I mean the beta which is popular in reliability-based designs. But I couldn't find any specific value for earthquake loads and different performance levels. It would be great kindness to introduce helpful references.
Unfortunately in the real world it is not this simple. The unknown factor is the variability in construction and the mistakes in construction that lead to failure - both design and building stage. Earthquakes always demonstrate those.
I always preferred Jacob's method from Lamont Observatory to actually run a building design through a set of earthquakes and see the direct response - but that is time consuming.
Christchurch showed that even the best can be horribly wrong - just ask Ingham.
If you could outline what exactly you want to do with them perhaps.
I took a look at publications that you have mentioned, but unfortunately could not find anything specific.
As you mentioned, there are lots of uncertainties in earthquake engineering which could result in biased responses. but in design cases of all other load types we have considered or accepted a level of safety. It is the point that I was searching to know that is there any suggestion for earthquake excitation or not. It would be great if I could find values corresponding to different hazard levels i.e. allowable safeties of buildings for earthquakes with different probability of exceeding.
Performing nonlinear dynamic analysis of a specific building induced several ground motion records will probably clear an estimation of demands on building but how we could know the safety is enough or not. I presume that it would be useful in performance-based seismic designs.
Thanks for your interest. I have seen attached paper and it contains some aspect but for steel buildings. Have you seen anything related for R.C buildings?
PBEE methodologies produced SEAOC’s Vision 2000 report (1995) and FEMA 273 (1997), a product of the ATC-33 project. Other important pioneering PBEE efforts include ATC-32 (1996a), ATC-40 (1996b), and FEMA 356 (2000).
These documents frame PBEE as a methodology to assure combinations of desired system performance at various levels of seismic excitation. The system performance states of Vision 2000 include fully operational, operational, life safety, and near collapse. Levels of excitation include frequent (43- year return period), occasional (72-year), rare (475-year) and very rare (949-year) events. These reflect Poisson-arrival events with 50% exceedance probability in 30 years, 50% in 50 years, 10% in 50 years, and 10% in 100 years, respectively.
FEMA 273 expresses design objectives using a similar framework, although with slightly different performance descriptions and levels of seismic excitation. Each global performance level is detailed in terms of the performance of individual elements. A design is believed to satisfy its global objectives if structural analysis indicates that the member forces or deformations imposed on each element do not exceed predefined limits.
Performance is binary and largely deterministic: if the member force or deformation does not exceed the limit, it passes; otherwise, it fails. If the acceptance criteria are met, the design is believed to assure the performance objective, although without a quantified probability.
The probability of failure (or the reliability index) is system dependent, i.e. it depends on the farming and strength reserves meaning how much extra capacity there is for a performance level. You need to perform a reliability analysis for your given structure under given loading condition, considering all uncertainties, to determine the reliability index. You can find a target value for the reliability index in codes, which is 3.5 to 4, but we won’t know the reliability index of a building, which satisfies PBEE, unless we perform reliability analysis.