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Acta Geotechnica (2014) 9:413423 DOI 10.1007/s11440-014-0307-2
RESEARCH PAPER
Heat-exchanger piles for the de-icing of bridges
Fabrice Dupray Chao Li Lyesse Laloui
Received: 1 October 2013 / Accepted: 3 February 2014 / Published online: 16 February 2014 Springer-Verlag Berlin Heidelberg 2014
Abstract Of the various types of road structures, bridges are the most exposed to icing; the problem of icing is widely addressed through salting, which reduces the lifespan of the bridge. One promising solution to avoid the use of salt is the seasonal storage of solar heat energy captured directly through the asphalt layer; however, this solution can only be achieved cost effectively if a necessary geo-structure is used as a heat exchanger. In this study, such an approach is studied for a bridge crossing a canal, and the geotechnical and energy-related challenges of such a solution are discussed. Bridge piers and abutments are located on piles, which are used as heat exchangers. Depending on local conditions, seasonal storage and natural thermal reload are two possible solutions for the operation of such a system. In particular, the presence of underground water ow is thought to be a signicant factor in such a design and is considered here. This study aims to determine the geotechnical and energy design parameters through thermo-hydro-mechanical simulations. A three-dimensional nite-element model analysis is necessary given the distance between bridge piles. Various underground water ow scenarios are studied. The capture of energy and de-icing requirements is based on the few existing structures that use other means of energy exchange with the ground. The results indicate that the use of heat-exchanger piles for de-icing bridges can only be considered
at specic sites; however, the efciency of the solution at those sites is high. Possible foundation and structure stability problems are also considered, such as vertical displacements due to the dual use of the foundation piles.
Keywords Energy piles Natural groundwater ow
THM couplings
1 Introduction
The formation of ice and the accumulation of snow on bridge decks and ramps have long been identied as serious problems in winter road maintenance. Because they occur earlier and more often on bridge decks and ramps than on normal stretches of road, solutions other than the typical techniques of applying road salt and snow ploughing could be...