The vulnerability assessment of bridges has proven to be a challenging task: as of yet, there is no universal approach for carrying out the assessment; besides, in spite of recent technological advances, it still greatly relies on visual inspections, hence with a certain degree of subjectivity, and the assessment outcome may be affected by some factors that are not obvious, such as full accessibility of the bridge and presence of latent defects. This paper compares the structural vulnerability assessment of existing highway bridges included in two national guidance documents, namely the well-established UK Design Manual for Roads and Bridges and the recent Italian Ministry of Infrastructure and Transport’s Guidelines. Both documents present risk-based methods for assessing the structural vulnerability of bridges, while exhibiting fundamentally different approaches. For instance, the Italian assessment defines a vulnerability class, to be combined with hazard and exposure classes in order to determine a structural risk rating; then, the overall rating affects the actions that need to be taken, e.g. subsequent inspections, structural assessment or monitoring. On the other hand, the UK guidance uses a risk scoring system, which also includes some parameters not strictly related to vulnerability, in order to determine whether the interval between principal inspections may be increased from the minimum requirement of 6 years; some input data for such risk scoring are also used to determine whether a structural assessment is required. Finally, both vulnerability assessments are applied to two sample bridges, highlighting similarities and differences between the two guidelines. The presented comparison may allow for a better understanding of the factors governing the assessment outcome, for potential improvement of guidelines, and ultimately for more effective intervention prioritisation.
A comparison of Italian and UK guidelines on the vulnerability assessment of bridges
Lipari A.;Clemente P.
2024-01-01
Abstract
The vulnerability assessment of bridges has proven to be a challenging task: as of yet, there is no universal approach for carrying out the assessment; besides, in spite of recent technological advances, it still greatly relies on visual inspections, hence with a certain degree of subjectivity, and the assessment outcome may be affected by some factors that are not obvious, such as full accessibility of the bridge and presence of latent defects. This paper compares the structural vulnerability assessment of existing highway bridges included in two national guidance documents, namely the well-established UK Design Manual for Roads and Bridges and the recent Italian Ministry of Infrastructure and Transport’s Guidelines. Both documents present risk-based methods for assessing the structural vulnerability of bridges, while exhibiting fundamentally different approaches. For instance, the Italian assessment defines a vulnerability class, to be combined with hazard and exposure classes in order to determine a structural risk rating; then, the overall rating affects the actions that need to be taken, e.g. subsequent inspections, structural assessment or monitoring. On the other hand, the UK guidance uses a risk scoring system, which also includes some parameters not strictly related to vulnerability, in order to determine whether the interval between principal inspections may be increased from the minimum requirement of 6 years; some input data for such risk scoring are also used to determine whether a structural assessment is required. Finally, both vulnerability assessments are applied to two sample bridges, highlighting similarities and differences between the two guidelines. The presented comparison may allow for a better understanding of the factors governing the assessment outcome, for potential improvement of guidelines, and ultimately for more effective intervention prioritisation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
