轨道交通荷载下桩板结构主动隔振效果研究

为了研究在轨道交通荷载作用下桩板结构主动隔振措施的隔振效果,通过无限元边界与有限元边界相结合的有限元分析方法在路基中建立桩板结构模型,并在沙土地基中设置混凝土桩板结构进行模型试验,通过模型试验对有限元数值模拟结果加以验证,将桩长、埋深及置换率3个因素考虑在内,研究其对隔振效果的影响。结果表明:模型试验验证有限元计算方法的可靠性;随桩长增加振幅降低比减小,隔振效果明显,随着振源距离增加其振幅降低比减小明显;埋深为桩板结构主动隔振措施中的主要影响因素,随着埋深增加振幅降低比明显减小,隔振效果越明显;有限元计算过程中置换率对隔振效果的影响不明显,但是在模型试验中置换率对隔振效果影响较显著。

Active Vibration Isolation Effect of the Pile-PlankStructures under Rail Traffic Loads

In this study, a pile-plank structure model was set on the roadbed using the finite element analysis method, which combines the boundaries of the infinite element method and the finite element method, to study the effect of the active vibration isolation measures of the pile-plank structures under rail traffic load. Subsequently, the model test was conducted by setting a concrete pile-plank structure in a sandy soil foundation. Further, the finite element numerical simulation results were verified based on the model test, and the effects of the pile length, burial depth, and filling rate on vibration isolation were studied. The model test results verify the reliability of the finite element method. (1) The amplitude reduction ratio decreases and the effect of vibration isolation becomes obvious with increasing pile length. (2) The burial depth is the main factor that influences the active vibration isolation measures of a pile-plank structure; with increasing burial depth, the amplitude reduction ratio obviously decreases and the effect of vibration isolation becomes more obvious. (3) The effect of filling rate is more obvious during the finite element calculation process when compared with that in the model test.