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SEM-FEM Co-Simulation via Substructure Coordination for Train-Track-Tunnel-Soil System Dynamics

Liu Pan, Lei Xu^*, Bin Yan

School of Civil engineering, Central South University, Changsha, 4100075, China

* Corresponding Author: Lei Xu. Email:

The International Conference on Computational & Experimental Engineering and Sciences 2025, 33(3), 1-1. https://doi.org/10.32604/icces.2025.012221

Abstract

To address the issue of computational inefficiency arising from the large dimensionality of dynamic matrices in the train-track-tunnel-soil (TTTS) dynamic model, this study integrates the spectral element method (SEM) and finite element method (FEM) to develop a highly efficient dynamic model for the TTTS system. The model leverages the distinct vibration characteristics of the near- and far- field regions of TTTS system, employing different modelling approaches: the FEM, known for its superior shape adaptability and precise high-frequency dynamic response computation, is applied to the tunnel and near-field soil; the SEM, recognized for its rapid convergence and suitability for low-frequency dynamic response, is utilized for the far-field soil. Additionally, this paper introduces a substructure coordination technique combining the FEM and SEM, based on the elimination method. This technique establishes the near-field-far-field soil interaction matrices through the principle of displacement field equivalence at the boundaries of the near-field and far-field, thereby maximizing the advantages of both methods. Subsequently, using the aforementioned model, the dynamic response of the tunnel-soil system induced by train is analyzed. The result indicated that the maximum ground vibration does not occur directly above the tunnel but rather at a distance of 10-30 meters from the track central line. Furthermore, as the tunnel depth increases, the ground vibration becomes more uniform, with a reduction in peak vibration, particularly affecting the surface vibration within 0-15 meters from the track central line.

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Keywords

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