Ground condition measuring device

Abstract

To grasp moisture content and inclination state of ground without requiring much effort and time.SOLUTION: A tip end fixing member 5 and a base end fixing member 6 are held in a borehole 3 by being in close contact with a wall surface of the borehole 3, and a resistivity is measured using electrodes in close contact with the hole wall surface 3 to detect moisture content of the ground (moisture content detection means 8), and inclination detection means 7 detects relative movement between the tip end fixing member 5 and the base end fixing member 6 to measure the inclination of the ground.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a ground condition measuring device that measures the inclination and moisture condition of the ground. [Background technology]

[0002] The ground is constantly changing due to vibrations caused by earthquakes, etc., and the amount of moisture underground due to rainfall, etc. For this reason, in order to prevent landslides and other landslides, it is necessary to take measures by measuring, for example, the moisture status of the ground (layers) and the inclination status from the movement of the ground.

[0003] As a technique for grasping the amount of moisture in the ground, it is common to collect samples and measure (calculate) the amount of moisture, or to measure the condition of the wall of a borehole on-site. As a technique for grasping the movement of the ground, a technique for measuring the relative movement (tilt) of the ground by placing an inclinometer in a borehole has been known for some time (for example, see Patent Document 1).

[0004] In order to grasp the condition of the ground, methods such as installing tiltmeters to measure the tilt and carrying out excavation work to grasp the moisture content are being implemented. For this reason, the current situation is that it takes a lot of effort and time to grasp the condition of the ground accurately. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-216227 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a ground condition measuring device that can grasp the ground's inclination and moisture content without requiring a great deal of effort and time. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the ground condition measuring device of the present invention according to claim 1 is characterized in that it comprises a tip-side fixed member in which the tip-side movable part is expanded in diameter so that the tip-side movable part is in tight contact with the hole wall surface at the back side of the borehole, a base-end fixed member in which the base-end movable part is expanded in diameter so that the base-end movable part is in tight contact with the hole wall surface at the base end side of the borehole, a tilt detection means provided across the tip-side fixed member and the base-end fixed member, which measures the tilt condition, which is the relative movement of the base-end fixed member with respect to the tip-side fixed member, and a moisture content detection means provided on the tip-side movable part of the tip-side fixed member and / or the base-end movable part of the base-end fixed member, which detects the moisture content of the ground in the borehole.

[0008] In the present invention according to claim 1, the tip-side fixed member and the base-side fixed member are held in a borehole (for example, a borehole drilled in a slope) in close contact with the wall surface of the borehole, and the inclination detection means detects the relative movement between the tip-side fixed member and the base-side fixed member to measure the inclination of the ground. Then, the tip-side movable part and the base-side movable part are pressed against the wall surface of the borehole, so that the moisture detection means comes into close contact with the wall surface of the borehole and the moisture content of the ground is detected.

[0009] Therefore, for example, by digging a single borehole in any direction relative to the slope, such as vertical or horizontal, it is possible to perform inclination and moisture content measurements that are suitable for investigating landslides and lateral ground flow, making it possible to grasp the ground's inclination and moisture content without requiring a great deal of effort and time.

[0010] Because tilt and moisture content measurements can be performed in a single borehole, the monitoring conditions can be adjusted as needed depending on the site conditions, such as monitoring that focuses primarily on moisture content, monitoring that focuses primarily on tilt, or monitoring that measures both over a selected time series, allowing the ground conditions required for each site to be accurately grasped.

[0011] The ground condition measuring device of the present invention according to claim 2 is characterized in that, in the ground condition measuring device described in claim 1, the moisture content detection means has a plurality of electrodes in contact with the hole wall surface, a resistivity deriving means for deriving resistivity by a current applied to the electrodes, and a saturation degree detection means for determining the degree of saturation of the ground in the borehole based on the resistivity derived by the resistivity deriving means.

[0012] In the present invention of claim 2, a resistivity derivation means applies a current to an electrode in contact with the hole wall surface, and a resistivity is derived based on the applied current and a potential difference according to the arrangement of the electrodes, and a saturation degree detection means determines the degree of saturation of the ground based on the resistivity and measures the moisture content.

[0013] Furthermore, the ground condition measuring device of the present invention according to claim 3 is characterized in that, in the ground condition measuring device described in claim 2, the moisture content detection means has a long insulating member arranged across the tip movable part and the base movable part, and the multiple electrodes are attached to the hole wall surface side of the borehole of the insulating member, and are tightly attached to the hole wall surface of the borehole by expanding the diameter of the tip movable part and the base movable part.

[0014] In the present invention of claim 3, a metal (e.g., SUS) electrode attached to the outside of a long insulating member (e.g., polyvinyl chloride resin: PVC) is adhered to the wall surface of the hole in conjunction with the expansion of the tip movable part and the base movable part, thereby measuring the resistivity of the ground.

