JP2010078593A - Scour measuring device of river - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scour measuring device of a river, reducing costs with a simple constitution without having a bad influence on an environment. <P>SOLUTION: This scour measuring device 10 is provided with: a segment unit 12 buried in a river bed in the state where a plurality of segments 12a are laminated in the vertical direction, wherein a height of the segments 12a and a distance from the upper end or the lower end which is an operation standard of a scour depth to a river bed face which is a measuring object are known; a plurality of sensors 14 arranged individually on each segment, whose electric characteristic is changed corresponding to a laminated or separated state of the segments 12; and a measuring recording device 16 buried on the lower end of the segment unit 12, for supplying power to the sensor 14, and measuring and recording its electric characteristic with elapse of time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a scour measuring apparatus for rivers that measures the scouring state or maximum scouring depth in which river sediment sediment (approximately 10 mm or less in diameter) is washed away downstream during flooding or flooding.

  Here, flooding means that the amount of water in the river increases due to heavy rain, melting snow, etc., and flooding means that water flows from the normal river channel into the riverbed due to an abnormal increase in the water level and flow rate of the river. It means overflowing and overflowing from a breach or embankment and flooding outside the riverbed.

  River sediments are constantly changing due to flooding and scouring during floods. When the bottom sediment is scoured, the height to the upper part of the levee body changes, and the flow until the set planned high water level is changed, which affects the river plan. It is necessary to know the digging situation and the date and time of the maximum scouring depth. When knowing the changes in river bottom sediment, the depth of scouring is measured by measuring the depth and measuring the bottom sediment. However, it is not possible to identify changes during floods because of the measurement results before and after the flood in the measurement results of the depth survey. Therefore, in Patent Documents 1 and 2, the amount of riverbed degradation is measured along with changes over time, and riverbed degradation measuring devices and riverbed scouring status remote devices that are useful for predicting disasters that occur with riverbed changes are disclosed. A monitoring system has been proposed.

  In the river bed degradation measuring devices and monitoring systems disclosed in these patent documents, a sensor unit embedded in a river bed in a river channel and having a built-in transmitter and a radio wave transmitted from the sensor unit are received via an antenna. It has a receiver and a reception recorder that records the reception status received by this receiver, and there are multiple sensor units in the target measurement range (corresponding to the predicted scouring depth) from the riverbed downward. The basic configuration is to embed in a stacked state.

  According to the river bed lowering measuring apparatus or monitoring system configured in this way, when the sensor section is separated and ascends in the event of a flood, the transmitter built in the sensor section is driven and radio waves transmitted from now on are driven. Is received by the receiver via the antenna, and further, the reception state received by the receiver is recorded in the reception recorder, so that the river bed drop is measured according to the temporal change. .

However, the riverbed lowering measuring apparatus or monitoring system having such a configuration has the following technical problems.
JP 2002-365046 A JP 2004-271243 A

  That is, in the conventional measuring apparatus or monitoring system described above, it is a basic component requirement to incorporate a transmitter in the sensor unit, but in order to drive the transmitter, a built-in battery is required in the sensor unit. And

  If a built-in battery is installed in the sensor unit, the sensor unit will flow down, and if left as it is, it will have an adverse effect on the environment, and in order to lift the sensor unit, a floating body is required. In order to drive the transmitter by detaching the part, a switch mechanism is also required, so that the structure is complicated and the sensor part is expensive.

  The present invention has been made in view of such conventional problems, and its object is to scour rivers that do not adversely affect the environment and can reduce costs with a simple configuration. It is to provide a measuring device.

  In order to achieve the above object, the present invention is embedded in a river bed in a state where a plurality of segments are stacked in the vertical direction, and is measured from the upper end or the lower end which is a calculation reference for the height of the segments and the scouring depth. A segment unit with a known distance to the riverbed surface, a plurality of sensors that are individually arranged in the segment and detect the stacked state and the detached state of the segment, and embedded in the lower end of the segment unit And a measurement recording device that measures and records the detection state of the sensor over time.

  According to the river scouring and measuring apparatus configured as described above, when the segment unit is exposed by scouring of earth and sand, it is pushed by the flow rate of water in order from the segment on the upper end side and leaves the laminated state.

  When the segment is detached, the state is detected by the sensor, and this is recorded in the measurement recording device with time. By collecting the measurement recording device in which such information is recorded, it is possible to know the time when the segment is detached.

  In this case, the segment unit is known for the segment height and the distance from the upper or lower end, which is the calculation reference for the scouring depth, to the riverbed surface to be measured. You can know the depth.

