Influence of Existing or Newly Constructed Pile on Flexible Circular Footing Settlement

Due to the space constraint, sometimes new construction activities have to invade into the footprints of existing structures. An example is that the planned piles to support new superstructures are in conflict with the footprints of existing bridge abutment footings, or vice versa. As a result, the footings have to be re-evaluated for their settlement to consider the influence of piles. As a dilemma, there is no method taking the influence into account. In this study, a numerical approach was adopted to investigate the influence of the new pile on the settlement of the existing footing (Application 1) and also the influence of the existing piles on the settlement of newly constructed footing (Application 2). FLAC was employed in this study. The pile and footing were simulated as elastic material with appropriate properties. Subgrade soil was modeled as elastic material. Firstly, the simulation was carried out for a pile and a footing separately and the results were compared with theoretical solutions serving as model calibration. Then the simulation was carried out to exam the influence for both applications. For each application, various conditions were investigated including different footing load, footing size and pile load. The results were compared and discussed.