[0015] Furthermore, the ground condition measuring device of the present invention according to claim 4 is characterized in that, in the ground condition measuring device described in claim 3, the insulating members are elongated members having an arc-shaped cross section and are arranged in multiple numbers around the circumferential direction of the borehole.

[0016] In the present invention of claim 4, multiple (e.g., a pair) elongated insulating members having an arc-shaped cross section are arranged, so that when the multiple insulating members simultaneously expand in diameter in conjunction with the expansion of the tip movable part and the base movable part, the electrodes can be brought into surface contact with the curved wall surface of the cylindrical drilling hole. Effect of the Invention

[0017] The ground condition measuring device of the present invention makes it possible to grasp the moisture content and inclination condition of the ground without requiring a great deal of effort and time. [Brief description of the drawings]

[0018] [Figure 1] 1 is a conceptual diagram of an installed ground condition measuring device according to an embodiment of the present invention. [Diagram 2] 1 is an external view of a ground condition measuring device according to an embodiment of the present invention. [Diagram 3] 1 is an exploded perspective view of a ground condition measuring device according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of a ground condition measuring device according to an embodiment of the present invention installed. [Diagram 5] FIG. 2 is a block diagram of a control means. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Fig. 1 shows the concept of a ground condition measuring device according to an embodiment of the present invention installed in a borehole that has been bored vertically across different strata in the ground that constitutes a slope. For the sake of convenience, the state in Fig. 1 is shown in proportion to the depth of the borehole, the size of the strata of the ground, and the actual size of the device configuration.

[0020] As shown in the figure, for example, in the ground constituting a slope, a borehole 3 is formed (in the vertical direction) across different strata (lower stratum 1, upper stratum 2), and a situation measurement device (measurement device) 4 is installed in the borehole 3. The measurement device 4 is equipped with a tip-side fixing member 5 (packer) and a base-side fixing member 6 (packer).

[0021] The tip movable part 5a (see Figure 2) of the tip fixed member 5 is expanded in diameter, for example, by driving a piston, and as the tip movable part 5a (see Figure 2) is expanded in diameter, the tip movable part 5a (see Figure 2) is brought into close contact with the hole wall surface 3a (see Figure 4) at the back side of the borehole 3 (lower stratum 1).

[0022] The base end movable part 6a (see Figure 2) of the base end fixed member 6 is expanded in diameter, for example, by driving a piston, and as the base end movable part 6a (see Figure 2) is expanded in diameter, the base end movable part 6a (see Figure 2) is tightly attached to the hole wall surface 3a (see Figure 4) on the base end side (upper stratum 2) of the borehole 3.

[0023] The measuring device 4 is provided with a tilt detection means 7 extending from the tip side fixed member 5 to the base side fixed member 6, and the tilt detection means 7 measures the tilt condition, which is the relative movement of the base side fixed member 6 with respect to the tip side fixed member 5 (the deviation between the lower stratum 1 and the upper stratum 2).

[0024] In addition, the measuring device 4 is provided with a moisture content detection means 8 extending from the tip movable part 5a (see Figure 2) of the tip fixed member 5 to the base movable part 6a (see Figure 2) of the base fixed member 6, and the moisture content of the ground is detected (derived) by the moisture content detection means 8 (means including a resistivity derivation function and a saturation degree detection means in the control means described later).

[0025] The information detected by the inclination detection means 7 and the moisture content detection means 8 is managed by the control means 9, which grasps the inclination state and moisture content of the ground.

[0026] The tip-side fixing member 5 and the base-side fixing member 6 are in close contact with the hole wall surface 3a (see FIG. 4) of the borehole 3 to hold the measuring device 4 in the borehole 3. If a shift occurs in the stratum, the inclination detection means 7 detects the relative movement between the tip-side fixing member 5 and the base-side fixing member 6, and measures the inclination of the ground.

[0027] Then, when the tip movable part 5a (see Figure 2) and the base movable part 6a (see Figure 2) are pressed against the hole wall surface 3a (see Figure 4) of the borehole 3, the moisture content detection means 8 comes into close contact with the hole wall surface 3a (see Figure 4) and the moisture content of the ground is detected.

[0028] Therefore, for example, by drilling one borehole 3 into ground that forms a slope, it is possible to simultaneously measure the inclination and moisture content. This makes it possible to measure the inclination and moisture content suitable for investigating landslides and lateral ground flow using one device depending on the condition of the inclination, ground, and environment, making it possible to grasp the condition of the inclination and moisture content of the ground without requiring a lot of effort and time.

[0029] Since both inclination and moisture content measurements can be performed in a single borehole 3, the monitoring conditions can be adjusted as desired depending on the site conditions, such as monitoring that focuses primarily on moisture content, monitoring that focuses primarily on inclination, or monitoring that measures both in any desired time series, allowing the ground conditions required for each site to be accurately grasped.

