On the Relationship of the Mechanical Properties of Soils and Rocks to the Velocity of Elastic Waves

Abstract

The velocities of the elastic longitudinal and transverse waves in soils and rocks are measured using the ultrasonic pulse method. The comparison of the dynamic elastic constants of soils and rocks determined by the ultrasonic method with static ones obtained by the uniaxial compression test, the possibility of estimating their compressive strength from the dynamic shear modulus and the effect of pore fluids on the ultrasonic volocity in soils are investigated. From these results, the following conclusions are drawn: (1) for relatively isotropic material such as soil and mortar, the dynamic shear modulus G_a increases with the increasing of the compressive strength q_v and q_v/G_a becomes larger with q_v, (2) the velocity of longitudinal wave V_l in soils is affected by pore fluids and the presence of air in the pore causes the decrease in V_l, (3) Young's dynamic modulus E_α increases with the increasing of the static one E_s and it seems that the relationship between E_a and E_a/E_s for a soil is approximately represented by hyperbola.