JPH01119721A - Automatic observation system machinery for landslide - Google Patents

Abstract

PURPOSE:To determine the movement of a landslide by a reduced number of channels, by measuring the movement quantity between the points with respect to the moving state of a moving clod. CONSTITUTION:A displacement measuring wire W1 low in coefficient of linear expansion is stretched between two points (A1, A2) measuring displacement quantity and one end thereof is fixed to a part to be measured such as a moving stake while the other end thereof wound around the take-up drum D1 of a ground surface displacement meter 1. When the part 11 to be measured generates displacement in the stretching direction of the measuring wire W1, the measuring wire W1 is delivered or drawn in to rotate the drum D1. The rotary encoder E connected to the shaft of the drum D1 rotates with the rotation of the drum and the absolute position on the circumference thereof is outputted as digital quantity. This output value is taken in a microcomputer MC and, from the difference between the output quantities of the encoder E before and after the part 11 to be measured is displaced, displacement quantity and cumulated displacement quantity are operated in succession to be stored in the microcomputer MC. The input/output between the displacement meter 1 and a data recording part is performed through an interface 1F and a communication line 5.

Description

[Detailed Description of the Invention] 1) Industrial Field of Application The present invention relates to the continuous observation of landslides and similar phenomena, specifically, the tensile and compressive changes in the ground surface due to landslides, and the observation of slip surfaces and underground cracks. This invention relates to a pure digital, digital measuring instrument that automatically observes groundwater level fluctuations related to displacement, landslide fluctuations, and precipitation weight closely related to these, and an automatic observation system 81 equipped with the same.

2) Conventional technology Landslide refers to a phenomenon in which a part of land slides due to underground water, etc., or moves along with this.
In many cases, the upper soil mass slides down relatively slowly along areas of weak shear resistance in the soil (called slip surfaces).

Landslide surveys to plan landslide prevention measures.
-・Landslide motion is measured as a ring, but the conventional observation equipment is a pipe strain meter.

Borehole inclinometers, ground inclinometers, ground extensometers, underground extensometers, moving gage gauges, float-type groundwater level gauges, stylus-type groundwater level gauges, and tipping basin-type rain gauges are used.

Observations have been made manually or by individual records.

3) Problems that the invention aims to solve In recent years, disasters caused by landslides and landslides have become a major social problem, and high-density and high-precision dynamic FI observation is required to detect these disasters in advance. In order to achieve this, it is necessary to introduce automatic observation using a computer, but it is a long-term one-tll measurement in the field, and the area of the observation site is extremely large, and it is difficult to automate the conventional observation items as they are. This requires a huge number of channels, which poses problems in terms of reliability and economy of one operation.

The purpose of the present invention is to eliminate the above-mentioned problems in automating the observation of the dynamics of landslides, etc., to reliably understand the dynamics of landslides, etc. with a small number of channels, and to realize economical landslides, etc. in terms of cost. The objective is to provide an automatic observation system for

4) Means to solve problems The present invention solves the above problems.

The contents will be explained in detail below.

, - Observation items regarding dynamic observation of landslides, etc. in the present invention can be summarized into the following three items.

■ Movement status of moving earth clods: movement speed of earth clods, movement distance,
Thickness of the moving soil mass (depth of the sliding surface),...Change in the distance between two points on the ground surface [AI, A21] across the crack [C], or the movement of the soil mass relative to the immovable ground [r3] [ All you have to do is measure the amount of deviation along the AI displacement plane [S].
(Figures 1 and 3) ■ Groundwater level height related to landslides: The height of the water level in the polling hole and its changes,
- Old... All you need to do is measure the change in the distance between the ground surface and the water level [WL] inside the polling hole. (Figure 2) ■ Rainfall related to groundwater level and landslide movement: rainfall, snowmelt ...It is sufficient to count the pulses from the falling rain gauge [R].

