Evaluation of Seismically Designed Reinforced Concrete Buildings with Respect to Progressive Collapse Resistance (Structural and Economical Analysis)

Many buildings have experienced progressive collapse around the world over the past decades. After the increase of terrorist activities against public and civilian buildings, many countries decided to apply more design procedures to reach higher levels of structural safety against progressive collapse. The large cities in Europe are areas of high population density; therefore using high-rise buildings has technical and economic advantages. These structures are categorized as important buildings and require high level of structural safety against progressive collapse. When these buildings are located in seismic zones, then they are often seismically designed using the dual structural system because of its high lateral resistance against earthquakes. In this thesis, the resistance of the reinforced concrete dual system buildings that are seismically designed against progressive collapse was evaluated, and a cost study to estimate the increase in building cost was implemented. Three-dimensional finite element models for buildings with different heights (8, 16, and 24 stories) were developed using the program SAP2000, then these buildings were firstly designed according to EC2, and then they were seismically designed for three seismic areas: low, moderate, and high, according to EC2 and EC8. Nonlinear dynamic analysis was conducted following the alternate path provisions of the UFC guidelines to assess the potential for progressive collapse and the evaluation of the enhanced local resistance was performed too. The influence of the different parameters on the vulnerability to progressive collapse was evaluated. Costs were estimated to evaluate additional costs due to applying seismic designs, according to EC8. The additional costs of implementing the progressive collapse design requirements based on UFC 4-023-03 were also investigated. The results confirmed the positive effect of seismic design and detailing, on the progressive collapse resistance of reinforced concrete structures. The cost study showed that with only a minor increase in the total cost, the building can obtain an integrated optimal structural system against seismic loads and progressive collapse.