JP3249906B2 - Slope failure time prediction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for monitoring the condition of a target slope and predicting the time at which the slope will collapse, and more particularly to predicting the start time of a slope failure early and with high accuracy. The present invention relates to a device which enables the device to be handled and is extremely easy to handle.

[0002] If it is possible to predict when a slope will collapse, many civil works can be performed safely.

In addition, it is possible to prevent the collapse of the slope by taking appropriate measures in advance, and to avoid the damage caused by the collapse.

[0004]

2. Description of the Related Art A displacement meter is installed on a slope of a large embankment or cut (a slope box is used in an experiment), and the displacement (strain) of the slope surface is measured by the displacement meter.

[0005] This measurement result is continuously input to a computer,
The computer calculates the predicted time of slope failure in the secondary creep region or the tertiary creep region using the input measurement result in accordance with the procedure of the graphical solution.

[0006]

The predicted time of slope failure greatly differs depending on the time used as the reference for the graphical solution, and it is extremely difficult to set the reference time.

[0007] Further, the predicted time of the slope failure can be accurately obtained only when the slope is immediately before the collapse, and measures for safety and prevention of the collapse are delayed.

Further, it is almost impossible to specify in advance the position where the displacement of the slope surface which is a sign of the slope failure will occur (the position where the deformation of the slope surface will be confirmed). For this reason, it is necessary to install a large number of displacement meters.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an apparatus which can predict a slope failure time early and accurately and which is extremely easy to handle. Is to do.

[0010]

[Means for Solving the Problems]

-Apparatus according to the first invention (see Fig. 1) AE signal detection means 10 for detecting an AE signal generated inside a slope whose collapse time is to be predicted, and the detected AE
An AE signal generation number accumulating means 12 for accumulating the number of signal generations over a certain period t; the period t, the constant b, the integration constant C, the time T elapsed from the time when the detection of the AE signal is started, and the generated AE signal; Elapsed time T-
AE time curve storage means 14 for storing an equation N = C · T ^t · exp (b · T) indicating the characteristic of the accumulated number AE of generated AE signals, and the time T and the time T when the time t has elapsed. In the calculation of the least squares method using the accumulated number of generated AE signals N, the parameter determining means 16 for determining the period t, the constant b and the integration constant C, and the determined period t, the constant b and the integration constant C are stored. And a collapse time calculating means 18 for determining, as the slope start time, the time at which the rate of increase of the characteristic with respect to time exceeds the upper limit value α.

An apparatus according to the second invention (see FIG. 1) AE signal detecting means 10 for detecting an AE signal generated inside a slope whose collapse time is to be predicted, and an AE signal detected
An AE signal generation number accumulating means 12 for accumulating the number of signal generations over a certain period t; the period t, the constant b, the integration constant C, the time T elapsed from the time when the detection of the AE signal is started, and the generated AE signal; Elapsed time T-
AE time curve storage means 14 for storing an equation N = C · T ^t · exp (b · T) indicating the characteristic of the accumulated number AE of generated AE signals, and the time T and the time T when the time t has elapsed. In the calculation of the least squares method using the accumulated number of generated AE signals N, the parameter determining means 16 for determining the period t, the constant b and the integration constant C, and the determined period t, the constant b and the integration constant C are stored. Into the above equation, the collapse time calculating means 18 for determining the time at which the rate of increase of the characteristic relative to the time indicated by the equation after the substitution exceeds the upper limit α as the collapse start time of the slope, and the properties of the slope Upper limit value setting means 20 for adjusting and setting the upper limit value α accordingly.

(Operation) The AE signal detection operation is started after the upper limit value α is adjusted and set according to the property of the slope for which the collapse time is to be predicted.

Then, the number of occurrences of the AE signal is accumulated over a certain period t, and the period t, a constant b, and an integration constant are determined.

Further, the period t, the constant b, and the integration constant C are substituted into a previously prepared equation, and the time at which the rate of increase of the characteristic shown by the equation with respect to time exceeds the upper limit α, the collapse of the slope b starts. Find as time. The upper limit value α is adjusted and determined in advance in consideration of the nature of the slope.

[0015]

FIG. 2 shows a longitudinal section of a slope 200, the slope 200 of which is a wavy surface 202.
It slips and collapses.

A waveguide 204 is inserted in a horizontal position parallel to the vertical section at an intermediate position of the height of the slope 200.

The waveguide 204 is made of aluminum and has AE sensors 206 at both ends.

The AE signal generated inside the slope 200 is transmitted to the AE sensor 206 via the waveguide 204, and the AE sensor 206 outputs a detection signal corresponding to the transmitted AE signal.

The signal is taken out from the slope surface side of the waveguide 204 and amplified by the amplifier 300 of FIG.

Further, the output of the amplifier 300 is given to the A / D conversion board 302, and the output of the A / D conversion board 302 is taken into the computer main body 304.

A display 306 and a keyboard 308 are connected to the computer main body 304. The computer main body 304 predicts the collapse start time of the slope 200 and outputs it to the display 306. Therefore, the equation of N = C · T ^t · exp (b · T) is stored.

The value N is an accumulation signal of AE signal generation, the value C is an integration constant, the value T is elapsed time, the value t is a period for accumulating the number of AE signal generations, and the value b is a constant.

The user inputs information necessary for the processing of the computer main body 304 from the keyboard 308, and causes the computer main body 304 to start the slope prediction time prediction processing by operating the keyboard 308.

FIG. 4 illustrates a process of predicting the time of slope failure performed by the computer main body 304 using a flowchart. First, the user operates the keyboard 308 to determine the property of the slope 200 whose failure time is to be predicted. The upper limit value α is adjusted and set accordingly, and the detection period t of the AE signal is determined (step 400).

