In order to simulate the high temperature condition of deep underground bedrock and analyze the progressive thermal cracking characteristics of rock under thermal stresses loading,a real-time monitoring apparatus for rock ther-mal damage was independently developed.The apparatus mainly includes furnace,waveguide rod,calibration rod,de-formation monitoring system and acoustic emission(AE)monitoring system,which can simultaneously monitor the AE and thermal deformation of rock caused by temperature to quantify the thermal damage.The results are as follows.With the increase of the target temperature,the cumulative AE hits and AE energy level increase significantly,that is,the higher the target temperature,the more significant thermal damage will be caused by thermal loading,and the grea-ter thermal deformation.With the increase of heating rate,the surface temperature of rock when cracking begin increa-ses.When cooling in room,the cumulative AE hits has a sudden increase,and the deformation in the cooling stage is manifested as the extreme deformation recovery stage and the stable deformation recovery stage.Different heating rates and cooling methods do not cause significant differences in AE and thermal deformation,and the target temperature plays a dominant role on thermal cracking.The accuracy and reliability of the rock thermal damage monitoring appara-tus are verified by conducting multiple heating and cooling path tests on cylindrical rock samples.
关键词
岩石热损伤/声发射/热变形/高温/花岗岩
Key words
rock thermal damage/acoustic emission/thermal deformation/high temperature/granite
维普
万方数据