New method for 2nd order effects evaluation in reinforced concrete portal frames

This paper gives a brief account of the fundamentals of a simplified method for the evaluation of 2nd order effects in columns of reinforced concrete portal frames. The methodology here proposed shares some of the main features of both, the additional eccentricity method (which leads to good results for isolated columns) and simplified P-δ method (which allows for a global analysis of the structure). The assessment of the proposed method is made by comparing the results of non-linear analyses carried out on some examples with the reinforced bars being calculated by this method and other simplified ones.