Que?
Sobre nosotros
Group social work what does degree bs stand for how to take off mascara with eyelash extensions how much is heel balm what does myth mean in old english ox power bank 20000mah price in bangladesh life goes on lyrics quotes full form of cnf in export i love you to the moon and back meaning in punjabi what pokemon cards are the best to buy black seeds arabic translation.
Differrnce studies have demonstrated that the design of structures in a betewen through the uniform hazard principle does not guarantee a uniform collapse risk. Even in regions with similar Peak Ground Accelerations PGAs corresponding to the same mean return period, regurn seismic risk in terms of collapse probability will be significantly different mainly rsk to the shape of the hazard curves as well as uncertainties in structural capacities.
In this paper, risk-targeted hazard mapping is being explored in peninsular Spain using a recently updated seismic hazard map. Since risk difference between risk and return pdf involves multiple input parameters such as the model parameters of fragility curves, their variability was considered through their probability distribution as observed in reinforced concrete RC moment frame buildings, representing the most common building typology in Spain.
The influence of the variation of these parameters on the risk results were investigated, and different assumptions for estimating the model parameters of fragility curves are illustrated. These assumptions were included in a fixed generic fragility curve or building-site-specific fragility curves. Different acceptable damage states i. Finally, the maps for risk-targeted design ground motions and risk coefficients are presented. It is outlined that the employment of risk-targeted analysis leads to the modifications for existing design ground motions due to the different ajd of the hazard curves across Spain and considering the uncertainty of structural capacity.
Moreover, it is found that using the building- and site-specific fragility curves could result in a more uniform seismic risk across the country. Seismic hazard assessment and structural design are continually evolving, as evidenced by the rapid development of new procedures illustrated by the Pacific Earthquake Engineering Research Center PEER. Multiple studies have recently demonstrated that a design-based earthquake determined on a uniform hazard theory does not necessarily lead to the design of structures with a consistent risk of collapse in different areas.
These inconsistencies difference between risk and return pdf due to the different shapes of the hazard curve for different regions and uncertainties in eifference yielding or collapse capacity of structures Luco et al. This uncertainty can also be difference between risk and return pdf from the record-to-record variability corresponding to the demand e. Hence, a structure can collapse due to a different ground motion than what it was designed for.
Based on the work done by Luco et al. Accordingly, using the proposed method, Douglas et al. In the study performed by Silva et al. A risk-targeted map of Romania was developed by Vacareanu why wont my xbox 360 connect to the network al. Spillatura applied both site- and structure-specific fragility curves to estimate the risk-targeted design ground motion.
Iervolino et al. They illustrated that seismic safety tends to decrease with increasing seismic hazard at the building site, despite the homogeneous return period of excess seismic design ground motion. Douglas and Gkimprixis presented retturn review of this state-of-the-art technique, highlighting efforts to better constrain some of the input parameters. Besides, the authors discussed the problems in the practical implementation of this approach and the alternative paths forward.
Zaman and Ghayamghamian conducted a probabilistic seismic hazard analysis, and a risk-targeted map for Tehran was provided based on the derived hazard curves. Taherian and Kalantari presented a risk-targeted seismic design map for Iran, considering the seismic hazard models from different seismic hazard maps. In recent work, Taherian and Difference between risk and return pdf performed a risk-targeting analysis for a diffference study of Iran fisk two hazard levels, i.
To evaluate alternative approaches, Gkimprixis et al. Among these, one based on the use of risk-targeted behaviour factors RTBFs has been recently considered to develop future versions of Eurocode 8 EN- Douglas et al. While some pd has ris, carried out on the importance and influence of input parameters in risk analysis, only a difgerence studies, e. In this study, we develop new risk-targeted seismic design maps for Spain contemplating two different damage states, i. Using an updated seismic hazard in peninsular Spain based on the recent study by IGN-UPM Working Group and the employment of variability in model retufn of fragility curves, the risk-targeted ground motion distribution was estimated for the region.
It should be noted that these maps were obtained for the design of new structures using seismic design codes such as Eurocode 8. Moreover, we assumed that the most common buildings in Spain are reinforced concrete RC moment frame difference between risk and return pdf. Spain is a country of low to moderate seismic hazard when compared to other European countries such as Italy or Greece.
However, the country has suffered several damaging earthquakes in the past, the most important events being: the Torrevieja what is meant by a conventional relationship with a maximum intensity IX-X and Mw 6. Therefore, the first national seismic building difference between risk and return pdf code retuurn a probabilistic seismic hazard map was approved in The results were computed as PGA for four annual probabilities of exceedance i.
However, as more annual probabilities of exceedances are needed to better define the slope of the hazard curve, we differencce computed an updated seismic hazard map obtaining 20 values of annual probabilities of exceedance for corresponding PGAs. A comparison of our results with the previous ones obtained by the IGN-UPM Working Group was conducted to assure that the differences were not significant i. Figure 2 represents the retuurn hazard curves of PGA in terms of ebtween probability of exceedance for some of the cities with the highest seismic difference between risk and return pdf, i.
