A NEW METHOD TO SEISMIC COLLAPSE ASSESSMENT OF MID-RISE STEEL FRAME BUILDINGS

Abstract eng:
Collapse of Buildings due to the earthquakes causes a great number of casualties, financial losses and makes accessing locations difficult for the rescue teams. So, the collapse assessment of existing buildings under severe earthquakes is significant. The most accurate approach of collapse assessment is nonlinear dynamic analysis of a detailed structural model with hundreds of degrees of freedom. But analysis of the detailed model requires a lot of computational efforts that making the process prone to error and thus complicating the interpretation of results. Hence an alternative approach is using an equivalent MDOF model that is capable to predict major structural demands. In this paper, to evaluate the collapse capacity an equivalent nonlinear MDOF system is proposed. This model, consisting of a column with concentrated plastic hinges at two ends and a series of rotational springs that represent bending behavior of beams in each floor. Lignos and Krawinkler empirical relationships are used to determinate the cyclic moment-rotation relationships of the plastic hinges and rotational springs. The incremental dynamic analysis (IDA) is utilized to structural analysis and collapse capacity evaluation. Accuracy of the proposed method is estimated in comparison with detailed model of a 4 story moment resisting frame. The results indicate that the proposed method has appropriate ability to calculate the collapse capacity with a proper speed, accuracy and cost.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket