Rational decisions for seismic collapse-prevention design of low-rise asymmetric RC buildings considering deterioration properties

This research points to an essential need to develop a well-defined design method considering the deterioration properties of structural elements. Although the seismic design provisions have changed over the past decades, they ignore the deterioration effects and the collapse probability of frames designed to the latest specifications still exceed the expected norms. The issue becomes more significant for asymmetric buildings where the lateral load-resisting elements behave differently. To this end, several sensitivity analyses are performed using a new index to show the importance of deterioration sources on the seismic performance of analysis models. The evalu-ation showed that the deterioration effects depend on the torsional flexibility of asymmetric models. The results recommended not to adopt a unique design decision for all resisting frames of an asymmetric building. Simple and efficient design strategies were presented to improve the seismic behavior of plan-irregular buildings up to the collapse state, while keeping their seismic performance the least sensitive to the deterioration effects. Among the proposed approaches, those strategies that vary the plastic rotation capacity of elements have a large effect on the deteriorating behavior.