Nonlinear analysis of reinforced concrete columns subjected to combined effects of axial and blast-induced transverse loads / Mohammed Gamal Abdelwahab ; Supervised Waleed A. Attia , Mostafa M. Elsayed

Thesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Civil Engineering

The use of explosives by terrorist groups around the world that target critical structural buildings is a growing problem in modern societies. Consequently, blast loads gained a great importance over the past few decades from structural engineers due to its ability to cause a significant damage to existing buildings that may lead progressive collapse. As a result, many researches and blast standards were developed in order to mitigate the blast damage. Existing blast resistant design standards have estimated the out-of-plane behavior of one-way bending elements by utilizing an equivalent single degree-of-freedom (SDOF) system assuming a pre-defined deformed shape. However, this is only valid as long as the applied axial load does not exist, which its presence would typical require a second order analysis. This thesis focuses on analytically evaluating the influence of changing the axial load level on the out-of-plane resistance of reinforced concrete (RC) columns under blast loading; which is a load that they are typically not designed to withstand. In this regard, a nonlinear equivalent single-degree-of-freedom (ESDOF) model is developed in order to determine the out-of-plane response of RC columns. To achieve this, an analytical tool consists of five subroutines is coded using the programming language (MATLAB) in accordance to both the new American (ASCE/SEI 59-11) and canadian (CAN/CSA S850-12) standards for blast resistant design. The five coded subroutines are as follow: moment-curvature subroutine, resistance-function subroutine, load-prediction subroutine, nonlinear-analytical subroutine, and finally the damage-assessment subroutine

Issued also as CD