Utilizing building foundations as micro-scale compressed air energy storage vessel: Numerical study for mechanical feasibility

Abstract

This paper explores a new idea of using building pile foundations as compressed air energy storage (CAES) vessels. A critical assessment is made to determine whether the foundation maintains its primary function as a load-bearing element when subjected to the internal pressurization and depressurization cycle. This is achieved by investigating the behavior of a closed-ended steel pipe pile, subjected to various axial structural loads from building weight, under the pressure cycle using finite element analysis. Particular emphases are placed on the investigation of 1) axial displacements of the CAES pile and 2) developments of axial and hoop stresses in a pile during the pressure cycle. Results from the numerical analyses imply that stress boundary conditions developed along the pile due to the application of the structural load before pressurization play a major role in the mechanical behavior of the CAES pile. Under working loads, induced displacements at the pile head during pressurization are found to be within tolerable limits allowed for typical building foundations. Furthermore, the analysis results show that the axial and hoop stresses in the CAES pile wall do not exceed the yield strength of the high-grade steels during pressurization.