JP2021135127A - Slope displacement-amount measurement system - Google Patents

Abstract

To provide a slope displacement-amount measurement system that detects an indication of a slope collapse by acquiring an amount of movement of a surface soil of a slope in a time sequence.SOLUTION: A slope displacement-amount measurement system has: a sensor pole that is buried so that the pole penetrates through a surface soil layer from a ground surface in a slope, and its tip part reaches below a slipping face; a reference inclination sensor that is provided in the tip part of the sensor pole and a plurality of inclination sensors that are provided intermittently from the slipping face in the surface soil to the ground surface, with respect to the sensor pole; and communication means that is installed in a top end of the sensor pole, and transmits a tilt of the inclination sensor. A control device receiving the tilt from the communication means when the sensor pole bends is configured to calculate a coordinate of one inclination sensor from a tilt of one inclination sensor and a tilt of the other inclination sensor next to the one inclination sensor.SELECTED DRAWING: Figure 4

Description

The present invention relates to a slope displacement measuring system that detects the amount of movement of soil covering the surface layer of a slope.

As for the soil structure on the ground, the topsoil is covered by the uppermost layer of the stratum, and on slopes such as mountains, the topsoil collapses as a slip surface between the topsoil layer and the layer below it due to heavy rain, etc. Sediment disasters may occur. Therefore, before installing a wire-type displacement sensor on the slope to detect surface collapse such as landslides by expanding and contracting the wire, or to detect slight displacement of the topsoil such as cracks and develop into a large-scale surface collapse. I am preventing it.

In addition, an inclinometer or the like may be installed on the slope to detect surface collapse due to fluctuations in inclination, an acceleration sensor or the like may be installed to detect the movement of the surface soil, or pore water pressure may be measured with a strain gauge or the like to detect surface collapse. Is predicted. As described in Patent Document 1, an invention of an inclinometer device for measuring the inclination / displacement of the ground due to a landslide or the like by burying a pipe provided with a sensor is also disclosed.

Various sensors are installed at multiple locations on the slope, collected via communication means such as wireless, and various analyzes are performed to predict surface collapse. As described in Patent Document 2, the invention of a slope failure sign detection system that collects measurement data from sensors dispersed on a slope and detects a sign of slope collapse is also disclosed.

Further, as described in Patent Document 3, the invention of a collapse risk notification service information providing device capable of monitoring the slope state acquired in real time and specifically grasping the collapse danger sign of the measurement target point. It is disclosed. Similarly, an invention that evaluates the risk of slope failure in real time and warns when the risk becomes high (Patent Document 4), a slope monitoring system that predicts slope collapse (Patent Document 5), and the like are also disclosed. ing.

Japanese Unexamined Patent Publication No. 2011-169705 Japanese Unexamined Patent Publication No. 2017-134019 Japanese Patent No. 5804034 JP-A-2018-195111 JP-A-2019-105130

However, in the prior art, a sensor is installed on the slope to measure the slope of the ground surface and the displacement of the soil to predict the surface collapse such as landslide. For example, the surface soil slides and moves together with the sensor. Depending on the sensor, it may not be possible to detect the movement of the surface soil on the slope, such as when the inclination fluctuates little. In addition, the topsoil may be washed away together with the sensor, making the sensor uncollectible.

Therefore, an object of the present invention is to provide a slope displacement amount measuring system that detects signs of slope failure by acquiring the amount of movement of the surface soil of the slope in time series.

In order to solve the above problems, the slope displacement measurement system of the present invention includes a sensor pole embedded so that the tip portion penetrates the surface soil layer from the ground surface on the slope and reaches below the slip surface. With respect to the sensor pole, a reference tilt sensor provided at the tip, a plurality of tilt sensors intermittently provided from the slip surface in the surface soil to the ground surface, and a tilt sensor installed at the upper end of the sensor pole to adjust the tilt of the tilt sensor. The control device having the communication means for transmitting and receiving from the communication means when the sensor pole is bent is the inclination of one of the inclination sensors and the other inclination adjacent to one of the inclination sensors. It is characterized in that the coordinates of one tilt sensor are calculated from the tilt of the sensor.

In the slope displacement amount measuring system, the sensor pole is characterized by having a concavo-convex structure at its tip.

In the slope displacement amount measuring system, the sensor pole is embedded in a direction perpendicular to the slope.

In the slope displacement measurement system, the tilt sensor has a reference tilt sensor at the tip, a first tilt sensor at a position closer to the slip surface in the surface soil, and a position near the ground surface in the surface soil with respect to the sensor pole. A second tilt sensor is provided in the control device, and the control device estimates that the first tilt sensor is tilted from the reference tilt sensor only between the tilt of the first tilt sensor and the tilt of the reference tilt sensor. It is estimated that the second tilt sensor is tilted from the first tilt sensor by an intermediate distance between the tilt of the second tilt sensor and the tilt of the first tilt sensor.

