Train-induced ground vibrations are all generated by the vehicle, by static or dynamic vehicle loads. The most important and most accepted excitation are the dynamic wheel loads from the passage over track irregularities. Dynamic wheel loads will be compared from parallel axle-box and ground vibration measurements at more than seven sites. Some low-frequency excitation of ground vibrations, typically between 10 and 30 Hz, cannot be found in the axle-box measurements. Therefore, other vehicle modes, such as rigid bogie modes, flexible carriage modes, rigid and flexible wheelset modes, have been analysed for additional excitation forces. These vehicle dynamics analyses give an explanation for higher axle-box results at high frequencies, but not for the excitation of the higher low-frequency ground-vibration component. Finally, the effect of the moving static train loads will be analysed. For a regular track and soil, the moving static train loads yield the quasi-static response which exists only in the low-frequency nearfield of the track. If the support stiffness is randomly varying along the track, the pulses on the track generate an additional low-frequency component which is called the irregular pulse responses. This component will be demonstrated by numerical analysis where all axle pulses are superposed in frequency domain.

列车引起的地面振动都是由车辆产生的，由静态或动态车辆载荷产生。最重要和最被接受的激励是来自不规则轨道的通道的动态车轮载荷。动态车轮载荷将在超过七个地点的平行轴箱和地面振动测量中进行比较。在轴箱测量中找不到一些地面振动的低频激励，通常在 10 到 30 Hz 之间。因此，其他车辆模式，如刚性转向架模式、柔性车厢模式、刚柔轮对模式，已经被分析为额外的激振力。这些车辆动力学分析解释了高频下较高的轴箱结果，但不能解释较高频率的地面振动分量的激励。最后，将分析移动静态列车载荷的影响。对于规则的轨道和土壤，运动的静态列车载荷产生仅存在于轨道低频近场的准静态响应。如果支撑刚度沿轨道随机变化，则轨道上的脉冲会产生额外的低频分量，称为不规则脉冲响应。该分量将通过数值分析来证明，其中所有轴脉冲都在频域中叠加。轨道上的脉冲会产生一个额外的低频分量，称为不规则脉冲响应。该分量将通过数值分析来证明，其中所有轴脉冲都在频域中叠加。轨道上的脉冲会产生一个额外的低频分量，称为不规则脉冲响应。该分量将通过数值分析来证明，其中所有轴脉冲都在频域中叠加。