Use of piezoelecric transducers to measure dynamic stresses in elements of mine workings

Journal Article · Thu Sep 01 04:00:00 EDT 1977 · Sov. Min. Sci. (Engl. Transl.); (United States)

OSTI ID:5581254

Baikonurov, K O; Ermekov, T M; Ovsyannikov, P I; Pomogov, I G

Underground rock blasting generates intense shock waves which have adverse effects on support pillars, roofs, etc. These become cracked and lose their theoretical stability. To devise methods to reduce the destructive action of these waves, we must make instrumental measurements of their parameters (pressure, frequency, etc.) with the aim of finding the laws of action of the waves on various objects. The greatest damage to elements of mine workings occurs at short distances from the focus of the blast; but here it is most difficult to measure the wave parameters. Furthermore, underground workings have a large number of free surfaces which cause various types of reflected, refracted, and different waves. These, interacting with the incident waves, create a complex pattern in the vibrational process. Widely varied types of wave interaction are possible. In particular, in an investigated part of the rock they may arrive in the same phase, and then the amplitude of the vibrations will be increased; or they may arrive in opposite phases, so that the amplitude of the vibrations is reduced while the stress is increased. Evidently the various seismic receivers which are now often used in uderground conditions to measure shock wave parameters can lead to certain errors. The apparatus chosen must work without distortion at over 300 Hz. Its response must be uniform over the whole range of frequencies to be measured. This facilitates calibration and the processing of the results. For this reason, to investigate the dynamic stresses arising in the material of a pillar in industrial blasting, we used the piezoelectric method, based on piezoelectric transducers. These convert mechanical loads to electrical quantities and consist of disks of various sizes, made of polarized barium titanate ceramic of TsTS material. The design of the transducer and piezoelement is similar to that described in a reference.

• Research Organization: Inst. of Mining, Alma-Ata, USSR
• OSTI ID: 5581254
• Journal Information: Sov. Min. Sci. (Engl. Transl.); (United States), Journal Name: Sov. Min. Sci. (Engl. Transl.); (United States) Vol. 13:5; ISSN SMNSA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
012000* -- Coal
Lignite
& Peat-- Mining
440300 -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
ASIA
COAL MINING
COMMINUTION
DYNAMIC LOADS
ELECTRICITY
EUROPE
EXPLOSIVE FRACTURING
FRACTURING
MEASURING INSTRUMENTS
MEASURING METHODS
MINING
PIEZOELECTRICITY
SAFETY
SEISMIC ARRAYS
SEISMIC DETECTORS
SHOCK WAVES
STABILITY
UNDERGROUND MINING
USSR