NICHOLAS SITAR
Professor & Director of the Earthquake Engineering Center

Phone: (510) 643-8623

Campus Office: 449 Davis Hall

nsitar@ce.berkeley.edu

 

CURRENT COURSES:

Fall 2007

o        CEE 281 ENGINEERING GEOLOGY -  Tu, Th 9:30-11 a.m., 406 Davis Hall

o        F 1-4 p.m., 406 Davis Hall

Spring 2008

o        CEE 70 ENGINEERING GEOLOGY -  Tu, Th 12:30- 2 p.m., 502 Davis Hall

 

OFFICE HOURS – Spring 2008:

o        Tu, W 10 – 11:30 a.m.

EDUCATION AND EXPERIENCE

B.A.Sc. Geological Engineering, University of Windsor, 1973.

M.S. Geology - Hydrogeology, Stanford University, 1975.

Ph.D. Civil Engineering - Geotechnical, Stanford University, 1979.

Registered Geological Engineer in British Columbia.

TEACHING AND RESEARCH

On the undergraduate level, Professor Sitar has taught introductory courses in Engineering Geology, Soil Mechanics and Foundation Engineering, and Groundwater and Seepage. On the graduate level he is currently teaching Engineering Geology and Environmental Geotechnics. His current research interests include seismic slope stability, seismic response of reinforced soil structures, analysis of seismically induced earth pressures on retaining structures, behavior of discontinuous rock masses, and the application of GIS to seismic slope stability. In Environmental Geotechnics his research interests are in groundwater remediation and in probabilistic risk assessment applied to groundwater flow and contaminant transport. The emphasis is on developing methodologies for practical field applications.

 

Application of Wireless Sensor Technology to Environmental Monitoring

 

Ubiquitous wireless sensor networks have numerous potential applications in many areas.  The main objective of this research is to develop affordable, reliable wireless instrumentation for a variety of applications such as wild fire monitoring, landslide and rock fall monitoring, and monitoring on underground space.

Application of Reliability Methods to Probabilistic Slope Stability Analysis

It is well recognized that the natural heterogeneity of the subsurface environment introduces a significant level of uncertainty in making predictions of the expected contaminant pathways and concentration levels. The approach taken in this work is to use reliability methods developed primarily in structural engineering and to apply them to slope stability analyses in soil and rock. These techniques appear to offer considerable computational advantage in the analysis of events with a very low probability of occurrence. The current emphasis is on development of new applications.

Earthquake Engineering

Evaluation of Seismically Induced Earth Pressures on Retaining Structures – It is generally accepted that retaining structures are subject to increased loads due to seismic loading.  However, observations in a number of recent earthquakes suggest that well designed retaining structures perform quite well even if they are not particularly designed for seismic loading.  The purpose of this current research is to perform seismic centrifuge studies of seismically induced earth pressure in order to calibrate analytical techniques used in design.

 

Seismic Response of Improved Ground Ground improvement using different techniques is extensively used to mitigate the seismically induced liquefaction hazard.  In this project, dynamic centrifuge tests are being used to evaluate the influence of the geometry of the improved zone on the expected performance of the improved ground.

Analysis of Deformation of Discontinous Media  and Rock Slope Stability

The deformations of large rock masses are governed among other factors by the kinematics of the interaction between individual blocks. The Discontinuous Deformation Analysis (DDA) method is being used to develop a better understanding of this mechanism of deformation. A new PC-based version of the DDA code for Windows 95 and NT has been developed as a part of this effort.

RECENT PUBLICATIONS

  • Grubb, D. and Sitar, N., "Evaluation of Technologies for In-Situ Cleanup of DNAPL Contaminated Sites," U.S. EPA, Office of Research and Development, Report No. EPA/600/R-94/120, August, 1994, 173p.
  • Grubb, D., and Sitar, N., "Review of Technologies for In-Situ Cleanup of DNAPLs," Proceedings, Geoenvironment 2000, Acar, Y.B. and Daniel D.E. editors, ASCE, Geotech. Spec. Pub. No. 46, Vol. 2, 1995, 1646-1662.
  • MacLaughlin, M.M., Sitar, N., and Dobson, T.S., "Slope Stability Evaluation Using Discontinuous Deformation Analysis," Proc. 31st Symp. on Engineering Geology and Geotechnical Engineering, Logan, Utah, March 29-31, 1995, pp. 144-156.
  • Ashford, S.A., and Sitar, N., "Analysis of Inclined Shear Waves in Vertical Bluffs," Proc. Third Int. Conf. on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, April 2-7, 1995, St. Louis, Missouri, Vol. II, pp. 693-697.
  • Anderson, S.A., and Sitar, N., "Shear Strength and Slope Stability in a Shallow Clayey Soil Regolith," in Geological Society of America, Reviews in Engineering Geology, Volume X, W.C. Haneberg and S.A. Anderson, editors, 1995, pp. 1-11.
  • Udell, K.S., Grubb, D.G., and Sitar, N., "Technologies for in Situ Cleanup of Contaminated Sites," Central European Journal of Public Health, Vol. 3, No.2, May 1995, pp.67-76.
  • Stewart, J.P., Chang, S.W., Bray, J.D., Seed, R.B., Sitar, N., Riemer, M.F., "A Report on Geotechnical Aspects of the January 17, 1994, Northridge Earthquake," Seismological Research Letters, Vol. 66, No. 3, May-June 1995, pp.7-19.
  • Anderson, S.A., and Sitar, N., "Analysis of Rainfall-Induced Debris Flows," J. of Geotechnical Engineering, ASCE, Vol. 121, No. 7, Jul. 1995, pp. 544-552.
  • Sitar, N. (editor and co-author with 18 members of the geotechnical reconnaissance team), "Geotechnical Reconnaissance of the Effects of the January 17, 1995, Hyogoken-Nanbu Earthquake, Japan," Earthquake Engineering Research Center, University of California, Report No. 95-01, August 1995, 143 p.
  • Ashford, S.A., and Sitar, N., "Topographic Amplification in Steep Slopes," Proc. First Int. Conf. on Earthquake Geotechnical Engrg., K. Ishihara ed., A.A. Balkema, Rotterdam, November, 1995, pp. 1153-1158.
  • MacLaughlin, M.M. and Sitar, N., "Kinematics of Sliding on a Hinged Failure Surface," in Rock Mechanics: Tools and Techniques, Aubertin M., Hasani, F., and Mitri H., eds., Proc. of the 2nd North American Rock Mechanics Symposium: NARMS ‘96, Balkema, Rotterdam, Vol. 2, June, 1996, pp. 2025-2030.
  • Shewbridge, S.E. and Sitar, N., "Formation of Shear Zones in Reinforced Sand," J. of Geotechnical Engineering, ASCE, 122(11), 1996, pp. 873-885.
  • Anderson, S.A. and Sitar, N., "Analysis of Rainfall-Induced Debris Flows," Closure, J. of Geotechnical Engineering, ASCE, 122(12), 1996, pp. 1026-1027.
  • Grubb, D.G. and Sitar, N., "Experimental Evaluation of in-situ displacement of Trichloroethene (TCE) from aquifer media using ethanol," Proceedings, Second International Congress on Environmental Geotechnics, Osaka, November 1996, M. Kamon, editor, A.A. Balkema, Rotterdam, Vol. 2, pp. 1005-1009.
  • Zornberg, J.G., Sitar, N., and Mitchell, J.K., "Failure of Steep Reinforced Soil Slopes," Geosynthetics ‘97 Conference Proceedings, Long Beach, CA, Industrial Fabrics Association International, publisher, Vol.1, 1997, pp. 55-72.
  • Ashford, S.A., Sitar, N., Lysmer, J., and Deng, N., "Topographic Effects on the Seismic Response of Steep Slopes," Bulletin of the Seismological Society of America, 87(3), 1997, pp. 701-709.
  • Ashford, S.A., and Sitar, N., "Analysis of Topographic Amplification of Inclined Shear Waves in a Steep Coastal Bluff," Bulletin of the Seismological Society of America, 87(3), 1997, pp. 692-700.
  • Dietrich, W.E., and Sitar, N., "Geoscience and Geotechnical Engineering Aspects of Debris-Flow Hazard Assessment," Invited Overview Paper, in Debris-Flow Hazards Mitigation: Mechanics, Prediction, and Assessment, C-L. Chen, ed., Proceedings of the First Int. Conf., San Francisco, 1997, ASCE, pp. 656-676.
  • Zornberg, J.G., Sitar, N. and Mitchell, J.K., "Failure Mechanisms in Geosynthetically Reinforced Soil Slopes," Proceedings of the Fourteenth Int. Conf. on Soil Mechanics and Foundation Engineering, Hamburg, Germany, 1997, Vol. 3, pp. 1661-1664.
  • Sitar, N., Ashford, S.A., Stewart, J.P. and Nova-Roessig, L., "Seismic Response of Steep Natural Slopes, Structural Fills, and Reinforced Soil Slopes and Walls," Invited Paper, in Seismic Behavior of Ground and Geotechnical Structures, Seco e Pinto, ed., Proceedings of a Special Technical Session on Earthquake Geotechnical Engineering at the Fourteenth Int. Conf. on Soil Mechanics and Foundation Engineering, Hamburg, Germany, 1997, A.A. Balkema, pp. 341-350.
  • Zornberg, J.G., Mitchell, J.K. and Sitar, N., "Testing of Reinforced Slopes in a Geotechnical Centrifuge," Geotechnical Testing Journal, ASTM, 1997, V20 N4: 470-480.
  • Zornberg, J.G., Sitar, N., and Mitchell, J.K., "Performance of Geosynthetically Reinforced Soil Structures at Failure," J. of Geotechnical and Geoenvironmental Engrg., ASCE, Aug. 1998, Vol. 124, No. 8, pp. 670-683.
  • Zornberg, J.G., Sitar, N., and Mitchell, J.K., "Limit Equilibrium as a Basis for Design of Geosynthetically Reinforced Slopes," J. of Geotechnical and Geoenvironmental Engrg., ASCE, Aug. 1998, Vol. 124, No. 8, pp. 684-698.
  • Nova-Roessig, L., and Sitar, N., "Centrifuge Studies of Seismic Response of Reinforced Soil Slopes," in Geotechnical Engineering and Soil Dynamics, P.Dakoulas, M. Yegian, R.D. Holtz, editors, Geotechnical Special Publication No. 57, ASCE, 1998, Vol. 1, pp. 458-468.
  • Rau, G.A., and Sitar, N., "Post-Cyclic Response of Holocene Bay Mud from San Francisco," in Geotechnical Engineering and Soil Dynamics, P.Dakoulas, M. Yegian, R.D. Holtz, editors, Geotechnical Special Publication No. 57, ASCE, 1998, Vol. 1, pp. 246-257.
