Progressive Collapse Resistance Performance Analysis Of Reinforced Concrete Space Frame That Considering The Action Of Slab

Since the fall of the Ronan Point condominium in Britain in 1968,scholars at home and abroad have gradually studied the progressive collapse of building structures under accidental loading.Although the current research on on this issue has achieved fruitful results,most of them ignore the influence of the floor elements.As one of the important structural components of reinforced concrete space frame,it is necessary to study the effect of the floor on progressive collapse.In this paper,the dismantling component method is used to simulate the progressive collapse process of the reinforced concrete space frame when the column at different positions in the bottom layer fails,and the progressive collapse resistance considering floor action is studied..The main work of this paper is as follows:(1)Aiming at the collapse test of an existing reinforced concrete frame,a verification model was established by using ABAQUS,compared the test results with the numerical simulation results to verify the correctness of the finite element modeling method and the simulation process.(2)Taking a two-span,two-story reinforced concrete space frame as the analysis object,the long-side center column,short-side center column,corner column,and inner column of the two models with or without consideration the floor slabs are dismantled respectively.The effect of floor factors on the displacement,the internal force of the key components,stress and strain of the material during the progressive collapse is studied.The results show that the corner column is the most dangerous when it fails,and it is necessary to increase the safety of the corner column during the structural design.The presence of the floor changes the force mechanism of the frame beam and improves the Structural collapse resistance.(3)The existing calculation methods for the collapse resistance of each force mechanism of the plane reinforced concrete frame were summarized,studies the contribution of the floor to the collapse resistance,and puts forward a theoretical calculation formula for the collapse resistance of the force mechanism of the space reinforced concrete frame which is suitable for the failure of the center column of the side span frame.Comparing the calculated results with(4)the experimental results,it is found that the formula has high calculation accuracy,and the floor slab can at least improve the collapse resistance of 20% of the RC frame structure.