Validation of pile analysis and design methods - Experimental Research
COFFEE has a track record of theoretical mechanics research on the response of pile foundations to loading as well as the development of design methods. To match these efforts, we have have an ongoing program of pile testing, both in the laboratory and in the field. COFFEE has performed a number of instrumented pile load tests together with careful site characterization. These tests have helped COFFEE researchers validate their work and have also become international reference for researchers working in offshore and onshore pile design.
Simulation of loading of non-displacement piles - Computational Geomechanics/Piling Engineering
Using advanced, two-surface-plasticity constitutive models, COFFEE researchers have been performing rigorous Finite-Element simulations of axially-loaded, non-displacement single piles and pile groups installed in sand/clay. These high-quality FE analyses have laid the theoretical foundation of the Purdue pile design methods and continue to shed light on the relationship between the global response of the pile-soil system and the behavior of soil elements.
Experimental Determination of Displacement and Strain Fields around Piles using Digital Image Correlation - Experimental Mechanics/Piling Engineering
COFFEE has performed model-scale tests on instrumented model piles pre-installed, jacked or driven into a half-circular calibration chamber with viewing windows in its flat-side wall. With the aid of the Digital Image Correlation(DIC) technique, digital images captured by high-resolution digital cameras and microscopic cameras during the tests are analyzed to produce the displacement and strain fields in the soil around the piles. The DIC technique enables COFFEE researchers to quantitatively study microscopic behavior, with the determination of displacement and deformation fields, in the soil. Near the pile surface, the development of shear bands or particle crushing during installation and loading of the piles can also be studied. With the DIC technique and other image processing techniques, COFFEE researchers have been actively working to unveil the complex mechanisms of the short-term (e.g., friction fatigue) and long-term (e.g., set-up effects) development of the pile resistance.