JP7316241B2 - SOIL MEASUREMENT DEVICE AND SOIL MEASUREMENT METHOD - Google Patents

Description

The present invention relates to a soil measuring device and a soil measuring method.

Techniques have been proposed for measuring the quality of soil by measuring the electrical resistance of the soil on the ground with electrodes in contact with the ground. For example, in Patent Document 1, soil measured by measuring the electrical resistance of the soil by pressing the lower ends of a plurality of vertically extending rod-shaped electrodes into embankment that has been compacted by a roller compactor. A technique for obtaining the degree of compaction of the soil based on the correlation between the electrical resistance of the soil and the dry density of the soil is disclosed.

Japanese Patent No. 3416908

By the way, the quality control of the heaping is often performed after some time has passed since the roller compaction, and there is a good possibility that the surface will dry during that time. When the above technique is used to measure an embankment with a dry surface, an extremely large electrical resistance is output that is out of the correlation between the electrical resistance of the soil and the dry density of the soil. There is a problem that it is not possible to obtain

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a soil measuring device and a soil measuring method capable of measuring the electrical resistance of ground soil while reducing the influence of drying of the soil.

The present invention comprises an electrode section that contacts the ground, and a measuring section that measures the electrical resistance of soil on the ground using the electrode section, and the electrode section has a protruding portion whose tip reaches below the ground. is.

The reason why the correct electrical resistance is not measured on soil with a dry surface may be that the dry surface of the soil creates a fine gap between the electrode and the current, making it difficult for the current to flow. There is Therefore, according to this configuration, in the soil measuring device provided with the electrode portion that contacts the ground and the measuring portion that measures the electric resistance of the soil on the ground by the electrode portion, the tip portion of the electrode portion is positioned below the ground. It has a protruding part to reach. As a result, it is possible to reliably bring the electrode section into contact with the moist soil below the ground, and to measure the electric resistance of the soil on the ground while reducing the influence of drying of the soil.

In this case, it is preferable that the electrode section has a plurality of protrusions each having a different depth to which the tip reaches below the ground.

According to this configuration, since the electrode section has a plurality of protrusions each having a different depth to which the tip reaches below the ground, the depth of the water-containing soil below the ground can be varied by a simple configuration. Expands the range of responses to situations.

In addition, it is preferable that the electrode section has a protrusion that can change the depth at which the tip reaches below the ground.

According to this configuration, since the electrode part has a protrusion whose tip reaches below the ground at a variable depth, it is possible to cope with situations where the depth of the water-containing soil below the ground varies. spread further.

Further, the electrode portion moves on the ground while being in contact with the ground, and in the direction along the ground, the width of the projection portion in the direction in which the electrode portion moves on the ground is perpendicular to the direction in which the electrode portion moves on the ground. It is preferably equal to or greater than the width of the direction.

According to this configuration, the electrode portion moves on the ground while being in contact with the ground, and in the direction along the ground, the width in the direction in which the electrode portion moves on the ground is the width in the direction perpendicular to the direction in which the electrode portion moves on the ground. Since the width is greater than or equal to the width, when the electrode moves on the ground while being in contact with the ground, the tip of the protrusion can easily reach below the ground.

Moreover, it is preferable that the electrode part has a flexible surface part at the base of the projection part that follows the unevenness of the ground.

According to this configuration, since the electrode part has a flexible surface part at the base of the projection part that follows the unevenness of the ground, fine particles that may be generated between the electrode part and the ground due to the drying of the surface of the soil are eliminated. The effect of drying the soil can be reduced by filling the gaps and ensuring contact between the electrodes and the ground.

On the other hand, the present invention is a soil measurement method for measuring the electrical resistance of soil on the ground by means of an electrode portion that is in contact with the ground. This is a soil measurement method for measuring electrical resistance.

In this case, the electric resistance of the soil on the ground is measured while the tips of the protrusions of the electrode part, which has a plurality of protrusions each having a different depth to reach below the ground, reach below the ground. is preferred.

Further, it is preferable to measure the electric resistance of the soil on the ground while the tip of the protrusion, whose depth to which the tip reaches below the ground can be changed, reaches below the ground.

Also, the electrode part is moved on the ground while being in contact with the ground, and the width of the electrode part in the direction along the ground in the direction of movement on the ground is greater than or equal to the width in the direction perpendicular to the direction in which the electrode part moves on the ground. It is preferable to measure the electrical resistance of the soil on the ground while the tip of the protrusion of the electrode section having the ridge reaches below the ground.

