JP5190300B2 - Underground water level detection pile and slope failure prediction system - Google Patents

Description

  The present invention relates to a pile embedded in the ground and capable of detecting the water level in the ground, and a slope failure prediction system capable of detecting the possibility of slope failure such as landslide.

The early detection of landslides is extremely important as a disaster countermeasure. Here, landslides tend to occur after it rains and soaks into the ground. In other words, by measuring the amount of rain that has penetrated into the ground, it is possible to detect the possibility of landslides and to take disaster countermeasures in advance. As such an instrument, there is one that detects an increase in moisture content in the ground by inserting a polymer into a pile-shaped pipe and absorbing the polymer to expand the volume ( Patent Document 1). Here, since the high molecular polymer which has absorbed water and expands contacts a predetermined contact, an alarm sounds and the danger is informed.
JP2007-026395A

  However, in the case of the instrument of Patent Document 1, since the polymer polymer has water retention, the polymer level that has once absorbed moisture cannot accurately determine the water level in the ground thereafter. Specifically, the amount of moisture in the ground increases due to rain, but if it rains again a few days later, not enough to generate an alarm, the amount of swelling of the polymer will It is no longer dependent on the amount of water in it and does not follow the water level in the ground.

  Then, an object of this invention is to provide the water level detection pile which can detect the water level in the ground correctly.

  In order to achieve the above object, an underground water level detection pile according to the present invention is a rod-like pile that is partly or entirely embedded in the ground, and has a columnar space extending in the longitudinal direction, and an external portion of the columnar space. A pile body having an entry port for allowing liquid to enter from the pile body, and a pile body in which a proximity detection device is installed on the head side of the entry port, and the columnar space is closed by covering the head of the pile body A floating member that floats on the surface of the liquid that has entered from the entry port, and the proximity detector detects the proximity of the floating member.

  According to the present invention, the pile main body has an entrance for allowing liquid to enter the columnar space from the outside, so that when the moisture in the ground increases in the state where the pile body is embedded in the ground, The water level rises. Here, since the floating member that floats on the water surface of the liquid is disposed in the columnar space, the position of the floating member follows the water surface and indicates the water level. On the other hand, since the proximity detector detects the proximity of the floating member, the water level can be detected, and thus the water level in the ground can be accurately detected.

Here, the “columnar space” includes a columnar shape, a quadrangular columnar shape, and the like, and preferably the transverse cross-sectional dimension is constant in the longitudinal direction.
The “intrusion port” is preferably a hole provided in the vicinity of the tip of the pile main body, and this hole opens laterally or obliquely downward when the pile is embedded in the ground.
The “floating member” is a member that floats on the surface of a liquid having a specific gravity of water or higher, and can maintain its posture in water.

  According to a preferred embodiment of the present invention, the proximity detector includes a plurality of proximity detectors arranged along the longitudinal direction of the pile body, and each proximity means that the floating member is located within a predetermined range. Each detector detects. According to this configuration, the proximity detector is composed of a plurality of proximity detectors arranged along the longitudinal direction of the pile body. Therefore, in the state where the pile is embedded in the ground, the proximity detector is arranged in the vertical direction. Will be. Therefore, each proximity detector detects that the floating member is located in the predetermined range, and if it is determined which proximity detector detects the proximity of the floating member from the detection result of the entire proximity detector, The height of the floating member, that is, the water level can be detected.

  According to a further preferred embodiment of the present invention, an IC tag is attached to the floating member, and an IC reader is attached to each proximity detector. According to this configuration, when the IC tag enters the predetermined range of the floating member, the IC reader can detect that, so if the IC reader that detects that the float is within the predetermined range is determined, The position of the floating member, that is, the water level can be specified.

  The slope failure prediction system according to the present invention detects the possibility of slope failure using the underground water level detection pile. According to this configuration, since the underground water level detection pile can accurately detect the underground water level, for example, when this water level exceeds a predetermined value, the possibility of occurrence of landslides is high. Because it can be judged, slope failure can be predicted.

  According to the underground water level detection pile of the present invention, the underground water level can be accurately detected by using the proximity detection device and the pile that can store the floating member, although it is a simple configuration. From this, slope failure can be predicted based on the detected water level by burying the underground water level detection pile in a place where the occurrence of slope failure is high.

Embodiments of the present invention will be described with reference to the drawings.
The underground water level detection pile concerning one embodiment of the present invention is shown in Drawing 1-Drawing 2 (a) and (b). This pile is installed in a place where slope collapse is likely to occur, but the installation position information that is information about the installation position (for example, the position of the land or road (position by longitude, latitude and elevation), or the site) It is also possible to serve as an installation position information indicator that displays a variety of information.

