Time-domain identification of the elastic modulus of simply supported box girders under moving loads: Method and full-scale validation

Dynamic measurements under known moving loads yield a novel procedure for the elastic modulus assessment of existing concrete bridges. The bridge deck is modelled as a single-span, simply supported Euler–Bernoulli beam excited by a travelling force. The elastic modulus assessment derives from an Ordinary Least Square procedure with a Bayesian uncertainty estimation, obtained by approximating the known term of the governing equations due to the travelling force with a square wave signal. The authors validated the procedure on six full-scale concrete girders of the A24 motorway in Italy and compared the results to the values obtained via in situ static load tests and further tests on concrete specimens. The procedure represents a straightforward test devised for supporting the drafting of quality control plans and the prioritization of the interventions.