Laser Vibration Characteristics of Marble Specimens and Failure Criterion

Abstract

Rock failure and instability usually lead to significant engineering disasters. This paper aims to establish an experimental failure criterion to predict rock failure via testing the laser vibration characteristics of marble specimens. Uniaxial compression tests and Brazilian tests were carried out on marble specimens coupled with acoustic emission technology and laser Doppler vibrometry measurement technology. The whole laser vibration waveform of the marble specimen was divided into elastic stage, plastic stage, and failure stage. Although different frequency spectrum characteristics were identified in different waveform phases, a wide frequency spectrum was always present prior to rock failure. Furthermore, the wide frequency band frequency spectra characteristics took place 30.9 s and 21.3 s earlier than the rapid increase of the acoustic emission counts in the uniaxial compression test and Brazilian test, respectively. Taking the wide frequency spectrum as a failure criterion for the failure of loaded marble is quick, convenient, and reasonable. Using laser Doppler vibrometry measurement has the advantages of being remote, non-contacting, and earlier warning. This research can provide a reference for the further study of forecasting rock failure.

Keywords

• laser vibration characteristics
• laser Doppler vibrometry (LDV)
• uniaxial compression test
• Brazilian test
• dominant frequency
• early warning