Analysis of failures of guardrail base-plates in scissors crossovers of the Athens Metro: The role of foundation-structure interaction

Anastasopoulos, I; Gazetas, G

dc.contributor.author	Anastasopoulos, I	en
dc.contributor.author	Gazetas, G	en
dc.date.accessioned	2014-03-01T01:25:54Z
dc.date.available	2014-03-01T01:25:54Z
dc.date.issued	2007	en
dc.identifier.issn	1350-6307	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17811
dc.subject	Base-plate failure	en
dc.subject	Finite element analysis	en
dc.subject	Railway engineering	en
dc.subject	Scissors crossovers	en
dc.subject	Turnouts	en
dc.subject.classification	Engineering, Mechanical	en
dc.subject.classification	Materials Science, Characterization & Testing	en
dc.subject.other	Bending (deformation)	en
dc.subject.other	Cracks	en
dc.subject.other	Finite element method	en
dc.subject.other	Guard rails	en
dc.subject.other	Soil structure interactions	en
dc.subject.other	Stresses	en
dc.subject.other	Base-plates	en
dc.subject.other	Scissors crossovers	en
dc.subject.other	Sleeper bending	en
dc.subject.other	Failure analysis	en
dc.subject.other	Bending (deformation)	en
dc.subject.other	Cracks	en
dc.subject.other	Failure analysis	en
dc.subject.other	Finite element method	en
dc.subject.other	Guard rails	en
dc.subject.other	Soil structure interactions	en
dc.subject.other	Stresses	en
dc.title	Analysis of failures of guardrail base-plates in scissors crossovers of the Athens Metro: The role of foundation-structure interaction	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/j.engfailanal.2006.11.004	en
heal.identifier.secondary	http://dx.doi.org/10.1016/j.engfailanal.2006.11.004	en
heal.language	English	en
heal.publicationDate	2007	en
heal.abstract	Connecting parallel rail tracks, scissors crossovers typically consist of four turnouts and a central diamond crossing, while flange-way gaps provide wheel flange clearance at the points of rail intersection. Guardrails, supported through base-plates, provide wheel guidance in the area of the gap. In the Athens Metro, within less than a year in operation, fracturing of a vast number of guardrail support base-plates was reported. This paper documents the methodology and results of a comprehensive investigation of the possible causes of these failures. This premature cracking was initially investigated through stress and acceleration measurements. Subsequently, a three-dimensional finite element model was developed to analyse the dynamic behaviour of the system with and without foundation deficiencies. It was unveiled that only the model with foundation deficiencies could reproduce the measured response. The role of foundation-structure interaction (FSI) proved doubly detrimental for the performance of the system: (i) the initial defective curved shape of the sleepers induced large bending pre-stress on the base-plates, and (ii) the defective gap-dominated foundation increased the flexibility of the system leading to further excessive sleeper bending, and thereby to increased distress of the base-plates. The combination of the two deficiencies was deemed responsible for the observed failure. The method of installation was shown to be of critical importance for the durability of the crossover. © 2006 Elsevier Ltd. All rights reserved.	en
heal.publisher	PERGAMON-ELSEVIER SCIENCE LTD	en
heal.journalName	Engineering Failure Analysis	en
dc.identifier.doi	10.1016/j.engfailanal.2006.11.004	en
dc.identifier.isi	ISI:000244802500002	en
dc.identifier.volume	14	en
dc.identifier.issue	5	en
dc.identifier.spage	765	en
dc.identifier.epage	782	en