■ Post-Repair Fragility Models of Initially Damaged Structures under Successive Earthquakes

The research team developed a unique framework for assessing the post-repair effect of column jackets on the reduced vulnerability of damaged structures. This framework has a unique ability to capture the residual deformation of damaged components after mainshocks, depending on the extent of existing damage, which was not included in existing methodologies. Additionally, the research team plans to provide guidelines for the amount of steel or FRP jackets as a function of the extent of exiting damage through extensive sensitivity analyses and cost-benefit assessment.

Selected Publications

• Jiuk Shin#, Jong-Su Jeon#, and JunHee Kim* (2018). Mainshock-aftershock response analyses of FRP-jacketed columns in existing RC building frames. Engineering Structures; 165: 315–330, June 15.

• Jong-Su Jeon, Reginald DesRoches, and Do Hyung Lee* (2016). Post-repair effect of column jackets on aftershock fragilities of damaged RC bridges subjected to successive earthquakes. Earthquake Engineering & Structural Dynamics; 45(7): 1149–1168, June 1.

■ Aftershock Vulnerability Assessment of Old and Modern Reinforced Concrete Frames

The central focus of this research was on the aftershock vulnerability assessment of damaged reinforced concrete buildings in California to advance the state-of-practice in post-earthquake inspection of RC buildings. The research was intended to quantifiably judge the current status of buildings (tagging), which is directly related to the evaluation of the residual capacity of damaged buildings as well as the computation of the probability of being in a damage state after an aftershock (aftershock fragility). The proposed framework can be used to i) develop tools and procedures to automate and accelerate post-earthquake loss estimation, ii) assess the safety of buildings after mainshocks along with tagging, and iii) provide decision makers with essential tools for maximizing investment in building repair after earthquakes.  

Selected Publications

• Seong-Hoon Hwang, Mehran Shokrabadi, Sujith Mangalathu, and Jong-Su Jeon* (2022). Effect of interior gravity framing system and composite floor slab action on the lifetime seismic risk assessment of steel frame buildings subjected to mainshock-aftershock sequence. Structures; 45: 2332–2342, November 1. 

• Jong-Su Jeon*, Reginald DesRoches, Laura N Lowes, and Ioannis Brilakis  (2015). Framework of aftershock fragility assessment–case studies: older California reinforced concrete building frames. Earthquake Engineering & Structural Dynamics; 44(15): 2617–2636, December 1. 

• Stephanie G Paal*, Jong-Su Jeon, Ioannis Brilakis, and Reginald DesRoches  (2015). Automated damage index estimation of reinforced concrete columns for post-earthquake evaluations. Journal of Structural Engineering ASCE; 141(9): 04014228, September 1.

• Stephanie German*, Jong-Su Jeon, Zhenhua Zhu, Cal Bearman, Ioannis Brilakis, Reginald DesRoches, and Laura Lowes  (2013). Machine vision-enhanced postearthquake inspection. Journal of Computing in Civil Engineering ASCE; 27(6): 622–634, November 1. 

■ Post-Earthquake Fire Damage Assessment of Civil Infrastructure 

The primary objective of this research is to estimate the residual capacity of civil infrastructure under successive extreme loadings (earthquake and earthquake-induced fire). Firstly, the residual capacity of structures damaged by earthquakes is qualitatively and quantitatively estimated to represent the realization of damaged structures. Several types of earthquake-induced fire scenario are accounted for to evaluate the additional structural damage associated with fire loadings. The predetermined fire scenario curves are implemented in ANSYS to perform high fidelity fire simulations using thermal-structural interaction and fluid-structure analysis. Finally, the final damage accumulation the structures subjected to successive extreme loadings is evaluated using additional external loadings to develop a scenario-based multi-hazard risk assessment tool.