Seminar: Characterizing the Mechanism of Rocking in Seismic-Resilient Precast Concrete and Masonry Walls

Mason Building, Room 5134
Thursday, March 15, 2018 - 10:45


Dimitrios Kalliontzis
Doctoral Candidate
Civil, Environmental, and Geo-Engineering Department
University of Minnesota, Twin Cities

Human safety and the economic impact of seismically-damaged structures underline the need to develop seismic-resilient structural systems. For this purpose, recent research investigates the use of rocking walls. Properly designed rocking walls undergo negligible damage when subjected to seismic loads, and can effectively re-center a building structure, upon removal of the loads. However, the intricacy and inadequate understanding of the damping mechanisms induced by rocking have prevented rocking walls from becoming a widely-accepted means for seismic resilience. My research uses carefully monitored experiments to provide unique insight into rocking motions of these walls. First, I test rocking precast concrete units, which are designed based on prototype seismic-resilient building structures. I use the experimental findings to develop analytical models for rocking precast concrete walls. The second component of my research uses the rocking mechanism to develop seismic-resilient masonry walls. To yield a resilient solution, my research strategically employs elastomeric pads at the wall-to-foundation interface. Combining experimental and analytical investigations, I provide evidence that appropriate design of the wall-to-foundation interface can make the elastomeric pads the only required mechanism for dissipating the seismic energy imparted to rocking masonry walls.


Dimitrios Kalliontzis is a Ph.D. Candidate in the Department of Civil, Environmental, and Geo- Engineering at University of Minnesota – Twin Cities, where he is completing his thesis on seismic- resilient precast concrete and masonry structures under the supervision of Prof. Arturo E. Schultz and Sri Sritharan (Iowa State University). He received his MSc in Structural Engineering from Iowa State University, where he was awarded a PCI fellowship and Research Excellence for contributions to Structural Engineering. He completed his Diploma Degree in Civil Engineering at Aristotle University of Thessaloniki, Greece. Prior to joining University of Minnesota, he worked as a Technical Intern at Simpson, Gumpertz & Heger Inc. During 2017, Dimitrios won the 1st place award in the Research Slam Competition among graduate students and junior faculty in the Department of Civil, Environmental, and Geo- Engineering at University of Minnesota, and his publication at the 13th Canadian Masonry Symposium was awarded an Honorable Mention for the H.W.H. West Award from the Canada Masonry Design Centre.