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Recent seismic design approaches developed under the umbrella of performance-based earthquake engineering (PBEE) pursue pre-defined performance objectives in terms of structural response, economic losses, or casualties. The earlier PBEE methods were mainly concerned with the deterministic evaluation of performance at a single ground motion intensity level. This premise, however, provides little insight into the long-term risk-based performance of a structure, and limits the ability to make informed design decisions. Given the inherent sources of uncertainty in all aspects of seismic design, probability theory needs to be employed to enable reliable design solutions. However, applying a risk-oriented design approach is not currently feasible for most practitioners, making it essential to understand how the current deterministic applications of these intensity-based PBEE approaches perform in terms of risk. Specifically, the aim is to investigate the capability of the direct displacement-based design (DDBD) method in producing reliable, risk-consistent designs. A probabilistic PBEE assessment framework is applied as the benchmark to determine the risk of exceeding performance objectives for multiple DDBD-based reinforced-concrete-wall and dual reinforced-concrete-wall/steel-frame buildings located at three different sites. The significant variation in the achieved risk estimates related to the limit states of damage limitation, life safety and global collapse for the buildings considered, questions the ability of DDBD—or any other intensity-based design method that does not account for uncertainty—to offer risk consistency. [ABSTRACT FROM AUTHOR]

We present a seismic source characterization model for the probabilistic seismic hazard assessment (PSHA) of the Isfahan urban area, Iran. We compiled the required datasets including the earthquake catalogue and the geological and seismotectonic structure and faults systems within the study region to delineate and characterize seismic source models. We identified 7 relatively large zones that bound each region with similar seismotectonic characteristics and catalogue completeness periods. These regions were used for calculating the b-value of the Gutenberg–Richter magnitude recurrence relationship and for estimating the maximum magnitude value within each region. The earthquake recurrence parameters were then used to build a spatially varying distributed earthquake rate model using a smoothed kernel. Additionally, based on a fault database developed in this study and on a local expert's opinion supported by tenable constraints about their slip velocity, a fault-based model is also created. We further performed sets of sensitivity analyses to find stable estimates of the ground motion intensity and to define alternative branches for both the seismogenic source and ground motion prediction models. Site amplification is considered based on a Vs30 map for Isfahan compiled within this study. The alternative source and ground motion prediction models considered in the logic tree are then implemented in the software OpenQuake to generate hazard maps and uniform hazard spectra for return periods of interest. Finally, we provide a detailed comparison of these PSHA outcomes with both those presented in the 2014 Earthquake Model of Middle East (EMME14) and with the national seismic design spectrum to further discuss the discrepancies between hazard estimates from site-specific and regional PSHA studies. [ABSTRACT FROM AUTHOR]

This study applies the latest probabilistic performance-based earthquake engineering tools in terms of nonlinear dynamic analyses in tandem with hazard-consistent record selection to assess the risk of collapse of RC tall buildings in the Istanbul metropolitan area and to quantify their seismic safety margin with respect to acceptable risk levels. Statistically representative archetype buildings selected from an extensive inventory form the basis for this assessment study. Accordingly, we chose five hypothetical building sites in Istanbul where tall buildings are densely populated to estimate the risk of collapse for 5 × 5 = 25 building-and-site specific cases. The results showed an average 10% probability of collapse under the ground-motion intensities with 2% probability of exceedance in 50 years. The mean annual rates of collapse range between 0.1 × 10–4 and 6.1 × 10–4 with an average of 1.7 × 10–4, which remains below the tolerable risk threshold value of 2.0 × 10–4 envisioned by the FEMA's Building Seismic Safety Council. However, 36% of the analyzed cases yielded collapse rates higher than this tolerable risk. Among the considered cases, the core walls and frame building was identified as the best design choice from a collapse safety point of view while the tunnel form archetype raised concern by exhibiting substantially higher collapse risk compared to other archetypes. [ABSTRACT FROM AUTHOR]

The influence of the effects of the degradation of materials on the seismic fragility of Cultural Heritage buildings in Granada (Spain) is investigated. The degradation of the material, which mainly happens at the lower levels of the façades, is obtained by using 3D photogrammetry data. Fragility curves for three cultural heritage constructions in Granada are calculated by using FE nonlinear dynamic analyses for both non-deteriorated and deteriorated geometries. The Finite Elements (FE) models, based on the macro-modelling technique, are subjected to ground motions for the city of Granada, which were selected by considering Probabilistic Seismic Hazard Analysis (PSHA) methodology with their probability of occurrence. The response of each model is analyzed for different seismic Intensity Measure (IM) levels, which, in this study, correspond to average pseudo-acceleration. The procedure is applied to three monuments in Granada that were built with two different constructions materials: calcarenite and rammed earth. The damage mechanisms considered are roof displacement or maximum compressive principal stress, depending on each case. The results show that the restoration works that have been carried out has prevented structural failures in the rammed earth construction studied, and that, during future seismic events, special attention must be paid to the level of compressive strengh reached in the Santa Pudia calcarenite used at the San Jerónimo monastery. [ABSTRACT FROM AUTHOR]

Automated Multi-Depth Shuttle Warehouses (AMSWs) are compact storage systems that provide a large surface occupation and therefore maximum storage density. AMSWs represent the future of storage technology, providing substantial savings in terms of cost, space, and energy with respect to traditional warehouses. Currently, designers refer to the standard building codes for the seismic design of AMSWs. Since structural characteristics of AMSWs are considerably different from the steel structures of typical buildings, this current approach used by designers is questionable in terms of safety and efficiency. In this article, the behavior of 5 AMSW structures has been studied performing 150 time-history analyses by direct integration including P-Delta effects. Demand/capacity ratios calculated for each element showed the dominance of the brittle failure mechanism in AMSWs subjected to low-to-moderate seismic actions. These mechanisms mainly took place in upright columns and their base connections prior to the activation of ductile energy dissipation mechanisms of the structure. Based on the results, further improvements have been recommended for the future design provisions, which may lead to a safer seismic design of AMSWs. [ABSTRACT FROM AUTHOR]