A Stochastic View on the Effect of Random Rail Irregularities on Railway Bridge Vibrations

Abstract

This contribution studies dynamic amplification factors that consider the impact of random rail irregularities on the deflection and acceleration response of simple railway bridges. Response statistics for a set of plane fully coupled bridge-vehicle interaction models with random irregularity profiles are derived by Monte Carlo simulations. The underlying samples of random irregularity profiles are generated from a power spectral density function, assuming that the uneven rail surface is governed by a Gaussian stochastic process in space. A modified bootstrap method is used to identify the required sample size of profiles for sufficiently accurate description of the random response. On the basis of this pilot study, a parametric response examination of short span railway bridges with variable length, fundamental frequency, structural mass and damping, and track quality in a range commonly observed in real structures is conducted. A statistical representation of the uncertain bridge response is employed for analytical modelling of the response amplification due to random rail irregularities considering limit state-based exceedance probabilities. The results are compared to outcomes of existing simplified approaches in design codes used to take into account the effect of rail irregularities on the dynamic bridge response, showing the improvement of the developed framework.

MDOF extension of the Modified Bridge System method for vehicle–bridge interaction

“…5b). The results confirm that the effect of irregularities is more evident on the acceleration rather than the displacement of the bridge, which is in agreement with the study of Salcher et al [27]. Figure 5c also shows the maximum permitted bridge deck acceleration according to Eurocode [14] and the Chinese Code for Design of High-Speed Railway [15], which, in both cases, is a max = 3.5 m/s 2 .…”

“…Furthermore, Eurocode suggests an amplification factor ϕ to estimate the increase in the vibration of a bridge due to the irregularities in the rails [14]. However, in many cases, ϕ underestimates the effect of rail irregularities on the bridge response, and especially acceleration [21,27].…”

A Novel Solution to Find the Dynamic Response of an Euler–Bernoulli Beam Fitted with Intraspan TMDs under Poisson Type Loading

“…This is accomplished by using the complex modal superposition principle, as defined by [10], where the complex modal impulse response function is used. This leads to [2].…”

“…Of course, railway networks are regularly maintained to avoid the most serious cases, but the elimination of all forms of imperfection is, for all intents and purposes, impossible. As such, these cases of small imperfections provide a significant source of excitation [2].…”

Optimization of Multiple Tuned Mass Dampers for Road Bridges Taking into Account Bridge‐Vehicle Interaction, Random Pavement Roughness, and Uncertainties

“…Initially, the bridge-vehicle interaction problem was considered only in railway bridges, in which Willis [3] was a pioneer in this area, and only years later, this problem was also studied in road bridges. Especially in the last 20-30 years, a growing number of studies on bridge-vehicle interaction, both on railway bridges (e.g., Frýba [4]; Delgado and Santos [5]; Xia et al [6]; Zambrano et al [7]; Salcher et al [8]; Gou et al [9]) as well as on road bridges (e.g., Da Silva [10]; Law and Zho [11]; OBrien et al [12]; Caprani et al [13]; Zhong et al [14]; Ma et al [15]; Pagnoncelli and Miguel [16]; Fisli et al [17]), have been conducted. An interesting book is due to Obrien et al [18].…”