成层地基非线性波动问题人工边界与波动输入研究

STUDY ON WAVE MOTION INPUT AND ARTIFICIAL BOUNDARY FOR PROBLEM OF NONLINEAR WAVE MOTION IN LAYERED SOIL

建立了考虑非线性效应的无限成层地基波动模拟的时域人工边界条件及相应的波动输入方法。首先,推导了线性阻尼介质中的一维人工边界公式,进而推广得到近似的二维人工边界方程;然后,通过等效线性化处理,获得了近似考虑远场成层地基非线性效应的人工边界;最后,建立了相应的波动输入方法。数值算例表明,所给出的人工边界与波动输入方法具有良好的精度,可以方便地应用于成层地基非线性波动问题的研究。

Wave motion input method and artificial boundary conditions in simulation of nonlinear wave motion in infinite layered soils are proposed. One dimensional artificial boundary equations of a linear damping material are derived first. Approximate two dimensional artificial boundary equations are then generalized. The artificial boundary conditions for simulating nonlinear effects of the far-field layered soils are developed by means of equivalent linearization method. Finally,the method of wave motion input is established. Numerical examples prove good accuracy of the artificial boundary conditions and wave motion input method,which can be easily used in study of problems of nonlinear wave motion in layered soils.