  • MacLaughlin, M.M., Sitar, N., and Dobson, T.S., "Discontinuous Deformation Analysis in Slope Stability Studies," Int. J. for Numerical and Analytical Methods in Geomechanics, accepted for publication
  • Sitar, N., and MacLaughlin, M.M., "Kinematics and Discontinuous Deformation Analysis of Landslide Movement," Invited Keynote Lecture, II Panamerican Symposium on Landslides, Rio de Janeiro, Nov. 10-14th, 1997
  • Nova-Roessig, L., and Sitar, N., "Centrifuge Model Studies of the Seismic Response of Reinforced Soil Slopes," Proc. of the Second Int. Conf. on Earthquake Geotechnical Engineering, Seco e Pinto ed., Balkema, Rotterdam, 1999, pp. 679-684.
  • Sitar, N., and Nova-Roessig, L., "A Review of Experimental Studies of Seismic Behavior of Reinforced Soil Structures," Invited Paper, Proc. of the Second Int. Conf. on Earthquake Geotechnical Engineering, Seco e Pinto ed., Balkema, Rotterdam, 1999, pp. 1083- 1088.
  • MacLaughlin, M.M. and Sitar, N., "A Gravity Turn-On Routine for DDA," Proc. Third Int. Conf. on Analysis of Discontinuous Deformation, B. Amadei ed., ARMA, Washington, 1999, pp. 65-74.
  • Grubb, D.G. and Sitar, N., "Horizontal Ethanol Floods in Clean, Uniform and Layered Sandpacks under Confined Conditions," Water Resources Research, AGU, 1999, 35(11), 3291-3302.
  • Grubb, D.G. and Sitar, N., "Mobilization of Trichloroethylene (TCE) During Ethanol Flooding in Uniform and Layered Sandpacks," Water Resources Research, AGU, 1999, 35(11), 3275-3290.
  • Khazai, B.and Sitar, N., "Assessment of Seismic Slope Stability Using GIS Modeling," Geographic Information Sciences, Vol.5, No. 2, 2000, 121-128.
  • Doolin, D.M. and Sitar, N., "DDAML - discontinuous deformation analysis markup language," Int. J. of Rock Mechanics and Mining Sciences, V38, N3, April, 2001, 467-474.
  • Zornberg, J.G., Sitar, N. and Mitchell, J.K., "Performance of geosynthetic reinforced slopes at failure - Closure," J. of Geot. and Geoenv. Engrg., V126, N3, March, 2001, 285-286.
  • Sitar, N. and Khazai, B., "Characteristics of Seismically Induced Landslides in Recent Earthquakes," Invited Keynote Paper, Proc. Int. Conf. on Landslides: Causes, Impacts and Countermeasures, M. Kuhne et al., editors, Verlag Gluckauf GmbH, Essen, 2001, 227-237.
  • Doolin, D.M. and Sitar, N., “Numerical accuracy of the DDA solution algorithm: a single sliding block case,” In: Rock Mechanics in the National Interest, Proc. 38th U.S. Rock Mechanics Symposium, Washington D.C., July 5-7, 2001, Balkema, Rotterdam, pp. 1429-1435.
  • MacLaughlin, M., Sitar, N., Doolin, D. and Abbot, T., "Investigation of Slope-Stability Kinematics Using Discontinuous Deformation Analysis,”  Int. Journal of Rock Mech. & Mining Sciences, July 2001, V38, N5, 753-762.
  • Ashford, S.A. and Sitar, N., "Effect of Element Size on the Static Finite Element Analysis of Steep Slopes,” Int. J. for Numerical and Analytical Methods in Geomechanics, V25, N14, Dec. 2001, 1361-1376.

