Editorial Note – Issue 2-3 (2017) – Award Issue

Abstract

We are pleased to publish this special award issue featuring a set of outstanding manuscripts submitted to the DFI 2017 Young Professor and Student Paper competitions. Since 1985, DFI and the DFI Educational Trust have held an annual Young Professor Paper Competition as a means to help bridge the gap between practice and study. This year the range of submission covered a broad technical spectrum, ranging from numerical modeling to large scale experimental testing of axially and laterally loaded pile foundations, statistical analyses and uncertainty predictions using big data analysis methodologies, state-of-the-art evaluation of regional, national and international design recommendations, laboratory and model scale studies on soil behavior, ground improvement and installation effects during foundation construction, as well as QA/QC analysis pertaining to drilled shaft installation and long term shaft integrity. The winning papers as well as a set of manuscripts that received a special recognition are published in this issue. The editors would like to thank the competition reviewers for their constructive feedback to all manuscripts and the substantial amount of time spent on more than 15 paper submissions. We are so grateful for the successful competition and sincerely appreciate your service to DFI and your encouragement of our rising and promising young professionals. Mobley and Costello, a graduate student co-author team from the University of South Florida won the 2017 student paper competition for their research work on “The Effect of Slurry Type on Drilled Shaft Cover Quality”. Sarah Mobley and Kelly Costello, both PhD candidates in the Civil and Environmental Engineering Department at USF, study and research under the supervision of Prof. Gray Mullins. The research team examined 24 tremie-placed laboratory drilled shaft specimens, constructed using bentonite, polymer or natural slurry to identify correlations between slurry type and laitance channel formation. The authors received their award during DFI’s annual conference in NewOrleans and delivered a stellar presentation during the conference’s technical sessions. Mobley and Costello’s work is a critical contribution to increasing the long term resilience of drilled shaft foundations by identifying and quantifying the effects of shaft surface degradation triggered by the use of different slurry types. Closely followed, with extremely high review scores are two runner-up researchers in the student paper category: Van Wijngaarden received a runner-up award for his work on the “Modelling of Pore Pressure Developments below Cyclically Loaded Offshore Gravity Foundations”, a study that investigates the effects pore pressure increase and dissipation on the stability of the foundation system. Martijn van Wijngaarden recently graduated from the Delft University of Technology in the Netherlands and currently works at Volker Staal en Funderingen in Rotterdam. In his paper, he outlines an approach to assess the time dependent pore pressure development below a marine foundation by establishing load spectra due to wind, waves and turbine operations as well as the dynamic amplification of the loading. Van Wijngaarden concluded that a reliable prediction of excess pore pressures can only be accomplished by utilizing a large set of generated time series, as the irregular nature of cyclic loading results in significant spread in maximum pressures below a foundation. Ostrowsky won a runner-up paper award for her manuscript presenting “A New Approach for Evaluating the Ductility, Volumetric Stiffness and Permeability of Cutoff Wall Backfill Materials”. Jennifer Ostrowsky is a PhD student at Utah State University working with her graduate advisor Prof. John Rice. The research team developed a laboratory testing procedure to quantify the ductility of soilcement and plastic concrete relative to changes in permeability (hydraulic conductivity) with strain. The group performed extensive testing on soil-cement specimens with various cement and bentonite contents. The test results showed that the proposed method is effective in illustrating and quantifying the differences in 2017 DFI Board of Trustees