Three test sections were designed to investigate their effectiveness in reinforcing railway subgrades by using concrete compacted base-enlarged piles and geogrids based on the construction practice in the k337?665 ? ?770 section of the Da-Cheng Railway. Track smoothness and associated dynamic responses such as the stress

dynamic deformation and acceleration rate under the locomotive load are recorded during the tests. Test results show that the dynamic response in test sections is below the relevant limits. Running speed has an different impact

and the rule of acceleration increase with run-up is most obvious. Smoothness and stabilizing of railway have remarkable influence on dynamic responses such as the stress

dynamic deformation and acceleration rate in railway line and subgrade structure.