Bažant, Zdenek

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Zdenek Bažant

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Zdenek Pavel Bažant (b. December 10, 1937) is McCormick School Professor and Walter P. Murphy Professor of Civil Engineering and Materials Science in the Department of Civil and Environmental Engineering at Northwestern University's Robert R. McCormick School of Engineering and Applied Science.

Born in Prague to a geothermal engineering professor and a sociology Ph.D., and the grandson of a professor of structural mechanics and former university president, Bažant was the winner of the 1955 Mathematical Olympics. He studied civil engineering at Czech Technical University (?VUT), where he received straight A's and was first in his class. He was awarded the C.E. degree with the highest distinction in 1960. While working as a bridge engineer for the state consulting firm Dopravoprojekt in Prague, he studied for his Ph.D. in structural mechanics at the Czech Academy of Sciences, which he received in 1963. In his dissertation on concrete creep theory, he developed a new method to analyze fracturing and cracking in concrete structures.[1] He went on to earn a postgraduate diploma in theoretical physics from Charles University in 1966 and attained docent (Associate Professor) habilitation in concrete structures from ?VUT in 1967.

In 1966, he accepted a visiting research appointment at the Centre Experimental de Recherches et d’Études du Bâtiment et des Travaux Publics followed by appointments at University of Toronto and University of California, Berkeley. The Russian invasion that followed the Prague Spring convinced him to remain in the United States,[2] and in 1969, he joined the Northwestern faculty as Associate Professor of Civil Engineering. He was promoted to Professor in 1973.

Bažant, who is generally regarded as the world leader in research on scaling in the mechanics of solids,[2] has published over 450 refereed journal articles[3] and is the author of six books. He is an ISI highly cited researcher in Engineering, which places him among the 250 most cited authors in all engineering fields worldwide. He was elected to the National Academy of Engineering in 1996 and the National Academy of Sciences in 2002, and is a Registered Structural Engineer in the state of Illinois. He has supervised 60 Ph.D.s in addition to receiving six honorary doctorates of his own (?VUT 1991, TU Karlsruhe 1997, CU Boulder 2000, Politecnico di Milano 2001, INSA Lyon 2004, and TU Vienna 2005).

Bažant's research entered the public sphere when, in the days after the attack on the World Trade Center, he circulated a structural analysis of the WTC 1 and 2 collapse.[4] A later, related paper provides a comprehensive analysis of the mechanics of progressive collapse in tall buildings.[5]

Bažant's analysis led him to a four-point failure scenario.

  1. Severed and significantly deflected columns at the point of impact redistributed stress to other columns, exhausting their load capacity.
  2. Because insulation was stripped from many structural steel members, the jet-fuel induced inferno heated remaining columns up to 600°C, causing them to lose up to 85% of their strength.
  3. Heat and stress combined to induce both viscous and plastic properties in the remaining columns. That, and thermal expansion, caused the floor trusses to sag, pulling perimeter columns inward. These factors along with the deflection of some columns due to aircraft impact induced multistory buckling of the outer frame wall tube.
  4. As a result of the buckling of the outer frame, the upper part of the tower fell through at least one floor height. The kinetic energy of the falling upper part exceeded by an order of magnitude the energy that could be absorbed by the floor below, triggering progressive collapse.

Bažant speaks English, Czech, French, German, and Russian.[6]

[edit] References

  1. ^ Bažant,, Z. P. (1966). "Creep of Concrete in Structural Analysis". State Publishers of Technical Literature.  via Bundesen, LQ (2004). "Biography of Zdenek P. Bazant.". Proceedings of the National Academy of Sciences of the United States of America 101 (37): 13397–9. doi:10.1073/pnas.0405856101. PMID 15353582. 
  2. ^ a b Bundesen, LQ (2004). "Biography of Zdenek P. Bazant.". Proceedings of the National Academy of Sciences of the United States of America 101 (37): 13397–9. doi:10.1073/pnas.0405856101. PMID 15353582. 
  3. ^ "Publications of Zden?k Bažant" (pdf). Retrieved 2007-08-25. 
  4. ^ Bažant, Zden?k P.; Zhou, Yong (January 2002). "Why Did the World Trade Center Collapse?—Simple Analysis". Journal of Engineering Mechanics 128 (1): 2–6. doi:10.1061/(ASCE)0733-9399(2002)128:1(2). Retrieved 18 June 2009. 
  5. ^ Bažant, Zden?k P.; Verdure, Mathieu (March 2007). "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions". Journal of Engineering Mechanics 133 (3): 308–319. doi:10.1061/(ASCE)0733-9399(2007)133:3(308). Retrieved 22 August 2007. 
  6. ^

[edit] Biographies

[edit] Bibliography

  • Bažant, Zden?k P. (1966). Creep of Concrete in Structural Analysis. Prague: State Publishers of Technical Literature (SNTL). 
  • Bažant, Zden?k P.; Luigi Cedolin (1991). Stability of Structures: Elastic, Inelastic, Fracture and Damage Theories. New York: Oxford University Press. pp. 1011 pages. ISBN 0-486-42568-1. 
  • Bažant, Zden?k P.; Maurice F. Kaplan (1996). Concrete at High Temperatures: Material Properties and Mathematical Models. London: Longman (Addison-Wesley). pp. 412 pages. ISBN 0582086264. 
  • Bažant, Zden?k P.; Jaime Planas (1998). Fracture and Size Effect in Concrete and Other Quasibrittle Materials. Boca Raton and London: CRC Press. pp. 616 pages. ISBN 0-8493-8284-X. 
  • Jirásek, Milan; Zden?k P. Bažant (2002). Inelastic Analysis of Structures. London and New York: J. Wiley & Sons. pp. 735 pages. 
  • Bažant, Zden?k P. (2002). Scaling of Structural Strength. London: Hermes Penton Science. ISBN 1-56032-984-X.