列车振动荷载作用下隧道围护结构性能实测分析

为有效缓解既有线路列车经过软土明挖隧道产生振动荷载对围护结构性能的影响,确保隧道工程安全可靠,采用现场实测和数据分析方法,研究不同列车、不同距离、不同深度情况下既有线列车振动荷载对地层振动的影响,从而确定列车振动影响范围、围护桩振动速度、锚索轴力以及桩身位移.实例分析表明,列车经过时,围护桩的水平振动速度较大,竖向振动速度相对较小,下行车引起的振动速度大于上行车；东西对应测点的锚索轴力变化规律基本一致,西侧锚索轴力大于东侧锚索轴力；桩身水平位移随着深度的增加先增加后减小.通过对列车振动荷载作用下的锚索轴力及桩身位移进行实测分析,可为锚索性能变化规律提供基础数据,从而为隧道工程设计和施工提供有价值的参考.

Field Measurement and Analysis of Retaining Structural Function for Tunnel under Vibration Loads of Train

In order to relieve the influence of existing lines train vibration loads when possthrough the open-digging tunnel and to make the tunnel construction safe and reliable,the methods of field measurement and the data analysis are used to sutdy the performance influence of the vibration loads on the tunnel retaining structure under different train,different distance and different depth when the train passes through,so as to determine the train vibration influence scope,the vibration velocity of the retaining pile,the force of the anchor axial and displacement of the pile body.Results show that the horizontal vibrant velocity of the retaining piles is greater than the vertical one,and the vibrant velocity of the down train is greater than the up train.The anchor axial forces variation of the western monitoring sites are corresponded with the eastern,and the axial forces of the cable anchor on the eastern are stronger than on the eastern.The horizontal displacements of the pile bodies begin to increase and then decrease with increasing the dig depth.Thus,the field measurement and analysis of retaining structural function for tunnel under vibration loads of train can provide the foundation data of the cable anchors performance valuable reference for tunnel design and construction.