JPH0443158B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to borehole wall observation in which the borehole wall is observed using a scanner built into a sonde that moves up and down inside the borehole (borehole, pipe hole, etc.). It is about the method.

[Conventional technology]

When excavating underground cavities such as dams and tunnels, it is necessary to conduct a geological survey of the construction site and reflect this in the design, as well as to take every precaution in selecting the construction method to be adopted, how to proceed with construction, and taking safety measures. be. In geological investigations in such cases, it is generally necessary to know the direction, inclination, and properties of cracks in the rock, as well as the direction and inclination of the strata. For this reason, investigations are being carried out by drilling at the construction site and collecting and observing cores, or by directly observing the borehole walls. Direct borehole wall observation methods use equipment such as borehole televisions, borehole periscopes, borehole cameras, and borehole scanners.

FIG. 10 is a diagram showing a specific example of the configuration of the borehole scanner, and FIG. 11 is a diagram showing the locus of the developed surface of the hole wall scanned by the light beam. In the figure,
31 is a borehole, 32 is a sonde, 33 is a turning motor, 34 is a direction indicator, 35 and 42 are lenses,
36 is a mirror, 37 is an optical head, 38 and 41 are slits, 39 is a photoelectric converter, 40 is a half mirror, and 43 is a light source.

In FIG. 10, the sonde 32 moving up and down inside the borehole 31 includes a direction indicator 34 and a lens 3.
An optical head 37 having an optical head 5 and a mirror 36 is connected to the rotation motor 33. Also, a light source 43 for sending a light beam to the optical head 37 through the half mirror 40, a lens 42 for creating the light beam, a slit 41, and a slit 38 for detecting the reflected beam from the optical head 37. , a photoelectric converter 39 are provided.
With such a configuration, the light from the light source 43 is
The light is formed into a beam by a lens 42 and a slit 41, and is irradiated onto the inner wall of the borehole through a half mirror 40, a mirror 36, and a lens 35. The intensity of the reflected beam is then measured by a photoelectric converter 39 through a lens 35, a mirror 36, a half mirror 40, and a slit 38. Therefore, when the sonde 32 is lowered while the optical head 37 is rotated by the rotation motor 33, the inner wall of the borehole is scanned as shown in FIG. 11, and an electric signal corresponding to the intensity of the reflected beam is transmitted to the photoelectric converter 39
It will be obtained from

[Problem that the invention seeks to solve]

As described above, observation of the borehole wall using the borehole scanner is performed while always checking the reference direction using the built-in direction indicator 34. Therefore, it is necessary that the borehole be completely vertical; otherwise, it is predicted that observation accuracy will drop significantly.

However, as the boring length becomes longer, crushed stone pieces may become trapped near the drilling bit, or due to differences in drilling resistance when diagonally drilling strata interfaces with different hardnesses, or due to the boring rod. Due to deviations in material deformation characteristics, boreholes may be dug in an irregularly curved manner, resulting in the problem that the geological information obtained through boring does not indicate the correct coordinates and direction. In addition, when observing the hole wall of horizontal or inclined boring, the values on the absolute axes (vertical axis and N-S, E-W axes) of fracture planes, strata planes, etc. obtained by hole wall observation. It is not possible to directly read the data, and the complicated work of illustrating the data on a desk is required.

The present invention is based on the above considerations, and includes:
No matter how tilted the sonde with built-in scanner is, the direction the scanner head is facing can be calculated and the borehole wall can be continuously observed based on accurate position even in inclined holes.Borehole wall observation The purpose is to provide a method.

[Means for solving problems]

To this end, the borehole wall observation method of the present invention is a borehole wall observation method in which the borehole wall is continuously photographed using a scanner built into a sonde that moves up and down inside the borehole. Detect the direction of inclination of the sonde, the inclination angle of the sonde, and the direction of rotation of the sonde,
This method is characterized in that the hole wall is observed by calculating the position of the sonde, the inclination of the sonde, and the direction in which the scanner head built into the sonde is facing.

[Effect]

In the borehole wall observation method of the present invention, it is possible to grasp the observation position such as the position on the ground surface and the depth from the sonde position and the sonde inclination, and the situation such as the direction and angle of the hole bend. The observation position of the borehole wall can be accurately determined from the direction in which the borehole is facing.

〔Example〕

Examples will be described below with reference to the drawings.

Fig. 1 is a diagram showing an example of how the compass, inclinometer, and rotation meter are installed, Fig. 2 is a diagram for explaining the detection angle of the compass and inclinometer, and Fig. 3 is a system configuration of one embodiment of the present invention. 4 is a diagram for explaining the processing by the system shown in FIG. 3, and FIG. 5 is a diagram showing an example of display output by the system shown in FIG. 3.
In the figure, 1 is a sonde, 2 is a direction meter, 3 is an inclinometer, 4 is a rotation meter, 5 is a depth meter, 6 and 7 are calculation units,
8 is a storage unit, 9 is a control unit, 10 is an output control unit,
CL indicates each cable.

