Abstract: To study the effect of vibration frequency on soil dynamic characteristics, firstly the related research outcomes are reviewed, then the dynamic triaxial tests which used core material of one rockfill dam were performed. The results of dynamic intensity tests show that with the increasing of vibration frequency f, dynamic intensity increases when f equals to 0.1－4 Hz; and with the increasing of f, dynamic porewater pressure ratio increases during f equals to 0.1－1.0 Hz while decreases during f equals to 1.0－6.0 Hz. Under the sustaining operation of higher frequency, there are phenomena of sample sopping up and dynamic porewater pressure declining. This means it hasn’t enough time for dynamic porewater pressure to climb and extend when f is much higher. And the results of dynamic modulus and damping ratio tests show that the lower the vibration frequency acting on the sample, the more sufficiently dynamic deformation could develop; both dynamic modulus Ed and damping ratio D increase with vibration frequency.

Key words: vibration frequency, saturated cohesive soil, dynamic intensity, dynamic porewater pressure, dynamic modulus and damping ratio