Seismic Fragility Estimates of LRB Base Isolated Frames Using Performance-Based Design

Abstract

With improving technology, the idea of using energy dissipater equipment has been strengthened in order to control the structures response in dynamic loads such as wind and earthquake. In this research, we dealt with seismic performance of base isolated structures with lead-rubber bearing (LRB) using incremental dynamic analysis (IDA). For this purpose, 3- and 9-story buildings have been utilized in the SAC project undergoing 22 earthquake records which were far-fault. Plotting the fragility curve for various states of design time period and isolator damping of LRB, it is observed that, by increasing damping, the isolator has not been activated in small spectrum acceleration, which shows that the annual exceedance probability is increased in immediate occupancy (IO) performance level and decreased in life safety (LS) performance level. The results show the reduction of determined failure probability in fragility curves for two levels of performance of uninterrupted use and lateral safety. Likewise obtained results show that, with increasing design time period of isolator, the amount of failure probability is decreased rather than the isolator with smaller design time period, for both LS and IO states. And the isolator illustrates better performance.

Incremental Explosive Analysis and Its Application to Performance-Based Assessment of Stiffened and Unstiffened Cylindrical Shells Subjected to Underwater Explosion

“…In addition, another useful and more convenient tool for designers who deal with design and assessment of marine structures subjected to probabilistic loadings is fragility curves [26]. After performing preliminary analysis to attain the IEA data, the fragility curves can be extracted to anticipate whether the structure has exceeded a certain limit state such as general buckling limit state or the occurrence of multiple buckling mode.…”

“…A relatively similar concept called incremental dynamic analysis (IDA) has been established in recent years in order to assess the performance of the building and fixed offshore structures subjected to seismic loading (see, e.g., [18][19][20][21][22][23][24][25]). Mansouri et al [26] implemented the IDA method 3 on several-story buildings to analyze the damping effect of the lead-rubber bearing on the seismic performance of base isolated structures and represented the fragility curves to study the annual exceedance probability of some limit states. Based on the IDA, relatively novel methodologies have been proposed by some researchers for environmental loads other than earthquakes, such as Incremental Wave Analysis (IWA), Endurance Wave Analysis (EWA), and Incremental Wind Wave Analysis (IWWA) (Golafshani et al [27], Zeinoddini [28]).…”

Effects of Brace Configuration and Structure Height on Seismic Performance of BRBFs Based on the Collapse Fragility Analysis

“…Seismic probabilistic risk assessment aims to determine the probability distribution of the frequency of adverse consequences due to the potential effects of the earthquake [25,26]. The probabilistic analysis of seismic demand is a method to estimate the mean annual frequency of the exceeding limit state and hazard demand.…”

Seismic Fragility Analysis of Mid-Story Isolation Buildings

“…Vamvatsikos et al developed and applied the incremental dynamic analysis to predict collapse under the effect of scaled earthquake records [5]. Mansouri et al conducted the seismic fragility analysis for 3-and 9-story base-isolated buildings [6]. It was found that the installation of the isolation layer decreased the amount of failure probability.…”