SU1430526A1 - Apparatus for monitoring strained state of rock mass - Google Patents

Abstract

The invention relates to mining. The purpose of the invention is to increase the informativeness of the operation of the device due to the simultaneous recording of quasistationary mechanical stresses and wave processes in the array. The device includes a sensitive element 1 in the form of a piezoplate with two interdigital transducers. 2 surface waves, amplifiers 3, a differential frequency separation unit 4, a band pass filter 5, a phase separation unit 6, an integrated filter 7, a controlled oscillator 8, a high pass filter 9 and a frequency averaging unit 10. Element 1 is subject to bending deformation. Transducers 2 produce two frequencies, the difference of which, separated by blocks 3 and 4, characterizes the acting force. The characteristics of the wave process in the array are determined from the dynamic component of the difference extracted by blocks 5,6,7,8 and 9. The value of quasi-stationary stresses is determined from the static component of the difference obtained by the averaging unit 10 of the frequency. The device allows simultaneous measurement of static and dynamic voltage components. 1 il. with S (L 4 00 O SL KR Od

Description

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The invention relates to mountain eny and is intended to record changes in the stress-strain region of a mountain massif.

The aim of the invention is to increase the informativeness of the operation of the device due to the simultaneous registration of quasi-stationary mechanical stresses and wave processes in the assive.

The drawing shows a schematic setup.

The device contains a sensitive element 1 in the form of a piezoplate, a pin-head transducer 2 of the surface waves, amplifiers 3, Spock 4 in the differential frequency section, a kolosovy filter 5, block 6 in the section, an integrating filter 7, a controlled oscillator 8, a filter 9 high frequencies and block 10 averaging frequency.

The sensing element 1 is made in the form of a piezoplate with two encounters in two-pin converters 2 in surface waves, arranged for a fee of large faces, one of the electrodes of each pair of which is grounded, and the second is connected to the input of the corresponding amplifier-3 The outputs of the amplifiers 3 are connected to the inputs of block 4 of high-voltage differential frequency 4, the output of which is connected to the input of band-pass filter 5. The output of band-pass filter S is connected to the first input of block 6 of the phase gap, connected by its output to the inputs of the integrating bill 7 and phi tra 9 highpass. The output of the integrating filter 7 is connected to the input of the controlled oscillator iopa 8, and the output of the latter is connected to the second input of the phase separation unit 6 and the input of the frequency averaging unit 10.

The device works as follows.

The sensing element 1 of the device as a result of the processes of redistribution of stresses in the mountain massif when it is worked out is affected by the force P, which can be represented as a static and dynamic component

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57, С - quasi-stationary stress in the rock massif; sensor acceleration as a result of wave processes in the mountain range; frequency of wave processes in the mountain range.

Moreover, K and K. depend on the specific design of the sensor.

Under the action of force P, the sensing element 1 undergoes bending deformation, which leads to a change in the distance between the electrodes of the interdigital transducers 2, as a result of which the frequencies f and fi of autogeneration in the amplifiers 3 change, and with a different increment sign. From the outputs of the amplifiers 3, the signals are fed to the inputs of the differential frequency allocation unit 4. Thus, the difference frequency f, separated by block 4, carries information about the magnitude and nature of the effect on the sensitive element 1

h k (K sinflt), where k is the coefficient of sensitivity of the device.

Then, through a band-pass filter 5, tuned to the average value of the frequency fj, the voltage is fed to the phase detector, imaged by the phase division block 6, the integrating filter 7 and the controlled generator 8. In the detector, the periodic component of the frequency f, reflecting dynamic array state. After passing through the high-pass filter 9 at its output, the voltage is

and sinQ t, where and is the voltage at the output of block 9.

From the output of the controlled oscillator, the voltage is removed with a frequency fj proportional to the instantaneous value of the force P acting on the sensitive element 1, and goes further to the unit 10 of averaging frequency, the output of which yields the average value of the frequency f proportional to the static component of the force P

(K, C-HK.ja sinil t) kK., C,

 sinfjt

K, j is the conversion factor for the static component;

CL is the conversion factor for the dynamic component;

Claims (1)

Apparatus of the Invention A device for monitoring a stress-strain state of a mountain massif, comprising a sensitive element in the form of a piezoplate with two counter-stranded straps located on its large faces, surface waves., amplifiers and a differential frequency block; one of the electrodes of each pair of transducers is grounded, and the other is connected to the input of a suitable amplifier, the outputs of which are connected to the inputs of a differential frequency split block, in order to increase the information content of the device due to the simultaneous registration of quasi-stationary mechanical stresses and wave processes in the array, it is additionally equipped with a bandpass filter, a phase separation unit, integra a running filter controlled by a generator, a high-pass filter and a frequency averaging unit; the input of a band-pass filter is connected to the output of a differential frequency allocation unit, and its output is connected to the first input of a phase separation unit, the output of which is connected to a high-pass filter and an integrating filter, and the output of the integrating filter is connected to the input of the controlled oscillator, the output of which is connected to the second input of the phase separation unit and to the input of the frequency averaging unit.