  In the present invention, the segment need only be separated from the laminated state by scouring that occurs during river flooding or flooding, so there is no need to mount a functional component such as a transmitter, as in the case of incorporating a transmitter. Since there is no need to incorporate a power battery, there is no risk of adverse effects on the environment even if the segment is lost, the structure is simple, and the cost can be reduced.

  The segment can be composed of a columnar body having a thin metal surface that corrodes and disappears relatively quickly with the passage of time, or a special corrugated columnar body that naturally disappears with the passage of time. According to this configuration, the environmental load of the segment can be further reduced, and the cost reduction effect is increased.

  The measurement recording apparatus can incorporate a transmitter and receive a transmission signal from the transmitter to enable detection of the embedded position of the measurement recording apparatus. According to this configuration, the measurement recording apparatus can be easily collected.

  The embedded position of the segment and the measurement recording device can be specified by on-site surveying or GPS surveying. Even with this configuration, the measurement recording apparatus can be easily collected.

  The sensor can detect the laminated state and delaminated state of the segments based on a change in electrical characteristics.

  In this case, the sensor may be formed of a fine copper wire, and the fine copper wire may be disposed so as to be folded back into the segment, and the fine copper wire may be cut when the segment is detached. According to this configuration, the sensor structure is simplified and the cost reduction effect is increased.

  The electrical characteristics of the sensor can be selected from voltage, current, and resistance. According to this configuration, it is possible to easily record without requiring a large capacity for recording the change over time in the measurement recording apparatus.

  The sensor can detect the lamination state and the delamination state of the segments by a change in light propagation characteristics.

  In this case, the sensor may be configured of an optical fiber, and the optical fiber may be arranged so as to be folded back into the segment, and the optical fiber may be cut when the segment is detached. When the laminated state and delaminated state of a segment are detected by an optical signal, the influence of leakage current is completely eliminated as in a sensor using electricity.

  According to the river scour measuring apparatus according to the present invention, the segment used for measuring the scouring state may be separated from the layered state by scouring generated during river flooding or flooding. There is no need to install functional parts, and there is no need to install a power supply battery as in the case of incorporating a transmitter, so even if a segment is lost, there is no risk of adverse effects on the environment, and the structure is simple and cost-effective. Reduction can be achieved.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 5 show an embodiment of a river scour measuring apparatus according to the present invention. The scour measuring apparatus 10 shown in these drawings includes a segment unit 12, a sensor 14, and a measurement recording apparatus 16.

  The scour measuring device 10 is used when measuring the bottom sediment of a river. As shown in FIG. 1, a plurality of scour measuring devices 10 are buried in a water bottom ground B of a river bed A at a predetermined interval. Installed. The installation position at this time is not particularly limited. For example, the installation position can be set at an arbitrary position so that the upstream and downstream devices do not overlap with each other along the flow. In addition, when installing the several scour measuring apparatus 10 as shown in FIG. 1, it is desirable to attach a number etc. so that each measuring apparatus 10 can be identified.

  FIG. 2 is an enlarged view of the scour measuring apparatus 10 shown in FIG. In the case of the present embodiment, the segment unit 12 is a cylindrical segment 12a having a known height of 100 mm and a diameter of about 60 φmm with a through hole in the center. A plurality of segments 12a are stacked in the vertical direction. The segment 12a is formed, for example, by forming a water-repellent liner paper into a cylindrical shape having an outer diameter of 6 cm, an inner diameter of 5 cm, a height of 10 cm, and a thickness of 5 mm, color-coding the outside with a paint material, Yes. This is to facilitate identification of which layer segment during collection. The segment 12a made of a paper tube is thick and hard, and has a durability of about one year when installed in a sediment. The segment 12a is not limited to this configuration. For example, the segment 12a may be a columnar body having a thin metal surface that corrodes and disappears relatively quickly with the passage of time. In this case, the columnar body may be a hollow body made of a metal shell, or may be filled with the liner paper described above. Furthermore, it is possible to use, for example, a biodegradable plastic instead of the metal surface material.

  A more specific configuration example of the segment 12a is as follows: actual basis weight 222.0g / m2, density 0.76g / m3, thickness 0.29mm, specific burst strength 2.95kPa · m2 / g, specific compressive strength (horizontal) 173N · m2 / g, tear length (vertical) 6.43km, specific tear strength (vertical) 9.7mNm2 / g, water repellency (table) 6.5, water absorption 67g / m2 · 2min, moisture (reel) 8.1% water repellency Water liner paper can be suitably used. When the segment 12a having such properties is used, even if it is left as it is, the environmental load is extremely reduced.

