Strategies for load rating of infrastructure populations: a case study on T-beam bridges

Abstract

There is consensus on the importance of objectively and reliably assessing the condition and load capacity of aged bridges. Although each bridge may be considered as a unique structure, the behavior of many bridge types may be governed by only a few mechanisms and related parameters, especially if a population is constructed from standard designs. By identifying these parameters, and their variation within the population, it is possible to extend findings such as load rating obtained from a statistical sample to the entire population. Bridge type-specific strategies for load rating and condition assessment in conjunction with statistical sampling may therefore offer significant advantages for inspecting and load rating bridges sharing common materials, similar geometry and detailing, and the same critical behavior mechanisms. In this paper, the writers present their recent work on load rating of the reinforced concrete T-beam bridge population in Pennsylvania to objectively re-qualify them based on field-calibrated finite element models.

Monitoring structural responses during proof load testing of reinforced concrete bridges: A review

“…For example, diagnostic load tests have been used to determine the transverse flexural distribution by measuring the strains over the width of the bridge and the deflections. Examples have been reported in the USA (Saraf, 1998, Arockiasamy and Amer, 1998, Velázquez et al, 2000, Catbas et al, 2005, Jones, 2011, Sanayei et al, 2016, Diaz Arancibia and Okumus, 2018 and Australia (Al-Mahaidi et al, 2000). The strain measurements were obtained using strain gauges, clip gauges, wire vibrating strain gauges, and LVDTs.…”

Methodology for Diagnostic Load Testing

“…When the diagnostic test will be used to update the analytical model after the test to improve the rating of the bridge, the analytical model should be available prior to the testeither from previous rating calculations or as part of the preparation stage (Catbas et al 2004, Jauregui et al 2010, Hodson et al 2013). If material deterioration or damage is observed during the inspection stage, these conditions need to be taken into account in the analytical model.…”

State-of-the-art on load testing of concrete bridges

“…When comparing the transverse flexural distribution from the AASHTO LRFD code [9] to field measurements of the flexural distribution from diagnostic load tests, differences of over 500% in the resulting rating factor are found [10,11]. The use of diagnostic load tests for the determination of the transverse flexural distribution has been reported in Florida [12,13], Delaware [14] and Ohio [15] on concrete slab bridges, in Australia [16] on girder bridges, in Texas on reinforced concrete pan girder bridges [17], in Pennsylvania on concrete T-beam bridges [18], and in Poland on prestressed concrete bridges [19].…”