Soil non-linearity on high speed railway lines

• Type: Article in International Conference Proceedings Book
• Date: 2019

Authors

Pedro Alves Costa (Author) FEUP; Kaitai Dong (Author) Other; David Connolly (Author) Other; P. K. Woodward (Author) Other; O. Laghrouche (Author) Other

Conference proceedings International

Title: 7th ECCOMAS International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2019)

Pages: 5535-5542

Indexing

Scopus

Other information

DOI: 10.7712/120119.7325.18466

Abstract (EN): Increases in operational train speed have resulted in an elevated probability that dynamic effects will occur inside the railway track and subgrade structure. This is problematic because it causes soil non-linearity, thus resulting in reduced soil stiffness. Therefore, this paper outlines a numerical semi-analytical frequency domain model to compute and analyse non-linear stiffness degradation below railway lines. An equivalent linear approach is used to incorporate non-linear stiffness and damping changes into a thin-layer element frequency-wavenumber domain formulation. The model is validated using published data and then used to analyse nonlinearity. It is shown that non-linearity plays an important role in track-ground response, with track displacements increasing significantly in magnitude. It is also shown that the critical velocity can be reduced significantly, which is important because many high speed lines set their dynamic threshold at 70% of the linearly calculated value. Similar findings are made for track velocities and soil strain levels, thus indicating it is vital to consider soil non-linearity when modelling high speed rail track behaviour.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8