  The shape of the segment 12a is not limited to that shown in the figure, and may be, for example, each columnar shape or polygonal columnar shape. Moreover, the following structures are mentioned as a concrete structure of the columnar body segment 12a which has the surface made from a thin metal which corrodes and disappears comparatively early. A tin steel plate having a width of 110 mm and a thickness of 0.22 mm is used and is welded into a hollow cylindrical shape having a major axis of 54 mm. When the segment 12a having such properties is used, it is relatively durable compared to the case of paper, and even if it is left as it is, it corrodes and therefore has a very low environmental load. The durability in this case can be appropriately changed by selecting the thickness of the steel plate.

  The segment 12a is embedded in the ground B of the river bed A in a state where a plurality of segments 12a are stacked in the vertical direction. When embedding the segment 12a in a stacked state, in this embodiment, as shown in FIG. 2, the upper surface of the segment 12a at the upper end is embedded so as to coincide with the riverbed surface C to be measured. In this case, the upper end of the laminated segment 12a is a calculation reference for the scouring depth, and this is matched with the riverbed surface C.

  In the embedded state of the segment unit 12 shown in FIG. 2, it is not always necessary to embed the upper end segment 12a so that the upper surface of the segment 12a coincides with the riverbed surface C to be measured. In this flow, if it fluctuates slightly, the upper end can be set to a position slightly depressed from the riverbed surface C in anticipation of this. The fluctuation value in this case means a scouring state within a range that does not lead to a flooding state.

  Furthermore, the embedded state of the segment unit 12 does not have to be limited to the state shown in FIG. 2, for example, the lower end of the stacked segments 12a can be used as a calculation reference for the scouring depth, In this case, the distance from the lower end to the riverbed surface C to be measured may be measured and made known.

  In addition, what is necessary is just to carry out uneven | corrugated fitting between the upper and lower segments 12a, for example, in order to stabilize the lamination | stacking state of the segment unit 12 which laminates | stacks the several segment 12a. In this case, there is no problem if it is in a loose fitting state in consideration of ease of detachment by scouring.

  The sensor 14 is individually disposed in each segment 12a, and detects the stacked state of the segment 12a and two states separated from the stacked state. In the case of the present embodiment, such a different state is detected by a change in electrical characteristics, and each sensor 14 is composed of an ultra-fine copper wire with insulation coating.

  In the case of the present embodiment, as shown in FIG. 3, the copper wire is arranged so as to be folded back in the vicinity of the lower end of the outer surface of each segment 12a and is fixed by an adhesive or the like. In addition, the fixing position of the sensor 14 may be any of the inner surface of the through hole of the segment 12a and the upper and lower end surfaces other than the illustrated location.

  In the sensor 14 configured in this manner, the copper wire is cut when the segment 12a is detached from the laminated state. At this time, if a minute voltage is applied to the sensor 14, the terminal voltage changes due to disconnection. If the voltage is monitored, the separation of the segment 12a can be detected.

  The target of the electrical characteristics when the sensor 14 detects the laminated state and the delaminated state is not limited to the voltage, and may be a current or a resistance value, for example.

  The measurement recording device 16 is disposed in a watertight casing 18 and is embedded in the lower end of the segment unit 12 in which the segments 12a are stacked. The measurement recording device 16 of this embodiment includes a ladder that combines a plurality of comparators 16a to which the sensors 14 are individually connected, a plurality of latch circuits 16b that are connected to the comparators 16a, and a resistor that is connected to the latch circuit 16b. Circuit 16c.

  The comparator 16a compares the terminal voltage detected from the sensor 14 with the reference voltage and sends a predetermined output signal to the latch circuit 16b. The latch circuit 16b temporarily sends the send signal from the comparator 16a. Hold on.

  The ladder circuit 16c is connected to a controller 16d, and a memory 16e and a transmitter 16f are connected to the controller 16d. The controller 16d is composed of a microcomputer, supplies a predetermined voltage to the sensor 14, receives a transmission signal from the comparator 16a via the ladder circuit 16c, and stores it in the memory 16e with time. An appropriate watertight structure is provided at a place where the sensor 14 is removed from the housing 18.

  FIG. 4 shows an example of the transmission signal of the sensor 14 stored in the memory 16e. In FIG. 4, the horizontal axis represents time and the vertical axis represents voltage. In the case of the present embodiment, the sensor 14 is composed of a coated fine copper wire, and measures the terminal voltage that is folded back on the outer surface of each segment 12.

  When the segment 12a is detached from the laminated state and the sensor 14 is disconnected, the terminal voltage is rapidly increased, and the separation of the segment 12a is detected with the time.

