Physical meaning and prediction efficiency of the load/unload response ratio of rocks in strain-weakening phase before failure*

(整期优先)网络出版时间:2002-01-11
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Rockexperimentresultsindicatethattheload/unloadresponseratio(LURR)ofrocksexpressedviastrainenergymayhavesingularornegativevalueafterthestressintherockreachesitsmaximumbeforerockfailureorwhentherockgoesintothestrain-weakeningphase.Theuniversalityofthisphenomenonisdiscussed.ExpressedviastrainorstrainenergyandthetraveltimeofPwave,thevariationformofthereciprocalofLURRduringtheprocessofrockfailurepreparationisderived.TheresultsshowthatafterasharpdecreasethereciprocalofLURRreachesitsminimumwhenthemainfractureoftherockisabouttoappear.Thisfeaturecanbetakenasanindicationthattherockmainfractureisimpending.