Experimental Evaluation of Drive-by Health Monitoring on a Short-Span Bridge Using OMA Techniques

In bridge health monitoring, experts have sought to reduce costs associated with data acquisition systems through the development of an indirect Operational Modal Analysis (OMA) style approach formally known as drive-by health monitoring (DBHM). DBHM is theoretically more cost effective than direct health monitoring strategies, as it can ideally utilize a less dense array of sensors mounted on a single vehicle to capture modal data across a network of bridges. The methodology has received considerable attention the past few decades, with several studies verifying its system identification and damage detection capabilities. However, there exists a noticeable lack of full-scale studies demonstrating the feasibility of the methodology on bridges shorter than 18.28 m (60 ft). Additionally, no studies have been conducted to compare the system identification capabilities of different OMA techniques under the DBHM framework. To address these gaps in research, this study experimentally investigates the feasibility of employing OMA techniques in DBHM to identify the modal properties of a full-scale bridge with spans shorter than 18.28 m (60 ft). Multiple OMA techniques are compared to identify if there exists an approach that offers superior system identification capabilities for data collected from a passenger vehicle traveling at moderate velocities. The results from the experimental study demonstrate that OMA techniques can be leveraged to successfully identify short-span bridge frequencies in the dynamic response of a passenger vehicle even when time variant and nonlinear system properties are present.