  Such a separation condition of the segment 12a varies depending on the flow rate of the river water, but can be set so as to be detached when, for example, half or more of the height of the segment 12a is exposed by scouring.

  6 and 7 show a method for installing the scour measuring apparatus 10 according to the present invention. In the installation methods shown in these figures, first, the excavation hole 20 is formed in the water bottom ground B of the measurement target riverbed A.

  As shown in FIG. 6, a hollow cylindrical casing 22 is used to form the excavation hole 20. The casing 22 has a diameter in which the scour measuring apparatus 10 can be inserted.

  When penetrating the casing 22 into the ground B, the guide pipe 24 is erected adjacent to the casing 22, and the surveyor visually recognizes the guide pipe 24 with the surveying instrument 24, whereby the coordinates of the installation position are measured. Note that the burial position of the scour measuring apparatus 10 including the segment unit 12 and the measurement recording apparatus 16 may be determined by not only the field survey as shown in the figure but also a GPS survey based on satellite observation, for example.

  In the case of the present embodiment, a jet water flow is used for penetration of the casing 20, and a jet boring pipe 26 for ejecting the jet water is inserted into the casing. The boring pipe 26 is connected to a jet pump 30 mounted on a hull 28 floating on the river surface.

  When the penetration of the casing 20 into the ground B progresses, and when it penetrates to a predetermined depth, the segment unit 12 and the measurement recording device 16 are inserted into the casing 20 as shown in FIG. At this time, the casing 18 in which the measurement surveying device 16 is installed is disposed at the lower end, and the segment unit 12 is disposed thereon.

  When the casing 18 reaches the lower end of the excavated water bottom ground, the installation is completed by removing the casing 20. In addition, the installation method of the scour measuring apparatus 10 concerning this invention does not need to be restricted to the illustrated method, For example, the excavation method which does not use the casing 20 may be sufficient.

  8 and 9 show an example of a recovery method of the scour measuring apparatus 10 according to the present invention. When collecting the scour measuring device 10, in the case of the present embodiment, the transmitter 16f is provided in the measurement recording device 16, and this is used.

  The search for the scour measuring apparatus 10 is performed by the operator having the receiver 30 and receiving the radio wave from the transmitter 16f to identify the installation location. In this case, the transmitter 16f may always transmit radio waves, but if the radio waves are transmitted only when a signal from the receiver 30 is received, battery consumption can be prevented.

  When the installation position of the scour measuring device 10 is specified, next, as shown in FIG. 9, the diver grasps the jet bore link pipe 26 and directs its tip toward the ground B, thereby causing the jet water flow. The ground is excavated and the scour measuring device 10 is recovered, and the recovered device 10 can be reused. In addition, the transmitter 16f is not necessarily required when the burial position of the scour measuring device 10 is specified by on-site surveying or GPS surveying.

  In the scouring measuring apparatus 10 configured as described above, when scouring occurs during flooding or flooding of a river, the segment 12a is pushed out by the flow rate of water when the segment 12a is exposed from the riverbed surface by scouring of earth and sand, and then leaves the laminated state. To do.

  At this time, when the sensor 14 disposed in the detached segment 12a is disconnected, its electrical characteristics change, and this is recorded in the measurement recording device 16 over time. When the measurement recording device 16 is recovered, the segment 12a You can know the time when you left.

  By collecting the measurement recording device 16 in which such information is recorded, it is possible to know the time when the segment 12a is detached. In this case, since the segment unit 12 knows the height of the segment 12a and the distance from the upper end or the lower end, which is the calculation reference for the scouring depth, to the riverbed surface C to be measured, You can know the scoured depth.

  FIG. 5 shows an example of the relationship between scouring depth and voltage obtained by the scouring measuring apparatus 10 according to the present invention. In this figure, the horizontal axis is time and the vertical axis is the scouring depth. In this embodiment, the height of the segment 12a alone is 100 mm. The one segment 12a at the upper end is detached, and the scouring depth at that time is 100 nm.

  Further, in the example shown in FIG. 5, the segment 12a sequentially departs from the stacked state from the upper end side with the passage of time, and at 12 o'clock on June 15, 7 segments 12a are detached and scoured. The depth is 700mm.

  In the scour measuring apparatus 10 configured as described above, the segment unit 12 only needs to be detached from the stacked state by scouring that occurs at the time of flooding or flooding of a river, so it is necessary to mount a functional component such as a transmitter. Since there is no need to incorporate a power source battery as in the case of incorporating a transmitter, even if the segment 12a is lost, there is no risk of adverse effects on the environment, the structure is simple, and the cost can be reduced. .