In the sonde 1 to which the present invention is applied, there is a first
In addition to the scanner components described in Figure 0,
As shown in FIG. 1, a compass 2 and an inclinometer 3 are provided as means for measuring hole bending, and a tachometer 4 is provided as a means for measuring the orientation of the scanner head. The compass 2 has first fulcrums A and A' that are rotatable around a line l that coincides with the axial direction of the sonde 1, as shown by the dotted line in the figure, and a line m that is orthogonal to the line l. It is attached to the sonde 1 at the fulcrums A and A' via the second fulcrums Q and Q', which have now become two fulcrums, and the measuring part is always supported in a state that does not change in the vertical direction from the ground, As will be described later with reference to FIG. 6, a magnet is built in to measure the inclination direction angle of the sonde 1. Similarly, the inclinometer 3 has fulcrums R and R' that are rotatable about line l, and the sonde 1 at points B and B'.
The measurement unit is attached to the sensor so that it rotates around the line l in accordance with the inclination of the sonde 1, and has a built-in weight as described later in FIG. 8.
Measure the inclination angle of sonde 1. Also, tachometer 4
is provided at the mounting fulcrum A of the compass 2, and measures the direction E that serves as the reference for the sonde 1.

Therefore, in the three-dimensional coordinate space consisting of x, y, and z shown in Figure 2, if the x-axis direction is the north-south direction, the y-axis direction is the east-west direction, and the z-axis direction is the direction of the earth's gravity. , the azimuth angle θ is the direction from the north, and the inclination angle φ is the inclination from the horizontal plane. For the sonde shown in FIG. 1, the azimuth angle θ shown in FIG. , Inclinometer 3
The inclination angle φ shown in FIG. 2 can be determined from the inclination angle indicated by . Therefore, now the reference point D shown in Figure 1 is set to the north direction, and this is set as the reference direction, and the azimuth angle θ and the inclination angle φ are 0 with the direction meter 2 and the inclinometer 3 shown in Figure 1. Suppose we define Then, for example, if the borehole is tilted northward by an angle α from the state shown in FIG.
The azimuth angle θ is 0, the inclination angle φ is α, and the rotation angle δ is 0. However, if the borehole is tilted toward the west by an angle α, the compass 2 and the inclinometer 3 are rotated 90° counterclockwise about line l.
Therefore, the azimuth angle θ is -90°, the inclination angle φ is α, and the rotation angle δ measured by the tachometer 4 is also
It becomes 90°. Also, here the sonde is 90° to the west.
When rotated (twisted), the azimuth angle θ and the inclination angle φ do not change, but only the rotation angle δ measured by the tachometer 4 changes to 0°. That is, the direction meter 2 and the inclinometer 3 measure the bending of the borehole, and the rotation meter 4 measures the direction of the sonde. In the case of measurement using a scanner, the direction in which the optical head 37 (scanner head) is facing can be determined by the amount of rotation (output from the direction meter 34) from the reference position E set in the sonde. . The tachometer 4 measures the orientation of the reference position E of the sonde in order to determine the orientation of the optical head 37 due to its twist. That is, as mentioned above, the azimuth of the reference position E of the sonde 1 is the azimuth angle θ measured by the azimuth meter 2.
It can be determined by adding the rotation angle δ measured by the tachometer 4 to . On the other hand, the direction indicator 34 of the scanner section indicates the direction of the optical head 37 (scanner head) from the reference position E of the sonde 1.
Since the direction in which the optical head 37 is facing is measured, the observation position of the scan data obtained from the photoelectric converter 39 can be determined by correcting the direction of the optical head 37 using this measured value. The observation position of this scan data can be calculated accurately by using a predetermined calculation formula based on data on the positional coordinates of the rotation center of the optical head 37, its direction, the diameter of the borehole, and the inclination of the borehole. can.

Next, the system shown in FIG. 3 will be explained. In FIG. 3, the depth gauge 5 is connected to the cable CL.
This device is installed on a ground limiter that controls the length of the cable CL that has been pulled out, and detects the length of the cable CL that has been pulled out. When the depth meter 5 detects that the length of the cable CL has reached the unit length, the calculation unit 6 reads the azimuth angle θ and the inclination angle φ from the compass 2 and the inclinometer 3, and calculates the length of the cable CL. Cable CL by each component corresponding to the coordinate space shown in Figure 2 from length ΔL, azimuth θ, and inclination angle φ
The protrusion lengths Δx, Δy, and Δz are calculated, and each is expressed as Δx=ΔL cosφ cosθ Δy=ΔL cosφ sinθ Δz=ΔL sinφ.

