Test Evaluation of Post-Construction Settlement of Subgrade in Beijing-Shanghai High-Speed Railway

The post-construction settlement of Beijing-Shanghai high-speed railway is strictly limited. And the current settlement calculation methods of soft soil are not satisfactory for design. Combined with the project of Fengyang trial section of Beijing-Shanghai high-speed railway, the field tests on composite foundation composed by CFG pile-cap-net with preloading were carried out. The settlements of subgrade and the lateral displacements of soil were measured. We analyzed the variation law for pile and soil settlement of the subgrade with the changes of both the filling height of embankment and the consolidation time, and the lateral soil displacement with the changes of the filling height of embankment. The hyperbolic method for prediction settlement of subgrade was discussed. The results show that using CFG pile-cap-net is a reasonable treatment technique for soft soil foundation and can control post-construction settlement of subgrade effectively. The research achievement can provide reference for the treatment technology of soft soil in high-speed railway, and have been applied to the project of Beijing-Shanghai high-speed railway.