盾构下穿施工对高速铁路无砟轨道变形影响的解析算法及验证

Analytical Algorithm and Verification of Shield Tunneling Influence on Ballastless Track Deformation of High Speed Railway

为更准确地反映盾构施工扰动下高速铁路无砟轨道的变形,采用给出假定、公式推导、数值验证相结合的方法:(1)将路基-轨道的变形传递假定为3个阶段,即无变形阶段、沉降槽形成阶段、轨道下沉阶段,认为轨道结构最终是否发生脱空取决于路基沉降槽的大小;(2)基于假定,结合梁的挠曲线方程、弹性地基梁理论以及Peck公式推导相应的解析计算方法,并应用在典型地层条件中计算上部CRTSⅡ型纵连板式无砟轨道的最大沉降值;(3)建立相应的地层-路基-轨道三维数值模型,计算轨道最大沉降值,并与同工况下的解析计算结果进行比较。结果表明,相较于数值仿真结果,主体砂卵石、主体泥岩2种地层条件下轨道最大沉降值的解析计算结果误差分别为12%和5%,说明了假定的合理性和解析方法的可行性。

In order to more accurately reflect the deformation of ballastless track of high-speed railway due to shield construction disturbance,the method of combining hypothesis,formula derivation and numerical verification is adopted:(1)The deformation transfer of subgrade-track is assumed to be in three stages of no deformation stage,settlement trough formation stage and track subsidence stage.It is concluded that whether or not the void of track structure eventually occurs depends on the size of the subgrade settlement trough.(2)Based on the assumption,combined with the deflection curve equation of the beam,the elastic foundation beam theory and the Peck formula,the corresponding analytical calculation method is deduced,and the maximum settlement value of the upper CRTS II longitudinal slab ballastless track is calculated in typical stratum conditions;(3)The corresponding three-dimensional numerical model of stratum-subgrade-track is established,and the maximum settlement value of track is calculated and compared with the analytical calculation results under the same working condition.The results show that,compared with the numerical simulation results,the error of the analytical calculation results of the maximum settlement value of the track under the condition of the main sandy cobble and the main mudstone is 12%and 5%,respectively,indicating the rationality of the assumption and the feasibility of the analytical method.