Finite element-discrete element coupling evaluation method for surface erosion of high-speed rail ballastless track bed

Abstract

The invention provides a finite element-discrete element coupling evaluation method for surface erosion of a ballastless track subgrade bed of a high-speed railway. The method includes: obtaining the initial hydraulic gradient of the dynamic finite element model of the vehicle-ballastless track-saturated roadbed system; calculating the n-1st step Porosity and deformation of the discrete element model of the subgrade surface; adjust the contact parameters and permeability coefficient of the base plate and the subgrade surface of the dynamic finite element model of the vehicle-ballastless track-saturated subgrade system, and calculate the hydraulic gradient of the nth step; YADE software calculation n+1 porosity and the deformation of the discrete element model of the subgrade surface; according to the macro response parameters of the finite element model, such as track subgrade, it is judged whether the porosity change exceeds the threshold and the dynamic process of fine particle loss on the subgrade surface is obtained. The invention accurately reflects the contact condition between the base plate and the surface layer of the foundation bed, obtains the mesoscopic process of the mud-blowing and mud-flowing disease of the foundation bed, and couples and evaluates the macroscopic and mesoscopic, which is helpful for early warning of high-speed rail operation and guarantees driving safety.

Description

technical field [0001] The invention relates to the technical field of computer-aided design of railway engineering, in particular to a finite element-discrete element coupling evaluation method for surface erosion of a ballastless track bed of a high-speed railway. Background technique [0002] The operation practice of my country's high-speed railway for many years shows that due to the lack of attention to the stability of the surface water of the subgrade bed in the early stage and the imperfect drainage design of the subgrade, the subgrade bed is in a stress field under the repeated action of long-term rainfall, climate and high-frequency impact dynamic loads of trains. Due to the coupling effect with the water seepage field, and the graded crushed stone filler is a granular material with uneven particle size, the ballastless track subgrade has inevitably suffered from subgrade bed swelling. Although the mud and mud flow on the surface of the foundation bed does not affe...

AI Technical Summary

Problems solved by technology

However, for the dynamic development of fine particle migration in railway engineering, it is difficult to accurately track and quantify the fine particle migration process by experiments and finite element methods, which hinders the progress of the mesoscopic research on the mud-ejecting disease of the subgrade bed.

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