Pore water pressure accumulation under dynamic loadings

Timothy Stark and Hyunil Jung

When the ground is shaken by dynamic events like earthquakes or heavy equipment vibrations, water pressure within the soil—called pore-water pressure—can build up. If these shaking events occur in quick succession, the pressure can accumulate because the soil doesn’t have enough time to drain and return to normal between events. This buildup can weaken the ground, sometimes leading to dangerous flow failures or landslides even after the shaking has stopped. Real-world examples include failures during the 1987 Superstition Hills earthquake, the 1971 Lower San Fernando Dam collapse, and more recent incidents like the 2018 Palu flow slide and the 2015 Fundão Dam disaster.
These events show that:

Water pressure in the soil can remain high after shaking if it doesn’t drain quickly.
Repeated shaking—like aftershocks or vibrations—can increase this pressure further.
Even weaker follow-up events can trigger soil failure.
Ground failure can happen after the shaking ends, not just during.

This webinar will explore these phenomena using real case studies and monitoring data. It will also introduce a practical approach to estimating how pore-water pressure builds up during dynamic events, helping engineers and planners better understand and mitigate these risks.

Timothy Stark Professor of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign

Timothy D. Stark is a Professor of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign with an expertise in Geotechnical Engineering. Dr. Stark has received a number of awards for his activities including: 2024 Distinguished Member, American Society of Civil Engineers (ASCE), 2023 J.E. Jennings Award, South African Institution of Civil Engineering; 2023 Martin S. Kapp Memorial Lecturer, ASCE Metropolitan Section; 2022-2023 Cross-USA Lecturer, 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.

Hyunil Jung Ph.D. Student, Civil and Geotechnical Engineer, University of Illinois Urbana-Champaign

Hyunil Jung is a Civil and Geotechnical Engineer with a strong academic and research background. He earned his M.S. in Civil Engineering from Hanyang University in Korea, where he focused on the seismic design of tunnels. Currently, he is pursuing a Ph.D. at the University of Illinois Urbana-Champaign under the supervision of Prof. Tim Stark. His research focuses on liquefaction, slope stability, advanced numerical modelling, and geosynthetics. Hyunil aims to bridge the gap between research and practice by applying his expertise in both industry and academia.

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