Investigation of Steel Curb Effect on Nonlinear Behaviour of Reinforced Concrete Frames With Finite Element Method

It is required to rehabilitate the existing structures due to many reasons including the retrofitting of damaged structures under earthquakes or the need to strengthen or retrofit an undamaged structure designed based on old building codes. So، the rehabilitation and retrofit of structures against seismic loads is unavoidable. This paper presents the results of a nonlinear finite element analysis of an ordinary reinforced concrete frame and also strengthened frame by steel prop and curb under monotonic lateral load. The effect of steel prop on linear and nonlinear behavior of reinforced concrete frame and also increasing the rigidity، ultimate strength، rate of energy absorption and ductility parameter of frame are investigated. The experimental results of a one-bay and one-story reinforced concrete frame are considered and after calibrating the numerical results against it، the mentioned parameters have been investigated. Numerical results show that using steel curb and prop box in compression and tension state with 5،7. 5،10 cm2 area in frame will considerably increase the rigidity، ultimate strength and decrease the ultimate displacement of frame. Furthermore، the yielding of steel prop as a preliminary defensive system against lateral loads will increase the energy absorption and ductility and also will decrease the stresses in panel zone.