地震-高铁荷载共同作用下桩网复合路基震动特性

Vibration characteristics of pile-net composite subgrade under the combined action of earthquake and high-speed train loads

为研究地震和高铁荷载共同作用下桩网复合路基震动特性,建立地震和高铁荷载共同作用下轨道-路堤-桩网复合路基震动的三维有限元分析模型,研究地震荷载类型和列车车速对桩网复合路基震动加速度和位移的影响规律,提出不同地震荷载下的列车运行建议。研究表明,Hollister地震与高铁荷载共同作用下,桩网复合路基地面震动加速度由两动载共同控制,震动位移主要由地震荷载控制,列车运行状态对地震动位移影响很小;Chi-Chi地震与高铁荷载共同作用下,地震动加速度主要由高铁荷载控制,地震动位移受地震荷载和列车荷载共同影响,地震发生时可先通过降低车速后停运列车有效减小地震动位移;Lytle Creek地震与高铁荷载共同作用下,地震动加速度主要由高铁荷载控制,地面震动位移受地震和列车荷载共同影响,且主要由列车荷载控制,地震发生时可通过降低列车车速有效减小地震动位移,以降低地震发生时列车脱轨的可能性。

This study examines the vibration characteristics of pile-net composite subgrade under earthquake and high-speed train loads.Using ABAQUS software,a three-dimensional finite element model involving rail,embankment,and pile-net composite subgrade under earthquake and high-speed train loads was established.The influences of seismic types and train speeds on the vibration acceleration and displacement of pile-net composite subgrade were discussed,and suggestions for train operation under different seismic loads were proposed.The results show that the ground vibration acceleration of pile-net composite subgrade is controlled by the Hollister earthquake and high-speed train loading.The vibration displacement is mainly controlled by the Hollister earthquake,which means the train speed has little effect on the ground displacement.Under the joint action of the Chi-Chi earthquake and high-speed train loading,the ground acceleration is mainly controlled by the high-speed train loading,while the ground displacement is controlled by the two dynamic loads.This suggests that when an earthquake occurs,the ground displacement can be effectively reduced by slowing down the speed until it reaches zero.Under the joint action of the Lytle Creek earthquake and high-speed train loading,the ground acceleration is mainly controlled by the high-speed train loading,and the ground displacement is controlled by the two loads,particularly the high-speed train loading.When an earthquake like the Lytle Creek earthquake occurs,the ground vibration displacement can be effectively reduced by slowing down the train speed,thus reducing the possibility of train derailment.