Experimental Stress-Strain Relations and Amplitude-Dependence of Wave Velocities in Sedimentary Rocks

Using the theory of microplasticity as the base, it is shown that the curvature of graph for the function describing the equation of state of rocks can change its sign depending on the value of the mechanical energy applied. The experiments on dolomites under the strains of order of 10_-6 reveal an increase in wave velocities as the amplitude grows.