The above observation items shall be handled with the least number of types of sensors and data loggers [L], and ■ and ■
As for the wire winding drum [Dl,
D2. D3] is rotated, and a sensor (rotary encoder [E
]), we decided to directly detect the rotation angle as a digital quantity. The rotation angle detected by the rotary encoder [1] is sent to a data logger [L] consisting of a one-chip microcomputer, where it is processed and stored. The thickness of the moving soil mass can be determined by inserting underground displacement measurement wires [W3] of different lengths into a poling hole drilled to a depth deeper than the displacement surface [31], as shown in Figure 3.
This is confirmed by fixing the tip with grout and measuring the amount of wire that is fed out and retracted, and based on the principle that only the wire fixed at a position deeper than the sliding surface is fed out.

Regarding ■, we made use of the extra capacity of the data logger [L]'s microcomputer and added a pulse counter function, making it possible to directly count and record the pulses from the tipping type rain gauge [R]. .

The above combination is very simple as shown in FIGS. 1 to 3, and is effective in reducing the manufacturing cost of one device.

Diagram JfLIy Blood Volume Figure 4 shows a schematic diagram of the ground surface displacement meter. Between the two points where the displacement is to be measured [Al, A21, there is a displacement measurement line with a small ta expansion coefficient such as an Imphal wire [W1] Stretch the
One end of it is fixed to the part to be measured [11] such as a moving pile, and the other end is wrapped around the winding drum [DI] of the ground surface displacement meter [1].The part to be measured [11] such as a moving pile is displaced. When a displacement occurs in the direction of extension of the quantity measuring line [W1], the displacement measuring line [W1] is paid out or retracted, and the winding drum [D1] rotates.The axis of the winding drum [D1] is accelerated. A rotary encoder [E] is connected via a gear, and the rotary encoder [E] also rotates as the take-up drum [D1] rotates. A rotary encoder is a sensor that outputs the absolute position on the circumference as a digital quantity, and the output value is taken into a 1-chip microcomputer [MC].

The amount of displacement is calculated from the difference in the output values of the rotary encoder [E] in front of which the part to be measured [11] is displaced. The amount of displacement is further calculated into cumulative displacement amount and microcomputer [
MC].

The time interval for measuring the amount of displacement can be set to any interval of one second or more, and can be changed at any time based on instructions from the computer [ITC] of the data recording section [6] shown in FIG.

The amount of rainfall Wi is measured by directly importing the pulses from the tipping rain gauge [rtl into the microcomputer [MC], counting them, and storing them inside the microcomputer [MC].

Data input and output between the ground surface displacement meter [1] and the data recording unit [6] is performed via a dedicated interface [IF] and communication ta [5].

Power is supplied from the power supply unit [PF3] of the data recording unit [6] through the communication line [5], but a backup battery [I3T] is also available for use in the event of a power outage.

As described above, (1) the present invention uses a purely digital method for measuring displacement, eliminates the need for a scanner, data logger, and AD converter, and significantly simplifies the measuring device, so there is very little risk of noise intrusion or malfunction. Features:

11 Dowata 1 Figure 5 shows a schematic diagram of a groundwater level meter.A water level detection electric switch [WS] is attached to the tip, and the other end is wrapped around the winding drum [D2].The signal line [W2] is connected to the servo The motor [M] moves the winding drum [D2
] By rotating the shaft in forward and backward directions, the water surface [WL] in the polling hole is tracked by feeding out and drawing in. To control the servo motor [M], the opening/closing status of the water surface detection electric switch [WS] is sent from the signal line [W2] to the motor control circuit [SI''L], which is installed coaxially with the winding drum [D2]. CT], which controls forward rotation, reverse rotation, starting and stopping of the servo motor [M], and adjusts F! so that the water surface detection electric switch [WS] touches the water surface inside the polling hole [WL]. be done.

The rotation of the winding drum [D2] is transmitted to the rotary encoder [E] via an increase/decrease gear, and the output data from the rotary encoder [E] is taken into the microcomputer [MC], calculated, and stored. The mechanism and function after the rotary encoder [E] is different from that in which the water level at the time of measurement is recorded as is, not the accumulated data value.

It is exactly the same as the ground surface displacement meter [1], and is also capable of measuring rainfall.

