Preventing the progressive collapse has been an important and complicated issue in structural failure and a lot of amount of research has been conducted on progressive collapse of structures since the progressive collapse of Ronan Point Apartment in 1986. For some time past, a lot of apartment houses and residential-commercial buildings adopting a column-supported wall system have been constructed in Korea. This structure has abrupt change in the structural properties between the upper and lower parts divided by transfer girders.
The transfer girder system has many problems and difficulties on the structural analysis and design process because of a sudden change of rigidity and excessive stress concentration at the transfer floor. Besides, the transfer girder is mainly affected by the behavior and load transmission process of not only the near floors but also the entire structural system. So the transfer girder systems are particularly vulnerable to abnormal load such as gas explosion, a traffic crash, fire etc.
So in this study the progressive collapse behaviors apply to the 5, 15 and 25 story transfer girder system structure were evaluated by linear static analysis, linear dynamic analysis and nonlinear static analysis following GSA guideline. The structural analysis is performed with MIDAS GEN (Ver. 785).

Following is a summary of conclusion I drew from the above described study.

(1) RC　Apartments adopted transfer girder system in accordance with the guidelines of progressive collapse resistance performance were examined by a variety of variables.　It can make figuring out the problems of the progressive collapse which depend on building scale, position of the transfer girder and structural analysis. It showed that we need additional codes.

(2) DCR evaluation of each member chosen by the general transition information install a typical residential apartment building models, were conducted. As a result, linear dynamic result value than the value for the linear static analysis result values according to the same column removal scenario collapse by an average of 15% higher. With linear static analysis of the results of evaluation, the progressive collapse criteria for reliability are achieved.

(3) When study of low-rise structure stability it has no problem. But case of high-rise structure stability has lots of problems with safety. So it need rehabilitation and also need new legislation.

(4) In case of the high-rise structural system which has serious problem is a broad distinction. Between has basement or not. So when do structural planning considering installation of basement or adjust the transfer girder location make heighten an effect for preventing progressive collapse.

(5) Nonlinear static analysis of the GSA satisfy the deflection criteria of the guidelines, it shows all models are safe when occur abnormal load is loading. But this result shows hinge. And hinge development process shows it propagation from near transfer girder. So even if transfer girder structure is safe, reinforcement transfer girder is important.