关键词: 真三轴压缩, 弹性波, 应力

Abstract: An experimental study on the travel time, magnitude and attenuation characteristics of elastic wave propagating along σ₂(x direction)and σ₃(y direction) in marble specimen has been carried out using a true triaxial(σ₁>σ₂>σ₃) compression apparatus. With increasing stress the travel time t and magnitude A of the first peak of P wave decrease, on the contrary while along the y direction it gives a completely opposite result. Starting from 95% of failure strength along both directions t increases rapidly, but A decreases and the attenuation coefficient K of wave magnitude also decreases. This phenomenon is considered as a characteristic change of the fracturing forerunners under true triaxial compression. For the I way of applying stress to the specimen the differential stress at the moment of rapid increase of t value is lower than that for the I way.

Key words: True triaxial compression, Elastic wave, Stress