Modeling, analysis, and preservation techniques for historic reinforced concrete structures in seismic prone regions

Throughout the world there are hundreds of historic monuments and structures considered to be invaluable and irreplaceable. They are symbols of cultural identity and a means of educating people about history. Preservation of historic monuments and structures is therefore an important part of safeguarding these cultural heritage sites so that they retain their value for future generations. This report discusses a procedure for the investigation of seismic hazards in existing buildings and possible steps that can be taken to avoid damage caused by these hazards. The Augusta Airship Hangar located in Sicily, will be used as a case study however the topics addressed in this paper can be applied to other structures of historic value around the world. First state-of-the-art scanning procedures were used to create scale digital models that were imported into a structural analysis program. Within this program dynamic analyses were performed on the model based on actual ground motions taken close to the site. This data was used to determine the period and mode shapes of the structure. Then a nonlinear analysis, including a static pushover analysis, was implemented on a two-dimensional model of the structural frame. From this analysis the failure mechanisms of the structure were revealed with relation to an allowable roof displacement. The structural integrity of the structure was evaluated based on pre-defined performance goals. Finally multiple suggestions were made how the Augusta Airship Hangar might be repaired and strengthened so that this structure will not be destroyed should an earthquake occur. The results of our study show that historic structures, despite their age, can still be strong and ductile. Also there are a multitude of effective preservation and retrofit techniques that can be used to strengthen these historic structures, should an earthquake occur. Through this study, the Augusta Airship Hangar has proven to be not only a historic symbol for Sicily but also can be used as an example for the rehabilitation of other historic structures. The techniques and processes discussed in this paper can be applied to other historic reinforced concrete structures and can be expanded upon in future investigations.