Fragility of Shear Wall Buildings with Torsional Irregularity Vesile Hatun Akansel, Ahmet Yakut Earthquake Engineering Research Center, Middle East Technical University, Ankara,Turkey Polat Gülkan Department of Civil Engineering, Çankaya University, 06810 Ankara,Turkey SUMMARY: Fragility curves are useful for damage assessment of structures. There are many criteria that affect the reliability of fragility curves such as transitional damage states, plan irregularity and different measures of seismic intensity. Determination of fragility of a shear wall structure is important, especially for installations that have torsional irregularity. In this study fragility curves of a shear wall building with torsional irregularity have been obtained. This building was subjected to synthetic earthquake motions on the AZALEE shaking table under the coordination of CEA (Commissariat à l’Energie Atomique) and Electricité de France (EDF) in Saclay, Paris under the scope of the SMART program. Maximum inter-story drift values have been used as the damage indicator to obtain the fragility curves and different seismic intensity measures such as PGA, PGV, PGD and CAV have been used. Thirty bi-directional horizontal ground motions have been applied for the time history analyses. These synthetic acceleration sets applied to the structure have different amplitudes in the range of 0.1 to 1 g. Micro modeling approach has been used to obtain reasonably accurate and consistent results with experiments. ANSYS finite element software has been used for the response history analyses. Fragility curves of shear wall building have been calculated according to pre-established damage indicators. The limits are light, controlled and extended damage indicators. These curves are compared with those of the HAZUS damage states for correlation. Keywords: Shear Wall Building, Fragility, Torsion, Micro- modeling 1. INTRODUCTION Calculation of three dimensional seismic effects on buildings involving torsion is a challenge, especially for non – linear behavior under earthquake effects. Modeling these types of buildings requires care to generate acceptable results. In spite of the computational technology and existence of numerical models, there still are deficiencies in modeling because of the assumptions made in the numerical models for material and seismic excitation estimation. One critical concept is the determination of fragility curves for different structural categories. These statistically-evaluated or empirically-derived curves provide a basis for the assessment of the performance of buildings under different ground motion intensities so that loss estimates can be made. In this study, the fragility curves for shear wall structures with torsional irregularity are examined. 2. FRAGILITY CURVES: DERIVATION 2.1 Literature For walls two main modeling approaches are used as macro and micro modeling depending on the chosen finite element technology. Micro modeling is a continuum mechanics based approach and uses two or three dimensional solid or shell finite elements.