As described above, 1. The present invention uses a pure digital method to measure water level fluctuations, eliminates the need for scanners, data loggers, and AD converters, and significantly simplifies the measuring device, so there is very little risk of noise intrusion or malfunction. Features: Furthermore, by introducing a servo mechanism to track the water surface and eliminating floats whose operation is extremely unreliable, another feature is that the reliability of the data has been greatly improved.

Figure 6 shows a schematic diagram of the underground displacement meter, and a poling hole drilled at the point where the amount of displacement is to be measured [[3Ll]
A special twisting method uses a special twisting method to protect the stainless steel wires and the wires, which are made of stainless steel and have less elongation due to tensile forces, and the wires are smooth in the axial direction. An underground displacement measurement wire [W3] consisting of a movable steel core and a sheath is inserted and fixed with grout. Wire for measuring underground displacement of above ground part [W3]
The sheath is removed and up to 8 detection pulleys [D3]
wrapped around each. Displacement surfaces such as underground slip surfaces and crack surfaces [When SI causes lateral slip, displacement surfaces [8]
Only the underground displacement measurement wire [W3] whose tip is fixed at a deeper position is pulled into the ground by a length equal to the displacement of the displacement surface [,S], and the detection pulley [D
3] Rotate.

A rotary encoder [E] is directly connected to the shaft of each detection pulley [D3].
] rotation is transmitted to the rotary encoder [E], and up to eight output data from the rotary encoder [E] are taken into the microcomputer [MC], calculated, and stored.

The mechanism and function after the rotary encoder [E] are as follows:
Ground surface displacement meter [
1].

As described above, the present invention uses a purely digital method to measure displacement, eliminates the need for a scanner, data logger, and AD converter, and significantly simplifies the measuring device, so there is very little risk of noise intrusion or malfunction. The feature is that it is possible to process data of up to 8 channels by changing only the software without changing the mechanism.

Second 1LL (・-Figure 7(a)
, (b) and (c) show schematic diagrams of the underground displacement measuring wire and its usage.

FIG. 7(a) shows a case where a wire without a sheath is inserted into the poling hole storage pipe [BF3] and only the tip of the wire is fixed to the immovable ground [B]. In this case, due to the play between the wire and the hole storage pipe [DP], even if the displacement surface [31] such as a slip surface or underground crack is displaced, the wire will not be drawn into the ground at the initial stage of displacement. Initial insensitivity interval [xO]
occurs.

Figure 7(b) shows a case where the wire is passed through a sheath that minimizes the play between the wire and the wire, inserted into the poling hole [Btl], and the area around the sheath is filled with grout. There are almost no sections [XO],
The displacement amount [X] of the displacement surface [SI] is accurately measured. Also, even when installing a large number of wires, since they are covered with a sheath, they do not interfere with other wires, and the wires do not touch each other, as when installing a large number of wires without sheaths. Another advantage is that there is no need to use a special jig to align the wires.

The underground displacement measurement wire [W3] of the present invention is made by a special twisting method that has a strong and flexible steel cored sheath [S H], as shown in Fig. 7(c). It uses stainless steel wire [SW] that has less elongation due to tensile force.1. The feature is that installation work can be carried out easily and reliably on site by adding the conditions shown in FIG. 7(b).

Figure 8 shows the configuration of the automatic observation system for landslides, etc. according to the present invention.The measuring instruments include a ground surface displacement meter [1], a groundwater level meter [2], and an underground displacement meter [3]. There is an overturning rain gauge [R] that can be connected to a ground surface displacement gauge [1] or a groundwater level gauge [2] that has sufficient microcomputer capacity.

Each measuring instrument is connected to the data recording section [6] in an arbitrary order through a six-core communication a[5]. The data recording section [6] has a dedicated interface [II7].

Computer [IIC], floppy disk unit [
T7D] and power supply! Consists of [PP]. For example, an 8-bit portable computer is used as the computer [11C]. The latest data stored in each measuring instrument is loaded into the computer [IIC] according to instructions from the computer [IC] at arbitrarily set time intervals, and recorded on the internal memory and floppy disk [FD]. be done.

The recorded data can be output to an external computer [9] via a display built into the computer [TIC], a printer built into the computer [TIC], or a communication adapter [7]. In addition, the alarm output is transmitted to a remote alarm device [8-11] through a communication line [5], or to an alarm device [It C] directly connected to the computer [It C].
8-21.

