Page 358 - 360.revista de Alta Velocidad - Nº 5

Campos Zaldiernas, Javier. Díaz García, Sarai. Galán Alguacil, Álvaro. González Pérez, Javier.

1. Introduction

Culverts are essential elements of any railway infrastructure, however this kind of assets tend
to be ignored until a catastrophic failure occurs. Culvert failure may range from structural
collapse to insufficient capacity to pass floods and it might affect not only the infrastructure
itself but also it could cause serious problems on the railroad and its surroundings, such as
damage to the nearest properties, floods and major traffic disruptions.

Although the design of railway culverts is currently subject to national technical regulation:
(Ministerio de Fomento, 2015), (Ministerio de Fomento, 2014); maintenance management aspects
and evolution of service levels through time are not considered. Experience in other countries
(USA, Australia) shows that having up-to-date and detailed information about culvert conditions
is crucial when it comes to maintenance management (Federal Highway Administration, 2010)
and planning of preventive maintenance activities (Balkham et al., 2010). As many of these
structures reach the limit of their service life, management administrations must need to
schedule their replacement or repair (Najafi and Bhattachar, 2010), however, currently they
do not have and adequate prioritization methodology that help them planning this operations
though time, so these operations are often undertaken once the incidence in the service level
has occurred (corrective actions).

Figure 1. Traffic disruption events caused by culvert failure: overtopping flows and infrastructure collapse.

The aim of this work is so to develop an objective methodology based on risk assessment
techniques for railway and road culverts in order to build investments prioritization models for
those infrastructures. The methodology is based on the combination of probabilistic models
related to the different culvert failure mechanisms and the repercussion or consequences that
the failure event on the global level of service of the infrastructure. Finally, a global assessed
risk level derived from the general likelihood and consequence analysis is obtained (Roads and
Traffic Authority, 2010). Failure likelihood assessment is based on the analysis of failure modes,
or situations where the service levels in the infrastructure are totally cut off due to culvert
malfunction, including slope instability, local scour and platform overtopping flows events.
Likelihood analysis of failure mechanisms is based on overall material deterioration evolution
models (Salem et al., 2012), hydrologic and hydraulic characterization and preliminary analysis
of embankment stability and local scour in inlets and outlets (Galán et al., 2016). On the other
hand, consequence analysis is not only based on economic costs quantification (Perrin and
Jhaveri, 2003), but also in the repercussion assessment for whole society.

Since the main objective of this work is to globally apply the proposed methodology to the
railway transport network, being able to massively address the preliminary risk assessment of a
large set of assets is a key issue of the process. Some specific applications have been developed

356 360.revista de alta velocidad