正交试验下地铁诱发的环境振动影响分析

Influencing Factors Analysis for Environmental Vibration Induced by Subway Operations Based on Orthogonal Experiments

结合南昌地铁实际情况,采用正交试验的方法,对地铁运行引起环境振动的敏感影响因素进行正交分析。以隧道中心正上方地面点Z振级为评价指标,选取三个因素:减振措施、隧道埋深和列车行驶速度,每个因素分析四个水平,采用正交表,进行16组实验。得出三个因素的显著影响程度依次是隧道埋深、车速和减振措施。在减振措施的四个水平中,从普通整体道床到钢弹簧浮置板的减振效果最好。另外,隧道埋深随着深度的增加影响逐渐减小,从埋深10 m到15 m变化最为显著,而深度到了20 m以后,影响迅速减弱。列车速度由40 km/h增加到60 km/h影响最为显著。同时,利用ANSYS建立了不同参数下浮置板道床的三维有限元模型,对浮置板在不同支座刚度和厚度下进行了模态分析,分析了浮置板的减振频率范围,得出了浮置板减振与它本身的固有频率关系。

An orthogonal experiment was designed to analyze the influencing factors for environmental vibration causedby subway operations. The Z vibration level at the point above the center of the tunnel was taken as an evaluation index. Threefactors, measures of vibration damping, tunnel depth and traveling speed of the train, were selected as the influencing factors.Four levels were analyzed and 16 experiments were tested for each factor using the orthogonal table. Results show that the successivearrangement of the three factors according to their significance was tunnel depth, travelling speed and vibration dampingmeasures. Among the four levels of vibration damping measures, the vibration reduction effect becomes better and betterfor the measures from the ordinary whole track bed to the floating slab. The influence of subway operation decreases graduallywith the tunnel depth increasing. The rapid changing of the influence occurs in the tunnel depth range from 10m to 15m. Theinfluence decreases rapidly when the depth exceeds 20 m. The influence of traveling speed increases significantly from 40 km/h to 60 km/h. Finally, a 3-dimensional finite element model for the floating slab track bed was established with ANSYS. Modalanalysis of the floating slab for different support stiffness and thickness was performed. The frequency range for vibration reductionof the floating slab was analyzed, and the relation between vibration reduction and inherent frequency of the floatingslab was discovered.