According to the soil measuring device and the soil measuring method of the present invention, it is possible to measure the electrical resistance of soil on the ground while reducing the influence of drying of the soil.

(A) is a plan view showing the configuration of the soil measuring device of the first embodiment, and (B) is a side view showing the configuration of the soil measuring device of the first embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 1st Embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 2nd Embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 3rd Embodiment. (A) is a plan view showing the configuration of a soil measuring device according to a fourth embodiment, and (B) is a side view showing the configuration of the soil measuring device according to a fourth embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 4th Embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 5th Embodiment. It is a perspective view which shows the electrode part of the soil-measurement apparatus of 6th Embodiment.

EMBODIMENT OF THE INVENTION Hereafter, embodiment of the soil-measurement apparatus based on this invention and a soil-measurement method is described in detail, referring drawings. A soil measuring device and a soil measuring method according to a first embodiment of the present invention measure the electrical resistance of ground soil after it has been compacted by a compaction machine such as a road roller, for example, and measure the electrical resistance of the soil that correlates with the electrical resistance. This is to confirm the effect of compaction by a compaction machine by deriving the dry density, etc. As shown in FIG. 1A, a soil measurement apparatus 1A according to the first embodiment of the present invention includes a left frame portion 2, a right frame portion 3, a left frame portion 2, and a right frame portion 3. and a central frame portion 4A that connects the

The total lengths of the left frame portion 2 and the right frame portion 3 are, for example, about 500 to 1000 mm. The overall width of the left frame portion 2 and the right frame portion 3 is, for example, approximately 100 to 400 mm. The total length of the central frame portion 4A is, for example, approximately 200 to 500 mm. The overall width of the central frame portion 4A is, for example, approximately 100 to 400 mm. As will be described later, the soil measuring device 1A of this embodiment can be self-propelled on the ground. That is, the soil measuring device 1A of this embodiment has a form like a model car, for example.

The soil measuring device 1A has a total of four electrode portions 5A in contact with the ground at both the left and right ends of the left frame portion 2 and the right frame portion 3, respectively, and the electrode portions 5A in the central frame portion 4A. and a measuring unit 11 for measuring resistance. As shown in FIG. 1(B), the electrode portion 5A forms a zone surrounding the front wheel 6, the rear wheel 7, and the front wheel 6 and the rear wheel 7 with their inner peripheral surfaces 8i. It has a track-like electrode 8 which is in contact with the ground S with its outer peripheral surface 8o between the ring 7. As shown in FIG. As the crawler belt electrode 8 rotates around the front wheel 6 and the rear wheel 7, the electrode part 5A is in contact with the ground S by the outer peripheral surface 8o of the crawler belt electrode 8 between the front wheel 6 and the rear wheel 7. Move S in direction X.

The crawler-belt-shaped electrode 8 is a continuous band made of synthetic resin such as rubber in which a metal electrode is embedded, or a continuous metal band whose entirety is an electrode. Electrode portion 5A further includes auxiliary wheel 9 that supports inner peripheral surface 8i of crawler belt-shaped electrode 8 in a range where outer peripheral surface 8o of crawler belt-shaped electrode 8 contacts ground S. As shown in FIG. The front wheels 6, the rear wheels 7 and the auxiliary wheels 9 are suspended by a suspension device so that the outer peripheral surface 8o of the crawler belt electrode 8 is always in close contact with the ground S in the range in which it contacts the ground S regardless of unevenness or rigidity of the ground S. has been

The electrode section 5A has a driving section 10 that causes the crawler belt-shaped electrode 8 to move the ground S by rotating the crawler belt-shaped electrode 8 around the front wheels 6 and the rear wheels 7 . The drive unit 10 rotates the crawler belt electrode 8 around the front wheels 6 and the rear wheels 7 by rotating either the front wheels 6 or the rear wheels 7 using an electric motor, an internal combustion engine, or the like. As a result, the soil measuring device 1A of the present embodiment can run on the ground S in the direction X by itself. Further, by changing the projection length of each of the crawler belt-shaped electrodes 8 in the direction Y perpendicular to the direction X from the left frame portion 2 and the right frame portion 3, each of the crawler belt-shaped electrodes 8 of the electrode portion 5A can be changed. The interval in the direction Y perpendicular to the direction X in which the moves on the ground S can be changed arbitrarily.

