Pitt HomeEngineering HomeContact Us
School of Engineering

Faculty and Staff Luis E. Vallejo

Professor, Civil and Environmental Engineering

Email:
Phone: (412) 624-9884
Fax: (412) 624-0135
Office: Benedum 938

Education

  • Ph.D. (Civil Engineering), University of Wisconsin- Madison, 1977

Professional Interests

Dr. Vallejo is the coordinator of the geotechnical Engineering Group in the Department of Civil and Environmental Engineering. His research interests lie in the area of shear strength of stiff and soft clays; the mechanics of crack propagation and interaction in soils forming part of earth dams, clay liners and natural slopes; the permeability of clays with isolated fissures; the mobilization mechanics of mud flows and debris flows, the stability and development of natural slopes; the liquefaction of sand lenses; and the application of fractals and fracture mechanics in geotechnical engineering.

Representative Publications:

  • Lobo-Guerrero, S., and Vallejo, L.E. (2007). Influence of pile shape and pile interaction on the crushable behavior of granular materials around driven piles: DEM analyses. Granular Matter (an International Journal) (in press).
  • Lobo-Guerrero, S., and Vallejo, L.E. (2006). Application of Weibull statistics to the tensile strength of rock aggregates. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 32, No. 6, pp. 786-790.
  • Lobo-Guerrero, S., Vallejo, L.E., and Vesga, L. (2006). Visualization of crushing evolution in granular materials under compression using DEM. International Journal of Geomechanics, Vol. 6, No. 3, pp. 195-200.
  • Lobo-Guerrero, S., and Vallejo, L.E. (2006). Modelling granular crushing in ring shear tests: experimental and numerical analyses. Soils and Foundations, Vol. 46, No. 2, pp. 147-157.
  • Lobo-Guerrero, S., and Vallejo, L.E. (2006). Discrete element method analysis of railtrack ballast degradation during cyclic loading. Granular Matter (an International Journal), Vol. 8, No. 3-4, pp. 195-204.
  • Vallejo, L.E., Lobo-Guerrero S., and Hammer, K. (2006). Degradation of a granular base under flexible pavement: DEM simulation. International Journal of Geomechanics, Vol. 6, No. 6, pp. 435-440.
  • Vesga, L.F, and Vallejo, L.E. (2006). Direct and indirect tensile tests for measuring the equivalent effective stress in a kaolinite clay. In: Unsaturated Soils, ASCE's Geotechnical Special Publication No. 147, Miller, G.A., Zapata, C.E., Houston, S., And Fredlund, D.G. (editors), pp. 1290-1301.
  • Lobo Guerrero, S. and Vallejo, L.E. (2005) DEM Analysis of Crushing Around Driven Piles in Granular Materials, Geotechnique, 55(8), pp. 617-623.
  • Chik, Z., and Vallejo, L.E. (2005). Characterization of the Angle of Repose of Binary Granular Materials. Canadian Geotechnical Journal, 42 (2), pp. 683-692.
  • Lobo-Guerrero, S. and Vallejo, L.E. (2005). Discrete Element Method Evaluation of Granular Crushing Under Direct Shear Test Conditions, ASCE Journal of Lobo-Guerrero, S. and Vallejo, L.E. (2005) DEM Analysis of Crushing Around Geotechnical and Geoenvironmental Engineering, 131(10), pp. 1295-1300.
  • Vallejo, L.E., Lobo-Guerrero, S., and Chik. Z (2005) A Network of Fractal Force Chains and Their Effect in Granular Materials under Compression. Published in the book: "Fractals in Engineering: New Trends in Theory and Applications", J. Levy-Vehel and E. Lutton (eds.), Springer Verlag, London, pp. 67-80.
  • Lobo-Guerrero, S., and Vallejo, L.E. (2005). DEM Evaluation of the Crushing of a Granular Gouge in Fault Zones; Proceedings of Alaska Rocks 2005, The 40th U.S. Symposium on Rock Mechanics (USRMS): Rock Mechanics for Energy, Mineral and Infrastructure Development in the Northern Regions, June 2005, Anchorage, Alaska. CD-ROM.
  • Vallejo, L.E., and Lobo-Guerrero, S. (2005). Evaluation of Porosity Changes in a Granular Material Undergoing Particle Crushing Using DEM; Proceeding of the 3rd Biot Conference on Poromechanics, May 2005, University of Oklahoma, Norman, Oklahoma. pp. 573-578.
  • Lobo-Guerrero, S. and Vallejo, L.E. (2005). Analyais of Crushing of Granular Materials under Isotropic and Biaxial Stress Conditions. Soils and Foundations, 45(4), pp. 79-87.
  • Lobo-Guerrero, S. and Vallejo, L.E. (2005) DEM Analysis of Crushing Around Driven Piles in Granular Materials, Geotechnique, 55(8), pp. 617-623.
  • Lobo-Guerrero, S. and Vallejo, L.E. (2005)Discrete Element Method Evaluation of Granular Crushing Under Direct Shear Test Conditions, ASCE Journal of Geotechnical and Geoenvironmental Engineering, 131(10), pp. 1295-1300.
  • Lobo-Guerrero, S., and Vallejo, L.E. (2005). DEM Evaluation of the Crushing of a Granular Gouge in Fault Zones; Proceedings of Alaska Rocks 2005, The 40th U.S. Symposium on Rock Mechanics (USRMS): Rock Mechanics for Energy, Mineral and Infrastructure Development in the Northern Regions, June 2005, Anchorage, Alaska. CD-ROM.
  • Vallejo, L.E., Lobo-Guerrero, S., and Chik. Z (2005) A Network of Fractal Force Chains and Their Effect in Granular Materials under Compression, Published in the book: "Fractals in Engineering: New Trends in Theory and Applications", J. Levy-Vehel and E. Lutton (eds.), Springer Verlag, London, pp. 67-80.
  • Vallejo, L.E., and Lobo-Guerrero, S. (2005). Evaluation of Porosity Changes in a Granular Material Undergoing Particle Crushing Using DEM; Proceeding of the 3rd Biot Conference on Poromechanics, May 2005, University of Oklahoma, Norman, Oklahoma. pp. 573-578.
  • Vallejo, L.E., Stewart-Murphy, A., "Influence of Pore Wall Roughness on the Slaking of Shales", Proceedings of the 38th Rock Mechanics Symposium: Rock Mechanics in the National Interest, Vol. 1, pp. 93-98, Washington, DC, July 7-10, 2001, D. Elsworth, J. P. Tinucci, and K. A. Heasley (Editors)
  • Vallejo, L.E., "Analysis of the Pore Structure in the Shear Zone of Granular Materials", Proceedings of the 15th International Conference on Soil Mechanics and Geotechnical Engineering, Istanbul, Turkey, Vol. 1, pp. 629-631, August 27-31, 2001.
  • Vallejo, L.E. "Interpretation of the Limits in Shear Strength in Binary Granular Mixtures." Canadian Geotechnical Journal (2001), Volume 38, Number 5, pp. 1097-1104, October.
  • Vallejo, L.E. "Fractal Assessment of the Surface Texture of Pavements." International Journal of Pavement Engineering (2001), Vol. 2, No. 2, pp. 149-156.

Leading Researchers

Faculty research encompasses the major areas of civil engineering

You are using a browser that does not support current Web standards. Although this site is viewable in all browsers, it will look much better in a browser that supports Web standards.