Yousef bozorgnia biography definition

Visit www. Center By-Laws. Request Interview. Skip to main content. Log In Register. Home My Account Dashboard. About Me Publications. Bozorgnia has extensively published research papers on seismic hazard analysis and structural earthquake engineering. Bozorgnia has been the Principal Investigator of the Next-Generation Attenuation NGA projects, a set of large multi-researcher and multi-institution projects with worldwide impacts on seismic hazard analysis and design.

Bozorgnia received his B. Bozorgnia with the prestigious Bruce Bolt Medal for his extensive contributions to seismic hazard analysis and earthquake engineering. Bozorgnia is the Principal Investigator of numerous large multidisciplinary research projects, including: seismic risk analyses of natural gas and water infrastructure, seismic GeoHazard analysis of lifelines, earthquake analysis of smart cities, probabilistic fault displacement hazard initiative, among others.

Add New. Stewart, J. SCEC Contribution Zengin, E. Clayton, R. The database is part of a multi-year research effort with the main goal of developing improved procedures to evaluate liquefaction susceptibility, yousef bozorgnia biography definition, and consequences. In NGL, a case-history is defined as the intersection of three components: 1 a site, 2 an earthquake event, and 3 post-earthquake observations.

The NGL database hosts case-histories used to develop existing liquefaction models, as well as new data derived from recent earthquakes such as the Canterbury earthquake sequence, the Tohoku-Oki earthquake, and th This database includes pseudo-spectral accelerations PSA for 11 damping ratios between 0. Development of NGA-Subduction database.

Kishida 1Y. Bozorgnia 2N. Abrahamson 3S. Ahdi 4T. Ancheta 5D. Boore 6K. Campbell 7B. Chiou 8R. Darragh 9N. Gregor 10R. Kamai 11D. Kwak 12A. Kwok 13P. Lin 14H. Magistrale 15S. Midorikawa 16G. Parker 17H. Silva 19J. Stewart 20C. Tsai 21K. Wooddell 22R. Selection of yousef bozorgnia biography definition vibration theory procedures for the NGA-East project and ground-motion modeling.

PSA is a relatively simple metric that correlates well with the response of several engineering systems and is a metric commonly used in engineering evaluations; however, characteristics of the PSA calculation make application of scaling factors dependent on the frequency content of the input motion, complicating the development and adaptability of GMMs.

By comparison, Fourier amplitude spectrum FAS represents ground-motion amplitudes that are completely independent from the amplitudes at other frequencies, making them an attractive alternative for GMM development. Using RVT to compute the expected peak response in the Ground motion time series are critical elements of earthquake engineering for performance analysi At present, the number of available instruments to record the free-field ground motions in the US is generally sparse.

Therefore, ground motion estimation methods are used to obtain input motion estimates at locations where there is no available instrumentation. All evaluations impl The recorded PGA was significantly larger than those at the nearby surface sites. This study considers surface and downhole recordings from the additional 28 earthquakes recorded at the same arrays to understand the effects of wave propagation and site response at these arrays.

Several site response analyses are performed to understand soil nonlinearity using the observed ground accelerations during the South Napa sequence. Apparent shear wave velocities are calculated from downhole records, which show clear reduction as ground motion intensity increases. Empirical transfer functions EFTs are also calculated in which the resonance frequencies became lower during strong shaking during the South Napa main shock.

The in-situ critical d Post earthquake studies show that the primary cause of reinforced concrete building collapse duri In cast-in-place beam-column frames, the most common cause of collapse is failure of columns, beam-column joints, or both. This study emphasizes failure of columns using data from laboratory studies. Failure models are incorporated in nonlinear dynamic analysis software, enabling complete dynamic simulations of building response including component failure and progression of collapse.

This approach enables more realistic simulation of building collapse than is possible using simplified assessment procedures, and provides insight into the conditions that cause collapse and the variability of collapse as a function of input ground motions. Using the version of the NGA-West2 project database of ground motions recorded from worldwide shallow crustal earthquakes in active tectonic regions, dependencies of the DSF on parameters such as spectral period, damping ratio, moment magnitude, source-to-site distance, and duration are examined.

The strong influence of duration is captured by inclusion of both magnitude and distance in the DSF model. Influences of other factors such as local site conditions are also examined; however, they do not show significant influence on DSF. The proposed model for DSF provides functional forms for the median value and the logarithmic standard deviation of DSF.

The model is developed based on the empirical data of spectral ordinates, and thus, is independent of any specific GMPE. It is also heteroscedastic, where the variance is a function of the damping ratio. Cumulative absolute velocity CAV has been proposed as an instrumental index to quantify the pot We explore this idea further by developing a relationship between the standardized version of CAV and the Japan Meteorological Agency JMA and Modified Mercalli MMI instrumental seismic intensities in order to correlate standardized CAV with the qualitative descriptions of damage in the corresponding macroseismic intensity scales.

Such an analysis statistically identifies the threshold values of standardized CAV associated with the onset of damage to buildings of good design and construction that is inherent in these scales. Based on these results, we suggest that CAV might be used to rapidly assess the potential damage to a general class of conventional structures after an earthquake.

Direct hazard analysis of inelastic response spectra.

Yousef bozorgnia biography definition

In this paper we present results of direct probabilistic and deterministic hazard analyses of ine Inelastic response spectra of over horizontal components of ground motions recorded in 64 shallow crsutal earthquakes in active tectonic regions were computed. This comprehensive database of inelastic response spectra was used to develop a ground motion prediction equation GMPE"attenuation" model, for inelastic spectra.

For given displacement ductility ratio, two-step nonlinear regressions, as well as random effects analyses, were performed on the inelastic spectral ordinates. The GMPE is capable to correlate inelastic spectral ordinates to moment magnitude, fault rupture distance, faulting mechanism, local site condition, and basin depth. The GMPE for inelastic spectra was subsequently used to carry out probabilistic hazard analysis for inelastic spectra.

In this computational process, deterministic and probabilistic inelastic responses were directly computed without any assumption and approximation on the relationship between inelastic and elastic response spectra. Given a site and the desired probability of exceedance, one can use the results of this study to directly estimate the inelastic response demanded by earthquake ground motion.

Damage spectrum and its applications to performance-based earthquake engineering. This paper presents the basic definitions of improved damage indices DIstheir corresponding d Specifically two formats of damage spectra are presented in this paper: The first format of damage spectrum is a plot of the computed DI for an existing system versus structural period.

Such damage spectra are convenient for performance-based damage assessment of existing facilities. For example, they can be used for post-earthquake near real-time damage assessment of structures based on recorded ground motions. The second format of the damage spectrum is a plot of the required strength, or maximum deformation, versus structural period for constant values of DI.

Such damage spectra can be used for performance-based design of new systems. To present the concept, strength and deformation spectra for ten near-fault ground motions with directivity effects are computed. Average required yield strength and maximum deformation spectra for these near-fault records for constant values of DI are presented.

Next generation attenuation NGA empirical ground motion models: can they be used in Europe.