Jonathan D. Bray


“RAPID/Collaborative Research: Advanced Site Characterization of Key Ground Motion and Ground Failure Case Histories Resulting from the Mw7.8 Kaikoura, New Zealand, Earthquake," National Science Foundation, 02/17-01/18, $39,971; Principal Investigator.

“Liquefaction Consequences of Stratified Deposits of Silty Soils,” National Science Foundation, 07/16-06/19, $489,337; Principal Investigator.

“United States-New Zealand-Japan International Workshop on Liquefaction-Induced Ground Movements Effects,” National Science Foundation, 07/16-12/17, $99,942; Principal Investigator.

“Collaborative Research: Geotechnical Extreme Events Reconnaissance (GEER) Association: Turning Disaster into Knowledge,” National Science Foundation, 08/13-07/18, $415,733; Principal Investigator.


Simplified Seismic Slope Displacement Procedures

Professor Jonathan D. Bray in collaboration with Dr. Thaleia Travasarou and Mr. Jorge Macedo have developed simplified procedures for evaluating the seismic slope stability of earth/waste structure and natural slopes. The procedures are described in these papers:

Bray, J.D. and Travasarou, T. (2007) “Simplified Procedure for Estimating Earthquake-Induced Deviatoric Slope Displacements,” J. of Geotech. & Geoenv. Engrg., ASCE, Vol. 133(4), 381-392.

Bray, J.D. and Travasarou, T. (2009) “Pseudostatic Coefficient for Use in Simplified Seismic Slope Stability Evaluation,” J. of Geotechnical and Geoenv. Engineering, ASCE, 135(9), 1336-1340.

Bray, J.D., Macedo, J. and Travasarou, T. (2017) “Simplified Procedure for Estimating Seismic Slope Displacements for Subduction Zone Earthquakes,” J. of Geotechnical and Geoenv. Engineering, ASCE, under review. *Until published use: Macedo, J., Bray, J.D., and Travasarou, T. (2017) “Simplified Procedure for Estimating Seismic Slope Displacements in Subduction Zones,” 16th World Conf. EQ Eng., Santiago, Chile, Paper 3563.

Simplified Seismic Slope Stability Excel Spreadsheets:



Modified-UBCSAND User-Defined Model

This model was developed at UC Berkeley by Dr. Nicolas K. Oettle in collaboration with Professor Jonathan D. Bray. The models are based on UBCSAND developed by Professor Peter Byrnes, Michael Beaty, et al. Documentation of UBCSAND can be found on the FLAC website. The modifications to the UBCSAND model for use in surface fault rupture interaction analysis can be found in these papers:

Oettle, N, and Bray, J.D., “Fault Rupture Propagation through Previously Ruptured Soil,” JGGE, ASCE, Vol. 139(10), 2013, pp. 1637-1647.

Oettle, N, and Bray, J.D., “Geotechnical Mitigation Strategies for Earthquake Surface Fault Rupture,” JGGE, ASCE, Vol. 139(11), 2013, pp. 1864-1874.

Modified-UBCSAND Model: