JP7449846B2 - Soil quality measurement device and soil quality measurement method - Google Patents

Description

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

Techniques have been proposed for measuring the soil quality of soil by measuring the electrical resistance of the soil on the ground using electrodes that are in contact with the ground. For example, Patent Document 1 discloses that the lower ends of a plurality of rod-shaped electrodes extending in the vertical direction are pressed against embankment soil that has been compacted by a rolling compaction machine, and the electrical resistance of the soil is measured. A technique is disclosed for obtaining the degree of compaction of soil based on the correlation between the electrical resistance of soil and the dry density of the soil.

Patent No. 3416908

Incidentally, quality control of the mounding is often carried out after some time has passed since rolling, and there is a good possibility that the surface will dry during that time. When measuring using the technique described above on an embankment with a dry surface, an extremely large electrical resistance is output that is out of correlation between the electrical resistance of the soil and the dry density of the soil, and the dry density of the soil is not correctly measured. There is a problem that it is not possible to obtain .

Therefore, an object of the present invention is to provide a soil quality measuring device and a soil quality measuring method that can measure the electrical resistance of soil on the ground while reducing the influence of soil drying.

The present invention includes an electrode part that comes into contact with the ground, and a measurement part that measures the electrical resistance of the soil on the ground using the electrode part, and the electrode part has a cylindrical shape and can rotate around a central axis. It has a ground contacting part that continuously contacts the ground on the side, and a disk-like shape that shares a central axis with the ground contacting part, and the outer periphery protrudes from the side of the ground contacting part, and the rotation of the ground contacting part This is a soil quality measuring device having a subsurface penetration part whose outer peripheral part is continuously penetrated below the ground.

The reason why correct electrical resistance is not measured on soil with a dry surface may be that the dry surface of the soil creates minute gaps between it and the electrode, making it difficult for current to flow. There is. It is thought that the area that dries between the compaction of the embankment and the quality control is a range of several tens of millimeters in the depth direction from the embankment surface. Therefore, this configuration includes an electrode section that contacts the ground, and a measurement section that measures the electrical resistance of the soil on the ground using the electrode section. The electrode part has a cylindrical shape, and has a ground contact part that continuously contacts the ground on the side by rotating around a central axis, and a disk-shaped part that shares a central axis with the ground contact part. and an under-ground penetrating portion, the outer circumferential portion of which protrudes from the side surface of the ground contacting portion, and the outer circumferential portion of which is continuously penetrated below the ground as the ground contacting portion rotates. This ensures that the moist soil below the ground comes into contact with the subsurface penetration part of the electrode section that is continuously penetrated below the ground, reducing the effect of drying the soil while The electrical resistance of can be measured.

In this case, the ground contact portion is preferably insulated from the ground.

According to this configuration, since the ground contact portion is insulated from the ground, the electrode portion electrically contacts the soil on the ground only through the underground penetration portion. Therefore, the electrical contact area between the electrode part and the soil becomes more constant, and the accuracy of measuring the electrical resistance of the soil on the ground can be improved.

Further, it is preferable that the width of the below-ground penetration part in the direction parallel to the central axis is narrower than the width of the ground contact part in the direction parallel to the central axis.

According to this configuration, the width of the underground penetration part in the direction parallel to the central axis is narrower than the width of the ground contact part in the direction parallel to the central axis, so that the underground penetration part is more reliably moved below the ground. It becomes easier to be penetrated.

Moreover, it is preferable to further include a load adjustment part that adjusts the load on the soil of the ground at the outer peripheral part of the below-ground penetration part.

According to this configuration, the load adjusting section adjusts the load on the soil at the outer periphery of the underground penetration section, so that the load on the ground at the outer periphery of the underground penetration section is adjusted to The depth can be kept more constant.

Moreover, it is preferable to further include a depth detection section that detects the depth from the ground into which the outer circumferential portion of the below-ground penetration section has penetrated.

According to this configuration, the depth detection section detects the depth from the ground into which the outer circumference of the below-ground penetration part penetrates, so the depth from the ground of the outer circumference of the below-ground penetration part is controlled. It becomes easier.

Further, it is preferable that a plurality of below ground penetrating parts each having a different depth from the ground through which an outer peripheral part of the below ground penetrating part penetrates is detachable from the ground contacting part.

According to this configuration, the plurality of underground penetration parts whose outer circumferences are penetrated at different depths from the ground can be attached to and detached from the ground contact part, so that soil that is sufficiently hydrated can be attached to and removed from the ground contact part. It becomes easier to respond to situations where the depth from the ground is different.

Preferably, the device further includes a spraying section that sprays a conductive liquid onto the ground, and the electrode section contacts the ground onto which the liquid has been sprayed by the spraying section.

According to this configuration, the conductive liquid is sprayed onto the ground by the spraying section, and the electrode section contacts the ground onto which the liquid has been sprayed by the spraying section. This makes it possible to bring the moist soil into contact with the electrode part more reliably, and to measure the electrical resistance of the soil on the ground while reducing the influence of soil drying.

Further, the present invention includes an electrode part contacting step of bringing the electrode part into contact with the ground, and a measuring step of measuring the electrical resistance of the soil on the ground with the electrode part brought into contact with the ground in the electrode part contacting step. In the contact process, a ground contact part that has a cylindrical shape and continuously contacts the ground on its side by rotating around a central axis, and a disc-shaped part that shares a central axis with the ground contact part. soil type in which an electrode part is brought into contact with the ground, and has an outer peripheral part protruding from the side surface of the ground contact part, and a sub-ground penetration part in which the outer peripheral part continuously penetrates below the ground as the ground contact part rotates. This is a measurement method.

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

(A) is a plan view showing the configuration of the soil measuring device of the embodiment, and (B) is a side view showing the configuration of the soil measuring device of the embodiment. (A) is a front view of the wheel-shaped electrode of the electrode part, (B) is a side view of the wheel-shaped electrode of the electrode part, and (C) is a side view of the wheel-shaped electrode in an exploded state; (D) is a side view showing a state in which the under-ground penetrating portion in (C) is replaced with an under-ground penetrating portion whose outer periphery has a different depth from the ground into which it is penetrated. It is a flowchart which shows the process of the soil quality measurement method of embodiment. It is a graph showing the relationship between dry density and electrical resistance. (A) is a diagram showing a conventional situation in which the electrical resistance of soil on dry ground is measured, and (B) is a diagram showing a situation in which conventional electrical resistance of soil in dry ground is measured, (C) is a diagram showing a situation in which the electrical resistance of dry ground soil is measured by the wheel-shaped electrode of the electrode section of the present embodiment. It is a graph showing the relationship between measurement points at which the electrical resistance of the soil on the ground was measured, the number of times liquid is injected onto the ground, and the dry density of the soil estimated based on the measured electrical resistance of the soil.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a soil measuring device and a soil measuring method according to the present invention will be described in detail with reference to the drawings. The soil measuring device and the soil measuring method of the embodiment of the present invention, for example, measure the electrical resistance of the soil on the ground after being compacted by a compaction machine such as a road roller, and dry the soil which has a correlation with the electrical resistance. This is to confirm the effectiveness of compaction by a compaction machine by deriving density, etc.

As shown in FIG. 1(A), the soil measuring device 1 according to the embodiment of the present invention includes a central frame portion 4 and an electrode portion 5 pulled by the central frame portion 4. The soil measuring device 1 includes a spraying section 31 in the central frame section 4 that sprays a conductive liquid L onto the ground S before the electrode section 5 passes.

A spray nozzle 34 is connected to the spray section 31 . The spray unit 31 has a liquid container (not shown), and supplies the conductive liquid L in the liquid container to the spray nozzle 34 by a pump (not shown). The spray unit 31 can change the amount of liquid L supplied to the spray nozzle 34. For example, water other than pure water can be used as the conductive liquid L. The spray nozzle 34 sprays the conductive liquid L onto the ground S before the electrode section 5 passes. Spraying means discharging the liquid L onto the ground S in a state where air exists between a plurality of discontinuous droplets.

The soil measuring device 1 has a drive unit 15 in the central frame portion 4 that drives a drive wheel 16 for moving the soil measuring device 1 on the ground S. The drive unit 15 rotates the drive wheels 16 using an electric motor, an internal combustion engine, or the like. Thereby, the soil measuring device 1 of this embodiment can run on the ground S in the direction X by itself. The electrode section 5 contacts the ground S on which the liquid L is sprayed by the spray section 31 . The electrode section 5 has an auxiliary wheel 17 and a traction body 18 that is pulled by the central frame section 4 . The electrode section 5 has four wheel-shaped electrodes 19 at the rear of the traction body 18.

As shown in FIGS. 1(A), 1(B), 2(A), and 2(B), the wheel-shaped electrode 19 of the electrode portion 5 has a ground contact portion 21 and an underground penetration portion 22. has. The ground contact portion 21 has a cylindrical shape, and by rotating around the central axis A, continuously contacts the ground S at the side surface 21s. The underground penetrating portion 22 has a disk-like shape that shares a central axis A with the ground contacting portion 21, and an outer circumferential portion 22s protrudes from a side surface 21s of the ground contacting portion 21, and the outer circumference changes as the ground contacting portion 21 rotates. The portion 22s is continuously penetrated below the ground S.

The diameter of the ground contact portion 21 is, for example, 100 mm to 200 mm. The width W2 in the direction Y perpendicular to the direction X in which the electrode portion 5 of the wheel-shaped electrode 19 moves on the ground S is, for example, 10 mm to 30 mm. The ground contact length in the direction X in which the electrode portion 5 of the wheel-shaped electrode 19 moves on the ground S is, for example, 20 mm to 30 mm. The interval in the direction Y perpendicular to the direction X in which each electrode part 5 moves on the ground S of the wheel-shaped electrodes 19 of the electrode part 5 can be changed arbitrarily, and can be changed to, for example, 200 mm, 300 mm, or 750 mm. The ground contact portion 21 is insulated from the ground S. The side surface 21s of the ground contact portion 21 is coated with, for example, insulating rubber, synthetic resin, or the like.

On the other hand, the diameter of the underground penetration portion 22 can be changed as appropriate depending on the degree of dryness of the soil on the ground S, as described later. Further, a width W1 of the under-ground penetration portion 22 in a direction parallel to the central axis A is narrower than a width W2 of the ground contact portion 21 in a direction parallel to the central axis A. The width W1 of the underground penetration portion 22 in the direction parallel to the central axis A is, for example, 2 mm to 10 mm. The width W1 of the underground penetration portion 22 in the direction parallel to the central axis A may be narrowed from the side surface 21s to the outer peripheral portion 22s.

As shown in FIGS. 2(C) and 2(D), in the wheel-shaped electrode 19 of the electrode part 5, the depth from the ground surface S into which the outer circumferential portion 22s of the underground penetration portion 22, 22' penetrates is A plurality of different underground penetration parts 22 and 22' are detachably attached to the ground contact part 21. The ground contact portion 21 can be separated into a bolt portion 21a and a nut portion 21b in a direction parallel to the central axis A. The bolt portion 21a has a cylindrical shape with a smaller diameter than the main body of the bolt portion 21a, protrudes in a direction parallel to the central axis A, and has a male screw portion 21m with a threaded groove on the side surface. The nut portion 21b has a female threaded portion 21f in which a threaded groove corresponding to the threaded groove of the male threaded portion 21m is provided on the inner peripheral surface of a hole corresponding to the shape of the bolt portion 21a. The male threaded portion 21m of the bolt portion 21a is screwed into the female threaded portion 21f of the nut portion 21b.

The under-ground penetration parts 22, 22' have a screw hole part 22h of a size corresponding to the male screw part 21m of the bolt part 21a of the ground contact part 21. The male screw portion 21m of the bolt portion 21a of the ground contact portion 21 is inserted into the screw hole portion 22h of the under ground penetration portion 22, 22′, and the under ground penetration portion is inserted between the bolt portion 21a and the nut portion 21b of the ground contact portion 21. The under-ground penetration parts 22, 22' are fixed to the ground contacting part 21 by screwing the male threaded part 21m of the bolt part 21a into the female threaded part 21f of the nut part 21b while the screws 22, 22' are sandwiched therebetween. On the other hand, by removing the male screw portion 21m of the bolt portion 21a from the female screw portion 21f of the nut portion 21b, the underground penetration portions 22, 22' are removed from the ground contact portion 21.

With the above configuration, a plurality of underground penetrating parts 22, 22' having different depths from the ground S into which the outer circumferential parts 22s of the underground penetrating parts 22, 22' are penetrated can be freely attached to and detached from the ground contacting part 21. . In the examples shown in FIGS. 2(C) and 2(D), the underground penetration part 22 is removed from the ground contact part 21, and the diameter is larger than that of the underground penetration part 22, and the outer peripheral part 22s is removed from the ground S into which it is penetrated. An underground penetration part 22' having a deeper depth is fixed to the ground contact part 21.