[0030] In the example shown in Figure 1, the measuring device 4 is placed in a borehole 3 formed in the vertical direction relative to the ground that forms the slope, but the measuring device 4 can be placed in a borehole formed in any direction, such as a borehole formed in the horizontal direction relative to the ground that forms the slope.

[0031] The configuration of the measuring device 4 will be specifically described with reference to FIGS.

[0032] Fig. 2 is a perspective view showing the overall appearance of the measuring device 4, Fig. 3 is a perspective view showing the appearance of the measuring device in an exploded state, and Fig. 4 shows a cross section of the measuring device 4 fixed (installed) in the borehole 3. Also, Fig. 5 shows the block function status of the main parts of the control means 9.

[0033] 2 to 4, the tip side fixing member 5 has a tip body 11 equipped with a driving means for expanding the diameter. A pair of tip movable parts 5a having an arc-shaped cross section is supported by the driving part of the tip body 11. The pair of tip movable parts 5a expand in diameter by the operation of the driving part of the tip body 11, and the tip movable parts 5a having an arc-shaped cross section are fixed in close contact with the hole wall surface 3a of the borehole 3.

[0034] The base end fixing member 6 also has a base end body 12 equipped with a driving means for expanding the diameter. A pair of base end movable parts 6a having an arc-shaped cross section is supported by the driving part of the base end body 12. The pair of base end movable parts 6a expand in diameter by the operation of the driving part of the base end body 12, and the base end movable parts 6a having an arc-shaped cross section are fixed in close contact with the hole wall surface 3a of the drilling hole 3.

[0035] The measuring device 4 is fixed to the borehole 3 by closely fixing the tip movable part 5a of the tip fixed member 5 and the base movable part 6a of the base fixed member 6 to the hole wall surface 3a of the borehole 3.

[0036] The tilt detection means 7 will now be described.

[0037] An inclination detection means 7 is provided across the tip side fixed member 5 and the base end fixed member 6. That is, one end (lower end) of a long measurement bar 14 is supported on the tip main body 11 of the tip side fixed member 5 via a universal joint 13. Moreover, the other end (lower end) of the long measurement bar 14 is supported on the base main body 12 of the base end fixed member 6 via a universal joint 15.

[0038] A tilt sensor 16 is provided in the center of the measurement bar 14, and, for example, the tilt movement of the measurement bar 14 is electrically measured by the tilt sensor 16, and the relative movement between the tip end fixing member 5 and the base end fixing member 6 is detected as the tilt movement of the measurement bar 14, and the inclination of the ground is determined.

[0039] Reference numeral 20 in the figure denotes a reinforcing cylindrical member fixed to the base end body 12, and is a member that prevents the opening at the base end side (upper end side) of the drilled hole 3 from collapsing.

[0040] The moisture content detection means 8 will now be described.

[0041] An elongated insulating member 17 (e.g., made of polyvinyl chloride resin) having an arc-shaped cross section is attached to each of the distal movable part 5a of the distal fixed member 5 and the proximal movable part 6a of the proximal fixed member 6. A pair of insulating members 17 are provided in the circumferential direction of the drilling hole, facing each other.

[0042] The pair of insulating members 17 are adapted to expand (contract) in diameter inside the drilling hole 3 in conjunction with the expanding (contracting) movement of the tip movable part 5a and the base movable part 6a. They are adapted to expand and contract inside the drilling hole in conjunction with the expanding and contracting of the tip movable part and the base movable part.

[0043] A plurality of electrodes 18 (e.g., made of SUS: resistivity derivation means) are attached to the insulating member 17 on the side (outside) of the hole wall surface 3a of the drilling hole 3, and the plurality of electrodes 18 are brought into close contact with the hole wall surface 3a of the drilling hole 3 via the insulating member 17 by expanding the diameter of the tip movable part 5a and the base movable part 6a.

[0044] A pair (or multiple) of elongated insulating members 17 having an arc-shaped cross section are arranged, so that when the pair of insulating members 17 simultaneously expand in diameter in conjunction with the expansion of the tip movable part 5a and the base movable part 6a, the electrode 18 can be brought into surface contact with the curved hole wall surface 3a of the cylindrical drilling hole 3.

[0045] With the electrode 18 in surface contact with the hole wall surface 3a of the borehole 3, a current is applied to the electrode 18 by command of the control means 9 (see FIG. 1). The control means 9 (see FIG. 1) derives resistivity based on the applied current and the potential difference according to the arrangement of the electrodes (resistivity deriving means), and determines the degree of saturation of the ground based on the resistivity (degree of saturation detection means) to measure the moisture content.

[0046] 5, the control means 9 has a resistivity deriving function 21 (resistivity deriving means). The resistivity deriving function 21 applies a current to the electrode 18 and derives a resistivity based on the applied current and a potential difference according to the arrangement of the electrode 18.

