Influence of tunnel excavation on adjacent existing pile considering soil spatial variability

Currently, tunnel construction in urban areas inevitably requires excavation near existing structures, leading to soil movement around the excavation zone. This movement may affect adjacent structures, particularly the pile foundations of nearby buildings. Previous studies have typically considered soil properties as homogeneous media. However, such analyses may be insufficiently reliable due to the spatial variability of soil properties. Therefore, this research emphasizes the importance of incorporating spatial variability of soil properties into the analysis of pile behavior influenced by tunnel excavation. A stochastic finite element method (SFEM) is applied using PLAXIS 2D to assess the effects of spatial variability. The analysis results demonstrate that the scale of fluctuation plays a significant role in both pile deformation and the probability of failure. Therefore, accounting for soil spatial variability is a suitable and necessary approach to assessing the potential risks affecting pile foundations near tunnel excavation.