scholarly journals Saturated Ground Vibration Analysis Based on a Three-Dimensional Coupled Train-Track-Soil Interaction Model

2019 ◽  
Vol 9 (23) ◽  
pp. 4991 ◽  
Author(s):  
Li ◽  
Su ◽  
Kaewunruen
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Interaction Model ◽  
Ground Vibration ◽  
Field Measurements ◽  
Soil Conditions ◽  
Layered Soils ◽  
Train Track ◽  
Dynamic Interactions ◽  
Vibration Responses

A novel three-dimensional (3D) coupled train-track-soil interaction model is developed based on the multi-body simulation (MBS) principle and finite element modeling (FEM) theory using LS-DYNA. The novel model is capable of determining the highspeed effects of trains on track and foundation. The soils in this model are treated as saturated media. The wheel-rail dynamic interactions under the track irregularity are developed based on the Hertz contact theory. This model was validated by comparing its numerical results with experimental results obtained from field measurements and a good agreement was established. The one-layered saturated soil model is firstly developed to investigate the vibration responses of pore water pressures, effective and total stresses, and displacements of soils under different train speeds and soil moduli. The multi-layered soils with and without piles are then developed to highlight the influences of multi-layered soils and piles on the ground vibration responses. The effects of water on the train-track dynamic interactions are also presented. The original insight from this study provides a new and better understanding into saturated ground vibration responses in high-speed railway systems using slab tracks in practice. This insight will help track engineers to inspect, maintain, and improve soil conditions effectively, resulting in a seamless railway operation.

NUMERICAL ANALYSIS OF VIBRATION EFFECTS OF METRO TRAINS ON SURROUNDING ENVIRONMENT

2007 ◽  
Vol 07 (01) ◽  
pp. 151-166 ◽  
Author(s):  
H. XIA ◽  
Y. M. CAO ◽  
N. ZHANG
Keyword(s):  
Three Dimensional ◽  
Interaction Model ◽  
Ground Vibration ◽  
Train Track ◽  
Ground Vibrations ◽  
Surrounding Environment ◽  
Element Approach ◽  
Specific Frequency ◽  
Propagation Properties ◽  
Dominant Frequencies

A finite element approach is extended to study the ground vibrations induced by metro trains and their propagation properties. Two dynamic interaction models are established: the two-dimensional train-track interaction model, which provides the excitation loads of moving trains onto the tunnel structure, and the three-dimensional track-tunnel-ground interaction model, by which the propagation properties of ground accelerations and velocities are analyzed. The results show that there exists a vibration amplifying area in certain distance away from the tunnel center, and the dominant frequencies of the ground vibration concentrate in a certain range. Buildings located in that area with their natural frequencies falling in the specific frequency range will be sensitive to the ground vibrations induced by metro trains.

High-speed train–track–bridge dynamic interactions – Part I: theoretical model and numerical simulation

2013 ◽  
Vol 1 (1-2) ◽  
pp. 3-24 ◽  
Author(s):  
Wanming Zhai ◽  
He Xia ◽  
Chengbiao Cai ◽  
Mangmang Gao ◽  
Xiaozhen Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
High Speed ◽  
High Speed Train ◽  
Train Track ◽  
Dynamic Interactions ◽  
Track Bridge

Computation of Rigid-Body Rotation in Three-Dimensional Space From Body-Fixed Linear Acceleration Measurements

1979 ◽  
Vol 46 (4) ◽  
pp. 925-930 ◽  
Author(s):  
N. K. Mital ◽  
A. I. King
Keyword(s):  
Rigid Body ◽  
High Speed ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Field Measurements ◽  
Moving Frame ◽  
Accelerometer Data ◽  
Hypothetical Data

The angular acceleration of a rigid body with respect to a body-fixed (moving) frame can be reliably computed from nine acceleration field measurements. Noncommutativity of finite rotations causes computational problems during numerical integration to obtain the transformation matrix, especially when the rotation is three-dimensional and there are errors in the measured linear accelerations. A method based on the orientation vector concept is formulated and tested against hypothetical data. The rigid-body rotations computed from linear accelerometer data from impact acceleration tests are compared against those obtained from three-dimensional analysis of high speed movie films.

Three-Dimensional Finite Element Simulations of Ground Vibration Generated by High-Speed Trains and Engineering Countermeasures

2005 ◽  
Vol 11 (12) ◽  
pp. 1437-1453 ◽  
Author(s):  
Judith C. Wang ◽  
Xiangwu Zeng ◽  
Robert L. Mullen
Keyword(s):  
Finite Element ◽  
Asphalt Concrete ◽  
High Speed ◽  
Three Dimensional ◽  
Ground Vibration ◽  
Finite Element Simulations ◽  
Modified Asphalt ◽  
Vibration Attenuation ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this paper we discuss the benefits of using rubber-modified asphalt concrete in high-speed railway foundations. We present the results from a series of three-dimensional finite element simulations modeling a high-speed train foundation utilizing various trackbed materials. Four trackbed materials were tested for their relative vibration attenuation capacities: ballast, concrete, conventional asphalt concrete, and rubber-modified asphalt concrete. Additionally, studies varying the speed and the weight of the passing train were performed. Parametric studies varying the dimensions of the trackbed underlayment were also examined. From these numerical simulations, it is shown that rubber-modified asphalt concrete outperforms other traditional paving materials in ground vibration attenuation. It is also shown that the speeds and weights of the passing trains and the dimensions of the trackbed have significant effects on the relative performance of the paving materials. Implications for design are discussed.

Dynamics of high-speed train in crosswinds based on an air-train-track interaction model

2015 ◽  
Vol 20 (2) ◽  
pp. 143-168 ◽  
Author(s):  
Wanming Zhai ◽  
Jizhong Yang ◽  
Zhen Li ◽  
Haiyan Han
Keyword(s):  
High Speed ◽  
Interaction Model ◽  
High Speed Train ◽  
Train Track

scholarly journals Sudden Variation Effect of Aerodynamic Loads and Safety Analysis of Running Trains When Entering Tunnel Under Crosswind

2020 ◽  
Vol 10 (4) ◽  
pp. 1445 ◽  
Author(s):  
Weichao Yang ◽  
E Deng ◽  
Zhihui Zhu ◽  
Mingfeng Lei ◽  
Chenghua Shi ◽  
...  
Keyword(s):  
High Speed ◽  
Coupling Effect ◽  
Reduction Rate ◽  
Interaction Model ◽  
Train Track ◽  
Wheel Load ◽  
Safety Risk ◽  
Aerodynamic Loads ◽  
Track System ◽  
High Speed Trains

Sudden variation of aerodynamic loads is a potential source of safety accidents of high-speed trains (HSTs). As a follow-up investigation on the aerodynamic response of a HST that enters a tunnel under crosswind environment, this paper focuses on the transient response of a HST’s safety indices based on the train–track coupling interaction model. Firstly, a wind–train–track coupling dynamic model is proposed by introducing transient aerodynamic loads into the vehicle–track system. Secondly, the temporal evolution of safety coefficients indicates that the train’s safety risk increases during tunnel entry with crosswind. Results show that the derailment coefficients and wheel load reduction rate during tunnel entry are not only larger than those in open air, but also those inside the tunnel are due to the sudden disappearance of wind excitation at the tunnel entrance. In addition, the characteristic wind curve, which is the wind velocity against the train speed, is presented for application based on the current specification of the safety criteria threshold. The investigation will be useful in assessing the safety risk of a running train subjected to other aerodynamic attacks, such as the coupling effect of an infrastructure scenario and crosswind in a windy area.

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