A SURFACE INSTABILITY DETECTION APPARATUS

A surface instability detection apparatus for investigating axial spli tting and spalling phenomena in rocks and rock-like materials is descr ibed. The apparatus simulates the conditions under which these phenome na occur and allows one to accurately measure them. Experimental resul ts from tests on Berea sandstone are presented where the successive fo rmation of spalling fractures was monitored with an acoustic emission system and the location of the seismic events was mapped. The test res ults show the potential for benchmark tests in determining the spallin g tendency and characteristics of different rocks.