Field Observations on Mud Pumping of Ballastless Track in High-Speed Railway

Abstract

Mud pumping is a relatively common subgrade distress in ballasted and ballastless track in high-speed railway (including passengers and freight transportation). Based on the preliminary literature research, it can be found that most of these researches focus on the fouled ballast, interlayer creation and mud pumping in ballasted track; however, little research paid attention to the mud pumping in ballastless track. Therefore, field observations were conducted to investigate the inducing factors of mud pumping in ballastless track. It is observed that the average water content of track roadbed layer is relatively high, and fine particles content are close to and sometimes can even surpass the upper limit of track roadbed specification of ballastless track. The upper limit specification just considered the compaction of track roadbed, but not considered whether this kind of limit specification can lead to mud pumping; therefore, a reconsideration is needed to be taken to the upper limit of track roadbed specification of ballastless track.