Stability of Pile Groups

Project summary:

Bridge structures are typically supported by groups of piles, which are connected at the top and, either by design or as a result of scour, are partially embedded in soil. Stability of such support is usually examined by analyzing an individual pile rather than the entire group. In addition this analysis employs various simplifying assumptions, in particular those related to the interaction of the piles and the soil. While such approach gives an estimate of the buckling load, it is felt that analysis of the entire group would provide more meaningful results. In the proposed research stability of the entire group of piles will be investigated. Interaction of the piles with soil will be considered using the best currently available models. In view of the complexity of the problem numerical methods will be used in most cases. However, when feasible, an attempt will be made to obtain analytical solutions. It is expected that the overall buckling load of the system obtained from the group analysis will be higher than that resulting in the current practice based on the analysis of a single pile in the group. If this expectation is confirmed, monitoring of scour could be less stringent, for example, leading to a reduction of the related expenditures. In addition, the general results of this research should also provide guidance for the selection of the specific cases to be analyzed experimentally in an independent research program, complementing the investigations proposed herein.