ANISOTROPY OF SMALL STRAIN STIFFNESS IN TICINO SAND

Comprehensive tests performed in a large calibration chamber and consi sting of the propagation of seismic body waves in dry Ticino silica sa nd are presented. By virtue of the fact that both shear and constraine d compression waves have been propagated in vertical, horizontal and o blique directions, five independent constants of the cross-anisotropic elasticity model of the test have been established. The tests have al so made it possible to evaluate the influence of the structural (inher ent) and stress-induced anisotropy on the velocity of the propagated s eismic body waves. The influence of the principal effective stresses o n the velocity of these waves is also described.