  As shown in FIG. 1, the pile 1 is a pile that is driven almost vertically into the ground, and has a pile main body 10 whose head 12 is covered with a protective cap 20 to ensure high environmental resistance. Has been. The pile body 10 and the cap 20 are made of plastic, for example, but may be made of metal or the like. Moreover, the pile main body 10 and the cap 20 are both waterproofed on both the outer side and the inner side, that is, the entire pile main body 10 and the entire cap 20.

  As shown in FIGS. 2 (b) and 2 (b), a rod-like pile body 10 of the pile 1 has a side wall 11, a tip part 16, and an inclined wall that is located between the side wall 11 and the tip part 16 and connects them 13. The pile body 10 also has a columnar space 15 extending in the longitudinal direction L of the pile body 10, which is defined by the side walls 11, the tip 16 and the inclined wall 13.

  On the other hand, the protective cap 20 has a square flat plate-like top wall 21 and a columnar protrusion 22 protruding from one main surface of the top wall 21 as shown in FIG. . The protrusion 22 engages with the columnar space 15 inside the head 12 of the pile body 10 and is fitted into the upper opening of the columnar space 15 of the pile body 10. In addition, you may make it form this projection part 22 so that it may have a thread part in an outer surface, and screw it in the thread part provided in the inner periphery of the head 12 of the pile main body 10. FIG.

  In the pile main body 10, intrusion ports 17 and 17 each having communication holes for communicating the columnar space 15 and the outside of the pile 1 are formed at two positions facing each other in the cross section of the inclined wall 13. Has been. In the present embodiment, the number of the entrances 17 is two, but any number may be formed. The intrusion port 17 may be formed in the side wall 11 instead of the inclined wall 13. Further, when a plurality of intrusion ports 17 are provided, some of the intrusion ports 17 may be provided on the inclined wall 13 and the other intrusion ports 17 may be provided on the side wall 11.

  In the state in which the pile 1 is embedded in the ground, the liquid contained in the ground in which the pile 1 is embedded enters the cylindrical space 15 from these intrusion ports 17 and 17, so that when the moisture content of the ground increases, Water enters the columnar space 15 and the water level in the columnar space 15 rises.

  In the columnar space 15, a spherical float (floating member) 25 that can float on the liquid surface having a specific gravity of water or higher is disposed. The size of the float 25 is preferably slightly smaller than the diameter of the cross section of the cylindrical space 15. As a result, the float 25 is restricted from moving in the horizontal direction in the cylindrical space 15. The float 25 is composed of, for example, a first half body 25a and a second half body 25b each made of plastic and hemispherical. The half bodies 25a and 25b have cylindrical recesses 25aa and 25ba, respectively, at the center of the circular plane. When the first half body 25a and the second half body 25b are joined together with an adhesive or the like, a sealed space 25c is formed by the opposing recesses 25aa and 25ba. Note that the float 25 is a member that floats on the surface of a liquid having a specific gravity of water or higher, and any material and shape may be used as long as the posture can be maintained in water.

  The proximity detection IC tag 40 is accommodated in the sealed space 25 c of the float 25. That is, the first half 25a and the second half 25b are bonded together in a state where the proximity detection IC tag 40 is disposed in the recess 25ba of the second half 25b. In the present embodiment, the proximity detection IC tag 40 is a passive type and incorporates a wireless IC tag including an IC chip 42 and a communication antenna 44. Note that the “passive type” IC tag is a passive type IC tag that receives radio waves from a reader or the like and operates using the electric power supplied thereby. The “IC tag” can record tag information and wirelessly transmit the tag information to the outside.

  The float 25 storing the proximity detection IC tag 40 is stored in the columnar space 15 of the pile body 10 before the cap 20 is put on the pile body 10. The float 25 accommodated in this way is located at the bottom of the cylindrical space 15 in a state where water does not enter the cylindrical space 15.

  A proximity detection device 50 is disposed on the side wall 11 of the pile body 10. In the proximity detector 50, a plurality of proximity detectors 51 each formed of an IC tag reader are arranged along the longitudinal direction L, and the proximity detector 51 is configured as a whole. These IC tag readers 51 are capable of reading the tag information of the IC tag 40 when the IC tag 40 accommodated in the float 25 comes close to the IC tag reader 51, and are arranged at predetermined equal intervals along the longitudinal direction L of the pile body 10. Is arranged in. That is, the IC tag reader 51 can detect that the IC tag has approached within a predetermined range. These proximity detectors 51 are also waterproofed.

  An active IC tag 60 is also attached to the side wall 11 of the pile body 10. The active type IC tag 60 is an active type, that is, an IC tag that includes a battery and transmits an electric wave by itself, and is connected to a plurality of IC tag readers 51 by wire (not shown). With this configuration, the active IC tag 60 can transmit the detection information of the proximity detection device 50 including the plurality of IC tag readers 51 together with the tag information, and the management for collectively managing the detection information from a large number of water level detection piles Processed at the center.

