Integrated Structural Assessment and Rehabilitation of Six Urban Viaducts with Minimum Traffic Disruption

A Case Study from Belo Horizonte, Brazil with Applications to Aging Urban Infrastructure in the United States

Abstract

This paper presents the integrated structural assessment, risk-based prioritization, and rehabilitation of six urban viaducts located on Avenida Dom Pedro I in Belo Horizonte, Brazil, one of the highest-traffic arterials in a metropolitan area of approximately 6 million inhabitants. The project was commissioned by the Municipal Government of Belo Horizonte under Contract DJ 125/2022 (total contract value: BRL 17,402,235.09, base value plus approved amendments) and executed from the issuance of the Ordem de Serviço on December 15, 2022, extending through 2023–2024 under approved contractual amendments to scope and schedule, under the technical responsibility of the author. The six structures presented distinct and critical pathologies of varying complexity, requiring a differentiated set of structural interventions: controlled viaduct lifting (a minimum of five hydraulic jacks, per project execution drawings, elevation of 12 cm over 5 days) for installation of new bearing devices; internal prestressing of box girder sections executed through access manholes of only 60 × 60 cm; pressed-pile foundation reinforcement (presso-ancoragem) pre-loaded at 70 tf; and carbon fiber reinforced polymer (CFRP) application, both sheet and laminate systems. All six interventions were executed while maintaining traffic flow on the arterial through a planned overlapping construction sequencing strategy, with the sole exception of a five-day planned full closure required for the most complex structure. All structural analyses were performed using CSi Bridge v21.2.0 finite element software under Brazilian standards NBR 6118:2014, NBR 6122:2019, NBR 7187:2003, and NBR 7188:2013, built on broadly comparable structural safety principles to AASHTO LRFD specifications, though requiring project-specific regulatory adaptation for direct application. The paper presents the decision-making methodology as a structured four-phase framework, Assessment, Prioritization, Rehabilitation, and Institutional Documentation (APRI), and discusses its potential adaptation and applicability to the American infrastructure context, where the Federal Highway Administration's 2025 National Bridge Inventory analysis identifies 41,685 bridges in poor condition nationwide, and where the Infrastructure Investment and Jobs Act of 2021 has allocated USD 40 billion for bridge rehabilitation.

Keywords: bridge rehabilitation; urban viaducts; carbon fiber reinforced polymer (CFRP); pressed-pile foundation; viaduct lifting; internal prestressing; traffic management; structural assessment; infrastructure prioritization; APRI Framework.