Railway critical speed assessment: A simple experimental-analytical approach

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Pedro Alves Costa (Author) FEUP; Aires Colaço (Author) FEUP; Paulo Soares (Author) Other; David Connolly (Author) Other; Patrícia Lopes (Author) Other

Journal

Title: Soil Dynamics and Earthquake Engineering

Vol. 134 No. 106156

Pages: 1-10

ISSN: 0267-7261

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 2 Citations

ScienceDirect (Elsevier)

Other information

Authenticus ID: P-00R-Z62

DOI: 10.1016/j.soildyn.2020.106156

Abstract (EN): When constructing a new railway line, its long length means there are significant financial implications associated with determining the geodynamic ground properties. Therefore, this paper presents recommendations to optimize the efficiency and depth of such a geotechnical site investigation. Firstly, a numerical analysis is performed to investigate the effect of soil layering, soil stiffness and track bending stiffness on critical velocity. It is shown that each of these variables play an important role, however for most practical cases, only the top 8 m of soil is influential. Track dynamics are rarely affected by soil properties at depths below this, meaning this is the maximum required depth of soil investigation. Using this knowledge, a hybrid experimental-analytical methodology is presented, based on a geophysical Spectral Analysis of Surface Waves (SASW) experimental setup to compute the ground dispersion curve and an analytical model to compute the track dispersion curve. The experimental and analytical results are combined directly, to accurately compute the critical velocity. This approach is attractive because: 1) SASW tests are typically accurate to approximate to 8 m (when using a mobile exciter) thus matching the required depth needed for critical velocity computation, 2) soil property uncertainties are inherently accounted for, 3) the uncertainties associated with SASW inversion are avoided. The approach is attractive when constructing new railway lines and upgrading the speed of existing lines because it can potentially yield site investigation cost savings. In-situ field work is performed to show the practical application of the technique.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10