Experimental study and numerical simulation of the impact of under-sleeper pads on the dynamic and static mechanical behavior of heavy-haul railway ballast track  

作　　者：Yihao Chi Hong Xiao Yang Wang Zhihai Zhang Mahantesh M.Nadakatti 

机构地区：[1]School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China [2]Beijing Key Laboratory of Track Engineering,Beijing Jiaotong University,Beijing 100044,China [3]Department of Mechanical Engg,KLSGIT,Belgaum,Karnataka 590008,India

出　　处：《Railway Engineering Science》2024年第3期384-400,共17页铁道工程科学（英文版）

基　　金：the project supported by the National Natural Science Foundation of China(Grant No.52372425);the Fundamental Research Funds for the Central Universities(Science and technology leading talent team project)(Grant No.2022JBXT010).

摘　　要：Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system,numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method(DEM)-multi-flexible body dynamic(MFBD)coupling analysis method.The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models.The results show that using the USP results in a 43.01%reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers.It effectively reduces the load borne by the sleeper directly under the wheel load,with a 7.89%reduction in the pressure on the sleeper.Furthermore,the laying of the USP changes the lateral resistance sharing ratio of the ballast bed,significantly reducing the stress level of the ballast bed under train loads,with an average stress reduction of 42.19 kPa.It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50%to 70%,which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs.In summary,laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.

关 键 词：Heavy-haul railway Under-sleeper pad Discrete element method Multi-flexible body dynamic coupling analysis Mechanical behavior Quality state 

分 类 号：U213.21[交通运输工程—道路与铁道工程]