space partitioning portion 1 is obtained.
The inside of 7 can be illuminated. Of course, it is possible to illuminate the tip jig 11 below.

By rotating the prism 1 in a plane by 360 degrees, the entire circumference of the boring hole 4 can be photographed and the measurement at an appropriate position (depth) can be realized.

The measurement accuracy can be improved by increasing the number of prisms 1 and CCD cameras 2 installed.

The accuracy can be improved by enlarging and capturing the lower image in the boring hole 4 captured by the CCD camera 2 using the zoom function.

As shown in FIG. 8, the prism 1 and the CCD
If the camera 2 can be tilted with respect to the axis of the probe main body 7, the three-dimensional flow velocity and flow direction can be measured even in the boring hole 4 that is drilled in an oblique direction.

[0035]

As described above, according to the present invention, the tracer image is captured by the same photographing means as the tracer image on a plurality of screens having different parallaxes by the parallax optical system inserted in the bowling hole, and the tracer image is moved on the plurality of screens. Since the three-dimensional flow velocity and flow direction of the groundwater flow are calculated from the above, the three-dimensional measurement of the flow velocity and flow direction of the groundwater flow can be performed easily and with high accuracy.

Since the peripheral wall image of the borehole is photographed by the same image pickup means by the parallax optical system, it is possible to determine the measurement position in the borehole from the photographed peripheral wall image of the borehole, and to measure the inside of the borehole. It is possible to simultaneously perform the search for the measurement position and the photographing for measuring the velocity and the direction of the groundwater flow with the same imaging means.

The lower image in the borehole and the peripheral wall image of the borehole can be economically realized by photographing them with the same CCD camera through the same prism which is a parallax optical system.

The parallax optical system can be simply constructed by vertically symmetric two pyramidal prisms.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in the above.

FIG. 3 is a traveling path diagram of light of a prism which is an optical system.

FIG. 4 is a schematic diagram showing a relationship between images of four regions simultaneously captured by a CCD camera through a prism.

FIG. 5 is an enlarged view of a scale.

FIG. 6A is an explanatory view showing a transmission path of a light beam of a prism and a movement trajectory of a tracer that has moved during a time period from time t1 to time t2; FIG. 6B is a plan view of the movement. It is explanatory drawing which shows a locus.

FIG. 7A shows images of two screens having different parallaxes of lower images at time t1, and FIG. 7B shows images of the same two left and right screens at time t2.

FIG. 8 is an installation diagram of a modified example of the present invention.

[Explanation of symbols]

1 Prism (parallax optical system) 1a ・ 1b Right angle prism 2 CCD camera 3 probes 4 boring holes 5 cables 6 Ground system 7 Probe body 7a bottom 8 lighting equipment 9 power supplies 10 connecting rod 11 Tip jig 12.13 Packer 14 ・ 15 Blocking plate 16 Tracer 17 space division 18 ・ 19 scale 20 dimension points 21 Water Michi

Continuation of the front page (72) Inventor Kazunobu Matsumoto 2 Sanbancho, Chiyoda-ku, Tokyo, Tobishima Construction Co., Ltd. (72) Inventor Masayuki Tsutsui 2 Sanbancho, Chiyoda-ku, Tokyo, Tobishima Construction Co., Ltd. (72) Invention Yuuki Kumagai 2 Sanbancho, Chiyoda-ku, Tokyo Within Tobishima Construction Co., Ltd. (56) References JP 2001-228165 (JP, A) JP 2001-183471 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) G01V 9/02 G01P 5/20 G01P 13/00

Claims (5)

(57) [Claims] 1. A groundwater flow measuring method in which a tracer in groundwater in a borehole is photographed by an imaging means and the velocity and direction of the groundwater flow are calculated from a moving tracer image. The feature is that three-dimensional flow velocity and flow direction of groundwater flow are calculated from the tracer images moving on multiple screens by capturing the same images as images on multiple screens with different parallax by the parallax optical system inserted in the borehole. Measuring method of groundwater flow. 2. A prism, which is a parallax optical system, and a CCD camera, which is an image pickup means, are built in a probe and inserted into a boring hole, and the lower image in the boring hole and the peripheral wall image of the boring hole are the same through the same prism. The groundwater flow measuring method according to claim 1, wherein the groundwater flow is photographed by a CCD camera. 3. The groundwater flow measuring method according to claim 2, wherein the position of the probe installed in the borehole is determined from an image of the peripheral wall of the borehole taken by a CCD camera. 4. A parallax for guiding a CCD camera built in the probe and a lower image in the boring hole and a peripheral wall image of the boring hole, which are also built in the probe, to the CCD camera as a plurality of screen images having different parallax. The three-dimensional flow velocity and flow direction of the groundwater flow are calculated from the optical system, the monitoring means for monitoring the image captured by the CCD camera, and the movement of the tracer images on a plurality of screens with different parallax in the lower image. An apparatus for measuring groundwater flow, comprising: flow velocity / flow direction calculating means. 5. The groundwater flow measuring device according to claim 4, wherein the parallax optical system is a prism having vertically symmetric pyramids.