  FIG. 10 shows another embodiment of the scour measuring apparatus according to the present invention. The same or corresponding parts as those in the above embodiment are designated by the same reference numerals and the description thereof is omitted. Only the feature points will be described in detail.

  In the example shown in the figure, an optical fiber is used for the sensor 14a that detects the laminated state and the detached state of the segment 12a. The optical fiber type sensor 14a detects the laminated state and the delaminated state of the segment 12a by changing the characteristics of light propagation.

  In this case, the sensor 14a is arranged so as to be folded back at each segment 12a as in the above embodiment, and the optical fiber 14a is cut when the segment 12a is detached. Since the optical fiber 14a is relatively easily broken, for example, when it is folded, it is better to fold it so as to go around the inner circumference or outer circumference of the segment 12a.

  In the casing 18, a photoelectric converter 16h is disposed at the end of the optical fiber sensor 14a. In the photoelectric converter 16h, a light emitting diode is disposed on the transmission side of the optical fiber, and a photodiode is disposed on the reception side.

  The optical signal transmitted from the light emitting diode propagates through the sensor 14a and is output to the photodiode, and the electrical signal converted by the photodiode is recorded in the memory 16e via the controller 16d.

  When the segment 12a enters the delamination state, the sensor 14a is cut and the propagating optical signal disappears. As a result, the output of the photodiode is lost, and the lamination state and delamination state of the segment 12a are detected.

  Even if the optical fiber type sensor 14a having such a configuration is used, the same effect as that of the above embodiment can be obtained. In addition, the sensor 14a using an optical signal is like a sensor using electricity. Therefore, it is not necessary to consider the influence of the leakage current.

  According to the scouring measuring apparatus according to the present invention, the scouring state of a river during flooding or flooding can be measured over time, so that it can be effectively used as data when designing a levee body. .

It is explanatory drawing of the installation state of the scour measuring device concerning this invention. It is an enlarged view of the scour measuring apparatus shown in FIG. It is a principal part enlarged view of the scour measuring apparatus shown in FIG. It is explanatory drawing which shows an example of the recording data in the scour measuring apparatus shown in FIG. It is a graph which shows a time-dependent change of scouring depth from the measurement result obtained with the scouring measuring device shown in FIG. It is explanatory drawing which shows the method at the time of installing the scouring measuring apparatus shown in FIG. It is explanatory drawing which shows the process performed following the installation procedure shown in FIG. It is explanatory drawing which shows the method at the time of collect | recovering the scour measuring apparatus shown in FIG. It is explanatory drawing which shows the process performed following the collection | recovery procedure shown in FIG. It is explanatory drawing which shows the other example of the sensor used with the scour measuring apparatus which concerns on this invention.

10 Scour Measurement Device 12 Segment Unit 12a Segment 14 Sensor 16 Measurement Recording Device

Claims (9)

A plurality of segments are embedded in the river bed in a state where they are stacked vertically, and the height of the segment and the distance from the upper end or lower end, which is the calculation standard for the scouring depth, to the river bed surface to be measured are known. A segment unit,
A plurality of sensors that are individually disposed in the segments and detect a lamination state and a lamination separation state of the segments;
A river scouring measurement apparatus comprising a measurement recording device embedded in the lower end of the segment unit and measuring and recording the detection state of the sensor over time.   The segment is composed of a columnar body having a thin metal surface that corrodes and disappears relatively early with the passage of time, or a special corrugated columnar body that naturally disappears with the passage of time. The river scour measuring apparatus according to claim 1. The river according to claim 1 or 2, wherein the measurement recording device includes a transmitter and receives a transmission signal from the transmitter to detect a buried position of the measurement recording device. Scour measuring equipment. The river scouring measurement device according to any one of claims 1 to 3, wherein the embedment position of the segment and the measurement recording device is specified by field surveying or GPS surveying. The river scour measuring apparatus according to any one of claims 1 to 4, wherein the sensor detects a laminated state and a laminated detached state of the segments based on a change in electrical characteristics. 6. The river according to claim 5, wherein the sensor is composed of a fine copper wire, the fine copper wire is arranged so as to be folded back into the segment, and the fine copper wire is cut when the segment is detached. Scour measuring equipment. The river scour measuring apparatus according to claim 6, wherein the electrical characteristic of the sensor is selected from one of voltage, current, and resistance. 5. The river scour measuring apparatus according to claim 1, wherein the sensor detects a laminated state and a detached state of the segments based on a change in light propagation characteristics. 9. The river scouring according to claim 8, wherein the sensor is composed of an optical fiber, the optical fiber is arranged so as to be folded back into the segment, and the optical fiber is cut when the segment is detached. measuring device.

Images