[0047] The control means 9 also has a saturation degree detection function 22 (saturation degree detection means). Information on the resistivity derived by the resistivity derivation function 21 is input to the saturation degree detection function 22, and the resistivity derivation function 21 determines the saturation degree (degree of saturation) of the ground based on the resistivity and determines (derives) the moisture content.

[0048] The control means 9 also has a tilt detection function 23. Detection information from the tilt detection means 7 (tilt sensor 16) is input to the tilt detection function 23. Based on the detection information from the tilt sensor 16, the tilt detection function 23 determines the relative movement between the tip-side fixing member 5 (see FIG. 1) and the base-side fixing member 6 (see FIG. 1) and grasps (measures) the tilt of the ground.

[0049] Information on the saturation degree of the ground obtained by the saturation degree detection function 22 and the condition of the inclination of the ground determined by the inclination detection function 23 are input to a judgment function 24. That is, in the judgment function 24, information on the saturation degree of the ground and the condition of the inclination of the ground are grasped simultaneously (the inclination and the moisture content are measured simultaneously).

[0050] Information on the saturation level (moisture content) of the ground and the inclination state of the ground grasped by the judgment function 24 are displayed by a display means or the like as necessary.

[0051] The information grasped by the judgment function 24 enables appropriate inclination measurements and moisture content measurements to be made when investigating landslides and lateral ground flow, depending on the slope conditions (natural slope, embankment, etc.), ground conditions (type and depth of rock, etc.), and environmental conditions.

[0052] An example of information output from the judgment function 24 is information showing changes in moisture content and inclination simultaneously. Also, when the moisture content exceeds a predetermined amount, the inclination is grasped and judged, and information for taking appropriate measures (such as draining water or solidifying) based on the moisture content and inclination is also output.

[0053] By displaying the degree of saturation (moisture content) of the ground and the inclination of the ground grasped by the judgment function 24, the monitoring conditions can be adjusted arbitrarily based on the moisture content and inclination measured in one borehole 3 (see Figure 1) depending on the on-site conditions, such as monitoring that focuses mainly on moisture content, monitoring that focuses on inclination, or monitoring that measures both in an arbitrary time series, and the ground conditions required for each site can be accurately grasped.

[0054] The above-mentioned measuring device 4 can measure moisture content and inclination in a single borehole 3, making it possible to grasp the moisture content and inclination conditions of the ground without requiring a great deal of effort and time. [Industrial Applicability]

[0055] The present invention can be used in the industrial field of ground condition measuring devices that measure the moisture and inclination conditions of the ground. [Explanation of symbols]

[0056] 1 Lower stratum 2. Upper Strata 3. Borehole 4. Situation measurement device (measurement device) 5 Tip fixing member 6 Base end fixing member 7 Tilt detection means 8. Means for detecting moisture content 9. Control Means 11 Tip body 12 Base end body 13, 15 Universal joint 14 Measuring Bar 16 Tilt Sensor 17 Insulating materials 18 electrodes 20 Reinforcing tube member 21 Specific resistance derivation function 22 Saturation detection function 23 Tilt detection function 24 Judgment function

Claims

1. A tip side fixing member in which the tip movable part is expanded in diameter so that the tip movable part is in close contact with the hole wall surface at the back of the drilling hole; A base end side fixing member in which the base end movable part is expanded in diameter to bring the base end movable part into close contact with the base end side hole wall surface of the drilled hole; a tilt detection means provided across the distal fixed member and the proximal fixed member, the tilt detection means detecting a tilt state, which is a relative movement of the proximal fixed member with respect to the distal fixed member; a moisture content detection means provided on the tip movable portion of the tip side fixed member and / or the base end movable portion of the base end fixed member for detecting the moisture content of the ground in the borehole; A ground condition measuring device characterized by the above.

2. The ground condition measuring device according to claim 1, The moisture content detection means is A plurality of electrodes in contact with the wall surfaces of the hole; A resistivity deriving means for deriving a resistivity based on a current applied to the electrode; a saturation degree detection means for determining a saturation degree of the ground in the borehole based on the resistivity derived by the resistivity derivation means. A ground condition measuring device characterized by the above.

3. The ground condition measuring device according to claim 2, The moisture content detection means is a long insulating member disposed across the distal end movable portion and the proximal end movable portion; The plurality of electrodes include The insulating member is attached to the wall surface side of the drilled hole, and the distal end movable part and the proximal end movable part are expanded in diameter to be in close contact with the wall surface of the drilled hole. A ground condition measuring device characterized by the above.

4. The ground condition measuring device according to claim 3, The insulating member is A long member having an arc-shaped cross section, and a plurality of members are arranged in the circumferential direction of the borehole. A ground condition measuring device characterized by the above.

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