It is conceivable that the contact area and contact time between the crawler-shaped electrode 8 and the ground S, which can reduce the measurement error, differ depending on the soil of each work site. Therefore, the drive unit 10 can adjust the speed of moving the crawler-belt-shaped electrode 8, and can set the speed appropriately for each work site. It is preferable that the speed of the crawler-belt-shaped electrode 8 is as fast as possible, because it shortens the time required for measurement. It should be noted that the crawler belt electrode 8 may be moved by pulling the soil measuring apparatus 1A with a self-propelled compaction machine such as a road roller, an electric standing two-wheeled vehicle, or human power. Alternatively, the crawler belt electrode 8 may be moved by integrating the soil measuring apparatus 1A with a self-propelled compaction machine such as a road roller.

A total of four electrode units 5A as described above are arranged in parallel in a direction Y perpendicular to the direction X in which the electrode units 5A of the soil measuring device 1A move on the ground in a direction along the ground S. For example, the Wenner method measures the electrical resistance of the soil. As shown in FIG. 1A, the measuring section 11 arranged on the central frame section 4A measures the electric resistance of the soil of the ground S using four electrode sections 5A. It should be noted that the fact that the measurement unit 11 measures the electrical resistance of the soil on the ground S does not necessarily mean only calculating the numerical value of the electrical resistance of the soil. It also includes outputting information about, etc.

Details of the electrode portion 5A of the present embodiment will be described below. As shown in FIG. 2, the electrode portion 5A has a plurality of protrusions 21A with the tip portions 22 reaching below the ground S on the outer peripheral surface 8o of the crawler belt-shaped electrode 8. As shown in FIG. For example, when the tip 22 reaches below the ground S, the tip 22 of the protrusion 21A contacts soil at a lower altitude than the highest point on the ground S in the range where the electrode part 5A is in contact. means to The projecting portion 21A has a plate-like shape, a conical shape, or a pyramidal shape with a pointed tip portion 22 . In this embodiment, each of the plurality of protrusions 21A has the same shape.

In the direction along the ground surface S of the electrode portion 5A, that is, on the outer peripheral surface 8o of the crawler belt-shaped electrode 8, a plurality of projection portions 21A are arranged in the direction X in which the electrode portion 5A moves on the ground surface S, and the electrode portion 5A moves toward the ground surface S. A plurality of protrusions 21A are arranged in a direction Y perpendicular to the direction X in which the . In this embodiment, three protrusions 21A are arranged in a direction Y perpendicular to the direction X in which the electrode portion 5A moves on the ground S. As shown in FIG. In the direction along the ground S, the protrusion 21A has a width W in a direction X in which the electrode portion 5A moves on the ground S, and a width w in a direction Y perpendicular to the direction X in which the electrode portion 5A moves on the ground S is greater than or equal to w. be. The protruding length from the base portion 23 of the protruding portion 21A, that is, the outer peripheral surface 8o of the crawler belt-shaped electrode 8 is, for example, 5 mm to 200 mm.

5 A of electrode parts have the flexible surface part 24 which follows the unevenness|corrugation of the ground S in the base 23 of 21 A of projection parts. The flexible surface portion 24 covers the entire outer peripheral surface 8o of the crawler belt-shaped electrode 8 in a layered manner. The soft surface portion 24 is made of, for example, either conductive sponge or conductive gel.

The soil measurement device 1 includes a positioning section 12 for acquiring the position of the crawler belt-shaped electrode 8 on the central frame section 4A. The measurement unit 11 measures the electrical resistance of the soil of the ground S associated with the position of the crawler belt-shaped electrode 8 acquired by the positioning unit 12 . The position of the soil measuring device 1, such as the central frame portion 4A, may be regarded as the position of the crawler belt electrode 8. FIG. The positioning unit 12 measures the position of the crawler belt-like electrode 8 by, for example, GNSS (Global Navigation Satellite System) surveying. In GNSS surveying, the position of the crawler-shaped electrode 8 (for example, the latitude and longitude of the crawler-shaped electrode 8) is measured by receiving signals from three or more satellites. Instead of GNSS surveying, the position of the crawler belt-like electrode 8 may be measured by an automatic tracking TS (Total Station) using an optical surveying function.

