The use of energy piles to facilitate thermal control of integral bridge displacements

Integral bridges are a very common type of bridges due to their quicker construction and
lower maintenance cost compared to traditional bridges, because of the absence of
expansion joints and bearings. However, integral bridges encounter several challenges due to bridge deck thermal displacement that impacts the cyclic movement of the abutment. The main challenge is the development of earth pressure on the abutment due to soil ratcheting occurrence in the backfill with the abutment cyclic movement. Hence, it is important to find a solution to control bridge deck thermal displacement to control earth pressure development on the abutment. The proposed solution in this thesis is using the stable energy from the ground to provide bridge deck with constant temperature during the year, and therefore, limit the deck temperature variation due to seasonal temperature changes. This could be done using energy piles that serve as a ground heat exchanger (GHE) and bridge foundation. To evaluate the possibility of using the proposed solution in controlling earth pressure development on integral abutments, this thesis conducted analytical and numerical analysis.
In the analytical analysis, earth pressure development on abutment, in addition to ground
and GHE temperature changes, were studied for initial evaluation of the proposed system. In the numerical analysis, three numerical models were developed to study the thermo-mechanical performance of energy piles and earth pressure development on integral abutments. Two of the numerical models were for energy piles analysis under different loading and ground conditions by using Axisymmetric and 2D plane strain models. The third model was 2D plane strain model to compare earth pressure development on integral abutment with and without the energy piles system.
This thesis provides the first evaluation of using an energy piles system to control earth
pressure development on integral abutment by controlling bridge deck temperature
variation.