Nonlinear Lateral Response of RC Pile in Sand: Centrifuge and Numerical Modeling

Centrifuge modeling has been considered as an effective means of studying flexural soil-pile interaction, yet the conventional use of elastic material to model an RC pile prototype is unable to reproduce the important nonlinear quasi-brittle behavior. It also remains a challenge to numerically model the soil-pile interaction due to the nonlinearity of both the soil and pile materials. This paper presents a small-scale model RC pile for testing soil-structure interaction under lateral pile head loading in sand within a centrifuge. Accompanying nonlinear finite-element numerical modeling is also presented to back-analyze the centrifuge observations and explore the influence of the constitutive models used. The physical model RC pile is able to (1) reproduce the pile failure mechanism by forming realistic tension crack patterns and plastic hinging and (2) give hardening responses upon flexural loading. Comparisons of measured and predicted results demonstrate that for the laterally loaded pile problem, the load-displacement response can be well approximated by models that do not incorporate strain softening, even though the soil behavior itself exhibits a strong softening response.