It is thought that the contact area and contact time between the wheel-shaped electrode 19 and the ground S, which can reduce measurement errors, differ depending on the soil at each work site. Therefore, the drive unit 15 can adjust the speed at which the wheel-shaped electrode 19 is moved, and can set the speed to be appropriate for each work site. It is preferable that the speed of the wheel-shaped electrode 19 is as fast as possible because the time required for measurement is shortened. Note that the wheel-shaped electrodes 19 may be moved by towing the soil measuring device 1 by some method such as a self-propelled compaction machine such as a road roller, an electric two-wheeled vehicle, or human power. Furthermore, the wheel-shaped electrodes 19 may be moved by integrating the soil quality measuring device 1 with a self-propelled compaction machine such as a road roller.

A total of four wheel-shaped electrodes 19 of the electrode section 5 as described above are arranged in parallel in the direction Y along the ground S and perpendicular to the direction X in which the electrode section 5 of the soil measuring device 1 moves on the ground. For example, the electrical resistance of soil is measured by the Wenner method. As shown in FIG. 1(A), the measuring section 11 disposed in the central frame section 4 measures the electrical resistance of the soil on the ground S using the four wheel-shaped electrodes 19 of the electrode section 5. Note that the measuring unit 11 measuring 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, but for example, measuring the electric current value and voltage value detected by the electrode unit 5. It also includes outputting information related to etc.

As shown in FIG. 1(A), the soil measuring device 1 includes a positioning section 12 in the central frame section 4 that acquires the position of the wheel-shaped electrode 19. The measuring unit 11 measures the electrical resistance of the soil on the ground S associated with the position of the wheel-shaped electrode 19 acquired by the positioning unit 12. The position of the soil measuring device 1 such as the central frame portion 4 may be regarded as the position of the wheel-shaped electrode 19. The positioning unit 12 positions the wheel-shaped electrode 19 using, for example, GNSS (Global Navigation Satellite System) surveying. In GNSS surveying, the position of the wheel-shaped electrode 19 (for example, the latitude and longitude of the wheel-shaped electrode 19) is determined by receiving signals from three or more satellites. Instead of GNSS surveying, the position of the wheel-shaped electrode 19 may be measured by automatic tracking TS (Total Station) using an optical surveying function.

The soil measuring device 1 includes a communication section 13 in the central frame section 4, which is a receiving section that receives command signals to the measuring section 11, the driving section 15, and the spraying section 31. As a result, the operations of the measuring section 11, the driving section 15, and the spraying section 31 are controlled by remote control based on the command signal received by the communication section 13. The communication unit 13 transmits information regarding the electrical resistance of the soil on the ground S measured by the measurement unit 11. Note that the measurement results by the measurement unit 11 may be recorded in a recording device installed in the soil quality measurement device 1.

The soil measuring device 1 also includes a control section 14 in the central frame section 4 that controls the operations of the measuring section 11 , the driving section 15 , and the spraying section 31 . Further, the control unit 14 may control the soil measuring device 1 to move behind a self-propelled compaction machine such as a road roller, for example. Further, the soil measuring device 1 may be controlled by the control unit 14 to move along an arbitrary route at the work site.

The soil quality measuring device 1 includes a load adjustment section 23 that adjusts the load of the outer circumferential portion 22s of the underground penetration section 22 against the soil of the ground surface S. The load adjustment unit 23 is, for example, a weight that is detachably attached to both ends of the rotating shaft of the wheel-shaped electrode 19. By attaching the load adjustment parts 23, which are weights having various weights, to both ends of the rotating shaft of the wheel-shaped electrode 19, the load of the outer peripheral part 22s of the underground penetration part 22 on the soil of the ground surface S is adjusted. . In addition, the load adjustment part 23 adjusts the load of the outer peripheral part 22s of the below-ground penetration part 22 with respect to the soil of the ground surface S by adjusting the load with which the traction body 18 is pressed against the ground surface S from the central frame part 4. You may.

The soil measuring device 1 includes a depth detection section 24 in the central frame section 4 that detects the depth from the ground surface S into which the outer peripheral section 22s of the subsurface penetration section 22 has penetrated. The depth detection unit 24 measures the distance between the side surface 21s of the ground contacting portion 21 and the ground S using, for example, an optical sensor or an ultrasonic sensor, and detects the distance from the side surface 21s of the ground contacting portion 21 to the outer circumference of the underground penetration portion 22. Based on the distance to 22s, the depth from the ground surface S into which the outer peripheral portion 22s of the underground penetration portion 22 is penetrated is detected. In addition, the depth detection part 24 may detect the depth from the ground surface S into which the outer peripheral part 22s of the below-ground penetration part 22 was made to penetrate based on the angle which the towing body 18 makes from the central frame part 4.

