| The effect of frequency on the dynamic properties of k0 consolidated saturated clay was studied by load-controlled cyclic triaxial tests on both reversal and non-reversal stress conditions.First, the cyclic strength curves of different frequencies were determined based on the test results. The results showed that the undrained cyclic strength decreased with the decreasing of frequency. The cyclic strength reduced 1% on non-reversal stress conditions when the frequency changed from 0.1Hz to 0.01Hz and the number of cycles causing failure was small, and the effect of frequency reduced with the increasing of number of cycles and the frequency had little effect on cyclic strength when the number of cycles was larger than 1000. The cyclic strength reduced 3% on reversal stress conditions when the frequency changed from 0.1Hz to 0.01Hz and the degree of the effect of frequency didn't changed with the increasing of the number of cycles. So the frequencies hardly effect the cyclic strength of k0 consolidated saturated clay. The k0 consolidated state diminished the degree of the effect of frequency by comparing with the results of previous studies.Second, The quasi-static stress-strain curves under the specific number of cycles were used to analysis the effect of frequencies on the cyclic strain of k0 consolidated saturated clay. The results showed that the cyclic strain increased with the decreasing of frequency under the specific cyclic numbers and the effect of frequencies reduced when the number of cycles increased on both reversal and non-reversal stress conditions. Then the quasi-static stress-strain relationship was proposed and then used to draw the stress and strain curve of different cyclic numbers on the special stress state and the result showed that there was no effect of frequencies on cyclic strain when the cyclic numbers were larger than 3000.Finally, The curves between ultimate pore water pressure and cyclic stress ratio were used to study the effect of frequencies on the pore water pressure of k0 consolidated saturated clay. The results showed that the frequencies hardly effect the pore pressure on non-reversal stress conditions, and the effect of frequencies on the pore water pressure was obvious on reversal stress conditions. The ultimate pore pressure reduced with the increasing of frequency and the degree of effect of frequencies didn't change with the cyclic stress ratio on reversal stress conditions. |
