Developing a risk-targeted seismic design framework for special concentric and buckling restrained braced frame buildings
I was born in the composite Andhra Pradesh State in India, and raised in the city of Hyderabad (now in Telangana). After four years of undergraduate study in Civil Engineering, my decision to pursue a master’s degree in Structural Engineering from Birla Institute of Technology & Science (BITS) Pilani-Hyderabad, stemmed from a desire to improve my understanding of structural and earthquake engineering. During the course of my summer internship, I got the opportunity to collaborate with some of the brightest scientists at the National Geophysics Research Institute in Hyderabad. This piqued my interest for seismic research. With more and more areas in India and outside being identified as earthquake-prone zones, there is a pressing need for developing low-cost earthquake-resistant devices. As a result, my master’s thesis focused on retrofitting existing reinforced concrete buildings with low-cost base isolation systems.
Following my master’s graduation, I was eager to acquire international research exposure by working under researchers who have years of experience in the field of earthquake engineering. Consequently, I applied for a PhD place at the University of Canterbury, Christchurch, with Dr. Reagan Chandramohan and Dr. Timothy J. Sullivan. To undertake my PhD study, I was fortunate enough to be offered a postgraduate scholarship from the Built Environment Programme of the Resilience to Nature’s Challenges Phase 2 National Science Challenge.
As for my hobbies, I enjoy playing football, cooking, travelling, and hiking in my spare time.
My Project
Modern building performance objectives, such as loss and downtime, are critical indicators of a structure’s seismic performance. Unfortunately, there is no clear connection between the performance objectives and current seismic design guidelines. Despite the fact that buckling-restrained braced frames (BRBFs) have become more popular since the Canterbury earthquakes, formal criteria for their design do not yet exist because the structural system is still relatively new in New Zealand. Furthermore, existing research suggests that in BRBFs and special concentrically braced frames (SCBFs), out-of-plane buckling of the gusset plates may occur before the brace yields, but this failure mode is not explicitly incorporated in the current braced frame numerical modelling approaches used in research and practice. Hence, my research will focus on establishing an accurate numerical modelling approach for BRBFs and SCBFs, as well as a risk-targeted seismic design framework for their design.
Next Steps
Current BRBF modelling approaches, which are widely adopted in research and industry, are incapable of simulating the out-of-plane buckling of gusset plates. As a result, the initial step in my research will be to create a novel braced frame numerical modelling approach capable of modelling this failure mode and understanding its effects on the overall seismic performance of braced frame structures. The next stage will be to benchmark the seismic performance of code-conforming BRBF and SCBF buildings. To this end, hazard-consistent ground motions will be used to conduct non-linear response history analyses on a wide range of code-compliant braced frame building models. These findings, together with New Zealand specific building data, fragility functions, and loss functions, will be used to benchmark the seismic performance of BRBFs and SCBFs.
The next phase will be to conduct parametric studies on a variety of BRBF and SCBF structures in order to identify the design characteristics that influence the performance objectives. Finally, a risk-targeted seismic design framework for these braced frames will be developed, based on the identified parameters.
The outcomes of this study will aid in the improvement of present BRBF and SCBF building design guidelines. Prior to construction, performance objectives assist stakeholders in making informed decisions. The major outcome of this research will be a design strategy that will enable practitioners to design BRBF and SCBF buildings that meet specific performance objectives.