The slope displacement amount measuring system is characterized in that a displacement vector is calculated and visualized from the coordinate difference between the position coordinates before displacement and the position coordinates after displacement of the inclination sensor.

The slope displacement amount measuring system is characterized in that a plurality of the sensor poles are embedded in the slope and are transmitted and received from each of the communication means to one control device.

In the slope displacement amount measuring system, the control device periodically receives an inclination from the inclination sensor, calculates the amount of movement of the surface soil of the slope in time series, and detects a sign of slope collapse. It is characterized by.

According to the present invention, a sign of slope failure can be detected from the amount of movement of the topsoil on the slope. The tip of the sensor pole has an uneven structure that does not easily come off, and by fixing it as a reference position, the sensor pole bends as the topsoil moves, so the displacement of the tilt sensor placed inside the sensor pole By looking at it, the amount of movement of the topsoil can be grasped. By installing sensor poles at multiple points on the slope, it is possible to estimate the location of cracks and predict the risk of the extent and scale of slope failure. Since it is not necessary to stretch a wire on the slope to measure the crack width after finding a crack, it is excellent in safety and economy.

It is an overview diagram explaining the usage situation of the slope displacement amount measurement system of this invention. It is a schematic diagram explaining the installation of each apparatus in the slope displacement amount measurement system of this invention. It is a perspective view which shows the measuring apparatus in the slope displacement amount measuring system of this invention. It is an overview diagram which shows the detection method of the slope displacement amount in the slope displacement amount measurement system of this invention. It is a figure explaining the calculation method of the position of the inclination sensor in the slope displacement amount measurement system of this invention. It is a figure explaining the communication control of the slope displacement amount measuring system which is this invention. It is a graph which measured the inclination angle at the time of actually bending a sensor pole in the slope displacement amount measurement system of this invention in time series. It is a figure which shows the position calculation from the inclination angle in the slope displacement amount measurement system of this invention. It is a table which compared the error of the position calculated by the slope displacement amount measurement system of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted.

The slope displacement amount measuring system of the present invention will be described. FIG. 1 is an overview view for explaining the usage status of the slope displacement amount measuring system. FIG. 2 is an overview view illustrating the installation of each device. FIG. 3 is a perspective view showing the measuring device. FIG. 4 is an overview view showing a method for detecting a slope displacement amount. FIG. 5 is a diagram illustrating a method of calculating the position of the tilt sensor. FIG. 6 is a diagram illustrating communication control.

As shown in FIG. 1, the slope displacement amount measuring system 100 intermittently installs a plurality of measuring devices 110 on a slope 200 such as a mountain, and acquires position coordinates from each measuring device 110 to obtain the position coordinates of the slope 200. Measure the amount of displacement. The measuring device 110 is installed at multiple points, for example, in a grid pattern or a staggered pattern, for tracking and monitoring in a range.

As shown in FIG. 2, in the slope displacement amount measuring system 100, the measuring device 110 is embedded so that the tip portion of the slope 200 penetrates the surface soil layer 210 from the ground surface 230 and reaches below the slip surface 240. A plurality of measuring devices 110 are embedded in the slope 200, and the position coordinates of each measuring device 110 are transmitted to the relay device 120 via the communication means.

As shown in FIG. 3, the measuring device 110 includes a sensor pole 300 pierced by a slope 200, a plurality of tilt sensors intermittently provided on the sensor pole 300, a control device 400 installed at the upper end of the sensor pole 300, and a power supply 500. And so on. The relay device 120 also has the same structure as the measuring device 110, and any one of the plurality of measuring devices 110 may be the relay device 120.

The sensor pole 300 is an elongated metal rod, and the tip portion 310 may have a concavo-convex structure so that threads and the like are not easily pulled out. It has enough strength to pierce the ground and has elasticity enough to bend when a strong force is applied from the side. In order to provide the inclination sensor, a tubular pipe having a hollow inside may be used. A resin pipe such as polyvinyl chloride may be used as the sensor pole 300.

The control device 400 calculates the position coordinates of the tilt sensors from the tilts of the plurality of tilt sensors provided in the sensor pole 300, and uses a communication means such as LPWA (low power consumption and wide area wireless communication) to relay the device 120. Or send to a server (including the cloud) using a communication network such as the Internet. It should be noted that these communication means may have a bidirectional communication function.

