Based on a two-and-half-dimensional finite element model (2.5D FEM), the layered ground vibration under combined seismic and high-speed train loads was investigated. On this basis, the effect of site category and earthquake intensity on ground vibration under the combined action of two dynamic loads was analyzed. Numerical examples indicated that ground vibration displacement due to combined loads decreases with the increase of soil stiffness, while the influence of soil stiffness on the ground vibration is small when the hardness of the subsoil is large. The peak ground displacement (PGD) is a reasonable seismic intensity index for predicting the ground vibration displacement at the track center under the combined loads, which has a higher accuracy for hard ground. In view of this, an equivalent shear wave velocity and PGD-based prediction formula was proposed to estimate the ground vibration under combined seismic and high-speed train loads. Reliability of the prediction formula was verified through comparison with results of numerical tests, indicating that the prediction formula has good applicability to different site conditions and seismic events. Compared with the previous study, it demonstrated that the prediction method provided an effective means for estimating ground vibration caused by a high-speed train load during earthquakes.

基于二维半维有限元模型（2.5D FEM），研究了地震和高速列车联合载荷下的分层地面振动。在此基础上，分析了场地类别和地震烈度对两种动力荷载联合作用下地面振动的影响。数值算例表明，组合荷载引起的地面振动位移随着土体刚度的增加而减小，而当地基土硬度较大时，土体刚度对地面振动的影响较小。峰值地面位移（PGD）是预测组合荷载作用下轨道中心地面振动位移的合理地震烈度指标，对于硬地基具有较高的精度。鉴于此，提出了一种等效剪切波速和基于PGD的预测公式来估计地震和高速列车联合载荷下的地面振动。通过与数值试验结果的对比，验证了预测公式的可靠性，表明该预测公式对于不同场地条件和地震事件具有良好的适用性。与以往的研究相比，表明该预测方法为估算地震期间高速列车荷载引起的地面振动提供了有效手段。