A study on the importance of seismic parameter selection for the vulnerability assessment of mid-rise reinforced concrete structures

摘要

The scope of this study was the creation of a methodology that would adequately quantify and incorporate the interrelationship between the various seismic parameters and recorded structural damage. Based upon the need to establish whether traditionally selected seismic parameters were truly representative of the expected structural damage and overall structural vulnerability an extensive set of seismic data and subsequent computer assisted analyses were synthesized and used throughout this project. Having established the fact that MMI and PGA seismic parameters are currently the seismic intensity indicating parameters of choice in most contemporary vulnerability studies it was only logical to test such hypothesis based on this study‟s results. In several of the above cases discrepancies between those parameters and the overall structural damage recorded has been observed. This led to the need of identification of other potentially more suitable seismic parameters that would better and more accurately convey structural damage information. This study provided a methodology that circumvents the shortcomings of such an a-priori selection by facilitating the selection of the most descriptive, in terms of seismic damage, earthquake parameter; hence, enhancing vulnerability methodology‟s usefulness as a mitigation tool in pre-earthquake damage assessment. This has been accomplished by studying the interrelationship between various seismic intensity parameters and the overall seismic structural damaging potential recorded during the analyses undertaken in an attempt to streamline the selection of a specific seismic parameter. The thesis essentially investigated a methodology that enables such a selection that better describes a strong motion event‟s damaging potential, for any individual type of structure, in accordance with regional or selected seismic characteristics. Due to the very nature of the methodology proposed can be utilized for different types of structures other than the mid-rise reinforced concrete frame type that has been used in this project, with the necessary modifications and due care. With the identification of the aforementioned parameter, the current trend of an a-priori selection of either PGA or MMI, as structural seismic demand descriptors, can be avoided: leading to the creation of more realistic vulnerability curves. In effect, allowing for a better approximation of structural vulnerability; hence more closely approximate the observed structural damage.