循环荷载作用下饱和软黏土海床的刚度衰减模型研究

在地震和波浪等循环荷载作用下,海床内部产生循环应力、循环应变以及超孔隙水压力累积,可能造成饱和软黏土地基强度和刚度的降低,对桩基础的承载性能产生较大的影响.将反映土体软化特性的参数引入等效黏弹性模型中,建立考虑循环荷载作用下饱和软黏土刚度衰减以及动应力-应变非线性和滞回性的修正模型,基于动三轴试验结果反演获得饱和Kao...

Research on the stiffness degradation model of saturated soft clay seabed under cyclic loading

Under the cyclic loading of earthquake and wave loads,the cyclic stress and cyclic strain,as well as the excess pore water pressure accumulates in the seabed,which may induce the degradation of the foundation strength and stiffness in the saturated soft clay,thus has significant adverse effect on the bearing capacity of pile foundation.In our research,the parameters that related to the soil stiffness degradation had been introduced into the equivalent viscoelastic model,the modified stiffness degradation model that takes account of the stiffness degradation,nonlinear and hysteretic cyclic stress-strain relationship had been established,in which the dynamic characteristic and stiffness degradation parameters of the saturated Kaolin soft clay were back-calculated based on the dynamic triaxial test results.The proposed modified model was secondary-developed by virtue of FLAC^3D,and validated by comparison with the triaxial test results.In addition,the modified model has been adopted to investigate the response of the free-field seabed under different-intensity earthquake motion,by comparing with the centrifugal test results,the applicability of the modified model has been verified for investigating the dynamic response of soft clay seabed under earthquake loading.