As the power source 500, for example, a dry battery, a solar panel 510, or the like may be used. A storage battery, a charger, or the like may be provided in case the sunlight cannot be obtained such as when the weather is bad or at night.

As shown in FIG. 4, the sensor pole 300 is inserted into the hole excavated in the direction perpendicular to the ground surface 230 of the slope 200. The topsoil layer 210 is penetrated so that the tip portion 310 reaches before the slip surface 240, which is presumed to be the boundary between the topsoil layer 210 and the base layer 220. The depth to the slip surface 240 may be estimated from the feeling when excavated with a drill or the like in advance. It may also be estimated from changes in soil quality. The sensor pole 300 may be installed in the direction of gravity or in the horizontal direction depending on the condition of the slope.

The collapse of the slope 200 is generally 1 to 2 meters on an artificial slope and 2 to 3 meters on a natural slope. Therefore, the sensor pole 300 needs to be longer than the depth of the topsoil layer 210, for example, 2 to 4 meters. The sensor pole 300 may be configured to be extendable. The control device 400, the power supply 500, and the like existing at the upper end of the sensor pole 300 come out above the ground surface 230.

The sensor pole 300 is provided with a reference tilt sensor 600 at the tip portion 310 and a plurality of tilt sensors intermittently from the slip surface 240 in the topsoil to the ground surface 230. For example, tilt sensors may be provided at intervals of 1 meter, a first tilt sensor 610 may be provided at a position 320 near the slip surface in the topsoil, and a second tilt sensor 620 may be provided at a position 330 near the ground surface in the topsoil. The dimensions between each sensor are measured in advance and used in the analysis.

The reference tilt sensor 600 provided at the tip portion 310 is fixed in the base layer 220, so that the position coordinates become constant. When a crack 250 or the like is generated on the slope 200 and the topsoil moves along the slip surface 240, the sensor pole 300 is bent accordingly.

As shown in FIG. 5, the tilt sensor (including the reference tilt sensor 600) in the sensor pole 300 does not directly acquire the position coordinates after movement, but acquires the tilt that fluctuates due to the bending of the sensor pole 300. do. The tilt is obtained as a tangent to the curved sensor pole 300. It should be noted that the inclination with respect to the gravity direction may be acquired, or the inclination changed relative to the case where the sensor pole 300 is embedded in the vertical direction with respect to the slope 200 may be acquired.

The control device 400 calculates the position coordinates of each tilt sensor from the tilts acquired from the plurality of tilt sensors. For example, the reference position coordinates of the reference tilt sensor 600 are set to P0 (X0, Y0, Z0), and from the tilt m0 of the first tilt sensor 610 to the position coordinates P1 (X1, Y1, Z1) and the tilt m0 of the second tilt sensor 620. The position coordinates P2 (X2, Y2, Z2) are calculated as initial values.

Since the reference tilt sensor 600, the first tilt sensor 610, and the second tilt sensor 620 are on a straight line, they are positioned from the distance and direction from the reference tilt sensor 600 to the first tilt sensor 610 and the second tilt sensor 620. The coordinates P1 and P2 can be calculated.

When the topsoil moves and the sensor pole 300 is bent, the inclination m1 of the first inclination sensor 610 and the inclination m2 of the second inclination sensor 620 are acquired. The control device 400 calculates the coordinates of one tilt sensor from the tilt of one tilt sensor and the tilt of the other tilt sensor adjacent to one of the reference tilt sensor 600 and the tilt sensors 610 and 620.

That is, it is estimated that the first tilt sensor 610 is tilted from the reference tilt sensor 600 by an intermediate portion (1/2) between the tilt m1 of the first tilt sensor 610 and the tilt m0 of the reference tilt sensor 600, and the first tilt sensor 600 is tilted. Position coordinates P1'(X1', Y1', Z1') are calculated from the distance and direction to the sensor 610.

Further, it is estimated that the second tilt sensor 620 is tilted from the first tilt sensor 610 by an intermediate (half) between the tilt of the second tilt sensor 620 and the tilt of the first tilt sensor 610, and the second tilt sensor 620 is tilted. Position coordinates P2'(X2', Y2', Z2') are calculated from the distance and direction to the sensor 620.

It is detected that the sensor pole 300 is bent and the position of the tilt sensor is changed due to the fluctuation of the tilt of the tilt sensor. Since the reference tilt sensor 600 is fixed to the base layer 220, its position does not change. It is detected that the surface soil layer 210 is displaced due to the fluctuation of the inclination sensors 610 and 620. The displacement vectors 630 and 640 may be calculated and visualized from the coordinate difference between the position coordinates before the displacement of the tilt sensor and the position coordinates after the displacement.

