October Meeting

Geo-Institute/Seattle Section Geotechnical Group – October Meeting
Co-organized by University of Washington GIGGS and Geotechnical Group

Wednesday, October 26, 2022, 5:30 PM
Alder Auditorium, University of Washington

Join us for the October meeting on Wednesday, October 26th.  Professor Tim Stark will be presenting the topic “Mobilized Shear Strength of Seattle Clays”.  Registration is $50 and available at https://www.brownpapertickets.com/event/5597394.

Online registration will close the day of the meeting, but walk-up registration will be available.

Topic: Mobilized Shear Strength of Seattle Clays
Presentation by Timothy D. Stark, Ph.D., P.E., F.ASCE and Abedalqadar Idries

This presentation will discuss the drained shear strength of overconsolidated glaciolacustrine clays in the Seattle area, which can range from the overconsolidated peak to residual strength depending on its geologic history, depth, softening, prior shear displacements, size of excavation, and application, e.g., long-term cut slope vs. short-term building excavation. An inverse analysis of slope failures reported by Palladino and Peck (1972) shows the mobilized shear strength for cut slopes in the overconsolidated and sparsely jointed Qvgl glaciolacustrine clay ranges from the residual to fully softened strength depending on the level jointing and prior shear displacements. Conversely, an inverse analysis of a 2011 slope failure in the frequently jointed and slickensided overconsolidated Qpgl glaciolacustrine clay shows the mobilized shear strength is near residual to in between the fully softened and residual strengths because of repeated glaciation cycles, softening, and localized shear displacements reflected in the presence of slickensided surfaces. These results will be used to suggest design strengths for future projects.

Dr. Stark has received a number of awards for his research, teaching, and service activities including recently: 2022 Cross USA Lecturer from the American Society of Civil Engineers (ASCE); 2022 T.H. Wu Lecture at The Ohio State University; 2019 George H. Norman Medal, ASCE; Best Paper in Geosynthetics International Journal, 2016; 2015 James M. Hoover Lecture at Iowa State University; Thomas A. Middlebrooks Award, ASCE, 2013 and 1998; Associate Editor Award, Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 2012; Journal of Legal Affairs and Dispute Resolution in Engineering Scholarly, Paper, ASCE, 2011; R.S. Ladd D18 Standards Development Award, Standard Designation, ASTM, 2014, 2011, 2002; R.M. Quigley Award from the Canadian Geotechnical Society, 2003, and Walter L. Huber Research Prize, ASCE, 1999.

Meeting Agenda

5:30  Check-in & Networking
5:45  Introduction & Announcements
6:00  Presentation
7:15  Dinner & Networking

Directions & Parking

Alder Auditorium is at the southwest corner of 1310 NE 40th Street.  The auditorium entrance is at NE 40th Street and Brooklyn Avenue.  Paid parking is available at the UW W12 Lot or the Central Plaza Garage.

Thank you to the UW Geo-Institute Graduate Student Society (GIGSS) for organizing this presentation.