简介:Basedontheprincipleformulaforthefour-componentstrainmeters,wecandirectlyobtainthespecificplanestrain,shearstrainandazimuthalangleoftheprincipalstrain,andthemaximumandminimumprincipalstrainscalculatedafterwardsaretheindirectresult.TheproblemsofpracticalityofthesensitivitycoefficientsAandBofplanestrainandshearstrainarethendiscussed.Basedonthisidea,weanalyzedtheobservationdataofseveralfourcomponentboreholestrainmetersneartheepicenteroftheYiliangMS5.7earthquakein2012andtheLudianMS6.5earthquakein2014intheZhaotongarea,YunnanProvince.Theresultsshowthattheanalysisbasedontheperspectiveofplanestrainandshearstrainhasanobviouslybettereffectthanthatbasedonthecomponentreadings,andcandirectlypeelofftherespectiveabnormalityoftheplanestrainandshearstrain.Inaddition,thecorrelationcoefficientcurvesbetweenmeasureddataoftwoplanestrainsshowsignificantanomalieswhichoftenoccurseveraldaysbeforeandduringtheearthquake.