Expeditious measurements for frequency estimation on masonry arch bridges

Expeditious measurements for frequency estimation on masonry arch bridges

Phenomenological Aspects of Civil Engineering (PACE) - an International Congress
Volume 1 - Issue 1 - PACE-2021

Anelise Dick Rui Manuel de Menezes e Carneiro de Barros Manuel Teixeira Braz César


Masonry arch bridges are structures that have complex behavior, despite being essentially old structures, they are still functional and constitute an important amount of European bridges that require inspection and monitoring. The aim of the present study is to apply an expeditious approach of ambient vibration measurement to masonry arch bridges to define the first vertical frequency and the associated damping ratio, the main characteristic of the expeditious methods is the ease and speed of execution, thus providing technical information for preliminary inspections on the structure. The expeditious approach was applied to 28 masonry arch bridges which have distinct geometric characteristics, inserted in the road structure of the district of Bragança Portugal. The application of the Enhanced Frequency Domain Decomposition (EFDD) and Stochastic Subspace Identification (SSI) Techniques allowed the determination of vertical frequencies in the range of (5-25) Hz with an average value of 14Hz and damping ratio with an average value (2.5-3)%. Correlations were established between the vertical frequency and the geometric characteristics of the bridges, with the relation of the arch span and width f=14.735 (S⁄Sw)(-0.429) which provides the best relation to estimating the frequency for masonry arch bridges. The results obtained are congruent with previous studies that applied the full Operational Modal Analysis Method.


Masonry arch bridges; Frequency estimation; Eigenfrequency; Ambient vibration.