PITA Fiscal Year 2013 Projects

Bridge Deicing Using Geothermal Foundations

Lead University: Lehigh University
PI: Muhannad T. Suleiman, Dept. of Civil and Environmental Engineering
Co-PI(s): Clay Naito, Dept. of Civil and Environmental Engineering
PA Industry: Central Atlantic Bridge Associates

Bridge infrastructure experiences high deterioration rates due to the use of deicing salt, which results in an annual direct cost of corrosion-related maintenance in the range of $5.9 to $9.7 billion. Deicing practices also reduce the longevity of bridge infrastructure making it difficult to achieve the national goal of a100-year or more bridge service life that was set by the Second Strategic Highway Research Program (SHRP 2) authorized by Congress in 2005. The AASHTO (2008) “Bridging the Gap” report specifically highlights bridge deterioration as the first problem on the list of the top five problems facing the nation bridge infrastructure. AASHTO (2008) also emphasizes the need for research in the areas of innovative materials and technologies to improve the safety, longevity and economy of bridge infrastructure.

The goal of the proposed research is to investigate the use of an integrated geothermal energy system for bridge deicing to avoid the use of deicing salts and minimize related bridge deterioration. The integrated system consists of geothermal deep foundations that support the structural loads of the bridge superstructure, provide heat exchange with surrounding soil, and distribute thermal energy into the bridge slab. In this system, the geothermal energy will be used for bridge deicing during the winter. During the summer, however, the bridge deck will collect solar heat and store it in the soil to help in balancing the used geothermal energy (i.e., the collected heat will be stored during summer and the geothermal energy will be used for bridge deicing during winter). The proposed research plan represents an initial phase that will focus on material characterization and concept validation, which will be followed by further research and implementation in the field.