Hereinafter, a soil quality measuring method using the soil quality measuring device 1 of this embodiment will be explained. In the soil measurement method using the soil measurement device 1 of the present embodiment, for example, the soil measurement device 1 is moved on the ground S that has been compacted by a compaction machine such as a road roller, and The electrical resistance of soil at any location is measured.

As shown in FIG. 3, the spraying unit 31 executes a spraying step of spraying the conductive liquid L from the spray nozzle 34 onto the ground S (S1). An electrode part contacting process is performed in which the wheel-shaped electrode 19 of the electrode part 5 is brought into contact with the ground S on which the liquid L has been sprayed in the spraying process (S2). A measuring step is performed in which the measuring section 11 measures the electrical resistance of the soil on the ground S by the electrode section 5 brought into contact with the ground S in the electrode section contacting step (S3).

In the electrode part contacting step, the ground contacting part 21 has a cylindrical shape and continuously contacts the ground S at the side surface 21s by rotating around the central axis A, and the ground contacting part 21 and the central axis A A ground surface having a disk-like shape in common, with an outer peripheral part 22s protruding from the side surface 21s of the ground contacting part 21, and the outer peripheral part 22s continuously penetrating below the ground S as the ground contacting part 21 rotates. The wheel-shaped electrode 19 of the electrode part 5 having the lower penetration part 22 is brought into contact with the ground S.

Hereinafter, the functions and effects of the soil measuring device and soil measuring method of this embodiment will be explained. As shown in FIG. 4, it is known that there is a correlation between the electrical resistance of soil and the dry density of soil, so the dry density of soil can be derived based on the electrical resistance of soil. Based on the derived dry density of the soil, the effectiveness of compaction by the compaction machine can be confirmed.

The measuring 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 regarding the current value, voltage value, etc. detected by the electrode unit 5, and information regarding the electrical resistance of the soil, and the communication unit 13 transmits the information and calculates the dry density of the soil. It may be performed using a mobile communication terminal outside the soil quality measuring device 1.

As shown in FIG. 5(A), when water W exists on the ground S of the soil E, a current C flows between the wheel-shaped electrode 19 of the electrode part 5 and the soil E, and the electrode part 5 Electrical resistance is measured. However, as shown in FIG. 5(B), the reason why the correct electrical resistance is not measured on the soil E when the ground S is dry is that the wheel-like shape of the electrode part 5 is caused by the dryness of the ground S of the soil E. This may be because a minute gap is created between the electrode 19 and the current C is difficult to flow. It is thought that the area that dries between the compaction of the embankment and the quality control is a range of several tens of millimeters in the depth direction from the embankment surface, as shown by the broken line in the figure.

Therefore, in this embodiment, as shown in FIG. 5(C), the wheel-shaped electrode 19 of the electrode part 5 has a cylindrical shape, and by rotating around the central axis A, the wheel-shaped electrode 19 is rotated around the central axis A. The ground contact part 21 continuously contacts the ground S, and the ground contact part 21 has a disk-like shape that shares the central axis A, and the outer peripheral part 22s protrudes from the side surface 21s of the ground contact part 21, and the ground contact part 21 has a disk-like shape that shares the central axis A with the ground contact part 21. It has an under-ground penetration part 22 whose outer peripheral part 22s continuously penetrates below the ground S as the part 21 rotates. As a result, the soil E below the ground S which contains water and the underground penetration part 22 of the electrode section 5 that is continuously penetrated below the ground S are brought into contact with each other, and the influence of drying of the soil E is reduced. The electrical resistance of the soil E on the ground S can be measured while reducing the electrical resistance.

In other words, as shown in Figure 6, the soil E on the ground S is dry, and the dry density of the soil is derived based on the electrical resistance of the soil E measured at the surface layer of the ground S at measurement points 6 to 8. Even if the dry density of the soil E on the ground S measured by the sand displacement method differs greatly, it is derived based on the electrical resistance of the soil E measured below the ground S at measurement points 9 to 11. The dry density of the soil is close to the dry density of the soil E on the ground S measured by the sand displacement method. Therefore, in this embodiment, the soil E below the ground surface S which contains moisture is brought into contact with the underground penetration section 22 of the electrode section 5 that is continuously penetrated below the ground surface S. It is possible to measure the electrical resistance of the soil E on the ground S while reducing the influence of drying.

