Development of load-transfer curves for axially-loaded piles using fibre-optic strain data, finite element analysis and optimisation

The load-transfer analysis method is a practical approach for analysing the deformation behaviour of foundation piles where the soil is modeled with a series of springs following a nonlinear response according to load-transfer (t-z and q-z) curves. Distributed fibre optic (FO) sensing following the Brillouin Optical Time-Domain Reflectometry/Analysis (BOTDR/A) methodology provides detailed information about the axial pile strains along the entire length of a pile. Direct integration and differentiation provide the corresponding values for vertical displacements and shaft friction which can therefore be used to develop relevant load-transfer curves. This paper presents an approach for developing such load-transfer curves for axiallyloaded pile using distributed FO strain data.