Analysis in seismic provisions for buildings: past, present and future

Fajfar, Peter

doi:10.1007/s10518-017-0290-8

Cited by 76 publications

(57 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Collins et al 1996;Wen 2001;Fragiadakis and Papadrakakis 2008; Barbato and Tubaldi 2013; Gidaris and Taflanidis 2015;Castaldo et al 2017;Altieri et al 2018;Franchin et al 2018). It is widely acknowledged that in the long term, risk-based assessment and design criteria will be recommended, or will even be mandatory, in design codes (Vamvatsikos et al 2015;Fajfar 2018). For instance, the United States has already incorporated such criteria in its seismic design codes ASCE 7-16 (2017) and FEMA P-750 (2009a); the new version of Eurocode 8 Part 1 will also include an Informative Annex on probabilistic assessment of structures (Fajfar 2018).…”

Section: Introductionmentioning

confidence: 99%

“…With this approach, the seismic uniform-hazard ground motion maps are modified to obtain more consistent levels of the collapse probability across the country. While risk targeted design maps have been already implemented in American seismic design codes (see Luco et al 2015), they have not yet been introduced in practice in Europe (Douglas and Gkimprixis 2018), where the implementation of probabilistic behaviour factor concepts in Eurocode 8 is still under consideration (Fajfar 2018).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of methods to develop risk-targeted seismic design maps

Gkimprixis

Tubaldi

Douglas

2019

Bull Earthquake Eng

View full text Add to dashboard Cite

The seismic design of structures according to current codes is generally carried out using a uniform-hazard spectrum for a fixed return period, and by employing a deterministic approach that disregards many uncertainties, such as the contribution of earthquake ground motions with return periods other than that assumed for the design. This results in uncontrolled values of the failure probability, which vary with the structure and the location. Risk targeting has recently emerged as a tool for overcoming these limitations, allowing achievement of consistent performance levels for structures with different properties through the definition of uniform-risk design maps. Different countries are implementing the concepts of risk targeting in different ways, and new methods have recently emerged. In the first part of this article, the most well-known approaches for risk targeting are reviewed, with particular focus on the one implemented in recent American design codes, the one based on the use of risk-targeted behaviour factors (RTBF), and an approach based on direct estimation of hazard curves for inelastic response of single-degree-of-freedom systems. The effect of the linearization of the hazard curve is investigated first. A validation of the RTBF approach is then provided, based on comparison with the results of uniform-risk design spectral accelerations for single-degree-of-freedom systems with elastic-perfectly plastic behaviour for two different sites. The effectiveness of the current risk-targeting framework applied in the United States is also investigated. In the last part of the paper, uniform-risk design maps for Europe are developed using the RTBF approach, showing how the seismic design levels may change when moving from a uniform-hazard to a uniform-risk concept.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Comparison of methods to develop risk-targeted seismic design maps

Gkimprixis

Tubaldi

Douglas

2019

Bull Earthquake Eng

View full text Add to dashboard Cite

show abstract

“…In Equation 3, k is the slope of the linearized hazard curve in the logarithmic plan. In general, k is between 1 and 4 [23], dependently on the site seismic hazard, and is assumed equal to 3 in the following preliminary evaluations, as also suggested in [3]; βc is the logarithmic standard deviation of the PGA capacity. It should be determined by considering, e.g., material properties and modelling uncertainties and record-to-record variability by means of non-linear time-history analyses [24].…”

Section: Level 1 Modelling Approach Level 2 Modelling Approach Level mentioning

confidence: 99%

“…The current Eurocode 0 [2] defines an acceptable risk level for residential buildings and ordinary structures with respect to the attainment of Ultimate Limit States (in general) roughly equal to 10 -6 . However, the next version of Eurocodes will set a specific value of the acceptable risk level with respect to seismic actions equal to 2×10 -4 in one year [3], which corresponds to a probability of failure equal to 1% in 50 years.…”

Section: Introductionmentioning

confidence: 99%

Parameters Affecting the Behaviour Factor and the Seismic Safety of Ec8-Designed Reinforced Concrete Buildings

Ricci¹,

Domenico²,

Verderame³

2019

Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

View full text Add to dashboard Cite

Currently, Eurocode 8 allows a force-based design and safety assessment of buildings accounting for their inelastic displacement capacity by means of a force-reducing factor named behaviour factor. The value of the behaviour factor for new buildings depends on the structural typology, on the structural regularity and on the ductility class of the building. However, recent studies showed that the use of an equal behaviour factor for structures realized in zones characterized by different seismicity fails in providing such structures with the same risk level. Therefore, to achieve this goal, to which the next generation of Eurocodes seems to be oriented within a more refined performance-based design approach, it is necessary to evaluate hazarddependent risk-targeted behaviour factors for new structures. In this study, non-linear static analyses are performed on reinforced concrete buildings designed according to Eurocodes and different for design seismic acceleration and number of storeys. This allows the post-design evaluation of the case-study buildings' behaviour factor. The potential dependency of the behaviour factor from different design parameters, namely the number of storeys of the structure and its design seismic acceleration, is investigated and discussed. Preliminary evaluations on the possible modifications of the currently-applied behaviour factors aimed at obtaining the same risk level for the case-study structures are presented and discussed. All the above results are obtained and compared by adopting different modelling approaches for RC elements.

show abstract

“…One of the most common approaches is the natural frequency method [Fajfar, 2018]. The complex geometry of the building is simulated by the set of springs and masses.…”

Section: Introductionmentioning

confidence: 99%

Full-wave 3D earthquake simulation using the double-couple model and the grid-characteristic method

Bagaev¹,

Golubev²,

Golubeva³

2019

CRM

View full text Add to dashboard Cite

One of the destroying natural processes is the initiation of the regional seismic activity. It leads to a large number of human deaths. Much effort has been made to develop precise and robust methods for the estimation of the seismic stability of buildings. One of the most common approaches is the natural frequency method. The obvious drawback of this approach is a low precision due to the model oversimplification. The other method is a detailed simulation of dynamic processes using the finite-element method. Unfortunately, the quality of simulations is not enough due to the difficulty of setting the correct free boundary condition. That is why the development of new numerical methods for seismic stability problems is a high priority nowadays.The present work is devoted to the study of spatial dynamic processes occurring in geological medium during an earthquake. We describe a method for simulating seismic wave propagation from the hypocenter to the day surface. To describe physical processes, we use a system of partial differential equations for a linearly elastic body of the second order, which is solved numerically by a grid-characteristic method on parallelepiped meshes. The widely used geological hypocenter model, called the "double-couple" model, was incorporated into this numerical algorithm. In this case, any heterogeneities, such as geological layers with curvilinear boundaries, gas and fluid-filled cracks, fault planes, etc., may be explicitly taken into account.In this paper, seismic waves emitted during the earthquake initiation process are numerically simulated. Two different models are used: the homogeneous half-space and the multilayered geological massif with the day surface. All of their parameters are set based on previously published scientific articles. The adequate coincidence of the simulation results is obtained. And discrepancies may be explained by differences in numerical methods used. The numerical approach described can be extended to more complex physical models of geological media.

show abstract

Analysis in seismic provisions for buildings: past, present and future

Cited by 76 publications

References 28 publications

Comparison of methods to develop risk-targeted seismic design maps

Comparison of methods to develop risk-targeted seismic design maps

Parameters Affecting the Behaviour Factor and the Seismic Safety of Ec8-Designed Reinforced Concrete Buildings

Full-wave 3D earthquake simulation using the double-couple model and the grid-characteristic method

Contact Info

Product

Resources

About