1. Structural Performance of Thermo-Active Foundations

This chapter focuses on the current understanding of soil-structure interaction effects on thermo-active foundations that occur due to their thermal expansion and contraction during heating and cooling, respectively. The first section of the chapter presents hypothetical representations of thermo-mechanical stress profiles in thermo-active foundations, along with the theoretical relationships between axial stress, axial strain, side shear stress, and axial displacement. The second section of the chapter presents relevant design criteria for the axial stress and displacement in thermo-active foundations. The third section of the chapter presents the details of thermo-mechanical load transfer analyses that can be used to predict the behavior of thermo-active foundations. Finally, the fourth section of the chapter presents a comparison of experimental results from two full-scale, instrumented thermo-active foundations in different soil layers. Despite the importance of considering the role of thermo-mechanical soil-structure interaction, the evidence presented in this chapter indicates that thermo-active foundations will provide a safe response in terms of both structural and architectural criteria in the soil strata where drilled shaft foundations are typically employed.