Time-evolution laws, Reliability, Knowledge updating, Degradation models, Action
models, Post-tensioned concrete bridges

Italian transport infrastructures are characterized by road networks that show important critical issues. Many bridges dates back to the post-World War II and often their standards are far away from those required by current design codes. In addition, traffic loads increased more and more, and traffic limitations are often implemented as temporary safety measures, while maintenance operations are limited, so the degradation processes can detrimentally evolve resulting in a reduction of the performances of structural components. Such a consequence can be particularly relevant for concrete bridges with post-tensioned deck, where the cables are not directly visible, therefore their state of conservation is not easily assessed with visual inspections only. All these aspects lead to serious problems for the transportation system, as recently reminded by several bridge collapses.

Assuming existing bridges as key components of road networks, the proposal aims at studying the time evolution of their reliability by developing a comprehensive probabilistic framework including: (a) uncertainties in the system knowledge, (b) evolution of progressive degradation, (c) evolution of service actions and conditions. Research focuses on concrete bridges with post-tensioned deck.

In previous studies, reliability assessment has been mainly studied as a “static” problem, and the “time dimension” has been usually neglected or included as an independent parameter (e.g. repeated analyses), without considering the interaction of different causes of evolution and without fully exploiting the uncertainty reduction due to monitoring and testing programs. The proposal aims at providing a prediction model to support the managing system, ensure an adequate reliability level during the lifetime and optimize the maintenance/restoration planning.

The problem is approached by a framework with original contents, where the evolution over time of the system is described as a Markov process involving two transition operators, the former related to the evolution of the basic variables, and the latter related to model updating and knowledge evolution. This way it is possible to evaluate how such different aspects reduce the variability of parameters and consequently influence the prediction of the residual life.

Knowledge advancements are expected about: methods for time-dependent reliability assessment of bridges with post-tensioned deck, evolution models for traffic actions and prestressing system effectiveness, procedures and confidence levels of testing of prestressing systems, Bayesian model updating and machine learning techniques in prestressing action modelling.

Periodo
01/12/2023 — 28/02/2026

Durata
24+3 mesi (proroga)

Responsabile scientifico
Andrea Dall'Asta

Tipologia di bando competitivo
PRIN 2022b

Gruppo di ricerca
Laura Gioiella, Fabio Micozzi, Michele Morici, Alberto Poeta, Fabrizio Scozzese, Alessandro Zona

Partner

• Università di Pisa
• Università di Perugia

Budget complessivo
€ 299.983

Finanziamento ad Unicam
€ 109.774

Altri progetti o proposte correlate a questa ricerca

• SAFOTEB (Bando Fabre concluso)
• HERO (Bando Fabre in valutazione)