Model Test of the Long-Term Behavior of a Pile-Net Structure Subgrade for Highspeed Railways

摘要

This article presents an experimental study on the long-term behavior of a pile-net structure soft subgrade of a highspeed railway. Based on the Xuzhou-Shanghai section of the Beijing-Shanghai highspeed railway, the model tests of the pile-net structure subgrade under static loading and dynamic loading were carried out. The characteristics of subgrade settlement, pile-soil stress ratio, and axial force distribution were investigated. The results showed that most of the settlement of the subgrade was caused by the deformation of the embankment under both static loading and dynamic loading. Piles carried much larger loads than the soils, especially within the loading area. Most of the pile axial force was caused by the negative frictional stress induced by the soil movement. Both the settlement and the axial force of the pile increased with increases in the loading cycles during a specific period.