Investigating Passive Loading of an MSE Wall Bridge Abutment Supported on a Piled Foundation

Consolidation of embankments constructed on soft soils generates lateral loading from the moving soils. Adjacent piles subjected to the lateral loading are known as passive pile loading. Passive pile loading can be critical in design of bridge abutments supported on a piled foundation when soft soil is present. This is a complex soil-structure interaction that can be assessed using finite element modelling. This paper compares the methods available to estimate passive pile loading against finite element modelling using PLAXIS 2D. A case study is presented of an MSE wall bridge abutment supported on a piled foundation with a soft layer present. This paper investigates options to reduce bending moments in the piles. The following cases were investigated: sand in lieu of the soft layer; isolating the MSE wall from the columns supporting the bridge; replacing the MSE wall with a cantilever-reinforced concrete wall; and an innovative cantilever extended pile cap. The last solution reduced pile bending moments and pile head deflections, offering the best solution amongst the cases studied.