Modélisation du comportement d'un remblai en sol renforcé sous chargement ferroviaire de type TGV

Abstract : This study focuses on the numerical modeling of the Mechanically Stabilized Earth (MSE) walls behavior under High Speed Train (HST) loading. First, the state of the art in reinforced earth as well as in railway dynamics modeling is analyzed. Then we present results coming from the testing of a one-scale reinforced embankment submitted to harmonic loading. They indicate that tensile forces in reinforcements, stresses and displacements depend on loading frequency which is related to train speed. One proposes a 3D Finite Element Model (FEM) in order to numerically reproduce this experimentation. The numerical results fit reasonably well with the experimental ones, highlighting the great importance of the choice of the constitutive law for the soil, reinforcement and facing. The same model is used to locally investigate the soil/reinforcement interface behaviour during a harmonic loading in steady-state. The confining pressure presents significant variations along the reinforcement strip during the dynamic loading while tensile forces are less affected by the load. Nevertheless, the global interface stability remains acceptable compared to a static load. A second numerical model is proposed, which represents a bigger embankment. The multiphase model is used to represent the reinforced soil and moving coordinates are used to take into account the moving train. Theoretical developments of this model and its implementation into CESAR-LCPC FEM code are detailed. The results indicate that the train speed does not play a big role in the overall response of the structure, in the case of a stiff reinforcement comparable to the experimental one. If the embankment is weaker, the HST speed may be close to shear waves speed within the soil, which has significant consequences into the structure, particularly on the stability of the soil/reinforcement interface. Globally the experimental results and those coming from both numerical models present the same trends: the dynamic effect coming from the train passing leads to the in-crease of displacements and confining pressure close to the highest strips, while tensile forces are less affected by the load. This leads us to the conclusion that the train speed does not have a significant effect on the stability of MSE walls, at least for embankments having similar parameters than the experimental one. However these results strongly depend on the embankment geometry, the way to model the train and the parameters and constitutive laws chosen for the soil, the soil/reinforcement interface and the facing
Document type :
Theses
Complete list of metadatas

https://pastel.archives-ouvertes.fr/tel-01286318
Contributor : Abes Star <>
Submitted on : Thursday, March 10, 2016 - 3:54:07 PM
Last modification on : Thursday, January 11, 2018 - 6:25:23 AM
Long-term archiving on : Monday, June 13, 2016 - 9:42:20 AM

File

TH2015PEST1104_complete.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01286318, version 1

Citation

Jean-Baptiste Payeur. Modélisation du comportement d'un remblai en sol renforcé sous chargement ferroviaire de type TGV. Matériaux. Université Paris-Est, 2015. Français. ⟨NNT : 2015PESC1104⟩. ⟨tel-01286318⟩

Share

Metrics

Record views

457

Files downloads

3386