Research On Cumulative Deformation Of Saturated Soft Clay Considering The Creep Effect Under Long-term Cyclic Loading

The soft clay is distributed extensively in our country,especially the coastal area.Soft clay has high compressibility,low strength,high natural moisture content,notable creep characteristics etc.In recent years,an increasing number of harbour engineering structures was built on the soft clay foundations.The foundation can exhibit obvious settlement deformation subjected to cyclic loading such as handling transport machinery load or wave load.Many scholars at home and abroad made research on cumulative deformation subjected to cyclic loading.A great number of theoretical achievements have been made,and some achievements have been applied widely to the project very well.But it is difficult to directly find out analytic solution for the issues about settlement and stability of large-scale structures Based on the finite element program ABAQUS,the proposed empirical model was secondarily developed.The accumulative deformation of soft clay considering the creep effect can be calculate,which can overcome some limitation of the indoor test and provide certain reference for the complex practical engineering.Based on the undrained cyclic triaxial tests on saturated soft clay under cyclic loading,the accumulative deformation of soft clay is performed considering the effect of cyclic deviatoric stress and initial static deviatoric stress.An empirical model which can be applied to practical engineering is proposed to calculate the plastic cumulative strain of saturated clay subjected to cyclic loading.Based on user subroutines CREEP of finite element program ABAQUS,the proposed empirical model is secondarily developed and verified by undrained cyclic triaxial creep test.On the basis of the above mentioned study,a quasi-static FE model of semi-circular and caisson breakwater considering the creep of soft clay subjected to cyclic loading is established.The deformation rule of soft foundation of breakwater is analyzed.And the Influencing Factors such as wave force,the amount of sand filling in the cabinet,bed bottom width and thickness of soft clay is taken into account.The comparation between the one without creep effect is made.It is concluded that the influence on foundation settlement by creep effect of soft clay is significant,which may provide reference for the designing of harbor engineering structure.