EXPLICIT MODEL FOR CUMULATIVE PORE PRESSURE OF SATURATED CLAY UNDER CYCLIC ROTATION OF PRINCIPAL STRESS AXIS SUBJECTED TO CYCLIC LOADING

The cumulative pore pressure dissipation of saturated clay is an important factor in the settlement of roadbed under traffic load． According to the characteristics of making the hollow cylindrical specimens of saturated clay，it was introduced the fabrication process of saturated clay hollow cylindrical specimen in detail． The specimens were consolidated under 100 kPa，150 kPa，and 200 kPa，then，the undrained cyclic loading test was done with the change in the principal stress axis rotation continuous range being ［－ 15，15］，［－ 30，30］，［－ 45，45］，and ［－ 60，60］，therefore，the effect rules that were confining pressure，the principal stress axis rotation angle and the static deviator stress respectively on the cycle cumulative pore pressure were obtained． Using the modified dynamic deviator stress level to consider the effect of initial static deviator stress and dynamic deviator stress on the undrained cumulative pore pressure，the cumulative pore pressure model of constant shear stress cycle deviation angle of principal stress axis under cyclic loading was established． Through the cumulative pore pressure value of non-isotropic consolidation cyclic torsional shear test，the correctness of the established cumulative pore pressure model was verified．