Mud pumping induced by moving train loads on rainwater-intruded roadbed causes intensive track vibra-tions and threatens safety of high-speed trains.In this paper,a vehicle-track-subgrade finite element model was estab-lished to analyze the dynamic responses of a ballastless track,and results showed that the concrete base and road-bed were detached because of the whipping effect arising from the rainwater intrusion channel.An in-situ soil core test showed that the intruded rainwater accumulated in road-bed to form standing water and saturated the roadbed.The flapping action of the concrete base caused by the whip-ping effect led to mud formation mixed with fine particles and rainwater,which migrated upward under the pore-water pressure(PWP)gradient.Mud pumping resulted from con-tinuous particle migration in the saturated roadbed under moving train loads:under normal roadbed condition,coarse and fine particles were uniformly distributed in the road-bed;in early period of mud pumping,fine particles migrated downward to bottom of the roadbed because of the rainwater infiltration flow;in middle stage of mud pumping,fine par-ticles migrated upward and gathered at the roadbed surface under PWP gradient;in later period of mud pumping,fine particles were entrained and removed with the dissipation of excess PWP.Moreover,a full-scale physical model was established to reproduce mud pumping,and polyurethane injection remediation against mud pumping was validated on this physical model.The remediation method was applied to an in-situ mud pumping.The deviation of the vertical track profile reduced remarkably and remained at a low level within half a year,showing a good long-term service perfor-mance of the polyurethane remediated roadbed.

Zhangbo Wan;Xuecheng Bian;Yunmin Chen

Key Laboratory of Soft Soils and Geoenvironmental Engineering,MOE,Department of Civil Engineering,Zhejiang University,Hangzhou 310058,People's Republic of China;Center for Hypergravity Experimental and Interdisciplinary Research,Zhejiang University,Hangzhou 310058,People's Republic of China

铁道工程科学（英文）

[1]Zhangbo Wan;Xuecheng Bian;Yunmin Chen-.Mud pumping in high-speed railway:in-situ soil core test and full-scale model testing)[J].铁道工程科学（英文）,2022(03):289-303

roadbed,ballastless,whipping,whip

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