Further, as shown in FIG. 5C, in this embodiment, as the wheel-shaped electrode 19 of the electrode section 5 rotates, the side surface 21s of the ground contact section 21 continuously contacts the ground surface S, and the side surface 21s The outer circumferential portion 22s of the subsurface penetration portion 22, which is equidistant from the ground surface S, is continuously penetrated from the ground surface S to the same depth. Thereby, the contact area Z between the wheel-shaped electrode 19 of the electrode part 5 and the soil E of the ground S becomes constant. For this reason, for example, compared to the case where the portion of the wheel-shaped electrode 19 of the electrode portion 5 that penetrates below the ground S is a protrusion that protrudes discontinuously from the outer periphery of the wheel-shaped electrode 19, the soil of the ground S is The accuracy of measuring the electrical resistance of E can be improved.

Moreover, in this embodiment, since the outer circumferential portion 22s of the below-ground penetration part 22 is penetrated continuously from the ground S to the same depth, for example, the outer peripheral part 22s of the below-ground penetration part 22 is penetrated below the ground S by the wheel-shaped electrode 19 of the electrode part 5. The disturbance of the soil E on the ground S is reduced compared to the case where the part that is disturbs is a protrusion or the like discontinuously protruding from the outer peripheral part of the wheel-shaped electrode 19. Therefore, for example, the state of the soil E on the ground S after being compacted by a compaction machine such as a road roller can be maintained.

Moreover, in this embodiment, since the outer circumferential portion 22s of the below-ground penetration part 22 is penetrated continuously from the ground S to the same depth, for example, the outer peripheral part 22s of the below-ground penetration part 22 is penetrated below the ground S by the wheel-shaped electrode 19 of the electrode part 5. The durability of the underground penetrating portion 22 can be improved compared to a case where the portion that is discontinuously protrudes from the outer peripheral portion of the wheel-shaped electrode 19 is a protrusion or the like.

Furthermore, in this embodiment, since the ground contact portion 21 is insulated from the ground S, the wheel-shaped electrode 19 of the electrode portion 5 electrically contacts the soil E of the ground S only through the underground penetration portion 22. . Therefore, the electrical contact area Z between the electrode portion 5 and the soil E becomes more constant, and the accuracy of measuring the electrical resistance of the soil E on the ground S can be improved.

Furthermore, in the present embodiment, the width W1 of the underground penetration part 22 in the direction parallel to the central axis A is narrower than the width W2 of the ground contact part 21 in the direction parallel to the central axis A. is more likely to penetrate below the ground S more reliably.

Furthermore, in the present embodiment, the load adjustment unit 23 adjusts the load of the outer peripheral portion 22s of the underground penetration portion 22 on the soil E of the ground S, so that the load on the soil E of the ground S of various hardnesses is adjusted. The depth of the outer peripheral portion 22s of the lower penetration portion 22 from the ground S can be kept more constant.

Furthermore, in the present embodiment, since the depth detecting unit 24 detects the depth from the ground S into which the outer circumference 22s of the below-ground penetration part 22 penetrates, the depth of the outer circumference 22s of the below-ground penetration part 22 from the ground S is detected. It becomes easier to control the depth from S.

Furthermore, in the present embodiment, a plurality of under-ground penetrating parts 22, 22' having different depths from the ground S into which the outer circumferential parts 22s of the under-ground penetrating parts 22, 22' penetrate are detachably attached to the ground contacting part 21. Therefore, it becomes easier to deal with situations where the depth of the soil E that is sufficiently hydrated from the ground S differs.

Further, in this embodiment, the conductive liquid L is sprayed onto the ground S by the spraying section 31, and the electrode section 5 contacts the ground S onto which the liquid L has been sprayed by the spraying section 31. This makes it possible to bring the moist soil E into contact with the electrode part 5 more reliably, and to measure the electrical resistance of the soil E on the ground S while reducing the influence of drying of the soil E. In other words, as shown in FIG. 6, as the amount of liquid L sprayed onto the ground S increases, the dry density of the soil derived based on the electrical resistance of the soil E measured at measurement points 1 to 5 increases. When the amount of liquid L sprayed onto the ground S reaches a certain level, the dry density of the soil, which is derived based on the electrical resistance of the soil E measured at measurement points 1 to 5, can be calculated using the sand displacement method. This value is approximately the same as the dry density of the soil E on the ground S to be measured. Therefore, by spraying the conductive liquid L onto the ground S, the soil E on the ground S can be brought into contact with the hydrated soil E and the electrode part 5 more reliably, reducing the influence of drying of the soil E. The electrical resistance of can be measured.