Next, an application example of the information transmission pile 1 according to the first embodiment will be described.
As shown in FIG. 2A, the float 25 is located at the bottom of the columnar space 15 in a state where no liquid has entered the columnar space 15 of the pile body 10 from the outside of the pile 1. In such a state, for example, only the IC tag reader 51 located at the lowest position can read the information of the proximity detection IC tag 40, and the other IC tag readers 51 above this can be read from the proximity detection IC tag 40. The information of the IC tag 40 cannot be read because it is separated.

  On the other hand, as shown in FIG. 3, when the amount of water in the ground where the pile 1 is buried increases due to rain or the like, water in the ground enters the cylindrical space 15 from the entrances 17 and 17. Since the water level rises, the float 25 floating on the water surface S also moves upward. As the float 25 moves, the lowest-order IC tag reader 51 cannot read the information of the proximity detection IC tag 40, whereas the other upper IC tag reader 51 detects the proximity detection IC tag. 40 information can be read. Information detected by the plurality of IC tag readers 51 in this way is transmitted via the active IC tag 60 provided on the side wall 11 of the pile body 10.

  Therefore, if the time change of the detection information of all the IC tag readers 51 is tracked, a schematic position change in the vertical direction of the float 25 that can float on the water surface S, that is, a change in the water level in the cylindrical space 15 is acquired. be able to. As a result, when the water level in the cylindrical space 15 suddenly rises or exceeds a predetermined threshold value, the water level is linked to the amount of moisture in the ground, so disasters such as landslides occur. It is predicted that the situation is likely to occur, and some measures can be taken.

  On the other hand, when the moisture content of the ground outside the pile 1 decreases, the water in the columnar space 15 flows out from the entrances 17 and 17 and the float 25 moves downward. Therefore, the IC tag reader 51 located above does not detect the proximity detection IC tag 40 in the float 25, and the lower IC tag reader 51 detects the proximity detection IC tag 40 in the float 25.

  When the float 25 moves in the horizontal direction, the proximity of the float detected by the IC tag reader 51 may depend not only on the movement of the float 25 in the height direction but also in the horizontal direction. is there. However, in this embodiment, since the float 25 is restricted from moving in the horizontal direction, the proximity of the float detected by the IC tag reader 51 depends only on the movement of the float 25 in the height direction. Exactly done.

  In this embodiment, the proximity detection sensor is realized by providing an IC tag on the float and detecting it with an IC tag reader arranged in the vertical direction. Such an IC tag and tag reader It is not limited to what is comprised by these. For example, by providing a simple transmitter on the float and arranging a plurality of simple receivers in the vertical direction on the pile body, the receiver does not detect tag information, but simply a predetermined frequency transmitted by the transmitter. The electromagnetic wave may be detected. In addition to this, there is nothing specially provided on the float, and the pile body is provided with a plurality of impact sensors in the vertical direction, and these impact sensors project into the course of the float so that the float is at the same height as the impact sensor. It may be arranged so as to collide with the float when it is positioned at. In the case of this configuration, it is estimated that the water level in the columnar space has risen to the height of the impact sensor that has detected the collision.

  Further, a sensor alarm (not shown) may be provided on the pile body 10 without providing the active IC tag 60 for transmitting detection information. In this case, the detection information of the proximity detection sensor 51 is not transmitted from the pile 1 and a warning is generated instead.

It is a perspective view of the underground water level detection pile which concerns on one Embodiment of this invention. (A) is a longitudinal cross-sectional view of the underground water level detection pile of FIG. 1, and is a figure which shows the state in which the liquid has not newly entered from the outside, (b) is the underground water level detection pile of (a). It is sectional drawing along the II-II line. It is a longitudinal cross-sectional view of the underground water level detection pile of FIG. 1, Comprising: It is a figure which shows the state which the liquid has penetrate | invaded from the outside.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground water level detection pile 10 Pile main body 15 Columnar space 17 Intrusion port 20 Cap 25 Floating member 50 Proximity detection device

Claims (2)

A rod-like pile that is partly or entirely embedded in the ground,
A pile main body having a columnar space extending in the longitudinal direction and an intrusion port for allowing liquid to enter the columnar space from the outside, and a pile main body in which a proximity detection device is installed on the head side from the intrusion port,
A cap that covers the head of the pile body and closes the columnar space ;
An active IC tag attached to the side wall of the pile body and connected to the proximity detector ;
In the columnar space, a floating member that floats on the water surface of the liquid that has entered from the intrusion opening, and a floating member that houses a passive IC tag is disposed,
The proximity detector includes a plurality of proximity detectors that are arranged along the longitudinal direction of the pile main body and are each attached with an IC tag reader that reads tag information of the passive IC tag, and the floating member is within a predetermined range. Each proximity detector detects that it is located in
The detection information detected by each proximity detector of the proximity detection device is a management center that collectively manages detection information from a number of water level detection piles, together with the tag information of the active IC tag. An underground water level detection stake to send . A slope failure prediction system that detects the possibility of slope failure using the underground water level detection pile according to claim 1 .

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