A Methodology Based on Structural Finite Element Method-Boundary Element Method and Acoustic Boundary Element Method Models in 2.5D for the Prediction of Reradiated Noise in Railway-Induced Ground-Borne Vibration Problems

Abstract

This work is focused on the analysis of noise and vibration generated in underground railway tunnels due to train traffic. Specifically, an analysis of noise and vibration generated by train passage in an underground simple tunnel in a homogeneous full-space is presented. In this methodology, a two-and-a-half-dimensional coupled finite element and boundary element method (2.5D FEM-BEM) is used to model soil–structure interaction problems. The noise analysis inside the tunnel is performed using a 2.5D acoustic BEM considering a weak coupling. The method of fundamental solutions (MFS) is used to validate the acoustic BEM methodology. The influence of fastener stiffness on vibration and noise characteristic inside a simple tunnel is investigated.

The effect of tunnel construction on future underground railway vibrations

“…If the problem cross-section is assumed invariant, the so-called 2.5D technique is used in order to obtain the 3D response of the problem in an efficient manner [8]. This concept has been explored using the finite element method (FEM) [9][10][11], the boundary element method [12][13][14], and the Method of Fundamental Solutions (MFS) [15]. If the problem requires the simulation of complex geometries, FEM is typically the preferred method.…”

“…However, it requires coupling with an absorbing condition to prevent spurious reflections contaminating the solution. This can be done by coupling with an alternative modelling approach [13][14][15][16][17] such as the boundary element method. Alternatively, rather than use multiple different approaches, an absorbing boundary condition can be used purely within the FE approach.…”

Hybrid approach for the assessment of vibrations and re-radiated noise in buildings due to railway traffic: Concept and preliminary validation

“…Since the computation of matrix Hbf requires a model able to simulate not only the ground but also the building structure, it is interesting to combine different numerical methods in order to achieve accuracy and versatility [5,15,16]., or, alternatively, to use FEM-PML approach [4].…”

“…On the other hand, analytical models are usually devoted for the prediction of vibrations in free-field and their application is limited for simple geometries [3]. Therefore, numerical approaches can be faced as the method of choice when versatility is a requirement, allowing the inclusion of whole system, from the source to the building, including re-radiated noise prediction [4,5] In the scope of numerical approach, Fiala et al [6] used a decoupled approach to assess the vibration response of the building. This approach considers a weak coupling between the tunnel/soil and the building/soil systems.…”

“…Thus, this method considers a weak coupling between the railway infrastructure and the building structure. Model is also extended to the prediction of re-radiated noise, following the approach proposed by Colaço et al [4,13] and more recently by Ghangale et al [5].…”