The arithmetic unit 7 stores the information from the storage unit 8 to the previous time Δx, Δy,
Sonde position coordinates determined by integrating Δz
Read X _i , Y _i , Z _i , add the protrusion lengths Δx, Δy, Δz calculated by the calculation unit 6, and calculate the current sonde position coordinates X _i+1 , Y _i+1 , Z _{i+ 1} , and each is expressed as X _i+1 = X _i +Δx Y _i+1 = Y _i +Δy Z _i+1 = Z _i +Δz.

Therefore, for example, if the opening is (0, 0, 0),
Point A 10m north, 30m west, 50m underground (10,
30, 50), the sonde moves from this position to θ=
0, If you extend the cable 10m in the direction of φ=30° and move it, the amount of change will be Δx=10×cos30°cos0=8.7 Δy=10×cos30°sin0=0 Δz=10×sin3°=5 , so its position (current position) is X _i+1 =10+8.7=18.7 Y _i+1 =30+0=30 Z _i+1 =50+5=55. In other words, 18.7m in the north direction and 30m in the west direction.
This means that the sonde is located 55m underground. Further, the calculation unit 7 calculates the observation position based on the rotation angle of the sonde from the tachometer 4 and the position of the sonde determined by the above calculation in response to the scan data from the scanner unit.

The storage unit 8 stores the sonde position coordinates X, Y, and Z calculated by the calculation unit 7 in chronological order, and also stores the corresponding sonde orientation, scan data, and its observation position. It is. The flow of processing up to storing the sonde position coordinates X, Y, and Z in the storage unit 8 in chronological order is shown in the fourth section.
It is a diagram. Then, the output control unit 10 converts the position coordinates X, Y, and Z stored in the storage unit 8 into, for example, a CRT.
You can draw and output the sonde trajectory on a display or XY plotter, or display it on a TV image.
It is used to output scan data as a hard copy. Note that a device for hard copying scan data has been separately proposed by the inventors of the present application (Japanese Patent Application No. 59-245664); For example, it is printed onto a film.
When observing the scan data of a diagonally curved borehole as a television image, the direction of the scan head is determined based on the sonde position and its inclination angle, that is, the coordinate values for each scan position ( This coordinate value is stored together with the scan data, and the point on the TV image of the fracture plane, strata plane, joint plane, etc. observed in the image is read with a light pen, etc.
By performing calculations in the calculation unit 7, the coordinates, strike, and inclination of the crack can be measured on the spot.

Figure 5a shows an example of the sonde trajectory drawn using a north-south cross section, and Figure 5b shows an example of the sonde trajectory drawn using an east-west cross section. Figure 5c shows an example of the trajectory of the sonde as seen in Figure 5c, and Figure 5d shows an example of the trajectory of the sonde drawn as a bird's eye diagram. Note that the control unit 9 includes each of the above-mentioned calculation units 6,
7. It controls the entire system including the storage section 8 and the output control section 10.

Fig. 6 shows an example of the compass used in the present invention, Fig. 7 shows an example of how the compass shown in Fig. 6 is attached, and Fig. 8 shows an example of the inclinometer used in the present invention. FIG. 9 is a diagram showing an example of how the compass shown in FIG. 8 is attached. In the figure, 11 and 21 are cases,
12 and 22 are specific gravity liquids, 13 and 23 are bearings, 14 are magnets, 15 and 25 are encoder plates, 16 and 26 are light receiving parts, 17 and 27 are light emitting parts, 24 is floating, 28
indicate the respective weights.