By calculating the position coordinate P1'of the first inclination sensor 610 and the position coordinate P2'of the second inclination sensor 620 in each of the measuring devices 110 embedded in the slope 200, the displacement amount of the surface soil at each point of the slope 200 is measured. Will be done. It should be noted that the position coordinates calculated by the control device 400 may be accumulated in time series as a history by acquiring them in real time or periodically.

As shown in FIG. 6, the relay device 120 includes a control device 400 and a power supply 500 like the measuring device 110, and tilts the tilt sensors 600, 610, and 620 and calculated position coordinates from each measuring device 110. , LPWA communication, etc. Receive via a communication means 420 capable of bidirectional remote communication.

The central processing device 410 of the relay device 120 analyzes the displacement amount of the slope 200 based on the information collected from each measuring device 110, and uses the cloud communication 430 such as the Internet to provide the displacement amount of the slope 200 to the cloud server 440. By accumulating information such as, the signs of slope failure are predicted. It will be possible to visualize and refer to it on other terminals such as personal computers and smartphones.

If there are signs of slope failure, an alert may be displayed to other terminals. As for the power source 500 of the relay device 120, the solar panel 510 may be used to generate solar power, and the storage battery 520 or the like may be used to manage the power source.

The results of the test on the slope displacement measurement system of the present invention are shown. FIG. 7 is a graph in which the inclination angle when the sensor pole in the slope displacement amount measuring system is actually bent is measured in time series. FIG. 8 is a diagram showing position calculation from an inclination angle in a slope displacement amount measuring system. FIG. 9 is a table comparing the position errors calculated by the slope displacement measurement system.

As shown in FIG. 7, the surface soil layer 210 of the slope 200 is experimentally moved (or assumed) to apply a force to the sensor pole 300 to change the bending amount 650 of the sensor pole 300 to 30 mm, 60 mm, and 90 mm. .. A reference tilt sensor 600 (origin), a first tilt sensor 610 (center), and a second tilt sensor 620 (tip) are installed on the sensor pole 300.

Every time the bending amount 650 fluctuates, the tilt angles of the tilt sensors 600, 610, and 620 also fluctuate. At the origin, since it is close to the tip portion 310 fixed to the base layer 220, the inclination angle does not fluctuate much. Since the center and the tip are not curved in a circular shape with respect to the bending amount of 650, the inclination angle does not increase in proportion to the bending amount of 650.

As shown in FIG. 8, the slope displacement amount measuring system 100 calculates the deviation amount 660 estimated from the inclination angles of the inclination sensors 600, 610, and 620. That is, it is estimated that the first tilt sensor 610 is tilted from the reference tilt sensor 600 by half the tilt of the first tilt sensor 610 and the tilt of the reference tilt sensor 600, and the second tilt sensor 620 is the second. It is estimated that only half of the tilt of the tilt sensor 620 and the tilt of the first tilt sensor 610 are tilted from the first tilt sensor 610.

In addition, the result when it is estimated that the second tilt sensor 620 is tilted from the reference tilt sensor 600 by half of the tilt of the second tilt sensor 620 and the tilt of the reference tilt sensor 600 is also calculated.

As shown in FIG. 9, when measured at three points, the inclination angle when the bending amount 650 is 30 mm is 89.7 degrees at the origin, 88.2 degrees at the center, and 87.8 degrees at the tip, which are estimated. The deviation amount 660 was 9.8 mm at the center and 18.4 mm at the tip, for a total of 28.2 mm, and the error was 1.8 mm.

When the bending amount 650 is 60 mm, the inclination angle is 89.4 degrees at the origin, 86.5 degrees at the center, and 85.6 degrees at the tip, and the estimated deviation amount 660 is 19.2 mm at the center and 36. It was 6 mm, 55.8 mm in total, and the error was 4.2 mm.

When the bending amount 650 is 90 mm, the inclination angle is 89.0 degrees at the origin, 84.8 degrees at the center, and 83.4 degrees at the tip, and the estimated deviation amount 660 is 28.8 mm at the center and 54. It was 7 mm, 83.4 mm in total, and the error was 6.6 mm.

Further, when measured at two points, the estimated deviation amount 660 when the bending amount 650 was 30 mm was 23.2 mm, and the error was 6.8 mm. When the bending amount 650 was 60 mm, the estimated deviation amount 660 was 46.7 mm, and the error was 13.3 mm. When the bending amount 650 was 90 mm, the estimated deviation amount 660 was 70.7 mm, and the error was 19.3 mm.

