Idealisations of Dynamic Modelling for Railway Ballast in Flood Conditions

Abstract

As the main component of a ballasted railway system, railway ballast is frequently used by the railway industry to enhance constructability and practicality. Numerous studies into train–track interactions focused on ballast modelling and idealisation in completely dry environments, but recent studies have found that, in extreme weather such as floods, water can clog natural ballast beds and change the initial state of their properties. Ballast models used in multi-body simulations have been mostly developed based on the instrumented impact hammering method considering the ballast as a spring/dashpot. The single degree of freedom (SDOF) idealization for ballast enables a non-destructive field testing technique for monitoring of railway components in practice. In this study, the suitability of the idealization of ballast for dynamic characteristics has been evaluated. A series of experiments have been performed with a variety of ballast conditions in flooding levels from 0 to 40 cm, with a frequency range of 0–500 Hz. The results clearly show that the increase in the flood level will result in increasing dynamic damping of more than 50% of dry natural ballast whilst reducing its stiffness and natural frequency. The novel insights are of great significance for exploring the non-linear dynamic traits of ballast in extreme environments, which can be integrated into the coupled train–track analysis that can better express more realistically the dynamic train–track interaction and load transfer mechanism of flooded railway tracks.

Influences of Flood Conditions on Dynamic Characteristics of Novel 3D-Printed Porous Bridge Bearings

“…On the other hand, dynamic modal parameters of a flood porous bridge bearing condition have never been examined before. According to a review in [ 27 ], rubber pads in a railway system can considerably face the climate, for example, long-term flooding. Thus, it is required to identify modal paraments of 3D-printed porous bridge bearings (3DPPBBs) subjected to flooding conditions.…”

“…It is necessary to understand their behaviour affected by floods, which has never been investigated. The effect of floods on railway structure could result in the change of dynamic material properties [ 27 ]. To investigate the vibration behaviour of porous bridge bearings under flood conditions, modal testing and analysis, a suitable tool used to obtain the dynamic parameters of a structure under flood conditions is considered in this paper [ 28 , 29 ].…”

Special Issue “Extreme Sciences and Engineering”

“…Kaewunruen and Tang [3] discovered new findings for railway ballasts in extreme weather conditions. The railway ballast is frequently used by the railway industry to enhance constructability and practicality.…”

Enhancing Railway Engineering Student Engagement Using Interactive Technology Embedded with Infotainment

“…The learning sequence in the railway engineering module can be designed as illustrated in Figure 2 [60][61][62][63]. As a result of a successful class in 2016, the development of learning resources to integrate interactive technology and infotainment was to foster individual responses and The analysis shows the flow of teaching tactics and pedagogies to enhance active learning and student learning outcome [59].…”