ABSTRACT
Extracting the bridge dynamic properties from a moving vehicle is a promising solution to the ever-increasing demand for monitoring of bridges. A traversing vehicle excites the bridge, while the vibrating bridge affects the response of the vehicle. By processing the “monitored” vehicle response, the dynamic characteristics of the bridge can be efficiently extracted. In this paper, the stochastic subspace identification (SSI) method is applied to the vehicle response to estimate the frequencies of the bridge. Specifically, the present study assesses the accuracy and the effectiveness of the SSI method that is used to identify the frequencies of a straight reinforced concrete bridge, from the response of a passing vehicle. As a proof of concept, the response of the vehicle is first estimated from a vehicle-bridge interaction dynamic analysis. The bridge frequencies are then identified with the proposed SSI method assuming the dynamic characteristics of the vehicle and its motion are known. The results of the identification are validated against the theoretically correct values from the numerical analysis, and conclusions regarding the feasibility of the method are drawn.
