2024 SFGI Officers
Chair – Pawan Kumar, Arup
Vice Chair – Jenna Fontaine, Langan
Treasurer – Leslie Ramirez, Langan
Secretary – Ashim Gajurel, Delve Underground
Email Coordinator – Rica Chen, Arup
Event Coordinator – Conner Sudol, Keller North America
Student Outreach Coordinator – Jessy Nepolien, Langan
Website Coordinator – Mahsa Jerdi, Arup
Rev: Feb 13, 2024
San Francisco Geo-Institute (SFGI)
For the latest announcements regarding events, dinner meetings, and news, please visit the SFGI LinkedIn Group or sign up for email updates. If you are interested in learning more about SFGI, check out our past events.
The Geo-Institute (G-I) is a specialty membership organization focused on geo-professionals and the geo-industry. It is one of American Society of Civil Engineers’ eight specialty Institutes. Similarly, SFGI is the local specialty chapter mirroring the goals and purposes of the G-I. The purpose of SFGI is to locally promote an interest in and the general advancement of engineering knowledge in the fields of geotechnical and geoenvironmental engineering, and related earth sciences.
Our geo-professionals work to improve the built environment, prevent the loss of life and property from natural and man-made hazards, and construct sound and reliable engineered facilities and structures.
SFGI Dinner Presentation
Thursday, February 29, 2024
5:30 – 8:30 PM PST
Bio-Based Ground Improvement from Theory to Practice
Leon van Paassen, Ph.D., M.ASCE
$70 – Professionals and Guests
$25 – Students
Bio-based ground improvement methods are being investigated for their potential to improve the geotechnical properties of soils. Most research on bio-based ground improvement has focused on microbially induced calcium carbonate precipitation (MICP) by urea hydrolysis. In this process, ureolytic bacteria are either injected in the ground or stimulated in situ by selective enrichment. Consequently, the ureolytic bacteria are supplied with a solution containing urea and calcium chloride. Hydrolysis of urea results in the precipitation of calcium carbonate, which increases the strength, stiffness and dilatancy or reduces compressibility and permeability of coarse granular soils. The byproduct (a solution containing ammonium chloride) is removed. Also, other biological processes may be used, such as microbially induced desaturation and precipitation (MIDP) by nitrate-reducing bacteria. In this process a solution containing calcium, nitrate and acetate (or other forms of dissolved organic carbon) is injected, which stimulates indigenous nitrate-reducing bacteria to grow and produce nitrogen gas, carbon dioxide and calcium carbonate minerals. Similar to MICP by urea hydrolysis, calcium carbonate increases the soil’s strength, stiffness and dilatancy, but the formation and entrapment of nitrogen gas desaturates the soil, which increases the compressibility of the pore fluid, and consequently suppresses pore pressure build up during cyclic loading, which can be used as a method to mitigate earthquake-induced liquefaction. The third product, biomass or biopolymers can also increase the erosion resistance of soils and studies have been performed on restoration of surficial biocrust by stimulating carbon sequestering micro-organisms. Besides micro-organisms other biological species, like plants or worms have been investigated for their potential in ground improvement applications. This contribution highlights the achievements so far developing these concepts from theory and bench-scale tests towards field scale implementation and addresses the challenges towards commercialization and opportunities for new research.
Leon van Paassen obtained his MSc in Applied Earth Sciences and PhD in Environmental Biotechnology from Delft University of Technology in The Netherlands. He has more than 20 years of experience in academia and industry. He has investigated and scaled up several bio-based ground improvement methods from laboratory concept to full scale applications and has authored more than 80 peer-reviewed papers in journals and conference proceedings. He currently works at Boskalis, where he is involved as an expert on Biogeotechnics in large dredging and land reclamation projects all over the world. He is still active as an adjunct professor and senior investigator at the Center for Bio-mediated and Bio-Inspired Geotechnics at Arizona State University.
Scott’s Seafood Jack London Square
Thursday, February 29, 2024
5:30 pm – 6:30 pm: Registration and Social Hour
6:30 pm – 7:15 pm: Dinner
7:15 pm – 8:30 pm: Presentation
**Send us an email at firstname.lastname@example.org to get involved!**