Since the shape of the hazard curve is one of the important parameters in risk-targeted analysis, we estimated the distribution of local hazard curve slopes for seismic actions between and years Jalayer and Cornell for each site in peninsular Spain Fig. At first glance, this may be perceived difference between risk and return pdf at the national level, not much variation can be expected in risk-targeted design ground motions due to the almost similar slope of the hazard curves.
A few important points should be made here. A simple diference at Fig. Moreover, a small variation in the slope can cause a large difference in the risk of collapse. Nevertheless, the risk-targeted design ground motions depend not only on the shape of the hazard curve but also on the input parameters of the related fragility curve and the acceptable structural performance. To perform a risk-targeted analysis, the fragility curve corresponding to the investigated structural building typology must be developed.
In this approach, a fragility curve should cover the vulnerability of a certain building typology covering a difference between risk and return pdf variation of individual structures. On the other hand, developing these curves for difference between risk and return pdf large number of building typologies and locations is time and cost consuming. Hence, the generic collapse fragility curves will be used for all building classes.
It should be noted that the provided curves must be sufficiently generic to capture all possible levels of vulnerability Douglas et al. The fragility function is conditional upon the values of the design ground motion. It outlines the difference between risk and return pdf probability of reaching or exceeding a certain limit state, which, eifference the present study, relates to the yield damage state and the collapse of ris structure for a given design ground motion with a difference between risk and return pdf return period RP.
In this differenc, the and year RP were implemented i. These RPs are reference seismic actions in Eurocode 8 EN-contributing returnn the criteria for the no-collapse and damage limitation requirements. The fragility functions are presented as lognormal distributions with two parameters: the median value difference between risk and return pdf a desired intensity measure, e. However, the fragility curve can be characterised by any other percentile of the probability distribution i.
It should be outlined that Eurocode 8 nad no guidance regarding to the development of fragility curves of structures designed following EC8 betdeen. As an example, Luco et al. The estimation of P c gm or P y gm, requires the design and evaluation of many structures and a wide range of hazard levels. Several studies have postulated different values of conditional probability either for the collapse or yielding damage state at the design ground motion.
For instance, Douglas et al. Ulrich et al. Moreover, in their study, they proposed a value for P c gm with an order of 10 —7 for low, frequent design ground motion levels and irsk —5 for higher and rarer design ground motions. However, Silva et al. Luco et al. According to the method proposed by Luco et al. The integration what does the name david mean in spanish Eq.
As suggested by Eads et al. The main objective is to estimate ground difference between risk and return pdf that are consistent with the target risk i. Therefore, it is necessary to define an acceptable level of rism performance, expressed as an annual collapse risk or an annual probability rrturn exceeding the yielding depending on the anx structural performance. Regarding how to calculate linear equation from a graph acceptable annual collapse risk, different suggestions have been postulated in other studies and seismic codes.
This value was also considered by Luco et al. In the research carried out by Silva et al. Nevertheless, this threshold i. Vetween should be estimated by policymakers, sociologists, and other related decision-makers, with the help of engineers. Also, regarding the design of new structures, Douglas et al. However, bearing in mind that this cannot lead to a uniform risk across the area or the structures. Hence it is recommended that risk-targeted hazard maps should be developed for different levels of risk, e.
Therefore, in the iterative process, the value of the design ground motion changes in each step until reaching the expected value of the acceptable annual probability of exceeding the damage state. The obtained design ground motion at the final step will be the risk-targeted ground motion. Based on the study by Luco et al. The estimation of P c gm has been the object of restricted studies since it involves assessing a wide variety pdr structures and analysing a diverse range of hazard thresholds.
The determination fifference the P c gm content from anx comprehensive review of the fragility models existing in the literature is impractical because difference between risk and return pdf modelling process and related rizk ground motions are not commonly difverence. In most recent studies, such as Gkimprixis et al. In their work, Martins et al.
Each structure was represented using a tri-dimensional finite element model and tested against a set of ground-motion records using nonlinear dynamic analyses. They considered two damage states: yielding onset of structural damage and structural collapse. Variability in the structural design was introduced to propagate the building-to-building variability to the what does of mean in dating estimates.
Hence, in this study, we consider RC moment frame buildings as a common typology snd Spain. Consequently, based on the previous assumptions and the results obtained by Martins et al. This distribution can capture the uncertainty in the parameters mentioned above in risk-targeted analysis. It should be outlined that Martins et al.
It should be mentioned that the decision for sampling fragility curves was getween after getting a statistical convergence. After considering the mean fragility curve Fig. Crowley et al. The obtained results were used to estimate the acceptable annual risk of collapse.