Mud Pumping in Ballastless Slab Track of High-Speed Railway and Its Remediation

Mud pumping in high-speed railway: in-situ soil core test and full-scale model testing

“…In recent years, the global warming has been increasing precipitation, and the occurrence of extreme weather presents an increasing trend. In the latest 10 years, the extreme precipitation in China has exceeded the annual precipitation, which primarily concentrates in the southeastern coastal areas of China, where the HSR lines are densely constructed [2,3]. Under the combined effect of moving train loads and the natural environment factors (such as the extreme precipitation), fine particles in roadbed are fluidized and begin to Abstract Mud pumping induced by moving train loads on rainwater-intruded roadbed causes intensive track vibrations and threatens safety of high-speed trains.…”

“…For ballasted track, mud pumping causes hardening of the ballast layer and uneven settlement of subgrade [12][13][14]. For ballastless track, mud pumping results in void areas under the concrete base, intensive track vibrations and track dislocations [4,[15][16][17][18], thereby threatening the safety of train operations in serious conditions [3,[18][19][20][21][22].…”

“…During the loading and unloading of the cyclic train loads, the volume of the void area created between sleeper and trackbed changes sharply, which results in suction in the void area and causes fine particles to migrate upward to the surface of ballast layer, thereby forming mud pumping [13,34]. For ballastless track, the existing studies have shown that mud pumping is the phenomenon of fine particle migration driven by excess pore-water pressure (PWP) generated by moving train loads on saturated roadbed [3,4,15,16,18,20,25,26,[37][38][39][40]. However, the channel of rainwater intruding into the roadbed, the distribution conditions of the intrusion rainwater, and the migration mechanism of fine particles all remain unclear.…”