Research On Loess Roadbed Reinforcement Of Datong-Xian Passenger Dedicated Raiway

This paper briefly analysised the theoretical of loess roadbed reinforcement relying on Datong-Xian Passenger Dedicated Raiway engineering and concrete researched the design proposal,construction technology and quality control of loess roadbed reinforcement,then forcasted the foundation settlement at every level during constructing roadbed,the main research in the paper as follow:1.the paper researched the arrangement form of compacted cement pile and CFG pile,technology of test pile and the main content of quality control.For compacted cement pile,it should re-check the geological condition and confirm the optimum water content of filler and other factor that may influence on the quality of pile, such as diameter of particles,construction technology and protection measures of filler when constructing; After construction, we detected the compacted density of pile body and the compaction coefficient, dry density,coefficient of settlement of loess of soil between piles,the results showed that settlement of loess had been eliminated and reinforced the bearing capacity of foundation. For CFG pile it should pay more attention on the influencing factors of quality,such as construction technology,the quality of concrete and so on; we sampling inspection the pile integrity and bearing capacity of single pile of CFG pile after construction, the results showed that it reached the design requirements.2.through finite element analysis based on PLAXIS software,this paper prediction analyzed the settlement of Datong-Xian dedicated passenger railway loess foundation that reinforced by using soil-cement compacted piles combined with CFG pile in roadbed filling stage,numerical analysis shows that the part which foundation stress changed obviously is which had been reinforced; the loess foundation settlement which had been reinforced could meet the requirements of dedicated passenger railway. Therefore, through filed conclusion and numerical analysis we know that the this composite foundation reinforcement can be popularization and application in loess foundation of dedicated passenger railway.