Towards axial capacity predictions through MWD data: what can we learn from installation efforts of drilled displacement piles

The future of performance-based foundation design involves integrating Measurement-while-Drilling (MWD) data to enhance the resilience and construction efficiency of pile foundations. During the installation of Drilled Displacement Piles (DDPs), measurements include penetration speed (vz), rotational speed (vr), downward thrust, torque (T) or hydraulic pressure (Pdrill). With these measurements in mind, data from 32 DDPs across 10 project sites in the US and Europe were collected and analyzed. A generalized formulation for installation effort was developed to compare existing pile databases with the data gathered by the authors. The proposed method uses a decomposed installation effort model that separately accounts for the shaft and toe portions of the pile. A regression analysis of the dataset shows the potential of using installation effort to predict pile capacity and provides fundamental knowledge towards establishing a basic framework for estimating pile load capacities during DDP installation. This application highlights the value of real-time monitoring data in performance-based foundation design.