CEE Contributes Conspicuously at Tufts Event
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The UMass Amherst Civil and Environmental Engineering (CEE) Department was prominently represented on January 28, when Tufts University organized a one-day gathering of faculty, students, and selected industry attendees to share their knowledge and research on “Trends in Coastal and Offshore Geotechnical Infrastructure.” CEE faculty participated in two of the 10 afternoon talks, and CEE graduate students presented six of approximately 20 posters.
The Tufts event featured: invited presentations from the United States Army Corp of Engineers, industry practitioners, and academic faculty; short presentations from faculty volunteers showcasing their research activities; a student poster session; and a panel session. Of the more than 90 attendees, roughly half were students, with more than 20 posters displayed.
One of the two UMass faculty presentations was an overview of the “Joint Industry Project: Piling in Glauconite Sands,” presented by CEE Associate Professor Zachary Westgate. The second UMass presentation described “Geotechnical Application of Cementitious Binder-polymers,” prepared by CEE Professor Guoping Zhang, who was absent due to illness. That second talk was presented by Zhang’s research colleague, Professor Mingjiang Tao from the Worcester Polytechnic Institute.
As Westgate explained during his talk at Tufts, glauconite is a heavy, greenish-black, iron-potassium pellet found in shallow marine depositional environments along the Atlantic outer continental shelf off the U.S. coast. Glauconite affects the geotechnical properties of sediments in which it forms, thereby posing risks to foundation installation and performance after its transformation from a coarse-grained to a fine-grained material due to crushing.
At Tufts, Westgate presented some highlights from the joint industry research, in which steel pipe piles were driven into high-glauconite-content sands at an onshore test site in New Jersey, followed by axial and lateral pile load testing.
As Westgate said about the project, “Improved understanding of the effects of glauconite sand behavior on offshore geotechnical foundation design can lead to reduced risk and [decreased] uncertainty for U.S. offshore wind development.”
Westgate added that “Developers planning to install offshore wind farms within these continental shelf geologic layers are finding that the unusual properties of this mineral pose significant geotechnical challenges.”
To address these challenges, the UMass Amherst team has been collaborating with scientists from Rutgers University, the University of Massachusetts Dartmouth, and consulting firm Haley & Aldrich, who were all contracted by a joint industry partnership led by the Norwegian Geotechnical Institute.
According to Zhang and Tao in their Tufts presentation given by Tao, next-generation cementitious binder-geopolymer, with its high strength, low cost, low energy consumption, and minimal CO2 emissions during synthesis, offers an environmentally friendly alternative to ordinary Portland cement for soil stabilization and improvement.
Geopolymer cement is made with minimal processing by combining metakaolin or fly ash, a user-friendly alkaline reagent such as sodium or potassium-soluble silicates, and water.
Zhang and Tao said the testing results indicated that, for clay deposits stabilized with geopolymer concentrations, the unconfined compressive strength, failure strain, and compressive stiffness of the stabilized soil specimens were significantly improved.
As Zhang and Tao concluded, “The experimental results confirmed that calcium-free geopolymer can be an effective stabilizer for clayey soils and sulfate-rich expansive soils.”
At the Tufts event, CEE graduate students also presented six posters. The posters covered the study mentioned above on the “Piling in Glauconite Sands,” research on floating wind mooring line configurations and foundation design, and the geotechnical behavior of silty soils. These projects involved various collaborations among Westgate, CEE Professor Don J. DeGroot, and CEE Professor Sanjay Arwade.
The CEE poster presenters were Ph.D. students Katherine Coughlan and Yuanjing Zou, as well as M.S. students Michael Davis, Leah Berlin, Elizabeth Hamilton, and Dongdong Guo. (March 2023)