The soil measurement device 1A includes a communication section 13, which is a receiving section for receiving command signals to the driving section 10 and the measuring section 11, in the central frame section 4A. As a result, the operations of the drive unit 10 and the measurement unit 11 are controlled by remote control using command signals received by the communication unit 13 . The communication unit 13 transmits information about the electrical resistance of the soil of the ground S measured by the measurement unit 11 . In addition, the measurement result by the measurement part 11 may be recorded on the recording device mounted in 1 A of soil-measurement apparatuses.

The soil measurement apparatus 1A also includes a control section 14 that controls the operations of the drive section 10 and the measurement section 11 in the central frame section 4A. Further, the controller 14 may control the soil measuring device 1A to move behind a self-propelled compaction machine such as a road roller, for example. Further, the control unit 14 may control the soil measuring device 1A to move along an arbitrary route on the work site.

In the soil measurement method using the soil measurement device 1A of the present embodiment, for example, the soil measurement device 1A is moved on the ground S, and the electrical resistance of soil at an arbitrary location on the work site is measured. In the soil measurement method of the present embodiment, in which the electrical resistance of the soil of the ground S is measured by the electrode portion 5A in contact with the ground S, the tip portion 22 of the projection portion 21A of the electrode portion 5A is caused to reach below the ground S, The electrical resistance of the soil of the ground S is measured. The electrode part 5A is moved on the ground S while being in contact with the ground S, and in the direction along the ground S, the electrode part 5A moves in the direction X in which the tip part 22 reaches below the ground S. The tip 22 of the protrusion 21A of the electrode 5A having the protrusion 21A whose width W is greater than or equal to the width w in the direction Y perpendicular to the direction X in which the electrode 5A moves on the ground S is caused to reach below the ground S. Meanwhile, the electrical resistance of the soil of the ground S is measured.

Since it is known that there is a correlation between the electrical resistance of soil and the dry density of soil, the dry density of soil can be derived based on the electrical resistance of soil. It is possible to confirm the effect of compaction by the compaction machine by the derived dry density of the soil. The measurement unit 11 may derive the dry density of the soil based on the measured electrical resistance of the soil, and the communication unit 13 may transmit the derived dry density of the soil. In addition, the measurement unit 11 outputs information on the current value and voltage value detected by the electrode unit 5 and information on the electrical resistance of the soil, the communication unit 13 transmits the information, and the dry density of the soil is derived. It may be performed by a mobile communication terminal outside the soil measuring device 1A.

The reason why the correct electrical resistance is not measured on soil with a dry surface may be that the dry surface of the soil creates a fine gap between the electrode and the current, making it difficult for the current to flow. There is Therefore, according to the present embodiment, in the soil measuring device 1A including the electrode portion 5A that contacts the ground S and the measuring portion 11 that measures the electrical resistance of the soil of the ground S with the electrode portion 5A, the electrode portion 5A is , the tip 22 has a protrusion 21A reaching below the ground S. As a result, it is possible to reliably bring the electrode portion 5A into contact with the water-containing soil below the ground S, and to measure the electric resistance of the soil on the ground while reducing the influence of drying of the soil.

Further, according to the present embodiment, the electrode portion 5A moves on the ground S while being in contact with the ground S, and in the direction along the ground S, the protrusion 21A has a width W in the direction X in which the electrode portion 5A moves on the ground S. is greater than or equal to the width w in the direction Y perpendicular to the direction X in which the electrode portion 5A moves on the ground S. is easier to reach below the ground S.

Further, according to the present embodiment, since the electrode portion 5A has the flexible surface portion 24 at the base portion 23 of the protruding portion 21A that follows the unevenness of the ground S, the electrode portion 5A and the ground S are separated by drying the surface of the soil. By filling minute gaps that may have occurred between them and ensuring contact between the electrode portion 5A and the ground S, the influence of drying of the soil can be reduced.

A second embodiment of the present invention will be described below. As shown in FIG. 3 , in the soil measurement device 1B of the present embodiment, the electrode section 5B has a plurality of protrusions 21B with different depths for the tip section 22 to reach below the ground surface S. As shown in FIG. In this embodiment, three projections 21B are arranged in a direction Y perpendicular to the direction X in which the electrode part 5A moves on the ground S, and from the outer peripheral surface 8o of the crawler belt-shaped electrode 8 of each of the three projections 21B, have different protruding lengths. In the soil measuring method using the soil measuring apparatus 1B of the present embodiment, the tip 22 of the projection 21B of the electrode part 5B having a plurality of projections 21B with different depths to reach below the ground S is made to reach below the ground S, the electrical resistance of the soil of the ground S is measured.

