公路桥梁车激振动对堤基砂土液化的影响研究

摘要

A bridge pier is adjacently located at a bank embankment, the bridge vibration induced by vehicle running on the uneven bridge deck would transfer to the piers and may further lead to liquefaction of the dike foundation that consist of saturated loose fine silt. Aiming at the potential dangers, we carry out a liquefaction analysis for the saturated loose silt under vehicle-in-duced vibration by 2D FEM. The calculation results show that the liquefaction potential of dike foundation arising from bridge deck vibration is slight and the limited liquefaction layer, mainly compose of saturated fine silt with loose and compacted features, is mostly around the piers. The vehicle-induced vibration would not exert unfavorable influence on the bridge and dike.%一公路桥桥墩位于河岸堤防附近，当车辆快速通过凹凸不平的桥面时，桥梁会产生振动，且该振动作用可能会导致桥墩周围的松散饱和粉细砂层发生液化。针对上述问题，采用有限元二维动力方法对车激振动作用下堤基饱和砂土的液化特征进行了分析。结果表明，由桥面不平顺导致的桥墩基础砂土液化范围很小，基本位于墩周附近的上部松散-稍密饱和粉细砂层内，不会对桥梁和堤防的安全产生不利影响。