轨道交通混凝土异形桩减隔振效果研究分析

为了研究轨道交通应用混凝土异形桩的减隔振效果,通过无限元边界与有限元边界相结合的有限元分析方法进行模型建立和分析研究,并通过模型试验方法对混凝土异形桩减隔振效果进行验证与研究。结果表明:有限元计算方法和模型试验方法得出结果的趋势吻合,可以有效反映出减隔振措施的实际效果;异形桩空心率越小减隔振效果越好,但随着距离增加空心率对减隔振效果的影响快速降低;异形桩内部形状变化对减隔振效果几乎没影响,而异形桩外部形状变化对减隔振效果有一定影响,同时不论是内部形状还是外部形状变化圆形都略好于方形;异形桩空心不填充原状土比填充原状土减隔振效果好,而填充原状土1 000~1 900 kg/m3,减隔振效果几乎没有变化。

Research on Vibration Isolation Effect of Profiled Concrete Piles in Rail Transit

In order to study the vibration isolation effect of profiled concrete piles in rail transit,this paper establishes the model by the finite elementmethod combined with infinite element boundary and finite element boundary,and measures for vibration isolation of profiled concrete piles in rail transit are verified and studied based model tests. The conclusion shows that the results obtained by the finite element method are consistent with those by the model test method,which effectively reflects the actual effect of the vibration isolation measures. The smaller the hollow ratio of the profiled concrete piles,the better the vibration isolation effect. But with the increase of distance,the effect of the hollow rate on the vibration isolation effect is reduced rapidly. The change of the internal shape of the profiled piles imposes little impact on the effect of vibration isolation,while the change of external shape imposes certain impact. The round shape is slightly better than the square in case of the change of either internal shape or external shape. The effect of the hollow profiled piles not filled with undisturbed soil is better than that of the same piles filled with undisturbed soil,and the vibration isolation effect achieved by filling undisturbed soil of 1 000 kg/m3 and 1 900 kg/m3 remains almost unchanged.