According to the present embodiment, since the electrode portion 5B has a plurality of protrusions 21B with different depths at which the tip portions 22 reach below the ground S, the water below the ground S is contained by a simple configuration. Greater coverage for situations with different soil depths.

A third embodiment of the present invention will be described below. As shown in FIG. 4, in the soil measuring device 1C of the present embodiment, the electrode section 5C has a protruding section 21C that can change the depth at which the tip section 22 reaches below the ground. For example, the projections 21C can change the projection lengths of the plurality of projections 21C from the outer peripheral surface 8o of the crawler-belt-shaped electrode 8 by power from an electric motor or hydraulic pressure. In the soil measuring method using the soil measuring device 1C of the present embodiment, the tip 22 of the protrusion 21C, which can change the depth at which the tip 22 reaches below the ground S, reaches below the ground S. Meanwhile, the electrical resistance of the soil of the ground S is measured.

According to the present embodiment, since the electrode portion 5C has the protrusion 21C whose depth at which the tip portion 22 of the protrusion 21C reaches below the ground S can be changed, the water-containing soil below the ground S can be The range of support for situations with different depths is further expanded.

A fourth embodiment of the present invention will be described below. As shown in FIGS. 5(A) and 5(B), the soil measuring device 1D of this embodiment has driving wheels 16 for moving the soil measuring device 1D on the ground S on the central frame portion 4B. It has a drive unit 15 that The electrode section 5D has auxiliary wheels 17 and a traction body 18 that is pulled by the central frame section 4B. The electrode section 5D has four wheel-shaped electrodes 19 on the rear portion of the traction body 18. As shown in FIG. An outer peripheral surface 19 o of the wheel-shaped electrode 19 contacts the ground S.

The wheel-shaped electrode 19 has a diameter of, for example, 100 mm to 200 mm. The width of the electrode portion 5D of the wheel-shaped electrode 19 in the direction Y perpendicular to the direction X in which it moves on the ground S is, for example, 10 mm to 30 mm. The contact length in the direction X in which the electrode portion 5D of the wheel-shaped electrode 19 moves on the ground S is, for example, 20 mm to 30 mm. Intervals in the direction Y perpendicular to the direction X in which the electrode portions 5D of the wheel-shaped electrodes 19 of the electrode portions 5D move on the ground S can be arbitrarily changed, for example, 200 mm, 300 mm, and 750 mm.

As shown in FIG. 6, the electrode section 5D of the soil measuring device 1D of the present embodiment has a protrusion 21A on the outer peripheral surface 19o of the wheel-shaped electrode 19, similar to that of the first embodiment. For example, the protrusions 21A may protrude from the outer peripheral surface 19o while being adjacent to each other at a narrower interval than in FIG. 6, like teeth of a sprocket. Others are the same as those of the first embodiment. As in the present embodiment, the soil measuring device 1D provided with the wheel-shaped electrodes 19 also has the same effect as the first embodiment.

Further, as shown in FIG. 7, the electrode unit 5E of the soil measuring device 1E of the fifth embodiment of the present invention has the electrode section 5E of the second embodiment on the outer peripheral surface 19o of the wheel-shaped electrode 19 similar to that of the fourth embodiment. It has a protrusion 21B similar to the form. Others are the same as those of the fourth embodiment. As in the present embodiment, the soil measuring device 1E provided with the wheel-shaped electrode 19 also has the same effect as the second embodiment.

Further, as shown in FIG. 8, the electrode section 5F of the soil measuring device 1F according to the sixth embodiment of the present invention has the outer peripheral surface 19o of the wheel-shaped electrode 19 similar to that of the fourth embodiment. It has a protrusion 21C similar to the form. Others are the same as those of the fourth embodiment. Even in the soil measuring device 1F provided with the wheel-shaped electrodes 19 as in this embodiment, the same effects as in the third embodiment can be obtained.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be implemented in various forms. For example, the soil whose electric resistance is measured by the soil measuring device and soil measuring method of the above embodiment includes not only general soil but also gravel and the like obtained at a construction site in the CSG (Cemented Sand and Gravel) method containing cement. Also included are those that are added and mixed, and those that are spread with ultra-hard kneaded concrete with a reduced amount of cement in the RCD (Roller Compacted Dam-Concrete) construction method and compacted with a vibrating roller or the like.

