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The Dongju Lee Memorial Lecture

Department of Civil Engineering and Engineering Mechanics

Columbia University

New York City


Liquefaction of Fine-Grained Soils and Its Effects on Buildings


Prof. Jonathan D. Bray

Department of Civil and Environmental Engineering
University of California, Berkeley


March 10, 2005 (Thursday)
5:00-6:30 pm

Davis Auditorium, CEPSR


Abstract: Ground failure in Adapazari, Turkey during the 1999 Kocaeli earthquake was severe.  Hundreds of structures settled, slid, tilted, and collapsed due in part to liquefaction.  The soils that led to severe building damage were generally low plasticity silts.  A comprehensive investigation was completed to understand the effects of subsurface conditions on the occurrence of ground failure and its resulting effects on building performance.  The CPT was able to identify thin seams of loose liquefiable silt, and the SPT (with retrieved samples) allowed for reliable evaluation of the liquefaction susceptibility of fine-grained soils.  State-of-the-practice CPT- and SPT-based liquefaction triggering procedures adequately identified soils that liquefied only if the Chinese criteria were disregarded.  Field observations and cyclic tests show that the Chinese criteria are not reliable for determining the liquefaction susceptibility of fine-grained soils.  Soils that liquefied did not typically meet the clay-size criterion of the Chinese criteria.  It is not the amount of “clay-size” particles in the soil; rather it is the amount and type of clay minerals that best indicate a soil’s susceptibility to liquefaction.  The soil’s plasticity index is thus a better indicator. A new liquefaction susceptibility criterion for fine-grained soils is proposed based on the results of this field and laboratory testing program.

The Dongju Lee Memorial Lecture was established with a generous contribution from the Lee Family. We would like to express our gratitude to DJ's father, Prof. Yong-won Lee (who is currently the President of Chinju National University of Education, Korea), for his support in establishing the Lecture and an Award. DJ, as Dongju preferred to be called, passed away on February 26, 2003 while he was a student working toward the doctoral degree. He obatined his Master's and Professional degrees from Columbia University.

more about
Dongju Lee


Biographical Sketch of Prof. Jonathan D. Bray
    Jonathan Bray is a Professor of Geotechnical Engineering at the University of California, Berkeley.  He earned engineering degrees from West Point (B.S.), Stanford University (M.S. in Structural Engineering), and the University of California, Berkeley (Ph.D. in Geotechnical Engineering).  Dr. Bray has been a registered professional civil engineer since 1985, and he has served as a consultant on several engineering projects and has served as an expert geotechnical engineer in several legal cases.  Professor Bray has authored more than 150 research publications.  His expertise includes the seismic performance of earth and waste fills, earthquake fault rupture propagation, seismic site response, liquefaction and ground failure and its effects on structures, and post-earthquake reconnaissance.  He has received a number of honors, including the Shamsher Prakash Research Award, ASCE Huber Research Prize, Packard Foundation Fellowship, NSF Presidential Young Investigator Award, and two North American Geosynthetics Society awards. 



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