Settlement analysis in the context of underground climate change

Abstract

Subsurface urban heat islands are a pressing global issue responsible for an underground climate change beneath cities. Over the past two decades, this phenomenon has been identified as a threat to subsurface ecosystems, hydrogeological systems, transportation systems, and public health. Recently, underground climate change has also been reported as a silent hazard for civil infrastructure due to thermally induced ground deformations. This paper expands the study of the impacts of underground climate change on civil infrastructure by presenting a simplified, one-dimensional settlement analysis that simulates the deformations driven by subsurface urban heat islands as a viscous process driven by thermally accelerated creep. Specifically, this investigation focuses on the vertical displacements of the ground surrounding a caisson foundation supporting a 39-storey building located in the Chicago Loop district under the influence of underground climate change for 100 years. The results reveal that the thermally induced ground displacements caused by underground climate change can be substantial and strongly depend on the ground warming rate and the spatial extent of subterranean temperature variations. The study provides new evidence about the relevance of underground climate change for the serviceability performance of civil infrastructure, motivating future research to identify which types of earth-contact structures and infrastructures may be particularly affected by thermally induced ground deformations caused by this phenomenon.