Poster Session 4, 2:15 PM - 3:00 PM: Campus Center Auditorium [A83]

Particle Degradation and Behavioral Transition in Glauconite Sands Under Simulated Pile Driving Stresses

Presenter: Daniel Benno Jaffe

Faculty Sponsor: Zachary Westgate

School: UMass Amherst

Research Area: Civil Engineering

ABSTRACT

Unlike many crushable sands, glauconite can exhibit measurable changes in plasticity during particle degradation, a behavior that may significantly influence soil–structure interaction and the performance of monopile foundations used in offshore wind systems. During pile installation, glauconitic soils may experience intense and poorly characterized stress regimes that promote rapid grain crushing, creating uncertainty in foundation response and long-term reliability. This study focuses on mechanical degradation using large ball milling to simulate extreme crushing conditions representative of these stresses, examining five authigenic glauconite outcrop sands from the Hornerstown and Navesink formations. Ball milling results demonstrate substantial increases in fines content, with variable effects on plasticity depending on the crushing mechanism and mineral release, indicating a shift in soil behavior toward more compressible and potentially less permeable conditions. One-dimensional compression and dispersion testing provide comparative context by illustrating how glauconite responds under conventional loading paths; however, they do not replicate the combined vertical and shearing stresses simulated by ball milling. Together, the results show that the degradation mechanism and stress environment strongly govern the evolution of glauconite engineering properties. Improved understanding of glauconite behavior across stress regimes supports more reliable interpretation of laboratory index tests and better prediction of soil response during monopile installation and in-place loading, contributing to safer and more efficient offshore foundation design.

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