Reliability Analysis in Performance-based Earthquake Engineering

AbstractThe performance-based engineering approach, as opposed to prescriptive rules of code-based design, is based on simulation of real structural behavior. Reliability of the expected performance state is assessed by using various methodologies based on finite element nonlinear static pushover analysis and specialized reliability software package.Reliability approaches that were considered included full coupling with an external finite element code based methods in conjunction with either first order reliability method or importance sampling method. The building considered in the actual study has been designed against seismic hazard according to the Moroccan code RPS2000

Détermination du point de performance des portiques en B.A par la méthode statique non linéaire pushover

The purpose of this work is determination of the performance point of a frame for different soil type, the location of this point on the curve capacity will predict the behavior of the frame in case of earthquakes, this method consists in a first step to apply static loads on the frame, the non linear behavior of the structure is defined, the nonlinearity of the structure is introduced with the use of plastic hinges, the second step is to find the capacity curve by transforming respectively shear at the base and displacement in the top to acceleration and displacement corresponding to a system of a single degree of freedom , finally results of performance point will be discussed. Le but du présent travail consiste à déterminer le point de performance des portiques en mettant l’accent sur l’influence du site sur les dégâts observés, l’emplacement de ce point sur la courbe capacité permettra de prédire le comportement réel du bâtiment en  cas de séismes. Cette méthode consiste dans une première étape à appliquer des charges statiques équivalentes d’allure triangulaire sur le portique étudié, le comportement non linéaire de la structure sera défini, la non linéarité de la structure est introduite au moyen  de rotules plastiques de flexion et de cisaillement., La seconde  étape  consiste à trouver la courbe de capacité en  transformant respectivement l’effort tranchant à la base et le déplacement du sommet de l’analyse push over à l’accélération et le déplacement correspondant à un système à un seul degré de liberté, finalement les résultats seront discutés

Determination of the performance point of reinforced concrete frames using the nonlinear static method pushover

Le but du présent travail consiste à déterminer le point de performance des portiques en mettant l’accent sur l’influence du site sur les dégâts observés, l’emplacement de ce point sur la courbe capacité permettra de prédire le comportement réel du bâtiment en  cas de séismes. Cette méthode consiste dans une première étape à appliquer des charges statiques équivalentes d’allure triangulaire sur le portique étudié, le comportement non linéaire de la structure sera défini, la non linéarité de la structure est introduite au moyen  de rotules plastiques de flexion et de cisaillement., La seconde  étape  consiste à trouver la courbe de capacité en  transformant respectivement l’effort tranchant à la base et le déplacement du sommet de l’analyse push over à l’accélération et le déplacement correspondant à un système à un seul degré de liberté, finalement les résultats seront discutés.The purpose of this work is determination of the performance point of a frame for different soil type, the location of this point on the curve capacity will predict the behavior of the frame in case of earthquakes, this method consists in a first step to apply static loads on the frame, the non linear behavior of the structure is defined, the nonlinearity of the structure is introduced with the use of plastic hinges, the second step is to find the capacity curve by transforming respectively shear at the base and displacement in the top to acceleration and displacement corresponding to a system of a single degree of freedom , finally results of performance point will be discussed.

Seismic performance reliability analysis for reinforced concrete buildings

Postprint (published version

Evaluating some reliability analysis methodologies in seismic design

Problem statement: Accounting for uncertainties that are present in geometric and material data of reinforced concrete buildings is performed in this study within the context of performance based seismic engineering design. Approach: Reliability of the expected performance state is assessed by using various methodologies based on finite element nonlinear static pushover analysis and specialized reliability software package. Reliability approaches that were considered included full coupling with an external finite element code and surface response based methods in conjunction with either first order reliability method or importance sampling method. Various types of probability distribution functions that model parameters uncertainties were introduced. Results: The probability of failure according to the used reliability analysis method and to the selected distribution of probabilities was obtained. Convergence analysis of the importance sampling method was performed. The required duration of analysis as function of the used reliability method was evaluated. Conclusion/Recommendations: It was found that reliability results are sensitive to the used reliability analysis method and to the selected distribution of probabilities. Durations of analysis for coupling methods were found to be higher than those associated to surface response based methods; one should however include time needed to derive these lasts. For the reinforced concrete building considered in this study, it was found that significant variations exist between all the considered reliability methodologies. The full coupled importance sampling method is recommended, but the first order reliability method applied on a surface response model can be used with good accuracy. Finally, the distributions of probabilities should be carefully identified since giving the mean and the standard deviation were found to be insufficient.Peer ReviewedPostprint (published version

Couplage mécano-fiabiliste direct d'une structure en béton armé (R+3)

Dans ce travail, on va s'intéresser à l'application de la méthode d'analyse statique non-linéaire sur un bâtiment R+3 conformément au règlement de construction parasismique R.P.S2000. Cette analyse dite « pushover » est une procédure dans laquelle la structure subit des charges latérales suivant un certain modèle prédéfini en augmentant l'intensité des charges jusqu'à ce que les modes de ruine commencent à apparaître dans la structure. Les résultats de cette analyse sont représentés sous forme de courbe qui relie l'effort tranchant à la base en fonction du déplacement du sommet de la structure

Effects of non-classical boundary conditions on the free vibration response of a cantilever Euler-Bernoulli beams

In this article, the problem of the free vibration behavior of a cantilever Euler-Bernoulli beam with various non-classical boundary conditions, such as rotational, translational spring, and attached mass is investigated. For describing the differential equation of the system. An analytical procedure is proposed firstly, and a numerical method based on the differential transform method DTM is developed in order to validate the obtained results. A parametric study for various degenerate cases is presented with the aim to analyze the influence of rotational stiffness, vertical stiffness, and mass ratio on the free vibration response of the beam, particularly on its modal characteristics. The results show that the non-classical boundary conditions significantly affect the natural frequency and mode shapes of the studied beam system in comparison to the case of a classical boundary conditions such as Simply supported, clamped-clamped, etc. The comparison between the obtained results based on the proposed analytical solution and numerical scheme, and those available in the literature shows an excellent agreement

Seismic performance reliability analysis of reinforced concrete buildings as parameterized by ductility

Reliability analysis assessment of seismic performance for regular reinforced concrete buildings was investigated in this work. This was performed through the response surface methodology in order to derive explicit expression of the failure function. Two limit states defined in terms of the total building roof displacement and the maximum inter-story drift were considered. The seismic behavior of the building was examined by using conventional pushover analysis through finite element computations conducted by means of a specialized software package. Three random variables characterizing material resistance variations of concrete and reinforcement steel as well as concrete members section were introduced. A complete factorial design of experiment table having three levels was used to define a finite set of data points where the failure function was evaluated, before using these results to perform identification of the building response surface model via polynomial regression. An application of this procedure was illustrated on a five story building and analysis of reliability in terms of the actual ductility coefficient was achieved. Discussion was carried out about the effect on reliability resulting from the distributions of probability modeling parameters uncertainties and from using the approximate methods: Monte Carlo based sampling analysis and first order reliability method.Peer ReviewedPostprint (published version