Instrumentation and computational modeling for evaluation of bridges substructures across waterways.

PDFTech ReportFHWA/MS-DOT-RD-13-229MS-DOT-RD-13-229Bridge substructuresSensorsInstrumentationField testsWireless communication systemsScourStatistical analysisComputer modelsTime domain reflectometersMississippiMississippi. Dept. of TransportationZheng, WeiJackson State University. Dept. of Civil & Environmental EngineeringUnited States. Federal Highway AdministrationUS Transportation CollectionThis State Study 229 was proposed as the Phase I study for implementing sensing technologies and computational analysis to assess bridge conditions and support decision-making for bridge maintenance in Mississippi. The objectives of the study are to: (1) prioritize the major detrimental bridge substructure deterioration in Mississippi waterway and their measurable parameters; (2) identify instrumentation technology for wirelessly in-situ monitoring of these parameters; (3) develop computational framework that can correlate the identified bridge substructure deterioration with the structure performance; (4) integrate research findings into education and professional preparation for students and professionals; and (5) prepare the field implementation for the next phase study and identify further needed research in above areas. This final report synthesizes the available findings from existing research and presents the major outcomes obtained from this State Study, which are summarized as follows. The bridge scour is determined as the major detrimental deterioration for bridges in Mississippi waterway by the project Technical Advisory Committee (TAC) members of Mississippi Department of Transportation (MDOT) and the project team. The fixed monitoring sensor for detecting scour at the bridge substructure has been identified as suitable means to ensure the bridge safety against scour. Literature reviews along with technical seminars on various scour monitoring devices, including Sonar, Magnetic sliding collars, Float-out devices, Tilt-sensor, and Time Domain Reflectometer (TDR), have been conducted and delivered to the inspectors and engineers at the MDOT Bridge Division. The TDR scour-monitoring sensor with wireless data transmission system was selected and evaluated for the field implementation of scour monitoring in the next phase study. A bridge in service has been chosen for implementing the field test of the selected scour monitoring system for the phase II study. The field installation plan and design was completed for the implementation of the selected sensor for the next phase II project. The computational model of the scoured bridge and probabilistic inference are proposed and examined for assessing the bridge performance and its associated uncertainties for given scour conditions based on dynamic measurements. The method for predicting the reliability of the performance scoured bridge based on quantified uncertainties associated with the bridge damage models and scour damage is presented. The acceptable performance reliability or predicted probability of failure of scoured bridge has been identified. The application and effectiveness of proposed assessment approach are illustrated and examined through a numerical simulation of a selected prototype bridge. The future research needs for field verification of the selected scour monitoring system and the proposed computational framework are discussed