Next, the operation of the keyboard 308 is instructed to the computer main body 304 to start taking in the AE signal detection signal (output of the A / D conversion board 302) (step 4).
02).

When this instruction is given, the computer main unit 304 starts a process of accumulating the number of times of generation of the AE signal, and the process is continued for a certain period t (step 404).

When the period t ends, the period t, the constant b, and the integration constant C are determined (step 406).

For this reason, the calculation of the least square method using the time T and the cumulative number of the generated AE signals is performed.

Further, an equation N = C · T ^t · exp (b · T) is prepared (step 408), and a period t, a constant b,
By substituting the integration constant C, the characteristic 500 shown in FIG. 5 indicating the relationship between the cumulative number N of times of AE signal generation and the time T is obtained (step 410), and is graphically displayed on the display 306 (step 412).

Further, the increase rate of the cumulative number N with respect to the time T is sequentially calculated in the elapse direction of the time T, and every time the increase rate is calculated, the increase rate is compared with the upper limit value α. The time T exceeding is warned on the characteristic 500 being displayed graphically as the time at which the collapse of the slope 200 will begin (step 414).

FIG. 6 shows an actual characteristic 600, and the characteristic 500 in FIG. 5 remarkably approximates this characteristic 600. The predicted time of collapse on the characteristic 500 due to the computer warning is exactly the same as the actual time on the characteristic 600. Matches.

After confirming the time of the computer prediction of the collapse of the slope 200, the user recommends evacuation to the civil engineer on or near the slope 200, or the slope 200, depending on whether there is enough time. Instruct them to take appropriate measures to prevent collapse.

As described above, according to the present embodiment, the time at which the slope 200 starts to collapse can be accurately predicted, so that evacuation can be recommended to civil engineering workers, and the safety can be ensured. Further, it is possible to immediately take appropriate measures to prevent the slope 200 from collapsing, and to avoid damage due to the collapse.

Then, since the collapse start time of the slope 200 is predicted from the AE signal generated inside the slope, a technique for setting the position of the AE sensor 206 (waveguide 204) is used.
No experience is required and therefore the handling of the device is very easy.

[0035]

As described above, according to the present invention, the time at which the slope starts to collapse can be predicted accurately, and evacuation is recommended to the civil engineering worker in consideration of the time margin up to that time. Then, safety can be ensured, or appropriate measures can be taken immediately to prevent slope collapse and avoid damage caused by the collapse.

Further, since the start time of the slope collapse is predicted from the AE signal generated inside the slope, no special technique or experience is required for setting the position of the sensor for detecting the AE signal.
For this reason, handling of the device becomes extremely easy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a slope portion in the embodiment.

FIG. 3 is a configuration explanatory diagram of a computer system part in the embodiment.

FIG. 4 is a flowchart illustrating the operation of the embodiment.

FIG. 5 is a diagram illustrating calculation characteristics of elapsed time T-cumulative number AE signal N generated in the embodiment.

FIG. 6 is a diagram showing actual characteristics of elapsed time T-accumulated number N of AE signals generated in the embodiment.

[Explanation of symbols]

 200 Slope 202 Sliding collapse surface 204 Waveguide 206 AE sensor 300 Amplifier 302 A / D conversion board 302 304 Computer main body 306 Display 308 Keyboard

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G04F 10/00 E02D 17/20 106 G01D 21/00

Claims (2)

(57) [Claims] An AE signal detecting means (10) for detecting an AE signal generated inside a slope whose collapse time is to be predicted.
AE signal occurrence number accumulating means (12) for accumulating the number of occurrences of the detected AE signal over a certain period (t); and the period (t), constant (b), integration constant (C), AE signal Expression (N) that includes the time (T) elapsed from the time when the detection of the AE signal was started and the cumulative number of generated AE signals (N) and shows the characteristic of elapsed time (T) -cumulative number of generated AE signals (N). An AE time curve storage means (14) for storing T ^t · exp (b · T); and using the time (T) and the accumulated number of generated AE signals (N) when the time (t) has elapsed. Parameter determining means (16) for determining the period (t), the constant (b) and the integration constant (C) in the calculation of the least squares method, and the determined period (t), the constant (b) and the integration constant (C)
Is substituted into the stored equation, and the time at which the rate of increase of the characteristic with respect to time, which is represented by the equation after the substitution, exceeds an upper limit (α) is determined as the collapse start time of the slope. A slope failure time prediction device, comprising: 2. An AE signal detecting means for detecting an AE signal generated inside a slope whose collapse time is to be predicted.
AE signal generation number accumulating means (12) for accumulating the number of occurrences of the detected AE signal over a certain period (t); and the period (t), constant (b), integration constant (C), AE signal Expression (N) that includes the time (T) elapsed from the time when the detection of the AE signal was started and the cumulative number of generated AE signals (N) and shows the characteristic of elapsed time (T) -cumulative number of generated AE signals (N). An AE time curve storage means (14) for storing T ^t · exp (b · T); and using the time (T) and the accumulated number of generated AE signals (N) when the time (t) has elapsed. Parameter determining means (16) for determining the period (t), the constant (b) and the integration constant (C) in the calculation of the least squares method, and the determined period (t), the constant (b) and the integration constant (C)
Is substituted into the stored equation, and the time at which the rate of increase of the characteristic with respect to time, which is represented by the equation after the substitution, exceeds an upper limit (α) is determined as the collapse start time of the slope. And an upper limit value setting means (20) for adjusting and setting the upper limit value (α) according to the properties of the slope.