Seismic assessment of reinforced concrete buildings and bridges

Several design and detailing deficiencies have contributed to the poor performance of older and modern reinforced concrete buildings in past earthquakes. As a step towards risk mitigation, seismic assessment procedures continue to be developed to assess the response of existing structures at the component and global levels. Such procedures are aimed towards identifying seismic vulnerable buildings that need to be prioritized for intervention. In certain cases, existing codified procedures can be too conservative, resulting in unwarranted retrofit or building closures. Conservative seismic assessment procedures pose a significant financial burden on the global economy and may have an unintended negative impact on community resilience.

 

Over the last few years, we have developed seismic assessment procedures to replace a number of conservative procedures in the New Zealand and American Seismic Assessment Standards. A distinct feature of our proposed approaches is that they are mechanics-based. Mechanics-based models do not suffer from extrapolation and data overfitting problems associated with purely empirical models.

 

A number of our seismic assessment procedures have been incorporated into the New Zealand Seismic Assessment Guidelines for Concrete Structures (C5). Furthermore, we have our models under consideration for adoption in ACI 369 (concrete chapter of ASCE/SEI 41) and other seismic assessment standards globally.

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Amongst relevant papers, the following published papers are worth highlighting:

• Opabola, E.A and Elwood, K. J. (2023) “Modelling the Flexure-axial-shear interaction of ductile beams with single-crack plastic hinge behaviour.”  Earthquake Engineering and Structural Dynamics https://doi.org/10.1002/eqe.3873

• Opabola, E.A (2022) “Development and splice length model for straight plain bars in tension” ACI Structural Journal. https://doi.org/10.14359/51736111

• Opabola, E.A and Mangalathu, S. (2022) “Seismic fragility assessment of pre-1970s box girder and seat abutment bridges” Bulletin of Earthquake Engineering https://doi.org/10.1007/s10518-022-01521-w 

• Opabola, E.A and Elwood, K. J. (2021) “Seismic assessment of RC columns with short splices”  Earthquake Spectra  https://doi.org/10.1177/8755293021994834 

• Opabola, E.A., Elwood, K.J., and Pujol, S (2020). “Influence of biaxial loading on seismic response of reinforced concrete columns.” ACI Structural Journal https://doi.org/10.14359/51728069

• Opabola, E. A., Elwood, K. J., and Oliver, S. (2018). “Deformation capacity of reinforced concrete columns with smooth reinforcement.” Bulletin of Earthquake Engineering, https://doi.org/10.1007/s10518-018-00540-w

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Other relevant papers are currently under review in reputable journals.