在Biot波动理论的基础上,分析移动点荷载引起的混凝土层表面振动情况.首先,建立问题的简化模型,地面假定由3层构成,其中第1层和第2层为黏弹性混凝土材料,第3层为饱和土半无限空间,将铁轨视作欧拉-伯努利梁,置于第1层和第2层的界面处.然后,通过对饱和土体运动方程进行时域-空间域双重Fourier变换,得到饱和土中以势函数形式表示的位移、应力和孔隙水压力.根据问题的边界条件,得到方程系统,利用Cramer法则以及分块矩阵计算行列式方法,求解势函数中的待定系数.进一步通过双重Fourier逆变换和Dirac函数的性质,得到混凝土表面位移的表达式.数值计算中对模型进行验证,并对影响地面位移的混凝土层厚度和剪切模量等进行分析.%The surface vibration induced by moving point load in concrete layers was investigated in this paper. First, the simplified model was built up, in which the ground was assumed to be composed of three layers. The first and second layers are concrete, and the third layer is half-space poroelastic soil. The rail was considered as an Euler-Bernoulli beam of negligible thickness located at the interface between the first and second concrete layer. The equation of poroelastic soil was decoupled by utilizing the double Fourier transformation and the displacement and stress expressions involving potential functions were given. According to boundary conditions, the system equation was obtained and solved by applying Cramer's rule and block matrix calculation method. Finally, the surface displacement was obtained using inverse Fourier transformation. The calculation results were validated and the thickness and shear modulus of concrete on the influence of surface displacement were analyzed.
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