Abstract:

The traditional accumulative pore pressure model of saturated soft clay under cyclic loading can not reflect the phenomenon of principal stress axial deflection. With the determination of consolidation time, under the condition of 100,150,200 kPa consolidation pressure, the undrained cyclic loading test with the principal stress axes angle of 15°,30°,45° was conducted on soft clay. The effects of confining pressure, the principal stress axis rotation angle and the static deviator stress on cycle cumulative pore pressure were obtained. On the basis of the cumulative pore pressure of the first cyclic loading and the revised dynamic deviatoric stress level, an explicit model was proposed to calculate the cumulative pore pressure of saturated clay subjected to cyclic loading. The validity of the model was verified based on undrained cyclic tests of consolidated soft clay. The parameters were of physical significance and are easy to be obtained. The proposed explicit model could reflect the phenomenon of principal stress axial deflection.

Key words: consolidation time, cyclic accumulative pore pressure, constant principal stress deflection angle, soft clay