Mechanism and Control of Subgrade Mud Pumping Under the Cyclic Load of Train

Abstract

Abstract. Railway subgrade mud pumping is one of the most common defects. Unfavorable combination of soil, water, dynamic load is the main cause of subgrade mud pumping. Based on the source of water causing railway subgrade mud pumping, it can be divided into 5 major categories; on the basis of three stages forming mud pumping, the defect mechanisms are explored and the influencing factors are analyzed; identifying the defect categories is the premise of determining railway subgrade rehabilitation schemes, while geological radar detection is proved to be an effective mean appropriate for railway mud pumping detection; common mud pumping prevention measures are concluded, so as to provide references for the railway subgrade mud pumping defect controlling project.

Ground Penetrating Radar Signals, An Efficient Way to Estimate Fouled Ballast

“…In addition to the recurrent train loads, the pressure from the soil and porewater also affects the subgrade's strength and stability. There is evidence of mud pumping of both the ballast-bed type and the subgrade kind, as claimed by (Yang (2002), Yi (2013), and Wang et al (2014). During the process of ballast-bed mud pumping, mud gathers inside the ballast bed and rises through the spaces in the ballast due to external fine-grained soil penetration or ballast abrasion.…”