Influence Of Slabs On The Progressive Collapse Behavior Of RC Frame Structures

Since the progressive collapse of the Ronan Point apartment in Britain caused by the gas explosion in1968,researches on structural progressive collapse resistance have been paid more and more attention. With the development of our country’s economy, and the worry about the structures at risk of accidental factors such as terrorist attacks, research of structures resisting progressive collapse also has become a hot issue in our country.The thesis studies the effects of the floor slab and the number of the structural stories on the progressive collapse capability of reinforced concrete frame structures using the finite element software SAP2000. The progressive collapse resistance of the six-story structural model considering the floor is assessed, investigating the progressive collapse of structures that have the local floor damage.1. Through the description and analysis of the progressive collapse accidents at home and abroad, illustrate the research background, significance and the definition of the progressive collapse, and classify the progressive collapse types. In addition, summarize the research status especially the latest progress in the study of this field.2. Introduce foreign progressive collapse criteria, present three most commonly used design methods, and make specific instructions for the problems of the analysis method used in this thesis.3. Using the vertical pushover analysis method, three-story, six-story and nine-story reinforced concrete frames based on the current codes are analyzed, respectively. Comparing the vertical displacements of monitoring points and the structural bearing capacity of the three structural models which are under the condition of considering floor and ignoring the floor, find that when considering the floor slab, the vertical displacement of the monitoring points greatly reduced, but the bearing capacity of the structure has greatly improved. The internal forces analysis in the key components of the three structural models has shown that with the increase of the number of the story, floor’s contribution to the frame collapse resistance increase gradually.4. A six-story structure model is designed and its progressive collapse performance is assessed, showing that when the local floor damage occurs, reinforced concrete frame structure still has good progressive collapse performance.