The external computer [9] is intended for more advanced data analysis and remote management of landslide areas, etc., and is not essential to this system.

As described above, the present invention does not require a complicated configuration such as [sensor] → [scanner (automatic changeover switch device)] → [data logger (including AD converter)] 1 - [computer]. As shown in the figure, it is characterized by a very simple configuration, consisting of [part of the sensor] → [data recording section].

5) Functions and Effects In the present invention, all measuring instruments are purely digital, and data can be recorded directly by a computer, so the configuration of the 81 instruments is extremely simple, and therefore there is no risk of noise intrusion or malfunction. It poses very little danger and enables stable observation with high density and high reliability. Meanwhile, underground displacement! In i-observation, measurement wires can be installed easily and reliably, and reliable observation without initial dead zones is possible.

If an analog sensor is used.

In many cases, the type and specifications of the sensor must be different for each observation item, each requiring a dedicated data logger, and furthermore, it is necessary to perform AD conversion before importing into a computer.

Even when using the same sensor, in order to handle multiple sensors, each sensor must be connected to a scanner, and the scanner and data logger must be connected. Therefore, the configuration of an automatic observation system is complicated and large. This tends to be the cause of data disturbances and missing data.

In the present invention, a ground surface displacement meter is used as shown in FIG.

The groundwater level meter and underground displacement meter can be connected in any order and directly connected to the computer in the data recording section.

The total length of communication lines can be short, and the configuration can be simple. Since it is a purely digital method that does not require intermediate data processing such as scanning or AD conversion, it is highly reliable and economically effective.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, and FIG. 3 are explanatory diagrams of necessary observation items and open side methods in dynamic observation of landslides, etc. according to the present invention. Figures 4 to 6 show the ground surface displacement meter [1] in the present invention,
FIG. 2 is an explanatory diagram of the configuration of a groundwater level meter [2] and an underground displacement meter [3]. The only difference between the measuring instruments is the mechanical part that captures displacement, indicating that they have simple configurations. FIG. 7 is an explanatory diagram of the structure and function of the underground displacement measurement wire [W3]. FIG. 8 shows the present invention. Ground surface displacement meter [1]. FIG. 2 is an explanatory diagram of the configuration of automatic observation system equipment including a groundwater level meter [2] and a groundwater level meter [3]. Figure 4 Figure 6

Claims (1)

