A geotechnnical ressonant column cell capable of subjeccting cylindrical soil specimens to longitudinal and torsional exictation is procured. The resonant eolumn cell will be uused in conjunction with a conventional triaxial loading system to provide a hybrid testing apparatus capable of static immposed loads (confining pressure, axial compression and torsion), and dynamic longitudinal and torsional loads. This hybrid system will permit studies of dynamic soil properties under a wide range of stress amplitudes and under conditions of stress induced anisotropy.
