PSI - Issue 22

H. Daou et al. / Procedia Structural Integrity 22 (2019) 17–24

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H. Daou, W. Raphael, A. Chateauneuf, F. Geara / Structural Integrity Procedia 00 (2019) 000 – 000

Fig. 1. (a) View of the terminal; (b) Collapsed area of the terminal (EL Kamari et al. (2015))

Therefore, in order to enhance the efficiency of MCS, a combination of RSM and MCS is used in this study. The combination of RSM and MCS method consists of two steps: the first step is to calculate the approximation input output relationship by performing a regression analysis using the values obtained by performing simulation loops to calculate the output value that corresponds of the input random variables; the second step is to calculate the probability of failure by performing MCS exploiting the calculated response surface. For a proper design of reinforced concrete structure, two main aspects must be taken into account; the first one is concerning the reliability to predict design serviceability and ultimate limit states within a certain specified probability. The second one is related to the accuracy of mechanical model, where equilibrium conditions and geometrical compatibility have to be satisfied, and appropriate models adopted to describe the material behavior (Soares et al. (2002)). In the assessment and designing of structures, probabilistic analysis is used widely to assess the safety of structures by taking into account uncertainties that may affect structural performance in order to prevent failure of structure, which can lead to injuries or loss of life as well as financial losses. Terminal 2E at Roissy at Charles De Gaulle Airport is a large and complex structure consisting of three main parts: a main building, a boarding area and an isthmus connecting these two buildings. The boarding area, where the collapse occurred, has a length of 650 m and consists of 10 shells stiffened by curved steel girders (ties) braced to the two sides and held away from the shell by regular steel struts. Part of the terminal collapsed in 2004, after eleven months of its inauguration, and resulted in four casualties. The inadequate design of the terminal was the principle reason of its failure; the long term concrete creep caused excessive unpredicted deformations resulting in excessive forces in the struts that led to punching shear (Raphael et al. (2012)). Another critical consequence of the deformations was the redistribution of efforts and moments that led to the fracture of the terminal shell (El Kamari et al. (2015)). The reliability analysis of the terminal performed by Daou et al. (2019) showed that the structure represented deficiencies and was prone to failure. The purpose of this paper is to assess the structural safety of the terminal using probabilistic approach taking into consideration uncertainty on material properties and loads on the flexural moment and the long-term deflection. Therefore, a nonlinear finite element model of the terminal was carried out using Ansys. Subsequently, probabilistic analysis was performed by using a combination of Response Surface Method (RSM) and Monte Carlo Simulation (MCS). The ratio of reinforcement required was calculated based on the results of the flexural moment values and compared to the existing reinforcement ratio. Reliability analysis in terms of long term deflection was also conducted. Moreover, sensitivity analysis of the flexural moment was also performed.

1. Modeling of the terminal 1.1. Description of the terminal

Terminal 2E at Roissy at Charles De Gaulle Airport, which was designed to handle more than 10 million passengers per year, has collapsed after eleven months of its inauguration. A main building, a boarding area and an