Impact of earthquakes on California’s Railways: A comprehensive correlation analysis of magnitude and hypocenter depths with infrastructure accident

Abstract

The seismic events have been suggested as one of the major causes of railroad infrastructure and facility damages in several rail networks located in active tectonic regions, such as California in the US. To prove if there is any correlation between the railway infrastructure and earthquakes, this study aims to investigate their relationship using geospatial density and Spearman Correlation methods. As a result, this study found that the 15-year cumulative numbers of moderate-to-large (≥ M4) magnitude crustal earthquakes, occurring at depth ≤ 40 km, have a strong correlation with the cumulative number of infrastructure incidents. Although the small earthquakes (3≤ M < 4) do not seem to have a strong correlation with the overall accidents, these events appear to have moderate to strong correlation with the T3 (rail switch worn/broken/defected issues) and T4 (flangeway and overall structural defects) accidents. This suggests that even smaller earthquakes have a correlation with the railway infrastructure accidents, and these earthquakes can lead to the damage in the long term since they seem to have occurred shallowly and repeatedly around the same areas. Accordingly, our study provides the initial results that can further be used to examine and develop a more complex model to represent the relationship between the railway infrastructure accidents and seismicity, and possibly to predict the damage and associated causes in the future.