[Claims] 1) At least a first point and a second point, one of which moves relatively, a winding drum is installed at the second point, and a winding drum is installed at the second point; A measuring wire is stretched between the points, and as either the first point or the second point moves relative to each other, the measuring wire is wound or fed out by a winding drum to connect the two points. a detection mechanism that converts the expansion and contraction of the measuring wire into a rotational motion of a pulley of a winding drum, and converts the amount of winding or unwinding of the measuring wire into a digital quantity using a rotary encoder connected to the pulley. A system for automatic observation of landslides, etc., characterized by a data logger that can input digital data, perform necessary data calculations, store it, and send and receive data to and from an external computer. Digital displacement meter. 2) The detection mechanism fixes the measurement wire at a first point on the moving soil block, bordering on a crack in the ground surface or a position of topographical displacement, and installs a winding drum at a second point on the immovable ground. 2
A measurement wire is stretched between points, and the expansion and contraction of the measurement wire caused by cracks in the ground surface or topographical displacement is converted into rotational movement of the pulley of the winding drum at arbitrarily set time intervals.
A purely digital displacement meter for automatic observation of landslides, etc., according to claim 1, which is a ground surface displacement detection mechanism that converts and detects the rotation angle as a digital quantity by a rotary encoder connected to a pulley. . 3) The detection mechanism detects the groundwater level in the borehole according to changes in the groundwater level, and a measuring wire is stretched between the water surface detection unit that follows the water surface and the winding drum to respond to changes in the water level. Claim 1 is a water level detection mechanism that converts the expansion and contraction of a measuring wire into a rotational movement of a pulley of a winding drum, and converts the rotation angle into a digital quantity using a rotary encoder connected to the pulley. A purely digital displacement meter for automatic observation of landslides, etc., as described in . 4) In a landslide where the upper layer is moving ground and the lower layer is immovable ground with the displacement surface as a boundary, the detection mechanism fixes one end of the measurement wire to the lower fixed ground, straddles the displacement surface, The measurement wire is passed through the upper layer of moving ground and wound around a winding drum, and as the moving ground moves along the displacement surface due to the landslide, the measurement wire moves along the displacement surface of the moving ground. It is paid out from the winding drum by a length approximately equal to the amount of displacement and pulled into the ground, converting the feeding of the measurement wire into the rotational movement of the pulley of the winding drum, and the rotation angle is transmitted to the rotary encoder connected to the pulley. 5) The data logger is a purely digital displacement meter for automatic observation of landslides, etc. according to claim 1, which is an underground displacement detection mechanism that converts and detects as a digital quantity. A purely digital displacement system for automatic observation of landslides, etc. according to claim 1, which is a data logger that can input signals, perform necessary calculations, store data, and transmit and receive data to and from an external computer. Total. 6) A wire with reduced elongation due to the tensile force caused by landslides, and an underground fixing fitting fixed to the tip of the wire,
A wire for measuring underground displacement characterized by comprising a sheath that protects the wire and allows the wire to swing in the length direction. 7) At least a first point and a second point, one of which moves relative to each other, a winding drum is installed at the second point, and a measuring drum is installed between the first point and the second point. The wire is stretched, and as either the first point or the second point moves relative to each other, the measuring wire is wound or unwound by a winding drum to expand and contract the measuring wire between the two points. A detection mechanism that converts the rotational motion of the pulley of the winding drum and converts the amount of winding or unwinding of the measurement wire into a digital amount using a rotary encoder connected to the pulley, and inputs the detected digital data. A purely digital displacement meter for automatic observation consists of a data logger that can perform necessary data calculations, store data, and send and receive data to and from an external computer, and is connected to the data logger via a communication line to perform control and data recording. An automatic observation system device capable of measuring and storing ground surface displacement, underground displacement, and groundwater level displacement, and outputting the stored data. 8) The detection mechanism fixes the measurement wire at a first point on the moving soil block, with the boundary between cracks in the ground surface or topographical displacement position, and installs a winding drum at a second point on the immovable ground. 2
A measurement wire is stretched between points, and the expansion and contraction of the measurement wire caused by cracks in the ground surface or topographical displacement is converted into rotational movement of the pulley of the winding drum at arbitrarily set time intervals.
The automatic observation system equipment according to claim 7, which is a ground surface displacement detection mechanism that converts and detects the rotation angle as a digital quantity by a rotary encoder connected to a pulley. 9) The detection mechanism detects the groundwater level in the borehole according to changes in the groundwater level and follows the water level.A measurement wire is installed between the water level detection unit and the winding drum to respond to changes in the water level. Claim 7, which is a water level detection mechanism that converts the expansion and contraction of the measurement wire into a rotational movement of a pulley of a winding drum, and converts the rotation angle into a digital quantity using a rotary encoder connected to the pulley. Automatic observation system equipment described in . 10) In a landslide area where the upper layer is moving ground and the lower layer is immovable ground, the detection mechanism fixes one end of the measurement wire to the lower unmoving ground, straddles the displacement surface, and detects the movement of the upper layer. The measurement wire is passed through the ground and wound around a winding drum, and as the ground moves along the displacement plane due to a landslide, the measurement wire moves along the displacement plane to a length that is approximately equal to the amount of displacement of the ground. The wire is fed out from the winding drum and pulled into the ground, and the feeding of the measurement wire is converted into the rotational movement of the pulley on the winding drum, and the rotation angle is converted into a digital quantity by a rotary encoder connected to the pulley. The automatic observation system device according to claim 7, which is an underground displacement detection mechanism. 11) A patent claim consisting of a computer that is connected to a data logger of a purely digital displacement meter for automatic observation through a communication line and performs control and data recording, and an external computer that controls the computer at a remote location and also performs data recording from now on. Automatic observation system equipment described in item 7.