The control device 400 of the slope displacement amount measuring system 100 can estimate the position coordinates of the tilt sensors 600, 610, and 620 from the tilt angles of the tilt sensors 600, 610, and 620 when the sensor pole 300 is curved. , The larger the number of measurement points, the smaller the error and the higher the accuracy.

According to the present invention, a sign of slope failure can be detected from the amount of movement of the topsoil on the slope. The tip of the sensor pole has an uneven structure that does not easily come off, and by fixing it as a reference position, the sensor pole bends as the topsoil moves, so the displacement of the tilt sensor placed inside the sensor pole By looking at it, the amount of movement of the topsoil can be grasped. By installing sensor poles at multiple points on the slope, it is possible to estimate the location of cracks and predict the risk of the extent and scale of slope failure. Since it is not necessary to stretch a wire on the slope to measure the crack width after finding a crack, it is excellent in safety and economy.

Examples of the present invention have been described above, but the present invention is not limited thereto. For example, as the tilt sensor, a triaxial acceleration sensor or the like may be used to acquire the tilt. Further, in addition to sequentially calculating the position coordinates from the inclination of the adjacent inclination sensors, the position coordinates may be calculated from the inclination of each inclination sensor with the reference inclination sensor as the origin.

Slope displacement is complicated and it is difficult to calculate exact coordinates. In addition, for example, for an arbitrary curve passing through three points, the position coordinates in the three axial directions should be calculated using the deflection curve calculation method. You can do it.

The slope displacement measurement system can be applied not only to large-scale slopes such as mountains, but also to small-scale slopes such as residential areas. Moreover, it may be used not only at the local government level but also at the individual level. Multiple sensor poles are set up along the slope to request the management center to collect information, and if there is a risk of slope collapse, a warning message is sent to the smartphone, etc., and the information from the smartphone to the management center, etc. You may receive the offer of.

100: Slope displacement measurement system 110: Measuring device 120: Relay device 200: Slope 210: Surface soil layer 220: Base layer 230: Ground surface 240: Sliding surface 250: Crack 300: Sensor pole 310: Tip 320: Sliding surface Position 330: Position near the ground surface 400: Control device 410: CPU (Central processing unit)
420: LPWA communication (communication means)
430: Cloud communication 440: Cloud server 500: Power supply 510: Solar panel 520: Storage battery 600: (Reference) Tilt sensor 610: (1st) Tilt sensor 620: (2nd) Tilt sensor 630: Displacement vector 640: Displacement vector 650 : Bending amount 660: Displacement amount

Claims (7)

A sensor pole that is buried so that the tip of the slope penetrates the topsoil layer from the ground surface and reaches below the slip surface.
With respect to the sensor pole, a reference tilt sensor provided at the tip, and a plurality of tilt sensors intermittently provided from the slip surface in the topsoil to the ground surface,
It has a communication means which is installed at the upper end of the sensor pole and transmits the inclination of the inclination sensor.
The control device received from the communication means when the sensor pole is bent is a tilt sensor of one tilt sensor from the tilt of one tilt sensor and the tilt of another tilt sensor adjacent to one of the tilt sensors. Calculate the coordinates,
A slope displacement measurement system characterized by this. The sensor pole has an uneven structure at the tip thereof.
The slope displacement amount measuring system according to claim 1. The sensor pole is embedded in the direction perpendicular to the slope.
The slope displacement amount measuring system according to claim 1 or 2. The tilt sensor is provided with a reference tilt sensor at the tip thereof, a first tilt sensor at a position near the slip surface in the topsoil, and a second tilt sensor at a position near the ground surface in the topsoil with respect to the sensor pole. ,
The control device estimates that the first tilt sensor is tilted from the reference tilt sensor by an amount intermediate between the tilt of the first tilt sensor and the tilt of the reference tilt sensor, and the second tilt sensor is the second tilt sensor. 2 It is estimated that the position is tilted from the first tilt sensor only between the tilt of the tilt sensor and the tilt of the first tilt sensor.
The slope displacement amount measuring system according to any one of claims 1 to 3, wherein the slope displacement amount measuring system is characterized. A displacement vector is calculated and visualized from the coordinate difference between the position coordinates before the displacement and the position coordinates after the displacement of the tilt sensor.
The slope displacement amount measuring system according to claim 4. A plurality of the sensor poles are embedded in the slope, and transmission / reception from each of the communication means to one control device is performed.
The slope displacement amount measuring system according to any one of claims 1 to 5, wherein the slope displacement amount measuring system is characterized. The control device periodically receives the inclination from the inclination sensor, calculates the amount of movement of the topsoil on the slope in chronological order, and detects a sign of slope collapse.
The slope displacement amount measuring system according to any one of claims 1 to 6, wherein the slope displacement amount measuring system is characterized.

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