In the direction meter shown in FIG. 6, the specific gravity liquid 12 sealed in the case 11 is a transparent liquid, such as silicone liquid, such that the weight applied to the bearing 13 of the movable part consisting of the magnet 14 and the encoder plate 15 is almost zero. It's oil. By supporting the movable part in the specific gravity liquid 12 with a bearing 13, the magnet 14 exhibits smooth movement as the amount of gravity is corrected due to the buoyancy and viscosity of the specific gravity liquid 12, and the magnet 14 always points in the north direction. I'll be heading there. A light emitting section 17 and a light receiving section 16 are arranged opposite to the encoder plate 15 that moves together with the magnet 14, and the light emitting section 17 irradiates the encoder plate 15 with light, and the light receiving section 16 receives the light. Then determine the direction. To determine the direction,
For example, by using the position of the encoder plate 15 when the observation direction of the sonde is facing north as a reference, the observation direction of the sonde changes, and when the case 11 rotates according to this displacement, the light receiving section 6 Determine the rotation angle of the encoder plate 15 using the signal,
Determine the displacement from the north direction. FIG. 7 shows an example of how this compass is mounted. In FIG. 7, the case 11 is connected via the rotatable fulcrums A, A' and Q, Q', and is attached to the sonde at the fulcrums A, A'.
The line connecting the fulcrums A and A' is adjusted so that it is vertical (coinciding with the direction of the axis of the sonde) when the sonde is facing straight down. Therefore, even if the inclination of the sonde changes and the inclination of the line connecting the fulcrums A and A' changes, the attitude of the case 11 will not change, and the encoder plate 15 will be maintained in a horizontal state, achieving high measurement accuracy. Obtainable. In addition, if rotational movement occurs on the line connecting fulcrums A and A' with the direction of the sonde axis facing directly below or directly above, the output will be unstable, but in this case, the horizontal direction of the sonde Since the component is 0, the output of the compass 2 is not necessary.

In the inclinometer shown in FIG.
5 is attached with a float 24 and a weight 28.
The encoder plate 25 is vertically supported within the case 21 by a bearing 23 so that the side to which the weight 28 is attached always faces downward. Therefore, although FIG. 8b represents a side view (cross-sectional view) of FIG. The position of will change, and the inclination will be measured by detecting the amount of change. FIG. 9 shows an example of how this inclinometer is installed. 9th
In the figure, the case 21 is connected via the rotatable fulcrums R and R' as described above.
It is fixed to the sonde at fixed points B and B'. The line connecting these fixed points B and B' is adjusted so that it is vertical (in a direction that coincides with the axis of the sonde) when the sonde is facing straight down. Therefore, no matter which direction the sonde inclines, the case 21 will move B,
The encoder plate 2 rotates around the line connecting B'.
5 can always be maintained vertically and high measurement accuracy can be obtained. That is, the inclinometer is supported so that it does not tilt in the left-right direction as shown in FIG. 8a, but only in the left-right direction as shown in FIG. 8b as the sonde inclines.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the position of each point is calculated by detecting the inclination angle, inclination angle, and length of the borehole, so accurate observation can be made even if the borehole is curved. You can know the location and depth. Furthermore, since the direction of the scanner head is calculated by detecting the rotation of the sonde within the borehole, the observation position and depth of the scan data can be accurately determined. Furthermore, even if the hole is an inclined hole, each scan data can be used to determine the strike direction with respect to the absolute axis (vertical axis, N-S axis, E-W axis) from the observation image.
Observations can be made by measuring inclination information, and oblique faults in inclined holes can be observed continuously based on accurate positions.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of how the compass, inclinometer, and rotation meter are installed, Fig. 2 is a diagram for explaining the detection angle of the compass and inclinometer, and Fig. 3 is a system configuration of one embodiment of the present invention. , FIG. 4 is a diagram for explaining the processing by the system in FIG. 3, FIG. 5 is a diagram showing an example of display output by the system in FIG. 3, and FIG. 6 is a diagram for explaining the orientation used in the present invention. FIG. 7 is a diagram showing an example of how the direction meter shown in FIG. 6 is installed. FIG. 8 is a diagram showing an example of the inclinometer used in the present invention. Figure 10 showing an example of how to install the compass.
The figure shows a specific configuration example of a borehole and a scanner, and FIG. 11 is a diagram showing a locus of a developed surface of a hole wall scanned by a light beam. 1...sonde, 2...compassion meter, 3...inclined type,
4... Tachometer, 5... Depth gauge, 6 and 7... Calculation section, 8... Memory section, 9... Control section, 10... Output control section, 11 and 21... Case, 12 and 22... …
Specific gravity liquid, 13 and 23...Bearing, 14...Magnet, 1
5 and 25... Encoder plate, 16 and 26... Light receiving section, 17 and 27... Light emitting section, 24... Float, 28
... Weight, 31 ... Borehole, 32 ... Sonde, 33 ... Turning motor, 34 ... Direction indicator,
35 and 42...lens, 36...mirror, 37...
...Optical head, 38 and 41...Slit, 39...
...Photoelectric converter, 40...Half mirror, 43...
...Light source, CL...cable.

Claims (1)

[Claims] 1. A borehole wall observation method in which the borehole wall is continuously photographed using a scanner built into a sonde that moves up and down inside the borehole, and the length of the cable suspended from the ground, the direction of inclination of the sonde, and the angle of inclination of the sonde are , and detect the rotation direction of the sonde,
Sonde position, sonde tilt, and scanner built into the sonde. A borehole wall observation method characterized by calculating the direction in which the head is facing and observing the hole wall.