A Probability-based Approach for the Definition of the Expected Seismic Damage Evaluated with Non-linear Time-History Analyses

2017 ◽  
Vol 23 (2) ◽  
pp. 261-283 ◽  
Author(s):  
Cristina Cantagallo ◽  
Guido Camata ◽  
Enrico Spacone
Author(s):  
Fatemeh Jalayer ◽  
Hossein Ebrahimian ◽  
Andrea Miano

AbstractThe Italian code requires spectrum compatibility with mean spectrum for a suite of accelerograms selected for time-history analysis. Although these requirements define minimum acceptability criteria, it is likely that code-based non-linear dynamic analysis is going to be done based on limited number of records. Performance-based safety-checking provides formal basis for addressing the record-to-record variability and the epistemic uncertainties due to limited number of records and in the estimation of the seismic hazard curve. “Cloud Analysis” is a non-linear time-history analysis procedure that employs the structural response to un-scaled ground motion records and can be directly implemented in performance-based safety-checking. This paper interprets the code-based provisions in a performance-based key and applies further restrictions to spectrum-compatible record selection aiming to implement Cloud Analysis. It is shown that, by multiplying a closed-form coefficient, code-based safety ratio could be transformed into simplified performance-based safety ratio. It is shown that, as a proof of concept, if the partial safety factors in the code are set to unity, this coefficient is going to be on average slightly larger than unity. The paper provides the basis for propagating the epistemic uncertainties due to limited sample size and in the seismic hazard curve to the performance-based safety ratio both in a rigorous and simplified manner. If epistemic uncertainties are considered, the average code-based safety checking could end up being unconservative with respect to performance-based procedures when the number of records is small. However, it is shown that performance-based safety checking is possible with no extra structural analyses.


2021 ◽  
Vol 879 ◽  
pp. 232-242
Author(s):  
A.N. Refani ◽  
Yuyun Tajunnisa ◽  
K. Yudoprasetyo ◽  
F. Ghifari ◽  
D.I. Wahyudi

Indonesia is a country located in the convergence of small plates and large plates. Furthermore, this causes Indonesia to be high potentially to earthquake hazards. The newest geological research published by Geophysical Research Letter (2016) shows the existence of Fault Kendeng, a fault stretches along 300 km from South Semarang, Central Java, to East Java with a movement of 0,05 millimeter per year [1]. As a result of its research, an evaluation using a non-linear time history analysis for structural buildings is necessary. The objective of this study is to evaluate structural buildings using a non-linear time history analysis. This study applies DSHA (Deterministic Seismic Hazard Analysis) method to obtain acceleration time history on bedrocks. Since the record of ground movement in Indonesia is limited, the attenuation function equation used to scale and match other country’s time acceleration history data. SSA (Site-Specific Analysis) is used to propagate earthquake acceleration from bedrocks to the surface. The earthquake acceleration on the surface generates as the earthquake load on the buildings. The results of Kendeng fault earthquake simulation using non-linear time history analysis shows that column members capacity is more robust than beam members capacity which the beam collapse mechanism occurs initially. From the maximum total drift ratio result, when the Kendeng fault earthquake occurs, the building structure performance level is at collapse prevention level Based on ATC-40 [2]. This research result shows that 96,7% of plastic hinge has not yielded. However, some elements are already damaged. Since most damage members are column, then it may require column strengthening to enhance maximum performance level at life safety condition category.


2011 ◽  
Vol 255-260 ◽  
pp. 2526-2531
Author(s):  
Nan Zhao ◽  
Yang Jiang

Three dimensional seismic responses of an isolated spatial beam string structure are studied by applying the non-linear finite element theory. The filtering effect of the main structure, which amplifies the ground input, is investigated. The results indicate that the vertical rare earthquake has great influence on the isolated spatial beam string structure, and stresses of cables, frames and slab shells under vertical rare earthquake are all much greater than that under gravity load. Results of non-linear time history analysis show that elements’ stresses are in elastic stage, thus the spatial beam string structure with isolation keeps safe under rare earthquake.


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