三种黏弹性本构模型描述的土中单桩的扭转振动

Torsional Vibration of a Single Pile in Soil Described by Three Viscoelastic Constitutive Models

针对土体中单桩的扭转振动问题,分别采用Kelvin黏弹性模型、三参数固体黏弹性模型和分数阶黏弹性(FDV)模型描述桩周土体的本构关系,对黏弹性土体和土体中单桩的扭转振动进行了求解,并对3种模型描述的黏弹性土中单桩的扭转振动进行了分析,讨论了有关参数对单桩扭转振动的影响.结果表明:三参数固体模型描述的土中单桩扭转振动的复刚度实部和虚部随频率变化曲线较其他两个模型波动要小,黏弹性土体中单桩的扭转振动特性与本构模型有关,经典黏弹性模型的桩顶扭转复刚度要比分数阶模型的复刚度大.

For the torsional vibration problem of a single pile in soil,the constitutive relationship of the pile around soil was described by Kelvin viscoelastic model,three-parameters viscoelastic model and fractional derivative viscoelastic（FDV） model,and the torsional vibration of the soil and the pile were also solved,respectively.The torsional vibration of a single pile in soil described by the three viscoelastic models were investigated,and the influences of the parameters on the torsional vibration were discussed.The results indicated that the fluctuation of the curves of the real and imaginary part of torsional complex stiffness of pile in soil described by three-parameters solid model varying with frequency was smaller than that of the other two models,the characteristics of torsional vibration of a single pile in viscoelastic soil had related with the constitutive relationship of the soil,and the torsional complex stiffness of the pile in the soil described by classic viscolestic model was larger than that of the soil described by fractional derivative viscoelastic model.