The dynamic responses of a layered foundation-track coupled system due to moving harmonic loads are evaluated using the Green's Functions method.The results are firstly obtained in the frequency-wave number domain and then results are obtained in the time-space domain using the inverse Fourier transformation.To do this,the Green's Functions of moving distributed vertical loads,which are acting on the surface of a layered half-space,are deduced based on the three-dimensional exact dynamic stiffness matrix.The validity of the method is confirmed by comparing the results with previously published results,and the effects of the frequencies and velocities of the moving load.In particular,some effects of layering on the dynamic responses are studied by taking a layered ground-track coupled system and a uniform ground-track coupled system as examples.The results show that the maximum ground surface displacements for the moving harmonic loads may not occur at the transonic speed compared to the moving static loads cases.The dynamic responses of the layered foundation-track coupled system are significantly different from those of the uniform case.The amplitudes of the surface ground displacement are much larger when the frequency of the load is close to the natural frequency of the layered ground.The displacement amplitudes of the ground vibrate more is bigger when the load moving on the track with the same frequency as the intrinsic frequency of the foundation.Also,the frequency spectrums of the displacement amplitudes migrate to the low frequency regions as the depth of the layer becomes thicker.%采用格林函数方法求解层状地基－轨道耦合系统在移动简谐载荷作用下的动力响应问题。通过求解层状地基表面作用移动均布线载荷时的动力格林影响函数，由位移连续条件实现层状地基与轨道的耦合，求得移动简谐载荷作用下频率－波数域内的系统动力响应，最后通过傅里叶逆变换求得时间－空间域内的动力响应；与已有结果的比较验证了方法的正确性，并以均匀半空间地基和基岩上单一土层地基－欧拉梁耦合系统为模型，研究载荷振动频率、移动速度、地基刚度以及土层厚度对动力响应的影响。研究表明移动简谐载荷频率较高时与移动静载荷情况不同，不再具有跨音速时地表位移幅值最大的规律；成层地基－轨道耦合系统在移动简谐载荷作用下的动力响应与均匀地基情况存在显著差异，当载荷频率与层状地基固有频率接近时，地基表面位移幅值较大；另外随着基岩与土层剪切波速比的增大，载荷以超音速经过后地基表面位移振动更加剧烈，振动时间更长，随着土层厚度的增大，位移幅值逐渐向低频区域迁移。
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