隧道变形引起的钢弹簧浮置板轨道变形与脱空分析

Analysis on deformation and detachment of the steel spring floating slab track induced by tunnel deformation

穿越施工引起既有隧道及其上的轨道结构产生变形,给列车运营安全带来不利影响。将钢弹簧浮置板轨道视为弹性地基梁,建立钢弹簧浮置板轨道变形的控制微分方程。采用傅里叶级数法求解微分方程,得到关于未知级数系数的线性方程组,进而给出求解线性方程组的迭代方法。基于本文方法分析钢弹簧浮置板轨道与隧道底板相互作用规律。研究结果表明:浮置板自身的抗弯刚度使其与隧道底板存在变形差异,进而与隧道底板产生脱空;随着隧道底板变形的增大,轨道结构变形及脱空范围均增大;随着沉降槽宽度的增大,轨道变形与隧道底板逐渐趋近,脱空范围呈先增大后减小的趋势;钢弹簧刚度越大,间距越小,轨道与隧道底板越容易产生脱空,脱空范围越大。研究成果可为穿越施工中既有线轨道结构的安全评价提供理论依据。

Traversing construction induces deformation of the existing tunnel and track structures within,which has side-effects on operation safety of trains.The steel spring floating slab track was simplified as a beam on elastic foundation.A governing differential equation for deformation of track structures was established and solved by Fourier series method.A set of linear equations for determining unknown series coefficients was obtained.An iterative method to solve the set of equations was given.Based on the method presented in this paper,interaction between steel spring floating slab track and tunnel floor was analyzed.Results show that,the flexural stiffness of floating slab causes differential deformation,or further detachment,between track slabs and the tunnel floor.The deformation of track structures and the detachment range increase with the increase of tunnel floor deformation.With the increase of width of settlement trough,the deformation of track and tunnel floor approaches gradually,and the detachment range first increases and then decreases.The greater the stiffness of steel springs or the smaller the spacing between two adjacent springs,the more likely the track separates from the tunnel floor,and the wider the detachment range will be.The research results provide theoretical guidance for safety evaluation of the existing track structures during traversing construction.