Stress State Effect Of The Existing Railway Subgrade By Train Running On Bridge Of High-speed Railway

With the development of high-speed railway,a lot of high-speed railway was built in parallel to the neighboring existing railway,the problem of the effect of high-speed railway on the existing railway has drawn increasing attention.Combined with the characteristics of high-speed railway and the existing railway,A pier-soil-subgrade finite element model was established, the model was then verified by means of numerical simulation and field test. Combined with theoretical models, the subgrade’s stress state and cumulative plastic deformation of the existing railway were analyzed under different distances between the existing and elevated high-speed railway. Results through this paper can be concluded as follows:(1)The regularity of subgrade’s stress state as follows:he maximum transverse dynamic deviator stress occurs within range of the sleeper and presents a saddle shape; it decreases along the depth direction with a fast attenuation below the surface of subgrade bed while the attenuation getting slower with the increasing depth. Through contrast analysis fore-after and vertical dynamic deviator stress of the subgrade change little compared with those under running of existing railway train only.(2)The effects of subgrade’s stress state caused by the operation of elevated high-speed railway with the different distances between the two railway, the transverse dynamic deviator stress of the subgrade varies within2%. The effect of distance on the depth distribution of dynamic deviator stress changes with different depths and is very small.The effect of track irregularities on the transverse dynamic deviator stress is5%less than that of normal load. When the subgrade was softened, the transverse dynamic deviator stress of the subgrade bed increases within the range of the sleeper, while that without the range of the sleeper decreases.(3) The operation of high-speed railway could not affect on subgrade’s cumulative plastic deformation of the neighboring existing railway.The different distances between the two railway and track irregularity and subgrade softening of high-speed railway have little effect on the cumulative plastic deformation of the existing railway as well.