Influence of Pile Cap Effect on Piled Embankment Supporting High-Speed Railway

Abstract

A field test was performed on a piled embankment of Beijing-Shanghai High-speed Railway to investigate the influence of pile cap effect on piled embankment supporting high-speed railway. The developments of pressures and settlements above pile cap and soil surface are obtained by hydrostatic levels and soil pressure cells. Test results indicate that both relative settlement and pressure ratio vary with filling when the height of embankment is less than 0.9 m. When the height of embankment is more than 0.9 m, the relative settlement tends to be stationary while pressure ratio keeps rising till the end of filling and becomes steady quickly in standing period. Furthermore, the numerical simulation is made using Plaxis 2D to analyze the influence of pile cap coverage ratio on settlement and pressure distribution in the single pile processing area. Results show that enlarging the diameter of pile cap can improve the settlement stability of soil between piles remarkably, while reducing pile spacing can reduce the settlement of soil effectively.