·         Ashford, S.A. and Sitar, N., “Simplified Method for Evaluating Seismic Stability of Steep Slopes,” J. of Geotech. And Geoenv. Engineering, ASCE, Feb. 2002, V128, N2, 119-128.

·         Mok, C.M., Sitar, N., and Der Kiureghian, A, "Improving Accuracy of First-order Reliability Estimate by Importance Sampling Simulations", Fourth International Conference on Calibration and Reliability in Groundwater Modelling-a few steps closer to reality, Prague, Czech Republic, 17-20 June, 2002, IAHS, Modelcare 2002.

·         E.A. Hausler, N. Sitar, O. Matsuo and M. Okamura, “Remediation Zone Geometry Under Shallow Foundations: A Comparison of Model Tests on Two Dynamic Centrifuges,” Proceedings, International Conference on Physical Modelling in Geotechnics, St. John’s, Newfoundland, Canada, July 10-12, 2002, 557-562.

·         Doolin, D.M. and Sitar, N., “Displacement Accuracy of the DDA Method Applied to a Sliding Block,” J. of Eng. Mech., ASCE, Nov. 2002, 1158-1168.

·         Kim, J. and Sitar, N., “Importance of Spatial and Temporal Variability in the Analysis of Seismically-Induced Slope Deformation,” Proceedings, ICASP 9, San Francisco, CA, July 2003, 1315-1322.

·         Jimenez-Rodriguez, R. and Sitar, N., “Probabilistic Analysis of Unstable Wedges in Excavations,” Proceedings, ICASP 9, San Francisco, CA, July 2003, pp. 1301-1308.

·         Harp, E.L., Jibson R.W., Kayen R.E., Keefer D.K., Sherrod B.L., Carver G.A., Collins B.D., Moss R.E.S., Sitar N., “Landslides and Liquefaction triggered by the M7.9 Denali Fault Earthquake fo 3 November 2002”, GSA Today, August, 2003 pp.4-10.

·         Khazai, B. and Sitar, N., “Evaluation of Factors Controlling Earthquake-Induced Landslides Caused by Chi-Chi Earthquake and Comparison with the Northridge and Loma Prieta Events,” Engineering Geology, Volume 71, Issues 1-2, January 2004, Pages 79-95.

·         Kim, J. and Sitar, N., “Direct Estimation of Yield Acceleration in Seismic Slope Stability Analyses”, J. of Geotech. and Geoenv. Engineering, ASCE, Jan. 2004, 111-115.

·         Doolin, D.M. and Sitar, N., “Time Integration in Discontinuous Deformation Analysis,” J. of Eng. Mech., ASCE, March 2004, 249-258.

·         Kayen, R., Thompson E., Minasian D., Collins B., Moss E.R.S., Sitar, N., Carver, G. “Geotechnical Observations of the November 3, 2002 M7.9 Denali Fault Earthquake,” Proceedings, Fifth International Conf. on Case Histories in Geotechnical Engineering, New York, NY, April 13-17, 2004.

·         Collins, B.D. and Sitar, N., “Application of High Resolution 3D Laser Scanning to Slope Stability Studies,” Proc. 39th Annual Symp. On Eng. Geology and Geot. Engineering, Butte, MT, May 18-21, 2004, 79-92.

·         Jimenez-Rodriguez, R. and Sitar N., “Identification of Rock Conditions for Tunnel Support Using a Statistical Classification Approach,” Proc. 39th Annual Symp. On Eng. Geology and Geot. Engineering, Butte, MT, May 18-21, 2004, 257-268.

·         Wang, G. and Sitar, N., “Numerical Analysis of Piles in Elasto-Plastic Soils Under Axial Loading,” Proc. 17th Eng. Mech. Conf., ASCE, Newark, DE, June 13-16, 2004.

·         Kayen, R., Thompson, E., Minasian, D., Moss, R.E.S., Collins, B.D., Sitar, N., Dreger, D., and Carver, C., “Geotechnical Reconnaissance of the 2002 Denali Fault, Alaska, Earthquake,” Earthquake Spectra, EERI, Vol. 20, No. 3, August 2004, pp. 639-667.

·         Collins, B.D., and Sitar, N., "Monitoring of Coastal Bluff Stability Using High Resolution 3D Laser Scanning" in Site Characterization and Modeling, Geotechnical Special Publication No. 138, ASCE, GeoInstitute, January, 2005.

·         Doolin, D.M., and Sitar, N. "Wireless Sensors for Wildfire Monitoring," Smart Structures and Materials 2005: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, M. Tomizuka ed., Proceedings of SPIE, Vol. 5765, San Diego, CA, March 2005.

