Dr. Sama specializes in geotechnical engineering, foundation analysis and design, and geotechnical earthquake engineering. His project experience includes landslide investigations, failure analysis and performance evaluation of shallow and deep foundations, retaining walls, and pipelines, and post-earthquake reconnaissance and assessment. His prior research has dealt with the numerical modeling of soil and rock behavior, and the characterization of localized failure patterns, such as faulting in rocks and slip surface formation behind slopes and earth-retaining structures. In addition, he has performed laboratory experiments seeking to understand the effects of specimen preparation, fines content, and stratification on the liquefaction behavior of sandy soils.
Dr. Sama’s project experience covers a wide range of structures. He has performed design peer reviews and investigated the performance and failure of retaining structures, including tieback walls, soil nail walls, and Mechanically Stabilized Earth (MSE) walls. Dr. Sama has also evaluated the design and performance of deep foundations such as drilled shaft and piles, as well performed conceptual design of deep foundations for slope failure remediation measures. He has performed geotechnical design evaluation and analysis of external loads on buried pipelines, including vitrified clay pipes (VCP), and concrete and plastic pipes. He has also performed post-earthquake reconnaissance and assessment of private residential and public facilities, as well evaluated earthquake-induced ground movement and failures.
Dr. Sama has also investigated a wide range of site conditions. He has evaluated the performance of foundation and structures on expansive soils and collapsible soils. His experience includes laboratory testing, extraction of soil data from laboratory results, and settlement and heave analysis. Dr. Sama has conducted numerous landslide investigations which included site visits, subsurface investigation, evaluation of ground movement and groundwater monitoring data, evaluation of laboratory data, slope stability analysis, and conceptual design and evaluation of remedial measures. He also investigated the effects of excavations, construction vibrations, and dewatering activities on adjacent structures.
Prior to joining Exponent, Dr. Sama was a research assistant in the Department of Civil and Environmental Engineering at Stanford University. He has served as instructor for soil mechanics laboratory courses and has assisted in the teaching of the fundamentals of geotechnical engineering, foundation engineering, and computational geomechanics.
Sama KM. Some stability characteristics of three-invariant plasticity models. GeoCongress 2006, Atlanta, GA, 2006 (Poster presentation with P.F. Sanz).
Borja RI, Sama KM, Sanz PF. On the numerical integration of three-invariant elastoplastic constitutive models. Computer Methods in Applied Mechanics and Engineering 2003; 192(9–10):1227–1258.
Borja RI, Lin CH, Sama KM, Masada GM. Modeling non-linear ground response of non-liquefiable soils. Earthquake Engineering and Structural Dynamics 2000; 29:63–83.
Borja RI, Lai T, Regueiro R, Sama KM. Modeling strain localization in soil-nailed excavations. XI Pan-American Conference on Soil Mechanics and Geotechnical Engineering, Sao Paulo, Brazil, 1999.
Amini F, Sama KM. Behavior of stratified sand-silt-gravel composites under seismic liquefaction conditions. Soil Dynamics and Earthquake Engineering 1999; 18:445–455.
Amini F, Sama KM. Effect of sample preparation on the liquefaction behavior of layered sand-gravel mixtures. 11th European Conference on Earthquake Engineering, Rotterdam, The Netherlands, 1998.