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Sensor-assisted Condition Evaluation of Steel and Prestressed Concrete Girder Bridges Subjected to Fire – Phase III

项目名称：	Sensor-assisted Condition Evaluation of Steel and Prestressed Concrete Girder Bridges Subjected to Fire – Phase III
摘要：	The overarching goal of this multi-phase study is to develop and validate a post-fire condition evaluation method for steel- and prestressed concrete-girder bridges (overpasses or viaducts) based on material and structural data, a fire scenario (e.g., a fuel tank on highway), and environmental factors (e.g., moisture and wind). The proposed method involves fire dynamics simulation underneath a bridge, thermomechanical analysis of the structure, and structural condition assessment against material strengths. One of the key challenges to achieve this goal is to measure strains in steel members on fire and detect concrete cracks in order to validate various computational models. Phases I and II of this study aimed to understand and validate the performance of distributed fiber optic sensors based on Brilliouin optical time domain analysis (BOTDA) for temperature and strain measurements in reinforced concrete (RC) bridges, and develop and validate a fire dynamics simulator and a thermomechanical model with measured data. In particular, the deployment scheme and data quality of distributed sensors embedded in concrete and attached on steel members are evaluated. The effects of multiple steel girders on the aerodynamics and heat distribution of a fire are investigated through fire dynamics and thermomechanical analysis. Phase III of this study aims to understand the performance and behavior of prestressed concrete girders under a fire and quantify the prestress loss over time using distributed fiber optic sensors such as BOTDA. Due to uncertain bonding between an optical fiber and concrete, strain measurements based on the transfer of strain from concrete to the optical fiber are less reliable particularly to determine the loss of prestress in tendon. Therefore, a new distributed fiber optic acoustic sensing system will be used to detect cracks developed in proximity of the concrete-tendon interface.
状态：	Active
资金：	165196
资助组织：	Mid-America Transportation Center<==>Office of the Assistant Secretary for Research and Technology
项目负责人：	Stearns, Amy
执行机构：	Missouri University of Science & Technology, Rolla
开始时间：	20191213
预计完成日期：	20201231
主题领域：	Bridges and other structures；Data and Information Technology；Highways；Maintenance and Preservation