In the heart of Tehran, a groundbreaking study is reshaping our understanding of how buildings withstand earthquakes, with significant implications for the energy sector. Iman Hakamian, a researcher at the School of Civil Engineering, Iran University of Science and Technology, has been delving into the seismic parameters of intermediate concrete moment-resisting frames, a common structural system in many urban buildings. His work, published in the journal ‘مهندسی و مدیریت ساخت’ (Civil Engineering and Management), offers a fresh perspective on how these structures behave under seismic loads, potentially influencing future construction codes and practices.
Hakamian’s research focuses on evaluating the seismic parameters proposed by building codes for reinforced concrete structures with intermediate moment-resisting frames. These frames are widely used in mid-rise buildings, including those that house energy sector facilities. “Understanding the seismic behavior of these structures is crucial for ensuring their safety and resilience during earthquakes,” Hakamian explains.
To conduct his study, Hakamian analyzed three concrete frames with varying heights—3, 6, and 9 floors—all designed with medium ductility. Ductility, or a material’s ability to deform without fracturing, is a key factor in a structure’s seismic performance. The frames were chosen to represent a range of influencing factors, including structural height, the ratio of lateral load to gravity load, and the structural period, which is the time it takes for a structure to complete one cycle of vibration.
One of the novel aspects of Hakamian’s research is his use of plastic joint modeling to simulate the nonlinear behavior of these structures. This method allows for a more accurate representation of how a structure’s stiffness and resistance change during an earthquake. “By using the relationships proposed by Ibarra and Krawinkler, and calibrated by Haselton and Deierlein, we can better understand the progressive degradation of a structure’s properties under seismic loads,” Hakamian says.
The models were then subjected to nonlinear static analysis, a process that applies increasingly larger loads to a structure until it reaches its failure point. The results of this analysis were used to calculate several important seismic parameters, including the behavior factor, overstrength coefficient, displacement amplification factor, and ductility coefficient. These parameters are crucial for designing structures that can withstand seismic events without collapsing.
So, what does this mean for the energy sector? Many energy facilities, such as power plants and refineries, are housed in mid-rise buildings with concrete moment-resisting frames. Ensuring the seismic safety of these structures is vital for maintaining the reliability of energy infrastructure during and after earthquakes. Hakamian’s research could lead to more accurate seismic design codes, ultimately resulting in safer buildings and reduced risk of damage to critical energy facilities.
Moreover, the insights gained from this study could pave the way for innovative design strategies that enhance the seismic resilience of buildings. As Hakamian puts it, “Our goal is to push the boundaries of current design practices and develop more robust structures that can better withstand the forces of nature.”
In the ever-evolving field of structural engineering, Hakamian’s work serves as a reminder that our understanding of seismic behavior is continually advancing. As we strive to build safer, more resilient communities, research like this plays a pivotal role in shaping the future of construction and design. With the energy sector’s growing need for reliable and resilient infrastructure, the implications of this research are far-reaching and profound.