Interpretation of pile lateral response from deflection measurement data : A compressive sampling-based method

The performance of piles under lateral loading, i.e., the lateral response of piles, may be evaluated by in situ lateral loading tests. Inclinometers are frequently installed along the pile depth to measure the pile lateral deflection during the loading tests. Other pile responses, such as the bending moment and shear force, may be further obtained through high-order differentiation of the deflection measurement data with respect to depth. As inclinometers measure the pile deflection at a number of pre-specified depths, the deflection measurement data are discrete. Performing high-order derivatives on discrete deflection data is tricky and sometimes provides misleading results, particularly when the pile response is nonlinear. This paper proposes an innovative approach for interpreting the lateral response of piles from discrete deflection measurement data. The proposed method is based on a new sampling theorem in digital signal processing called compressive sensing/sampling (CS). The method is illustrated using a real case history in the USA, and the results show that the proposed method can provide reasonable interpretations of the lateral response of piles. A sensitivity study is also carried out to systematically explore the performance of the proposed method.