基于非局部理论的一维饱和土层稳态响应分析

Steady State Response of One Dimensional Saturated Soil Based on Nonlocal Theory

  • 摘要: 基于非局部理论和多孔介质理论,针对一维饱和土层的稳态响应进行了研究。为了克服Biot饱和土理论的不足并考虑非局部效应的影响,利用非局部理论和多孔介质理论,建立了以位移表示的考虑非局部效应的一维饱和土振动微分方程。通过求解特征方程和特征向量并考虑问题的边界和初始条件,在频率域内得到了基于非局部理论的一维饱和土层的固相位移、液相位移和孔隙水压力的解析解。数值研究了考虑非局部效应的一维饱和土层的动力响应,分析了非局部效应和液-固耦合系数对固相位移、液相位移和孔隙水压力等动力响应的影响规律。数值研究结果表明:简谐荷载作用下一维饱和土层存在有共振,当考虑饱和土的非局部效应时,共振幅值将会减弱,系统阻尼有增大的现象;液-固耦合系数主要对固相位移、液相位移和孔隙水压力随频率变化曲线的峰值有影响。

     

    Abstract: Based on the nonlocal theory and theory of porous media, the steady-state response of one-dimensional saturated soil layer is studied. In order to overcome the shortcomings of Biot's saturated soil theory and consider the influence of nonlocal effect, one-dimensional dynamic differential equations expressed by displacement of saturated soil are established by using nonlocal theory and theory of porous media. By solving the characteristic equations and eigenvectors and considering the boundary and initial conditions of the problem, the analytical solutions of displacement of solid phase, displacement of liquid phase and pore water pressure of one-dimensional saturated soil layer based on nonlocal theory are obtained in frequency domain. The dynamic response of one-dimensional saturated soil layer considering nonlocal effect is numerically studied. The laws of influence of nonlocal effect and liquid-solid coupling coefficient on dynamic response are analyzed, such as displacement of solid phase, displacement of liquid phase and pore water pressure. The numerical results show that there is resonance in one-dimensional saturated soil under harmonic loading, when the nonlocal effect of saturated soil is considered, the resonance amplitude will decrease and the system damping will increase. The liquid-solid coupling coefficient mainly affects the peak values of the curves of displacement of solid phase, displacement of liquid phase and pore water pressure with frequency.

     

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