Analysis Of Resist The Progressive Collapse Of Concrete Frame On The Base Of Alternate Path Method

Since1960s, With the terrorist attacks, accidents, natural disasters occurred frequently, caused a great threat to the safety of human life and property, the important reason is the progressive collapse of structures. Borrowing GSA2003by the US public affairs administration, Modeling and analysis of structure by the SAP2000software, analysis the properties of the structure resist the progressive collapse by alternate path method base on static. The object is a ten floor regular pure frame structure and a actual four floor irregular building. Introduce the impact loads on the key columns of first floor in the regular framework, us the nonlinear time history analysis method, if the destruction analysis has the same conclusion with the alternate path method base on linear and nolinear static, it means the linear static alternate path method is true. Then use the linear static method analysis the actual irregular structure. In the regular framework,On same floor, dismantle the corner column is the easily lead the progressive collapse, then is the column of long side,column of short side and internal column. In the irregular framework, because of the connected the failed column’s beams, its section and span, made the conclusion different to the regular framework. Small and short beam has small internal force under the normal loading. After dismantle the column, it connect to another beam, turn out a long and variable cross-section beam. After the redistribution of internal force,the beams internal force rose dramatically. So in this irregular structure, dismantled the column of short side and the internal column are easily to lead the progressive collapse, then is the column of long side and corner column. According to the structure, put forward some improvement measures to improve the ability of structure resist the progressive collapse.