Quantifying the response of piled structures from displacements induced by pile installation in soft clay

The impact of pile installation in soft soils on its surroundings has been numerically investigated with a focus on the response of an existing piled structure. The originality is the parameterised 3D finite element analyses of far-field soil–structure interaction scenarios, i.e., interactions that are largely driven by mass-displacements. A main finding is that the geometry, which includes the number and length of newly installed and existing piles, the distance between the two pile groups, and also the distance to stiff boundaries in the system (in the field and in the numerical analysis), governs the problem to a large extent. Therefore, to simplify the analysis of such complex cases, modification factors for the displacements in greenfield conditions are proposed, to calculate the displacement and structural response of the existing structure. The proposed non-dimensional factors are a function of the length of the newly installed and existing piles and the distance between the two pile groups. No unique solution exists; hence, a series of charts have been compiled to provide a first assessment of the impact of an existing piled structure on the induced displacements from the installation of a nearby group of displacement piles in soft soil.