Sensitivity analysis of the failure time of reinforcement concrete frame under postearthquake fire loading

Abstract

Today, many scholars have drawn attention to consecutive events such as postearthquake fire (PEF). PEF is one of the rare occurrences that leads to many consequences. The resistance of structure against external loads is important for structure and earthquake engineers. The duration of structures' resistance against fire in damaged structures due to earthquake can be different from intact ones. Many parameters have an effect on the resistance of structures. This paper deals with the importance of design parameters and loading for the resistance of reinforced concrete frames during PEF loading. Three methods of Monte Carlo, Tornado diagram, and first-order second moment have been used to analysis based on random variables. The first failure time in the reinforcement concrete frame (RC) is considered as the strength of the reinforced concrete frame to PEF load. The results depicted that among design parameters, yield stress of rebar is the most significant parameter for the resistance of reinforced concrete frames. Among the loading parameters, the intensity of the seismic load is the most important parameter. The sensitivity of the failure time of members in RC frame shows that during the low intensity of earthquakes, the cover of concrete is the main design parameter after yield strength of rebar. As the intensity of seismic loads increases, the effect of concretes' cover on the resistance of structures against fire decreases. The sensitivity of the failure time to intensity of seismic load is higher between Sa = 0.3 g to Sa = 0.8 g. Also, results show the sensitivity of the design variable decreases by increasing the intensity of the seismic load. K E Y W O R D S postearthquake fire, random variable, RC frame, sensitivity analysis

Sensitivity analysis of reinforced concrete structures :

“…A similar approach is also reported by [121] and [122] for mass and reinforced concrete structures, respectively. A similar idea has been used by [123] for sensitivity analysis of the failure time in RC frames under post-earthquake fire.…”

Fragility assessment of an outrigger structure system based on energy method

“…Tavakoli et al (2019) utilized finite element and component‐mode synthesis methods to determine the optimum location of outriggers in buildings with different heights 11 . They also studied the seismic behavior of outrigger braced buildings considering the soil‐structure interaction effect 12 . Alhaddad et al (2020) prepared a comprehensive review of the outrigger and belt‐truss systems in high‐rise buildings and skyscrapers 13 …”

“…11 They also studied the seismic behavior of outrigger braced buildings considering the soil-structure interaction effect. 12 Alhaddad et al (2020) prepared a comprehensive review of the outrigger and belt-truss systems in high-rise buildings and skyscrapers. 13 One of the methods of evaluating the performance of the structures against loadings is defining the exceedance probability of the structure from a specific level of seismic loading.…”

A Parametric Study of Fire-Damaged Reinforced Concrete Columns under Lateral Loads

“…Another study was conducted in [19] on the seismic performance of reinforced concrete beam-column joints after a fire and their practical strengthening. The performance of RC frame structures in post-earthquake fire loading and their failure times were analyzed in [20,21]. In [22,23], the seismic performance of RC short columns with light transverse reinforcement and RC beam-column joints under varying axial forces was investigated.…”