振动荷载下铁路路基细粒土地基动力响应特征研究

细粒土地基在列车行驶荷载影响下易发生土体变形甚至出现土层液化情况，对列车行驶安全带来一定的威胁。为研究细粒土地基在振动荷载作用下的变形特征及动力响应特性，开展了地基细粒土室内振动台试验，对细粒土在振动荷载下的动力响应特征和变形进行了深入分析，并研究了动荷载下土层内孔隙水压力的变化规律。结果表明，列车行驶振动荷载影响下细粒土地基会出现大变形甚至失稳特征，根据Seed判别法可知细粒土地基存在液化风险，严重危害地基稳定性及列车行驶安全，应采取一定措施进行加固处理。

Study on Dynamic Response Characteristics of Fine-grained Soil Foundationfor Railway Subgrade under Vibration Load

Under the influence of the train running load, the fine-grained soil foundation is prone to deformation and even liquefaction of the soil layer, which poses a certain threat to the safety of the train running. In order to study the deformation characteristics and dynamic response characteristics of fine-grained soil foundation under vibration load, an indoor shaking table test has been carried out for fine grained soil under vibration load. The dynamic response characteristics and deformation path of fine-grained soil under vibration load have been deeply analyzed, and the variation law of pore water pressure in soil layers under dynamic load has also been studied. The results show that the fine-grained soil foundation will have large deformation and even instability under the vibration load of train running. According to the SEED discriminant method, the fine-grained soil foundation has the risk of liquefaction, which seriously endangers the stability of foundation and the safety of train running. Therefore, certain measures should be taken to strengthen the subgrade.