Research On Predict Soft Soil Subgrade Settlement Of High-speed Railway

The high speed train requirements of high speed railway tracks foundation must be moresmooth and stability, and as the basis of track structure of roadbed, track the designparameters of requirements shall be strictly controlled in standard range. Therefore, in softsoil foundation to build on high speed railway, the most key technical problem is strictlycontrol the work of subgrade settlement and its prediction.Based on the filed measurement, the subgrade settlement issue in high-speed railwayhave been analyzed. The main contents and conclusions as follows:（1） According to the technical requirements of settlement monitor in the high speedrailway, the dynamic deformation monitoring in typical workshop section, mainly inSuJiaTun sections,have been finished and the original data of the subgrade settlement versustimes have been achieved.（2） The settlement simulation analyses during the construction of roadbed filling on thetop of the Cement Fly-ash Grave Piles composite foundation have been executed by usingFLAC^3D finite difference programs.Simulation results show that, the difference between theanalog result and measured value is small under the conditions of layered filling andcompaction; the simulation results reflect the change trends of subgrade settlement well.（3） In the reasonable model, preparing and speed350km/h train loads of dynamicanalysis, to get the roadbed under dynamic load power features.（4） Based on the basic principle of prediction of grey theory, the same interval GM（1,1）model and grey Verhulst model are developed. And then the settlement is predicted for fivetypical sections （DK369+345, DK369+420, DK369+520, DK369+620, DK369+720） ofSuJiaTun passenger dedicated line. The prediction results are tested by the relative error toin-suit testing results, so that prediction effect of grey theory model to settlement of subgradeof passenger dedicated railway is analyzed.