JPH0688744A - Method for orienting slope rupture position by ae measurement - Google Patents

Abstract

(57) [Summary] [Objective] To provide a method for accurately locating a slope failure position by AE measurement using a waveguide having AE sensors at both ends. [Structure] The wave guide 1 having AE sensors 2 and 3 attached to both ends is installed in the ground K to generate AE in the ground.
Waves are measured, and data that can be located in position are selected from the data that have reached the AE sensors 2 and 3, and the characteristics of the individual AE waveforms in which the position is located are examined, and AE waves from the same source are detected. The slope failure position is located using only the determined location result as evaluation data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for locating a slope collapse position by AE measurement using a waveguide.

[0002]

2. Description of the Related Art As a conventional method for locating a natural rock collapse position,
AE that occurs due to cracks and deformations that occur inside the ground
(Acoustic emission, acoustic
(emission) is captured by a waveguide embedded in the ground and has AE sensors attached at both ends, converted into an electric signal, and the propagation time of the AE waves reaching each sensor at the both ends above a certain level. Has been measured by a computer, and this has been expressed on one-dimensional coordinates to locate the ground collapse position.

[0003]

When the ground collapse position is located by the above-mentioned conventional method, when a single wave as shown in FIG. 4 is generated, the wave a is generated from P at the same wave generation position. The correct AE generation position P can be obtained from the time difference t ₂ −t ₁ before transmission to the AE sensors b and c at both ends, but when a large number of waves are generated as shown in FIG. Occasionally, the position of occurrence may be obtained.

The present invention has been proposed in view of the above-mentioned problems of the prior art. The object of the present invention is to obtain the same source as the result of localization by a measuring instrument in AE measurement using a waveguide. The point is to provide a method for orienting the slope failure position by accurate AE measurement by determining whether or not the orientation result is from.

[0005]

In order to achieve the above object, according to the method for locating a slope collapse position by AE measurement according to the present invention, a waveguide having AE sensors at both ends is used as a predicted slip surface. The AE wave generated in the ground is measured by straddling the ground, and the data that can be located from the data reaching the AE sensors at the both ends is selected. The AE waveform characteristics are examined, and only the position orientation result determined to be the AE wave from the same AE source is used as the evaluation data to locate the slope failure position.

[0006]

According to the conventional method, when a large number of AE waves are continuously generated in the method of locating the collapse position of the natural ground by the AE measurement using the waveguides with the AE sensors attached to both ends, all the measured values are measured. However, according to the present invention, it is determined whether or not the waves are from the same AE generation source, and it is determined that the waves are from the same AE generation source. The collapse position is evaluated using only the determined position orientation result.

[0007]

The present invention will be described below with reference to the illustrated embodiments. Reference numeral 1 embeds a required number of steps of a waveguide 1 having AE sensors 2 and 3 attached at both ends thereof, over a slip surface 4 of a natural rock K where natural rock collapse is predicted. Thus, a wave guide 1 having AE sensors 2 and 3 at both ends of an AE wave generated due to a crack or deformation generated inside the natural ground
Data that has been captured and converted into an electric signal by the AE sensors 2 and 3 at the both ends, and the data for which the position has been determined is selected, and the individual AE waveform characteristics of the determined position are investigated, and the same source The collapse position is determined by using only the position determination result determined to be the AE wave from the above as evaluation data.

Incidentally, the A that has reached the AE sensors 2 and 3
A method for determining whether or not the E wave is the AE wave from the same source will be described below. (B) If the waves are the same wave, the energy moment values are almost the same. (B) In addition, the value of the wave that arrives earlier is larger in AE energy. Note that FIG. 2 is a chart showing the result of locating the collapse position of the natural rock according to the conventional method, and FIG. 3 is a chart showing the result of locating the collapse position of the natural rock according to the present invention using the AE waveform characteristics.

In the experiment, the load was applied until the model collapsed by the hydraulic jack installed on the trapezoidal model shown in FIGS. 2 and 3, and the dotted line in the figure indicates a crack generated during the experiment. , The graph shows the result of position localization by AE.

[0010]

As described above, according to the present invention, in the AE measurement using the waveguide, the collapse position locating of the natural ground using the AE waveform characteristic is better than the conventional collapse position locating method using the count number. Accurate and reliable.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an implementation state of an embodiment of a method for locating a slope collapse position by AE measurement according to the present invention.

FIG. 2 is a chart showing the result of rock mass locating by the conventional method.

FIG. 3 is a chart showing the result of rock mass locating by the method of the present invention.

FIG. 4 is an explanatory diagram of a transmission time difference to the sensors at both ends of the waveguide, which occurs when an AE wave is incident in one shot.

FIG. 5 is an explanatory diagram showing an error in transmission time to the sensors at both ends of the waveguide, which occurs when multiple AE waves are incident.

[Explanation of symbols] K Ground 1 Wave guide 2 AE sensor 3 AE sensor 4 Slip surface

Claims (1)

[Claims] 1. A waveguide having AE sensors at both ends is installed on the ground over a predicted slip surface to measure the AE waves generated in the ground, and the AE at the both ends is measured.
From the data that has reached the sensor, select the data that can be located, examine the characteristics of the individual AE waveforms that have been located, and evaluate only the results of the location that are determined to be AE waves from the same AE source. A method for orienting a slope failure position by AE measurement, which is used as a method for orienting a slope failure position.