·         Tsesarsky, M., Hatzor, Y., and Sitar, N., "Dynamic displacement of a block on an inclined plane: Analytical, experimental and DDA results", Rock Mechanics and Rock Engineering, v 38, n 2, April, 2005, p 153-167

·         Sitar, N., MacLaughlin, M.M., and Doolin, D.M., “Influence of Kinematics on Landslide Mobility and Failure Mode”, Journal of Geotechnical and Geoenvironmental Engineering, Vol. 131, No. 6, June, 2005.

·         Collins, B.D., and Sitar, N., "Failure Mode Identification and Hazard Quantification for Coastal Bluff Landslides," Proceedings 2005 International Conference on Landslide Risk Management, Editors O. Hungr and R. Fell R. Couture, and E. Eberhardt, Vancouver, BC, Canada, June 2005, pp. 487-496.

·         Jiménez-Rodríguez R. and Sitar N., "Probabilistic rock wedge stability analysis using system reliability methods", Paper J0880, CD Proceedings 2005 International Conference on Landslide Risk Management, Editors O. Hungr and R. Fell, R. Couture, and E. Eberhardt, Vancouver, BC, Canada, June 2005.

·         Jimenez-Rodriguez R. and Sitar, N. "Probabilistic identification of removable wedges in rock slopes: Influence of stochastic model parameters”, Proceedings, Eurorock 2005 - Impact of Human Activity on Geological Environment, P. Konecny ed., A.A. Balkema, Netherlands, May 2005.

·         Jimenez-Rodriguez R. and Sitar, N. "Maximum likelihood inference of discontinuity trace lengths based on observations at rock outcrops”, GeoEngineering Report No. UCB/GE-2005/01.

·         Jimenez-Rodriguez R. and Sitar, N. "Probabilistic identification of removable wedges in rock slopes: Influence of stochastic model parameters,” GeoEngineering Report No. UCB/GE-2005/02, May 2005, 51 p.

·         Jimenez-Rodriquez R., Sitar, N., and Bartlett, P. "Maximum likelihood estimation of trace length distribution parameters using the EM algorithm", in Prediction, Analysis and Design in Geomechanical Applications: Proceedings of the Eleventh International Conference on Computer Methods and Advances in Geomechanics (IACMAG-2005), G. Barla and M. Barla, eds., Torino, Italy, 19-24 June, 2005, pp. 619-626.

·         Jiménez-Rodríguez, R.,  Sitar, N., and Chacón, J. “Caracterización de discontinuidades en macizos rocosos mediante modelos gráficos probabilísticos” [Characterization of discontinuities in rock masses by means of probabilistic graphical models], Métodos Numéricos en Ingeniería 2005, J.L. Pérez Aparicio, A. Rodríguez Ferrán, J.A.C. Martins, R. Gallego and J. César de Sá editors, SEMNI, Sociedad Española de Métodos Numéricos en Ingeniería, publisher, Extended abstract in Proceedings; full paper on CD-Rom, 2005.

·         Wang G, Liu X.H., Li S.F., Sitar, N., “Smart element method II. An element based on the finite Eshelby tensor,” Int. J. for Numerical Methods in Engineering, 64 (10): 1303-1333, Nov. 2005.

·         Nova-Roessig, L. and Sitar, N., “Centrifuge Model Studies of the Seismic Response of Reinforced Soil Slopes” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 132, No. 3, March 1, 2006.

·         Jimenez-Rodriguez, R., Sitar, N.; and Chacon, J., “System reliability approach to rock slope stability”, International Journal of Rock Mechanics and Mining Sciences, v 43, n 6, September, 2006, p 847-859.

·         Jimenez-Rodriguez, R. and Sitar, N., “Inference of discontinuity trace length distributions using statistical graphical models”, International Journal of Rock Mechanics and Mining Sciences, v 43, n 6, September, 2006, p 877-893.

·         Jimenez-Rodriguez, R. and Sitar, N., “A spectral method for clustering of rock discontinuity sets”, International Journal of Rock Mechanics and Mining Sciences, v 43, n 7, October, 2006, p 1052-1061.

 

 

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