Professor, Civil and Environmental Engineering | Civil and Environmental Engineering
Troy, NY, UNITED STATES
Specializes in centrifuge modeling, soil-structure interaction, soil remediation, field advanced sensing, and data visualization
B.S., Structural Engineering
M.S., Geotechnical Engineering
1994
Ph.D., Geotechnical Engineering
1997
Model Tests and Numerical Simulations of Liquefaction and Lateral Spreading
Bruce L. Kutter, Trevor J. Carey, Nicholas Stone, Bao Li Zheng, Andreas Gavras, Majid T. Manzari, Mourad Zeghal, Tarek Abdoun, Evangelia Korre, Sandra Escoffier, Stuart K. Haigh, Gopal S. P. Madabhushi, Srikanth S. C. Madabhushi, Wen-Yi Hung, Ting-Wei Liao
2019-11-16
This paper compares experimental results from every facility for LEAP-UCD-2017. The specified experiment consisted of a submerged medium-dense clean sand with a 5-degree slope subjected to 1 Hz ramped sine wave base motion in a rigid container. The ground motions and soil density were intentionally varied from experiment to experiment in hopes of defining the slope of the relational trend between response (e.g., displacement, pore pressure), intensity of shaking, and density or relative density. This paper is also intended to serve as a useful starting point for overview of the experimental results and to help others find specific experiments if they want to select a subset for further analysis. The results of the experiments show significant differences between each other, but the responses show a significant correlation, R2 ~ 0.7–0.8, to the known variation of the input parameters.
view moreJournal of Geotechnical and Geoenvironmental Engineering
R. Dobry, M.ASCE; S. Thevanayagam, M.ASCE; W. El-Sekelly, M.ASCE; T. Abdoun, M.ASCE
2019-10-01
The effect of preshaking and repeated liquefaction on liquefaction resistance was studied in a large-scale shaking table experiment, in which a sequence of 51 shakings was applied to the base of a 5-m uniform deposit of saturated clean Ottawa sand. Three event types were used in a very intense repeated pattern: mild preshaking Events A, stronger preshaking Events B, and extensive liquefaction Events C, with each Event C typically liquefying most or all of the deposit. Relative density, cone penetration test (CPT) tip resistance, and liquefaction resistance to Events A and B were found to increase significantly throughout the 51-shaking sequence, with the shear wave velocity (Vs) increasing slightly. However, the CPT tip resistance and liquefaction resistance decreased temporarily after each Event C, recovering rapidly with additional preshaking—presumably due to a decrease and subsequent increase in the soil lateral stresses. The results for the different shakings were compared with available CPT- and Vs-based field liquefaction charts, with and without accounting for the fact that the soil deposit was much younger than the case histories covered by the charts (age factor). The liquefaction response for Events A, B, and C was reasonably well predicted by the CPT chart when the age factor was considered, including Events A immediately after liquefaction by an Event C. The implications of the research were discussed for the geologic age, preshaking and liquefaction effects observed in the field, including reliquefaction response of the same site by milder aftershocks after the main earthquake shock.
view moreModel Tests and Numerical Simulations of Liquefaction and Lateral Spreading
Evangelia Korre, Tarek Abdoun, Mourad Zeghal
2019-11-16
The Liquefaction Experiments and Analysis Projects (LEAP) is an international effort to use experimental data from physical modeling at different (international) centrifuge facilities to validate soil liquefaction numerical models and analysis tools. The goals of LEAP-2017 experimental efforts are to assess the repeatability potential at each facility, the reproducibility of centrifuge tests among different facilities, and the sensitivity of the experimental results to variation of testing parameters and conditions. A number of tests of the same (sloping deposit) centrifuge model were repeated at Rensselaer Polytechnic Institute in 2015 and 2017. This paper focuses on two specific tests to assess and demonstrate repeatability at this facility.
view moreSoil Dynamics and Earthquake Engineering
Vicente Mercado, Felipe Ochoa-Cornejo, Rodrigo Astrozac, Waleed El-Sekelly, Tarek Abdoun, Cesar Pastén, Francisco Hernández
2019-08-01
This paper combines data from laboratory, centrifuge testing, and numerical tools to highlight the predictive capabilities of the Bayesian method for uncertainty quantification and propagation. The Bayesian approach is employed to estimate uncertain parameters of a multi-yield constitutive model using data from cyclic-triaxial testing. Then, predictive capabilities of a finite element model in reproducing the dynamic response of a saturated sand deposit are investigated by drawing samples from the estimated posterior probability distributions of the constitutive model parameters. Variability of the predicted responses due to estimation uncertainty is evaluated. The response of centrifuge tests is used to assess the simulated responses.
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