Further, for example, in the above embodiment, the dry density of the soil is derived based on the measured electrical resistance of the soil of the ground S, and the derived dry density of the soil is used to confirm the effect of compaction by the compaction machine. Although aspects have been described, for example, confirmation of compaction effects by a compaction machine may be performed using a combination of other techniques and the technique of the present embodiment. Moreover, the measurement of the electrical resistance of soil according to the present embodiment may be performed not only for derivation of the dry density of soil, but also for soil quality measurement of factors other than dry density. Also, the shape and arrangement of the protrusions 21A, 21B, and 21C can be changed as appropriate.

(Experimental example)
Experimental examples of the present invention will be described below. A sample of mixed soil with a water content of 10.2% and a composition of sand:viscosity = 9:1, with a water content of 10.2% and an electrical resistance of 105.626 Ω·m is prepared. was done. After drying until the water content near the surface of the sample is 3.8% and the water content in the deep part is 8.1%, FIGS. The electrical resistance of the sample was measured by the soil measuring device 1D. The diameter of the wheel-shaped electrode 19 is 150 mm, and the protruding length of the protrusion 21A from the outer peripheral surface 19o of the wheel-shaped electrode 19 is 150 mm.

As a result of the measurement, the electrical resistance of the sample was measured to be 119.894 Ω·m, which agreed with the actual electrical resistance. On the other hand, when the sample was measured by the soil measuring device 1D in which the projecting portion 21A was removed from the outer peripheral surface 19o of the wheel-shaped electrode 19, the detected electrical resistance was too high and the correct value could not be measured. rice field.

1A, 1B, 1C, 1D, 1E, 1F... soil measuring device, 2... left frame part, 3... right frame part, 4A, 4B... center frame part, 5A, 5B, 5C, 5D, 5E, 5F... electrode part , 6... front wheel, 7... rear wheel, 8... crawler belt-like electrode, 8i... inner peripheral surface, 8o... outer peripheral surface, 9... auxiliary wheel, 10... driving unit, 11... measuring unit, 12... positioning unit, 13... communication Part 14... Control part 15... Driving part 16... Drive wheel 17... Auxiliary wheel 18... Traction body 19... Wheel-like electrode 19o... Outer peripheral surface 21A, 21B, 21C... Protrusion 22... Tip Part 23 Base part 24 Flexible surface part S Ground surface X, Y direction W, w Width.

Claims (7)

an electrode portion in contact with the ground;
a measuring unit that measures the electrical resistance of the soil on the ground using the electrode unit;
with
the electrode portion has a protrusion whose tip reaches below the ground;
the electrode portion moves on the ground while being in contact with the ground;
In a direction along the ground, the projection has a width in a direction in which the electrode moves on the ground, which is greater than or equal to a width in a direction perpendicular to the direction in which the electrode moves on the ground. . 2. The soil measuring device according to claim 1, wherein said electrode section has a plurality of said protrusions each having a different depth at which said tip reaches below said ground. 3. The soil measuring device according to claim 1, wherein said electrode part has said projection part capable of changing the depth at which said tip part reaches below said ground. The soil measuring device according to any one of claims 1 to 3 , wherein the electrode section has a flexible surface section at the base of the protrusion that follows unevenness of the ground. A soil measurement method for measuring the electrical resistance of soil on the ground by an electrode part in contact with the ground,
measuring the electrical resistance of the soil on the ground while allowing the tip of the protrusion of the electrode portion to reach below the ground ;
moving the ground while the electrode portion is in contact with the ground;
In the direction along the ground, the width in the direction in which the electrode portion moves on the ground in a state where the tip reaches below the ground is equal to or greater than the width in the direction perpendicular to the direction in which the electrode portion moves on the ground. A method for measuring soil properties, wherein the electric resistance of soil on the ground is measured while the tip of the projection of the electrode section having the projection reaches below the ground. Electricity of soil on the ground is reached below the ground while the tip of the protrusion of the electrode unit having a plurality of protrusions with different depths of the tip reaching below the ground is caused to reach below the ground. The soil measurement method according to claim 5 , wherein resistance is measured. 6. The electric resistance of the soil on the ground is measured while the tip of the protrusion, whose depth to which the tip reaches below the ground can be changed, reaches below the ground. 6. The soil measurement method according to 6 .

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