Experimental Studies of Ultrasonic Tomography on Fangshan Granite under Uniaxial Compression

Fangshan granite ultrasonic velocity was measured under uniaxial compression in Lab and its tomographic imaging was conducted at the different deformation. The imaging processes used 26 sensors putting around the sample. The p velocity continues to increase with increasing application of uniaxial compression in the whole body of the granite at the stages of compaction and linear elastic. Before catastrophic rock failure, the increasing velocity region gradually shrinks and the low-belt velocity zones are forming, on which the catastrophic failure takes place.