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 E whose electrical resistance is measured by the soil measuring device and the soil measuring method of the above embodiment includes not only general soil E but also sand and gravel obtained at a construction site using the CSG (Cemented Sand and Gravel) method. It also includes those in which cement is added and mixed, and those in which cemented carbide concrete with a reduced amount of cement is spread and compacted using vibrating rollers, etc. using the RCD (Roller Compacted Dam-Concrete) method.

For example, in the above embodiment, the dry density of the soil E is derived based on the measured electrical resistance of the soil E on the ground S, and the effect of compaction by the compaction machine is determined by the derived dry density of the soil E. Although the method of checking has been described, for example, checking of the effect of compaction by a compaction machine may be performed using other methods and the method of this embodiment in combination. Furthermore, the measurement of the electrical resistance of the soil E according to the present embodiment may be performed not only for deriving the dry density of the soil E, but also for measuring the soil quality of the soil E regarding other factors other than the dry density.

DESCRIPTION OF SYMBOLS 1... Soil quality measuring device, 4... Central frame part, 5... Electrode part, 11... Measuring part, 12... Positioning part, 13... Communication part, 14... Control part, 15... Drive part, 16... Drive wheel, 17... Auxiliary Ring, 18...Traction body, 19...Wheel-shaped electrode, 21...Ground contact part, 21s...Side surface, 21a...Bolt part, 21m...Male thread part, 21b...Nut part, 21f...Female thread part, 22, 22'...Below the ground Penetration part, 22s...Outer circumferential part, 22h...Screw hole part, 23...Load adjustment part, 24...Depth detection part, 31...Spray part, 34...Spray nozzle, S...Ground, E...Soil, W...Water, L... Liquid, C... Current, X, Y... Direction, A... Central axis, W1, W2... Width, Z... Contact area.

Claims (8)

an electrode part that contacts the ground;
a measuring unit that measures the electrical resistance of the soil on the ground using the electrode unit;
Equipped with
The electrode part is
a ground contacting part having a cylindrical shape and continuously contacting the ground on a side surface by rotating around a central axis;
The ground contacting part has a disc-like shape that shares the central axis with the ground contacting part, and the outer peripheral part protrudes from the side surface of the ground contacting part, and as the ground contacting part rotates, the outer peripheral part continues to touch the ground. an underground penetration portion that penetrates below the ground;
A soil measuring device with The soil measuring device according to claim 1, wherein the ground contact portion is insulated from the ground. The soil measuring device according to claim 1 or 2, wherein the width of the underground penetration part in the direction parallel to the central axis is narrower than the width of the ground contact part in the direction parallel to the central axis. The soil quality measuring device according to any one of claims 1 to 3, further comprising a load adjustment unit that adjusts a load of the outer peripheral portion of the underground penetration portion against the soil of the ground. The soil measuring device according to any one of claims 1 to 4, further comprising a depth detection unit that detects a depth from the ground through which the outer peripheral portion of the below-ground penetration portion penetrates. Any one of claims 1 to 5, wherein a plurality of the underground penetrating parts each having a different depth from the ground through which the outer peripheral part of the underground penetrating part penetrates is detachably attached to the ground contacting part. Soil quality measuring device described in . further comprising a spraying unit that sprays a conductive liquid onto the ground,
The soil measuring device according to any one of claims 1 to 6, wherein the electrode section contacts the ground onto which the liquid has been sprayed by the spray section. an electrode part contacting step of bringing the electrode part into contact with the ground;
a measuring step of measuring the electrical resistance of the soil on the ground with the electrode part brought into contact with the ground in the electrode part contacting step;
Equipped with
In the electrode part contacting step,
a ground contacting part having a cylindrical shape and continuously contacting the ground on a side surface by rotating around a central axis;
The ground contacting part has a disc-like shape that shares the central axis with the ground contacting part, and the outer peripheral part protrudes from the side surface of the ground contacting part, and as the ground contacting part rotates, the outer peripheral part continues to touch the ground. A soil quality measuring method, comprising: bringing the electrode section into contact with the ground surface;

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