Experimental study of acoustic emission of granite due to thermal cracking under high temperature and isostatic stress
Abstract：In order to obtain the rules of thermal cracking on granite, the evolution of the acoustic emission of granite sample（ φ200 mm×400 mm）within the temperature range from the room temperature to 500 ℃ under isostatic stress and the thermal cracking characteristics of the rock as manifested by the acoustic emissions in each stage were ana- lyzed and discussed based on experiments. It is shown in this research that 330 ℃ is the demarcation point of acoustic emission and hot rock changed. Thermal cracking is elastic rupture when temperature is lower than 330 ℃and it ap- pears a local plastic deformation and failure beyond 330 ℃ ;When the granite sample is heated to 330℃, a great num- ber of acoustic emission of lower energy rate occurres from local plastic failure. In concentrated area of acoustic emis- sion, most acoustic emission is in low energy rate and a little is in high energy rate, and the whole cumulative energy is lower than the cumulative energy at 330 ℃and below ; When the counts rate of acoustic emission abruptly changes, the micro-fracture zone of granite begins to form and the granite experiences two significant improvements of the thermal crack network respectively from the temperatures of 110℃ and 420 ℃.
Keywords：thermal crackingacoustic emissionhigh temperature triaxial stressgranite
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 1111-1117 )