Pile foundations, as critical components of deep foundation systems in civil engineering, play an essential role in transferring structural loads from superstructures to deeper, more stable soil layers. The dynamic instability of these foundations, particularly under seismic events, poses significant risks, potentially leading to property damage, structural failures, and loss of life.
The scientific consensus on climate change is clear: Earth's surface and oceans are warming at unprecedented rates due to anthropogenic greenhouse gas emissions. The Intergovernmental Panel on Climate Change (IPCC) has reaffirmed that the majority of observed warming over the past century is due to human activities. Even with significant emission reductions, warming is expected to continue. This warming trend influences various geophysical factors, including glacier extent, snow cover, and the thermal properties and distribution of permafrost. Such climatic shifts have direct and indirect implications for the stability of infrastructures worldwide, including pile foundations.
This research aims to investigate the impact of climate change on the dynamic stability of pile foundations, particularly focusing on temperature variations and their influence during seismic events. The study begins with the derivation of the equation of motion for a pile foundation subjected to earthquake forces, incorporating the thermal properties of materials. The equation is reduced to an ordinary differential equation with variable coefficients.
To analyze this, the harmonic balance method is employed to construct stability diagrams for pile foundations under dynamic loading. Additionally, a numerical approach is developed to study the stability behavior of piles under similar conditions. These numerical results will also serve as benchmarks to validate the analytical findings from the harmonic balance method.
As a practical application, the dynamic stability of an actual pile foundation will be analyzed using both the harmonic balance and numerical methods. A parametric study will then be conducted, examining key factors such as temperature variations, elastic foundation rigidity, damping, and the effects of both static and dynamic loads on the pile's stability regions.