ANALYTICAL AND EXPERIMENTAL SEISMIC ASSESSMENT OF IRREGULAR RC BUILDINGS

Seismic assessments of irregular buildings need special attention while regular structures can be readily idealized and assessed using 2D conventional methods. In this paper, an advanced analytical assessment methodology for irregular buildings is presented. In the proposed method, 3D modeling is utilized to capture the torsional and bi-directional response of the irregular buildings. A layering technique, termed Planar Decomposition, is proposed and shown to furnish detailed information on the demand and capacity of critical members. As an application, an irregular 3D structure intended for a full-scale experimental testing at the Joint Research Center, Ispra, Italy under the auspices of the EU project Seismic Performance Assessment and Rehabilitation (SPEAR) is assessed using the advanced methodology. Through its application to the test structure and comparison to the conventional methods, it is shown that normal assessment procedures may be inaccurate and even unconservative, in terms of the performance assessment of irregular buildings. This highlights the importance of monitoring the damage state on a member-by-member basis instead of a story or structure level as well as the significance of including torsional effect in the assessment procedure.