摘要
评价运营地铁线路减振轨道的减振效果时,常选取非减振参考轨道断面与其进行对比测试,计算得到"对比损失"。然而两测试断面背后地层动力特性通常存在差异,这种差异导致测试得到的"对比损失"不能准确的反映出减振轨道的实际减振效果。为定量分析这一因素对减振效果评价的影响,该文利用车辆-轨道耦合解析模型计算得到列车运行时钢轨的扣件支反力,利用有限元软件建立"轨道-隧道-地层"三维数值模型,考虑整体道床轨道和钢弹簧浮置板轨道两种轨道型式,计算并分析了地层动弹性模量等参量变化对浮置板轨道对比损失造成的影响,并对数值模型计算结果进行拟合,得到减振轨道Z振级对比损失的修正公式。结果表明:地层动弹性模量差异是测试断面地层动力特性差异的控制参数,对减振轨道减振效果评价结果影响显著;测试点所处地层动弹性模量若小于500 MPa,则对比测试断面之间的地层动力特性差异会对减振效果评价结果造成更加显著的影响。
When evaluating the mitigation effect of a vibration isolated track in an operating metro line,two test sections on the vibration isolated track and reference track are often selected,and then the contrast loss is calculated.However,the dynamic characteristics difference of the stratum behind a tunnel can affect the evaluation results.To quantitatively analyze the influence of this factor,a vehicle-track coupling model was established to calculate train loads.Using the finite element software,a track-tunnel-stratum three-dimensional numerical model was developed,considering two types of track-form.The difference between the contrast loss and the insertion loss caused by the three parameters(dynamic elastic modulus,Poisson's ratio and mass density)of the formation were analyzed and discussed.A quantitative correction method for contrast loss based on the difference of dynamic characteristics of strata is presented.The results show that:the difference of dynamic elastic modulus is the main parameter of the difference in dynamic characteristics of the stratum in the test section,which has a significant effect on the contrast loss of vibration isolated track;if the dynamic elastic modulus of the stratum at the test point is less than 500 MPa,the difference of stratum dynamic characteristics between the test sections will have a more significant influence on the evaluation results of damping effect.
作者
梁瑞华
马蒙
刘卫丰
杜林林
李林峰
LIANG Rui-hua;MA Meng;LIU Wei-feng;DU Lin-lin;LI Lin-feng(Key Laboratory of Urban Underground Engineering of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Beijing Materials Handling Research Institute Co.,Ltd.,Beijing 100007,China)
出处
《工程力学》
EI
CSCD
北大核心
2020年第S01期75-81,共7页
Engineering Mechanics
基金
国家自然科学基金项目(51508022)
国家自然科学基金项目(51778049)。
关键词
减振轨道
地层动力特性
减振效果评价
对比损失
插入损失
vibration isolated track
stratum dynamic characteristics
evaluation of vibration mitigation effect
contrast loss
insertion loss
