基于带隙性能评价函数的特征频段隔振周期排桩选型

Selection of Periodic Piles for Vibration Isolation of Characteristic Frequency Based on Performance Evaluation Function of Band Gap

针对轨道交通环境传播路径隔振,进行隔振周期排桩选型研究。在分析现有周期排桩隔振效果评价的基础上,提出以周期排桩带隙性能评价函数为单一指标,并考虑带隙分布的选型方法。该带隙性能评价函数综合考虑了带隙带宽、中心频率2个因素,基于该函数建立的选型方法规避了多指标分析的不确定性。考虑被阻隔对象的振动特征,将轨道交通环境振动的显著频率作为需要阻隔的关心频率引入该函数。该方法不再单独以首阶带隙为选型依据,而是综合考虑各阶带隙的分布情况。运用ABAQUS软件建立隧道—地层—周期排桩耦合三维动力有限元分析模型,进行选出隔振周期排桩的隔振效果分析。结果表明:所选隔振周期排桩在带隙分布范围内具有较好的振动隔离效果,验证了该选型方法的有效性。

Aiming at the transmission mitigation of the ambient vibration induced by rail transit,the selection of periodic piles for vibration isolation was studied.A selection method was proposed in which the performance evaluation function of band gap was the only index and the band gap distribution was considered on the basis of analyzing the evaluation for the vibration isolation effect of the existing periodic piles.The performance evaluation function of band gap took account of the two factors of band gap bandwidth and center frequency.The selection method based on this function avoided the uncertainty of the multi-index analysis.Considering the vibration characteristics of the isolated object,the characteristic frequency of the ambient vibration induced by rail transit was introduced to the function as the concerned frequency to be isolated.The first order band gap was no longer the only selection basis,but the band gap distribution of each order was comprehensively considered in the method.ABAQUS software was used to establish the coupled three-dimensional dynamic finite element analysis model of tunnel,stratum and periodic piles to analyze the vibration isolation effect of the selected periodic piles.Result shows that the selected periodic piles for vibration isolation have better vibration isolation effects in the range of band gap,which verifies the effectiveness of the selection method.